Unraveling functional neurological disorder in pediatric populations: A systematic review of diagnosis, treatment, and outcomes

Abstract

BACKGROUND

Functional neurological disorder (FND) in children is a complex and multifaceted condition characterized by neurological symptoms that cannot be explained by organic pathology. Despite its prevalence, FND in pediatric populations remains under-researched, with challenges in diagnosis and management

AIM

To synthesize the current literature on FND in children, focusing on clinical presentation, diagnostic approaches, treatment strategies, and outcomes.

METHODS

A comprehensive literature search was conducted across multiple databases, including PubMed, Scopus, and Web of Science, for articles published up to August 2024. Studies were included if they addressed FND in pediatric populations, specifically focusing on review articles, research articles, systematic reviews, meta-analyses, case reports, guidelines, expert opinions, and editorials. Data extraction and quality assessment were performed according to PRISMA guidelines. A total of 308 articles were included in the final analysis.

RESULTS

The analysis included 189 review articles, 57 research articles, 3 systematic reviews and meta-analyses, 5 case reports, 2 guidelines, 5 expert opinions, and 2 editorials. Key findings revealed a broad spectrum of symptoms, including motor and sensory disturbances and psychological factors contributing to the onset and persistence of FND. Diagnostic challenges were frequently highlighted, emphasizing the need for interdisciplinary approaches. Treatment strategies varied, with cognitive-behavioral therapy (CBT) and multidisciplinary care emerging as the most effective approaches. The outcomes varied, with early intervention being critical for a better prognosis.

CONCLUSION

Early diagnosis and multidisciplinary care, including CBT, are critical for improving outcomes in pediatric FND. Standardized diagnostic criteria and treatment protocols are needed to enhance clinical management.

Key Words: Functional neurological disorder; Children; Pediatric neurology; Conversion disorder; Psychogenic disorders; Cognitive-behavioral therapy; Multidisciplinary care; Diagnosis; Treatment outcomes

Core Tip: Functional neurological disorder (FND) in children presents unique diagnostic and therapeutic challenges due to its diverse symptomatology and the absence of organic pathology. Early diagnosis, often hindered by symptom variability, is crucial for effective intervention. Multidisciplinary management, including cognitive-behavioral therapy and comprehensive care involving neurologists, psychiatrists, and psychologists, has shown promise in improving outcomes. However, there is a need for standardized diagnostic criteria and treatment protocols to better guide clinical practice. This systematic review underscores the importance of timely and coordinated care to enhance the prognosis for pediatric patients with FND.

INTRODUCTION

Functional neurological disorder (FND) is characterized by neurological symptoms that cannot be fully explained by underlying structural or organic diseases. These symptoms, which affect motor (e.g., movement, speech) and sensory (e.g., vision, hearing) functions, are real and can be as disabling as those caused by organic conditions. However, they arise from dysfunction in the nervous system's operation rather than from detectable structural damage[1]. This distinguishes FND from other neurological disorders where a clear structural or biochemical abnormality is identifiable[2]. Historically, FND was referred to as "hysteria" or "conversion disorder", based on the psychoanalytic theory that emotional distress could be "converted" into physical symptoms[3]. Over time, understanding of the disorder has evolved, leading to a shift toward a biopsychosocial model that acknowledges the interplay of psychological, neurological, and social factors. The term "Functional Neurological Disorder" is now preferred as it highlights the neurological dysfunction without implying symptoms are purely psychological[4].

FND presents with a broad spectrum of symptoms, often resembling other neurological conditions such as stroke, multiple sclerosis (MS), or epilepsy. However, the absence of structural abnormalities makes diagnosis challenging. Addressing misconceptions is crucial, as patients with FND are not fabricating or exaggerating their symptoms; the condition is genuine and can cause significant distress. FND should not be viewed as a sign of psychological weakness but as a disorder arising from complex biological and psychological interactions. Importantly, while challenging to manage, FND is not untreatable—many patients experience substantial symptom improvement with appropriate intervention[5].

This systematic review aims to synthesize the current literature on FND in pediatric populations. The specific objectives are: To define and describe the epidemiology, pathophysiology, and clinical presentation of pediatric FND. To review diagnostic challenges and existing criteria for FND in children. To evaluate current management strategies, including cognitive-behavioral therapy (CBT) and multidisciplinary care. To analyze patient outcomes and identify gaps in current treatment protocols. To highlight future research directions for improving diagnosis and management in pediatric FND. By integrating recent evidence and clinical insights, this review seeks to enhance the recognition, diagnosis, and treatment of pediatric FND, ultimately improving patient outcomes and guiding future clinical practice.

MATERIALS AND METHODS

A systematic search was conducted across PubMed, Scopus, and Web of Science databases for articles published up to August 2024. Search terms included "Functional Neurological Disorder" "pediatric" "children" "conversion disorder" and "psychogenic". Additional searches were performed in the reference lists of included studies to identify relevant articles not captured in the initial search.

Studies were included if they focused on children aged 0-18 years diagnosed with FND, were published in peer-reviewed journals, were written in English, and included review articles, research articles, systematic reviews, meta-analyses, case reports, guidelines, expert opinions, or editorials. Articles were excluded if they focused on adult populations, did not specifically address FND, or were not available in full text.

The search terms included combinations of keywords such as "Functional Neurological Disorder" "FND" "Conversion Disorder" "Pediatrics" "Children" "Psychogenic Disorders" "Prefrontal Cortex" "Limbic System" "Basal Ganglia" "Brain Networks" "Neuroimaging" "Cognitive-behavioral therapy" "Multidisciplinary Care" "Diagnosis" and "Treatment Outcomes". Boolean operators (AND, OR) were used to refine the search results. Additionally, reference lists of the included studies were manually screened for additional relevant articles. Two independent reviewers (Reviewer 1 and Reviewer 2) screened the titles and abstracts of all identified articles for relevance. Full-text articles were retrieved for studies meeting the inclusion criteria or in cases of uncertainty. Discrepancies were resolved through discussion or by consulting a third reviewer (Reviewer 3) to reach a consensus.

Data extraction was performed independently by two reviewers using a standardized data extraction form. Extracted data included study design, sample size, diagnostic methods, treatment approaches, and outcomes. Quality assessment was conducted using appropriate tools for each study design: The Newcastle-Ottawa Scale for observational studies and the Cochrane Risk of Bias Tool for randomized controlled trials. Studies were categorized as high, moderate, or low quality based on selection bias, measurement validity, and confounding control. Disagreements in quality ratings were resolved through discussion. A PRISMA flowchart (Figure 1) was created to visually represent the article selection process. Given the heterogeneity in study designs, outcome measures, and patient populations, a meta-analysis was not feasible. Instead, a narrative synthesis was conducted to integrate findings across studies. As this study is a systematic review of previously published research, no ethical approval was required. However, all procedures adhered to ethical guidelines for conducting systematic reviews and meta-analyses.

Figure 1 The flow chart of the study.

RESULTS

Figure 1 shows the study flow chart. The search yielded 1870 articles. After removing duplicates and screening titles and abstracts, 345 full-text articles were assessed for eligibility. Of these, 263 articles met the inclusion criteria and were included in the final analysis. The final analysis included 189 review articles, 57 research articles, 3 systematic reviews and meta-analyses, 5 case reports, 2 guidelines, 5 expert opinions, and 2 editorials. The studies covered various topics related to FND in children, including clinical presentation, diagnostic challenges, treatment approaches, and outcomes. The studies highlighted a diverse range of symptoms in children with FND, including motor disturbances (e.g., tremors, gait abnormalities), sensory symptoms [e.g., non-epileptic seizures (NES), blindness], and psychological factors (e.g., anxiety, depression). The review identified significant variability in the diagnostic criteria and tools used across studies.

A comparison of pediatric and adult FND (Table 1) highlights key pathophysiology differences, symptom presentation variability, triggers, and response to treatment. Pediatric FND is influenced by ongoing brain development, acute stressors, and school-related challenges leading to fluctuating symptoms, while adult FND tends to be more stable and chronic. Environmental and psychological stressors, including school-related issues and family dynamics, are primary triggers in children, whereas adults experience symptoms linked to long-term psychological distress, trauma, and pre-existing psychiatric conditions. The review identified four primary symptom progression patterns for pediatric FNDs (Table 2): Sudden onset, gradual onset, relapsing-remitting, and persistent chronic. Sudden-onset symptoms often follow acute stressors and may resolve with early intervention, while gradual-onset symptoms worsen over time, leading to diagnostic delays and increasing the risk of chronicity. Relapsing-remitting patterns are associated with fluctuating stress levels, whereas persistent chronic FND presents long-term challenges requiring intensive long-lasting multidisciplinary care.

Table 1 Differences between pediatric and adult functional neurological disorder pathophysiology and clinical differences.

Aspect	Pediatric FND	Adult FND
Developmental factors	Symptoms reflect ongoing brain development and plasticity. Symptoms may fluctuate with developmental stages. Greater sensitivity to immediate stressors and emotional disturbances	Symptoms arise from more established neural circuits. Often involves chronic, stable symptom patterns. Symptoms may be more entrenched due to long-standing psychological factors
Brain network dysregulation	Dysregulation affects developing neural networks (e.g., motor control, sensory processing). Connectivity between brain regions may be less stable, leading to variable symptoms	Involves established, but maladaptive, brain network patterns. Persistent alterations in connectivity, especially in areas like the prefrontal cortex and limbic system. Results in more consistent symptomatology
Psychological and environmental triggers	Often linked to acute stressors, family dynamics, and school issues. Immediate life events, such as bullying or trauma, trigger symptoms. Impacted by developmental stage and coping abilities	Influenced by long-term stress, complex trauma histories, and chronic life stressors. Accumulation of stress leads to persistent symptoms. Higher likelihood of pre-existing psychiatric conditions complicating symptoms
Clinical presentation and symptom profile	Symptoms include functional movement disorders, non-epileptic seizures, and gait abnormalities. Symptoms are often variable and change with developmental progress. Presentation may fluctuate with emotional state and developmental milestones	Symptoms include persistent functional motor impairments, chronic pain, and complex dissociative symptoms. Symptoms are more chronic and stable. Higher prevalence of comorbid psychiatric conditions such as anxiety or depression
Onset of symptoms	Sudden, often linked to a stressful event or minor illness	It can be sudden or gradual, often with a clear link to psychological stressors
Symptom variability	High variability, with symptoms fluctuating throughout the day	Symptoms can vary but may be more consistent compared to pediatric cases
Common symptoms	Motor symptoms (e.g., weakness, tremors), non-epileptic seizures, sensory loss, and speech disturbances (e.g., mutism)	Motor symptoms, sensory disturbances, non-epileptic seizures, gait abnormalities, chronic pain
Triggers	Often associated with acute stressors like school pressures, family issues, or peer conflicts	Commonly linked to chronic stress, psychological trauma, or significant life changes
Psychosocial context	Frequently involves school-related stress, family dynamics, or bullying	Often involves work-related stress, relationship issues, or past trauma
Cognitive Factors	Children may exhibit magical thinking or have difficulty articulating psychological stress	Adults may have a more complex understanding of their symptoms but may also exhibit denial or minimization
Comorbidities	Higher prevalence of anxiety, depression, and other mental health issues, as well as somatic symptom disorders	Often associated with chronic pain syndromes, anxiety, depression, and PTSD
Prognosis	Generally better with early intervention, especially with multidisciplinary approaches	Prognosis can be variable; some patients improve significantly, while others may have persistent symptoms
Treatment Approach	Focuses on education, cognitive-behavioral therapy, family involvement, and physical therapy	Cognitive-behavioral therapy physical therapy, psychotherapy, and sometimes pharmacological treatment are commonly used
Response to treatment	Generally good, particularly with early and supportive intervention	Response can be slower and more variable; some patients may require long-term therapy
Social support and education	Involves significant education and support for family members and teachers	Social support is important but may focus more on workplace accommodations and relationship counseling
Legal and disability issues	Less commonly involves legal or disability claims	More likely to involve disability claims, legal issues, or workers' compensation cases

FND: Functional neurological disorder; PTSD: Post-traumatic stress disorder.

Table 2 Comparison between the different patterns of symptom onset and progression in pediatric functional neurological disorder.

Pattern	Onset characteristics	Progression	Common triggers	Prognosis
Sudden onset	Abrupt appearance of symptoms. Often after a significant stressor	Symptoms can be severe from the outset. May resolve quickly or persist	Acute psychological stress. Traumatic events	May resolve rapidly with early intervention. Can persist if underlying issues are not addressed
Gradual onset	Symptoms develop slowly over time. Initially mild and subtle	Symptoms progressively worsen. May become more disabling over time	Accumulation of stressors. Unresolved psychological issues	Delayed diagnosis is common. Symptoms may become chronic without treatment
Relapsing-remitting	Fluctuating symptoms. Periods of remission interspersed with exacerbations	Symptoms wax and wane. Exacerbations linked to stress	Fluctuating stress levels. Environmental changes	Requires ongoing management. Stress management can reduce relapses
Persistent chronic	Stable but persistent symptoms. Long-lasting with little fluctuation	Symptoms remain consistent over time. Can lead to significant disability	Long-standing psychological or emotional issues	Challenging to treat. Multidisciplinary approach needed for improvement

Several triggers and exacerbating factors contribute to pediatric FND (Table 3). Psychological stress, trauma, environmental changes, and coexisting mental health conditions such as anxiety and depression play a major role. Social influences, including bullying and family stress and conflict, further impact symptom development and persistence. Accurate diagnosis of FND is essential, given its overlap with other neurological and psychiatric conditions (Table 4). Differential diagnosis includes epilepsy, MS, migraine, and anxiety disorders. Distinguishing FND from these conditions requires a comprehensive clinical evaluation, including neuroimaging and electroencephalography (EEG) studies, when necessary, to avoid misdiagnosis.

Table 3 The triggers and exacerbating factors in pediatric functional neurological disorder.

Category	Trigger/exacerbating factor	Examples
Psychological stress	Acute stress	School-related stress (e.g., exams, academic pressure). Social stress (e.g., bullying, peer conflicts)
	Chronic stress	Family dynamics (e.g., conflict, divorce). Pressure to conform (e.g., social or familial expectations)
Psychological trauma	Acute trauma	Single traumatic events (e.g., car accident, sudden loss)
	Chronic trauma	Ongoing abuse or neglect (e.g., physical, emotional, sexual)
Environmental and social	Changes in environment	Relocation or change of school. Family financial stress
	Social influences	Peer pressure. Social media and cyberbullying
Physical health	Illness or injury	Previous medical conditions. Injury or pain
Cognitive and ermotional	Anxiety and Depression	Coexisting mental health conditions (e.g., anxiety, depression)
	Negative cognitive patterns	Catastrophizing. Negative beliefs about health

Table 4 The differential diagnosis of functional neurological disorder in pediatric patients.

Condition	Condition overlaps with FND	Key differentiating features
Epilepsy	NES resemble epileptic seizures (convulsions, altered consciousness)	NES lacks characteristic EEG findings of epilepsy. NES may be triggered by psychological stressors and can often be interrupted by distraction
MS	Symptoms like weakness, sensory disturbances, and visual changes can mimic MS	MS is typically associated with characteristic MRI lesions. Presence of oligoclonal bands in CSF. FND usually has normal imaging and lab results
Migraine with Aura	Visual disturbances, sensory changes, and motor symptoms (e.g., hemiplegia) may be confused with FND	Migraines are episodic with clear triggers and resolution. Accompanied by headache and often a family history of migraines
GBS	Sudden-onset weakness and sensory changes might be mistaken for FND	GBS typically involves ascending weakness and areflexia. Abnormal nerve conduction studies and elevated CSF protein in GBS, absent in FND
Anxiety disorders	Physical symptoms like tremors, dizziness, and palpitations may resemble neurological symptoms of FND	Anxiety symptoms typically correlate with excessive worry or panic and may improve with anxiolytic treatment, unlike the more persistent symptoms of FND
Depression	Presents with psychomotor retardation, fatigue, or somatic symptoms similar to FND	Depression is accompanied by pervasive low mood, anhedonia, and cognitive symptoms, whereas FND's neurological symptoms are more prominent and less tied to mood
Conversion Disorder	Historically considered synonymous with FND, involves neurological symptoms with no organic cause	Conversion disorder often follows psychological conflict. FND now understood as a broader category with various psychological and biological underpinnings
Somatic symptom disorder	Involves excessive preoccupation with physical symptoms, overlapping with FND presentation	Somatic Symptom Disorder focuses on distress or anxiety caused by symptoms, while FND symptoms are the primary focus, often less connected to emotional distress
ADHD	Tics or motor disturbances in ADHD may be confused with FND	ADHD is characterized by inattention, hyperactivity, and impulsivity across settings. FND symptoms are more variable and not typically linked to behaviour patterns

NES: Non-epileptic seizures; GBS: Guillain-Barré Syndrome; MS: Multiple Sclerosis; FND: Functional neurological disorder; ADHD: Attention-deficit/hyperactivity disorder.

The importance of a multidisciplinary approach, involving neurologists, psychiatrists, and psychologists, was emphasized to improve diagnostic accuracy. Treatment approaches emphasize non-pharmacological strategies, with CBT being the most effective intervention. Other beneficial therapies include physiotherapy, psychoeducation, and family therapy. Pharmacotherapy is generally reserved for comorbid conditions, as non-pharmacological interventions remain the mainstay of treatment (Table 5). Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used for anxiety and depression, while antiepileptic drugs like gabapentin and pregabalin may be prescribed for neuropathic pain. Short-term benzodiazepines and melatonin are considered for severe stress and sleep disturbances.

Table 5 The pharmacotherapy options for pediatric functional neurological disorder.

Medication class	Common medications	Indications
Selective serotonin reuptake inhibitors	Fluoxetine, Sertraline, Citalopram	Anxiety, depression, obsessive-compulsive disorder
Serotonin-norepinephrine reuptake inhibitors	Venlafaxine, duloxetine	Anxiety, depression, chronic pain
Antiepileptic drugs	Gabapentin, pregabalin	Neuropathic pain, severe somatic symptoms
Benzodiazepines	Lorazepam, clonazepam	Acute anxiety, severe stress, non-epileptic seizures (short-term use)
Melatonin and sedative-hypnotics	Melatonin, zolpidem	Sleep disturbances, insomnia

Prognostic outcomes (Table 6) are influenced by early diagnosis, family support, and adherence to treatment plans. Children with strong social and familial support tend to have better outcomes, whereas those with delayed diagnosis, severe symptoms, or psychiatric comorbidities face greater challenges. This review underscores the importance of standardized diagnostic criteria, early intervention, and continued research to optimize treatment approaches and refine therapeutic protocols for pediatric FND.

Table 6 Factors affecting prognosis of pediatric functional neurological disorder.

Predictors	Favourable outcomes	Unfavourable outcomes
Time of diagnosis and treatment	Timeliness of intervention: Early diagnosis and prompt treatment are crucial for favorable outcomes. Early intervention leads to better symptom resolution and improvement. Access to specialized care: Multidisciplinary care from pediatric neurologists, psychologists, and physical therapists enhances prognosis	Late diagnosis: Delayed diagnosis, especially with extended symptom duration, is linked to poorer outcomes. Chronic symptoms are harder to treat and may become resistant
Severity of symptomatology	Less severe initial symptoms: Mild symptoms at onset are often more responsive to treatment and less likely to become chronic. Limited symptom duration: Shorter symptom duration before treatment correlates with better outcomes, reducing risk of entrenched dysfunction	High symptom severity: Severe symptoms like persistent motor dysfunction or significant sensory loss are more challenging to manage and require intensive treatment. Widespread symptomatology: Multiple, widespread symptoms affecting various aspects of functioning complicate treatment and impact prognosis negatively
Levels of family and social support	Family involvement: Active family engagement, emotional support, and a positive environment contribute to better outcomes. Supportive social environment: Understanding peers and teachers, and a supportive social environment facilitate better outcomes by reducing stress and encouraging normal activities	Inadequate family support: Lack of family involvement or a stressful home environment can worsen symptoms and hinder recovery. Negative social environment: Social isolation, bullying, or lack of peer and teacher support increase stress and decrease motivation, leading to poorer outcomes
Presence/absence of comorbid psychiatric conditions	Lack of mental health disorders: The absence of comorbid psychiatric conditions like anxiety or depression reduces complexity and allows for focused FND treatment	Co-occurring mental health disorders: The presence of psychiatric conditions such as anxiety, depression, or PTSD complicates treatment and is associated with less favorable outcomes. Psychological resistance: Difficulty accepting the diagnosis or resisting psychological interventions may lead to slower progress and persistent symptoms
Level of adherence to treatment	Consistency in following treatment plans: High adherence to therapies and medications is a strong predictor of favorable outcomes, leading to symptom improvement and long-term stability	Poor compliance: Non-adherence to treatment plans due to resistance, family challenges, or other factors results in chronic symptoms and reduced quality of life

PTSD: Post-traumatic stress disorder; FND: Functional neurological disorder.

DISCUSSION

Epidemiology

FND is a significant clinical condition that affects individuals across various age groups, including children, adolescents, and adults. Understanding the epidemiology of FND, including its prevalence across different demographics, is crucial for improving diagnosis, treatment, and overall patient care[6]. FND is a relatively common condition within the general population, although its prevalence can be difficult to accurately measure due to underdiagnosis, misdiagnosis, and variability in diagnostic criteria. Estimates suggest that FND accounts for approximately 5-10% of outpatient visits to neurology clinics. Some studies indicate that up to one-third of patients referred to neurology services may have symptoms indicative of FND[7].

In children and adolescents, FND is less commonly diagnosed compared to adults, but it remains a significant concern. The prevalence of FND in pediatric populations is estimated to be around 2%-4% of all pediatric neurology referrals. A study by Yong et al[8] found that the annual incidence of FND is 18.3/100000 children, 70% of whom are females with a median age of 13 years[8]. However, these numbers may underestimate the true prevalence due to factors such as misdiagnosis and lack of awareness among healthcare providers. FND is particularly prevalent during adolescence, with a peak onset typically occurring between the ages of 10 and 18 years. This age group is particularly vulnerable due to the complex interplay of developmental, psychological, and social factors during this period[9].

Gender differences in FND are a well-documented and crucial aspect of the disorder's epidemiology. FND is more commonly diagnosed in females, with research indicating that females are 2 to 4 times more likely to develop the disorder compared to males. This disparity is particularly pronounced during adolescence, a period marked by significant hormonal, emotional, and social changes[10]. Biological factors, such as hormonal influences like estrogen, may contribute to this higher prevalence in females by affecting stress responses and brain function. Additionally, psychological factors, including the ways stress and emotional distress are experienced and expressed, play a role[11]. Females are generally more likely to report somatic symptoms and may express psychological distress through physical symptoms influenced by cultural and social expectations regarding gender roles. Social and cultural factors further shape these gender differences, with societal norms influencing how individuals perceive and respond to stress and illness[12]. These differences have important clinical implications, requiring healthcare providers to consider potential diagnosis biases and tailor treatment approaches accordingly. Understanding and addressing gender differences in FND is essential for providing accurate diagnoses and effective treatment, ultimately improving outcomes for all patients affected by this complex disorder[13].

Cultural and geographic factors play a crucial role in shaping the prevalence and presentation of FND, leading to significant variations in how the disorder is recognized, understood, and treated across different populations[14]. Culturally, the stigma associated with mental health issues often leads individuals to express psychological distress through physical symptoms, a phenomenon known as somatization. In societies where emotional expression is discouraged, individuals may present with physical symptoms that align with socially accepted norms of illness, such as paralysis or NES[15]. Geographic factors, including the availability of healthcare resources and regional differences in medical practices, also influence the prevalence of FND. In areas with limited access to healthcare, FND may be underdiagnosed or misdiagnosed due to a lack of awareness and resources. Social and economic factors further compound these issues, as economic stressors and disparities in access to care can increase the risk of FND, particularly in low- and middle-income countries[16]. Additionally, differences in healthcare systems and diagnostic practices across regions impact the recognition and management of FND. In some countries, there may be a stronger emphasis on organic explanations for symptoms, leading to delays in the diagnosis of FND. Stigma and cultural perceptions of illness further complicate the presentation and treatment of FND, as individuals may be reluctant to seek help or may present their symptoms in culturally acceptable ways, leading to misinterpretation and suboptimal care. Understanding these cultural and geographic influences is essential for providing effective, culturally sensitive care to individuals with FND, ensuring accurate diagnosis and appropriate treatment regardless of their background[17].

Several risk factors have been associated with the development of FND across different age groups. These include psychosocial stressors, comorbid psychiatric conditions, and positive family history. Individuals who experience significant psychosocial stress, such as trauma, abuse, or major life changes, may be at higher risk of developing FND. This is particularly relevant in children and adolescents, who may be more sensitive to environmental stressors[18]. FND frequently co-occurs with other psychiatric disorders, such as anxiety, depression, and somatic symptom disorders. In pediatric populations, comorbid conditions such as attention-deficit/hyperactivity disorder (ADHD) or other behavioral disorders may also be present. A family history of psychiatric or neurological conditions can increase the risk of FND. This may be due to genetic predispositions, learned behaviors, or shared environmental factors[19].

Pathophysiology

The current theories on the neurobiological mechanisms and underpinnings of FND: Recent research suggests that FND arises from a combination of dysregulated brain networks, altered neurotransmitter activity, corticostriatal-thalamo-cortical (CSTC) circuit abnormalities, and neuroinflammatory processes[20]. Neuroimaging studies highlight abnormal connectivity in the prefrontal cortex (PFC), limbic system, and parietal lobes, impairing the processing of sensory and motor signals. Dysfunction within the default mode network is linked to persistent symptoms[21].

Neurotransmitter imbalances, particularly involving serotonin, dopamine, and gamma-aminobutyric acid (GABA), play a key role in the emotional and cognitive symptoms of FND[22]. Disruptions in dopaminergic pathways affect motor control, while alterations in serotonergic and GABAergic systems contribute to mood instability and stress responses[23]. The CSTC circuit, which regulates motor function, cognition, and emotion, is also implicated in FND. Abnormalities in the basal ganglia, thalamus, and PFC may impair motor planning and execution, leading to involuntary movements and NES[24]. Dysfunction in this circuit may also reinforce maladaptive learning patterns, contributing to symptom persistence[25].

Additionally, neuroinflammation and oxidative stress have been proposed as mechanisms influencing FND. Microglial activation and elevated pro-inflammatory cytokines disrupt neural networks, while oxidative stress can lead to neuronal damage and impaired neurotransmission[26]. These findings suggest that targeting neuroinflammation through anti-inflammatory or antioxidant therapies may provide new treatment avenues[27]. Overall, FND involves complex interactions between neural circuits, neurotransmitters, and inflammatory processes. Understanding these mechanisms may lead to improved diagnostic and therapeutic strategies, ultimately enhancing patient outcomes[3,4].

The role of brain networks in FND: FND symptoms arise from dysfunctions in key brain networks, particularly the PFC, limbic system, and basal ganglia (Figure 2)[28].

Figure 2 The role of brain networks in functional neurological disorder. This diagram illustrates the interconnected role of various brain networks in developing and manifesting functional neurological disorder (FND). The prefrontal cortex, limbic system, and basal ganglia are highlighted as key regions that contribute to the symptoms of FND through their respective functions and interactions. Prefrontal cortex: Involved in executive functions, decision-making, emotional regulation, and integration of sensory and motor information. Dysfunctions in this area can lead to difficulties in controlling involuntary movements, exaggerated emotional responses, and dissociation between intention and action. Limbic system: Responsible for processing emotions, memories, and stress responses. Dysregulation in this system, particularly in the amygdala, hippocampus, and cingulate cortex, can cause physical symptoms triggered by emotional experiences. Basal ganglia: Plays a critical role in motor control, learning, and habit formation. Abnormalities in this region can lead to involuntary movements, abnormal motor patterns, and reinforcement of FND symptoms. Interconnectivity and network dysfunction: The diagram also emphasizes the complex interplay between these networks, where disruptions in communication can lead to the misprocessing of sensory information and inappropriate motor responses, which are characteristic of FND. The interconnected nature of these brain regions suggests that FND symptoms arise from widespread network dysfunction rather than isolated brain abnormalities. FND: Functional neurological disorder.

PFC: The PFC regulates executive functions, emotional control, and sensory-motor integration. Dysfunction in the dorsolateral PFC may impair motor inhibition, contributing to involuntary movements, while ventromedial PFC abnormalities can heighten emotional responses and stress reactivity, exacerbating FND symptoms[29].

Limbic system: The limbic system, including the amygdala, hippocampus, and cingulate cortex, processes emotions and stress responses. Hyperactivity in the amygdala can amplify fear and anxiety, triggering physical symptoms. The hippocampus may encode stressful experiences maladaptively, while anterior cingulate cortex dysfunction disrupts emotional regulation and bodily perception[30].

Basal ganglia: The basal ganglia regulate motor control and habit formation. Disruptions in this system can lead to involuntary movements and reinforce maladaptive motor patterns, contributing to persistent FND symptoms[31].

Network dysfunction and interconnectivity: FND is increasingly recognized as a disorder of network connectivity rather than isolated brain abnormalities. Dysregulated interactions between the PFC, limbic system, and basal ganglia impair sensory processing and motor regulation, leading to FND symptoms[22]. Disrupted PFC-limbic connectivity may exaggerate stress responses, while basal ganglia-motor cortex dysfunction can underlie motor symptoms. Targeted interventions, such as CBT, may help restore network balance and alleviate symptoms[32,33].

Influence of psychological stressors on neurological functioning in FND

Psychological stressors significantly impact brain function, contributing to the onset and exacerbation of FND symptoms[34]. Stress, trauma, anxiety, depression, and social or environmental factors can alter brain structure and function, influencing emotional regulation, sensory processing, and motor control.

Stress and trauma: Both acute and chronic stress affect key brain regions such as the amygdala, hippocampus, and PFC, which regulate fear, emotions, and executive function[35]. Stress-induced hyperactivity in the amygdala heightens arousal and misinterpretation of bodily sensations, leading to functional symptoms like NES and paralysis[36]. Traumatic experiences, particularly those involving helplessness or perceived threats, can be encoded in a way that predisposes individuals to future FND symptoms[37] (Figure 3).

Figure 3 The cascade of developing functional neurogenic disorders after psychological trauma.

Psychological factors (Anxiety, Depression): Anxiety and depression exacerbate FND symptoms by altering brain activity. Anxiety heightens alertness in the amygdala and PFC, increasing sensitivity to physical sensations and misinterpretations of normal bodily functions[1]. Depression, associated with reduced PFC activity, impairs emotional regulation and stress coping, increasing FND vulnerability[38]. Both conditions impact neurotransmitter systems (serotonin, dopamine, norepinephrine), further influencing mood, pain perception, and motor control in FND patients[39].

Social and environmental influences: Social stressors, such as interpersonal conflicts, socioeconomic struggles, and cultural perceptions of mental health, shape the expression and severity of FND symptoms[40]. In some cultures, psychological distress manifests as physical symptoms due to stigma surrounding mental illness[41]. Chronic stressors like financial instability or unsafe environments contribute to prolonged activation of stress-response systems, affecting brain regions involved in emotion regulation and motor control[42]. Psychological stressors play a crucial role in FND pathophysiology, necessitating holistic interventions that address both psychological and neurological aspects for better patient outcomes[43].

Environmental and genetic influences on FND

FND results from a complex interaction between genetic predisposition and environmental triggers. Understanding these factors is crucial for developing effective treatment strategies[44].

Genetic predisposition: While specific genes linked to FND remain unclear, variations in neurotransmitter-related genes (serotonin, dopamine) may influence mood regulation, pain perception, and motor control, increasing susceptibility[45]. Twin studies and familial aggregation suggest a hereditary component, though no single gene has been identified as a definitive cause. Instead, genetic influence appears multifactorial, involving interactions between multiple genes and environmental factors[46].

Environmental triggers: Environmental factors significantly contribute to FND onset and exacerbation. Stressful life events, trauma, chronic stress, infections, and physical injuries can act as triggers, particularly in genetically predisposed individuals[47]. Social and cultural attitudes toward mental health, socioeconomic status, and healthcare access also shape symptom expression and management[48].

Gene-environment interactions: Gene-environment interactions play a crucial role in FND development. Certain genetic variants may heighten susceptibility to environmental stressors, increasing the risk of FND when exposed to trauma or chronic stress[49]. Variations in stress-response genes, particularly those regulating the hypothalamic-pituitary-adrenal (HPA) axis, influence individual stress resilience[50]. Epigenetic modifications—environmentally driven changes in gene expression—may further impact neurotransmitter function and neural plasticity, contributing to FND pathophysiology[51].

The interplay between genetic predisposition and environmental influences underlies FND development. A comprehensive understanding of these factors is essential for refining treatment approaches that address both biological and environmental aspects of the disorder[52].

Potential mechanisms linking brain, mind, and body in FND

FND arises from complex interactions between brain function, psychological states, and physical symptoms. Three key mechanisms—psychophysiological interactions, embodied cognition, and neuro-immune interactions—help explain its pathophysiology[14].

Psychophysiological interactions: This mechanism highlights the bidirectional relationship between psychological processes and physiological responses. Stress and emotional distress can alter autonomic and HPA axis activity, leading to increased muscle tension, changes in heart rate, and altered pain perception—manifesting as functional movement disorders or NES[53]. Conversely, chronic physical symptoms can heighten psychological stress, perpetuating a symptom cycle. Addressing both psychological and physiological factors is crucial for treatment[54].

Embodied cognition: Embodied cognition suggests that cognitive functions are shaped by bodily experiences. In FND, disruptions in integrating sensory, motor, and cognitive processes can lead to symptoms like functional weakness and tremors[55]. Impaired sensory-motor integration may underlie symptom persistence, emphasizing the role of physical activity, sensory retraining, and cognitive-behavioral strategies in treatment[4,56].

Neuro-Immune interactions: Communication between the nervous and immune systems may contribute to FND. Chronic stress and psychological distress can induce neuroinflammation, releasing pro-inflammatory cytokines that affect neural circuits involved in emotion regulation, pain perception, and motor control[57]. This interplay between immune activation and neural processing may exacerbate symptoms, suggesting potential benefits from anti-inflammatory therapies and stress-reduction strategies[58].

Understanding these mechanisms underscores the need for integrated treatment approaches addressing mental, physical, and neurological health[20]. Advancing research in these areas may improve management strategies and outcomes for individuals with FND[59].

Differences between adult and pediatric FND pathophysiology

FND affects both adults and children, but its pathophysiology and clinical presentation differ across age groups. These differences stem from neurodevelopmental factors, brain network dysregulation, and psychological and environmental influences, necessitating tailored diagnostic and treatment strategies[1].

In children, FND manifests in the context of ongoing brain development, where evolving neural networks and immature regulatory systems contribute to symptom expression[60]. Motor control and sensory processing disruptions are more prominent during rapid brain growth, and children’s limited coping mechanisms make them more vulnerable to environmental stressors, leading to transient or fluctuating symptoms such as functional movement disorders or NES[61].

In adults, FND typically involves established neural circuits and cognitive processes. Chronic stress, trauma, and long-standing psychological factors contribute to persistent symptoms, including motor dysfunctions and dissociative manifestations[20,62]. While pediatric FND reflects the brain’s dynamic nature, adult FND is associated with more entrenched, maladaptive brain connectivity patterns. For example, abnormal connectivity between the motor cortex and basal ganglia may underlie pediatric motor symptoms[63], whereas adults often exhibit stable disruptions in networks involving the PFC, amygdala, and limbic system, contributing to chronic symptomatology[64].

Psychological and environmental triggers also vary. In children, acute stressors such as bullying, parental separation, or school-related pressures often precipitate FND, with symptom patterns fluctuating based on developmental stage and coping abilities[60]. In contrast, adult FND is frequently linked to cumulative stress, complex trauma histories, and psychiatric comorbidities like anxiety and depression, which reinforce chronic symptoms[65].

Clinically, pediatric FND symptoms, including functional movement disorders and NES, often change with developmental milestones and emotional states[18]. Adults, however, tend to present with more persistent functional motor impairments, chronic pain, or dissociative symptoms, often complicated by psychiatric comorbidities[19,66].

Understanding these differences is essential for age-appropriate interventions. Pediatric FND is marked by developmental vulnerability and evolving symptoms, whereas adult FND involves chronic dysfunction influenced by long-term stress and trauma[7]. Table 1 summarizes these distinctions.

Coronavirus disease 2019 pandemic and FND in pediatric patients

The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted paediatric FND, introducing stressors that may influence symptom development and severity[67].

Increased psychological stress: Lockdowns, social isolation, and disruptions to daily routines heightened anxiety, depression, and stress in children, contributing to the onset or exacerbation of FND symptoms, including functional movement disorders and NES[68].

Disruption of healthcare and support services: Delayed access to healthcare and reduced availability of school-based therapy and counseling may have worsened symptoms or delayed intervention, leading to more persistent FND presentations[69].

Exposure to trauma and acute stressors: Experiences such as illness, loss of loved ones, and financial instability acted as psychological triggers, influencing stress response systems and potentially precipitating FND symptoms[70].

Altered social and educational environments: Remote learning, increased screen time, reduced physical activity, and disrupted school routines affected mental well-being and stress levels, contributing to FND symptom variability[71].

Emerging evidence and research needs: While reports suggest increased FND cases during the pandemic, further research is needed to clarify its long-term impact and optimize management strategies for affected children[72].

Understanding these factors is essential for developing effective interventions and mitigating the pandemic’s lasting effects on pediatric FND[4].

Clinical presentation of pediatric FND

FND in pediatric patients can present with a variety of symptoms that mimic neurological conditions but are not explained by organic pathology. The clinical presentation of FND in children is diverse, reflecting the complex interplay between psychological, emotional, and physical factors[3]. The common symptoms seen in pediatric FND include motor symptoms, sensory symptoms, seizure-like episodes, and speech disturbances. A study by Yong et al[8] showed that Functional motor and sensory symptoms were the most common FND in children (41% for each), followed by other pain symptoms such as headache and somatic pain (31%and 27% respectively)[8].

Seizure-like episodes

NES: One of the most common and dramatic presentations of pediatric FND is NESs, also known as psychogenic NES or dissociative seizures[73]. These episodes resemble epileptic seizures but are not associated with abnormal electrical activity in the brain. NES may involve convulsions, hip thrusting, generalized limb shaking, loss of consciousness, or other seizure-like behaviors[72]. They may be longer than an actual seizure, with a waxing and waning course. Breathing patterns can also differentiate between epileptic (regular and loud prolonged inspiration and expiration) and NES (hyperpnea, tachypnoea, with short inspiration and expiration). NES often lack the stereotypical features of epileptic seizures, such as tongue biting, urinary or fecal incontinence, or postictal confusion[73].

NES can be triggered by emotional stress, psychological trauma, or other stressors. The episodes may vary in frequency and duration and often occur in heightened emotional arousal or stress. Unlike epileptic seizures, NES can sometimes be interrupted or stopped by verbal engagement or physical maneuvers, and they are not typically associated with postictal confusion[74]. They frequently do not respond to antiepileptic drugs, and attempts to treat them may actually exacerbate seizure-like symptoms. A notable physical exam finding is forced eye closure, where the examiner encounters resistance when opening the patient’s eyes—this is not typical of an epileptic seizure[75].

Motor symptoms

Weakness: Functional weakness is one of the most common motor symptoms in pediatric FND, often referred to as functional paresis or paralysis. Unlike organic weakness, functional weakness can vary in intensity and may be inconsistent. For instance, when observed by others, a child might show more pronounced weakness in a limb but may retain some strength during less scrutinized or spontaneous activities[1]. This type of weakness can affect one or more limbs, leading to difficulties in walking (functional gait disorder) or performing daily tasks. In cases of paralysis, it typically affects one side of the body or a single limb and does not follow any specific anatomical pattern. When paraplegia is present, deep tendon reflexes usually remain normal, and the Babinski sign is absent[76].

The key feature of psychogenic weakness is its inconsistency. The examiner should carefully observe the patient during the examination and when the patient is performing other actions, such as entering or leaving the room[77]. Hoover’s sign is a simple test based on the principle that patients extend their hip when the contralateral hip flexes against resistance. It is particularly useful for patients with functional weakness in the lower extremities. The examiner has the patient lie supine, places one hand under the affected heel, and asks the patient to lift the unaffected leg against resistance. Patients with functional weakness will exert downward pressure on the affected heel[78]. A co-contraction sign occurs when an antagonist muscle (e.g., the triceps) contracts simultaneously with the agonist muscle (e.g., the biceps). This test can be applied to any agonist/antagonist muscle group to detect the absence of true weakness[79]. Arm-drop test can be used to diagnose functional paralysis. In this test, the examiner holds the patient’s outstretched arm in front of them and then releases it. A jerky or slow descent of the arm onto the patient’s lap is characteristic of functional weakness[80]. In the sternocleidomastoid test, patients with FND often show weakness when asked to rotate their heads toward the affected side, unlike patients with organic disease[81]. Collapsing weakness is another sign of functional weakness. This phenomenon is observed when a patient is asked to hold a limb in a specific position, and upon the examiner applying light force, the limb suddenly appears to "collapse[82]".

Tremors: Functional tremors are another prevalent motor symptom in pediatric FND. These tremors can appear with abrupt onset at rest or during actions as rhythmic shaking of a limb, head, or entire body and are often characterized by variability in frequency and amplitude[83]. Unlike tremors caused by organic neurological conditions, functional tremors may decrease or disappear with distraction or during specific tasks but increase when weight is applied to the affected limb[84]. Additionally, functional tremors may be triggered or exacerbated by stress, anxiety, or other psychological factors. If an examiner asks the patient to perform a rhythmic movement with their unaffected limb, often, the unaffected limb will either adopt the frequency or rhythm of the affected limb, or the patient may struggle to maintain a consistent rhythm. This phenomenon is known as entrainment[85].

Other motor symptoms: Other motor symptoms in pediatric FND can include functional dystonia (abnormal muscle contractions leading to twisted postures), functional myoclonus (sudden, brief, involuntary muscle jerks), and functional tics[86]. These symptoms often occur in response to emotional distress or environmental triggers and can significantly impact the child’s quality of life. Functional dystonia is marked by features such as severe pain in the affected limb, adult-onset symptoms, fixed postures that persist even during sleep, a clenched fist, or an inverted foot. Inconsistent movements and multiple somatic complaints are often associated with functional dystonia. Notably, symptoms in these patients may completely remit following placebo administration, suggestion, or general anesthesia. Organic myoclonus involves jerking or spastic movements due to sudden muscle contractions or decreased muscle tone[41]. In contrast, functional myoclonus is inconsistent in both frequency and amplitude and may resolve with placebo treatment or suggestion. Patients with functional myoclonus can be highly sensitive to stimuli, but unlike typical responses to abrupt stimuli, their reactions tend to have a long and variable latency[87].

Gait disorder: Functional gait disorder presents a walking pattern that doesn't match typical neurologic or organic disorders. Patients with unilateral leg weakness may drag the affected leg behind them, with the hip either internally or externally rotated, causing the foot to point outward or inward[88]. Common features of functional gait disorder include sudden knee buckling without an actual fall, and a "walking on ice" pattern, where the patient appears as though walking on a slippery surface. This gait comprises stiff knees and ankles, a broad and slow stride, and sometimes abducted arms[89]. Patients may also demonstrate very slow initiation of gait, with their feet appearing to stick to the ground. Pseudoataxia, which involves a very unsteady gait, crossed legs, and sudden side-stepping, is also common. On examination, these patients may display uneconomical postures that shift the natural center of gravity[90].

Swallowing symptoms: Patients with swallowing difficulties often report a sensation of a lump or tightness in their throat, known as globus sensation or globus pharyngeus[91]. This condition is a functional esophageal disorder with no identifiable physiological cause, such as structural abnormalities, gastroesophageal reflux disease, or motility disorders. While it can also occur in individuals without FND, it is frequently associated with a comorbid psychiatric condition[92]. Key characteristics of globus pharyngeus include its occurrence between meals and the absence of pain when swallowing (odynophagia) or difficulty swallowing (dysphagia)[93].

Sensory symptoms

Numbness and sensory loss in pediatric FND: Pediatric patients with FND may experience sensory symptoms like numbness or altered sensation in various body parts. This numbness typically does not align with established neurological patterns and may present in a non-anatomical distribution, such as affecting an entire limb in a glove or stocking pattern[4]. The intensity and location of the sensory loss may change over time, further reflecting its functional nature. Functional sensory loss is a less specific but common manifestation of FND. The sensory impairment often does not follow typical dermatomal patterns or those indicative of neurologic disorders[22]. Patients might report a sharply defined area of sensory loss, frequently at a joint or the end of an extremity, such as the shoulder or groin. In some cases, patients may present with "hemisensory syndrome", where they experience sensory loss on one entire side of the body, sometimes accompanied by a sensation of being "cut in half" or experiencing ipsilateral hearing or vision problems[94]. A specific test for assessing this condition involves placing a tuning fork over the left and right sides of the sternum or the frontal bone. Under normal circumstances, the patient should feel the vibrations equally on both sides, as these bones vibrate as a single unit. However, patients with functional sensory loss often report not feeling the vibration on the affected side[95].

Vision disturbance in pediatric FND: Children with FND may experience visual disturbances such as blurred vision, double vision (diplopia), tunnel vision, or even complete vision loss in one or both eyes, known as functional blindness. These symptoms are not caused by any detectable abnormalities in the visual pathways or structures of the eyes and are often temporary[96]. Stress or emotional distress can trigger these visual symptoms, which may resolve spontaneously or with reassurance. Visual disturbances are common in FND, but when a patient presents with complete blindness, it may suggest factitious symptoms. In cases of functional vision loss, the pupillary reflex remains intact[97]. Unlike true blindness, which might result in difficulties maneuvering or an increased risk of injury, such signs are absent in FND. Several diagnostic tests can help differentiate functional vision loss from organic causes[98]. Mirror Test involves holding a mirror in front of the patient’s open eyes and moving it from side to side. If the patient tracks their reflection, it suggests they are not truly blind[99]. In the Fingertip Test, the patient is asked to bring the tips of their index fingers together. Patients with FND often struggle with this task, while those who are truly blind can complete it using proprioception[100]. A signature Test can be performed by asking the patient to write their signature on a piece of paper. Individuals with FND may be unable to do this, while truly blind patients typically have no difficulty signing their names. Inducing nystagmus can differentiate between true and functional blindness[101]. In the Optokinetic Test, a large rotating drum with black and white vertical stripes is placed in front of the patient. Observing optokinetic nystagmus indicates that the brain can detect the stripes, suggesting functional vision[102]. In addition, the Menace Reflex can also differentiate between true and functional blindness. This reflex is tested by quickly moving the examiner’s hand toward the patient’s face, simulating a threat. Patients with FND usually blink or flinch, while those who are blind will not. In the tearing reflex, shining a strong light in front of the patient’s eyes can induce tearing up if the patient’s vision is intact, as in FND[103].

Other sensory symptoms: Other sensory symptoms in pediatric FND, such as functional hearing loss, abnormal sensations (such as tingling or burning), and functional pain syndromes, are less common than visual disturbances[4]. These symptoms can be distressing for the child and may lead to multiple medical consultations and diagnostic tests, often yielding normal results, reinforcing the functional nature of the symptoms. Patients with anosmia can undergo a taste test, during which they typically demonstrate a normal sense of taste. In genuine cases of anosmia, patients often show a diminished sense of taste or may display signs of nutritional deficiency or malnutrition[104]. For patients presenting with symptoms of deafness, the examiner can expose them to a loud sound, which generally triggers a blink or some form of startle response[105].

Speech disturbances

Mutism: Functional mutism, or selective mutism, is a condition where a child who can speak normally suddenly becomes unable to speak in specific situations or environments. This speech disturbance is often related to underlying psychological factors, such as anxiety or trauma. In cases of FND, mutism may occur without an identifiable organic cause and can be triggered by stress or emotional events. The child may be able to communicate in other ways, such as through writing or gestures, but cannot vocalize in certain contexts[106,107].

Aphonia: Aphonia is the loss of voice or the inability to produce vocal sounds despite having intact vocal cords. In pediatric FND, aphonia can occur suddenly and is often associated with emotional stress or psychological factors. The child may whisper or speak in a very low voice, but the ability to produce normal speech is impaired. Like other functional symptoms, aphonia may resolve spontaneously or with appropriate therapeutic intervention, especially when psychological support is provided[108,109].

Other speech disturbances: Other speech-related symptoms in pediatric FND include functional stuttering, dysarthria (difficulty articulating words), or unusual speech patterns. These symptoms are often variable and may change depending on the child’s emotional state or environmental context. Speech disturbances in FND can be particularly distressing for both the child and their family, leading to significant communication difficulties and social challenges. Psychological, emotional, and environmental factors often influence these symptoms, which can vary in severity and impact the child’s life. Recognizing the functional nature of these symptoms and providing appropriate multidisciplinary care is essential for improving outcomes in pediatric FND[109,110].

Patterns of symptom onset and progression in pediatric FND

FND in pediatric patients presents with diverse onset and progression patterns, influenced by psychological stress, environmental triggers, and individual vulnerability[5]. Understanding these patterns aids timely diagnosis and management.

Sudden onset: Symptoms often emerge abruptly following significant stressors, such as family conflict, bullying, or academic pressure. Children may develop sudden limb weakness, NES, or speech loss immediately after emotional distress[60,111]. The severity of onset frequently leads to emergency consultations and extensive evaluations for organic conditions like stroke or epilepsy[1]. While some cases resolve quickly with early stressor identification, symptoms may persist if underlying emotional issues remain unaddressed[72].

Gradual onset: Some children experience an insidious onset, with mild symptoms—such as tremors, headaches, or fatigue—that progressively worsen over weeks or months, evolving into motor weakness, sensory loss, or NES[2]. Initially, symptoms may be dismissed as normal childhood complaints, delaying medical attention[1]. Without intervention, these cases risk chronic functional impairments[4].

Relapsing-remitting pattern: Some children experience symptom fluctuations, with episodes of exacerbation interspersed with periods of remission. Symptom flare-ups often correlate with stressors such as exams, family crises, or social conflicts[18]. The episodic nature can delay diagnosis, as symptoms disappear for weeks or months before reappearing in varying intensity[1]. Repeated medical evaluations may miss the functional origin of symptoms, underscoring the need for psychological support and stress management to reduce relapses[112].

Persistent chronic symptoms: In some cases, FND symptoms become chronic, leading to sustained functional impairments such as continuous limb weakness, tremors, or chronic pain. This pattern is often associated with long-standing psychological issues and multiple unsuccessful medical consultations[113]. Comorbid conditions like anxiety or depression are common, requiring a multidisciplinary approach involving physical therapy, psychological support, and educational accommodations[19].

Early recognition of these patterns improves outcomes. While sudden-onset FND prompts swift medical attention, gradual and relapsing-remitting cases often face diagnostic delays. Chronic FND presents greater challenges, emphasizing the need for sustained therapeutic efforts and psychological intervention[1].

Diagnostic criteria for FND

Although an FND diagnosis is not exclusion-dependent, a physician should rule out major neurologic diseases and exclude all other organic disorders with a thorough clinical examination. To help the physician diagnose these disorders, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), provides specific criteria for diagnosing FND, previously known as conversion disorder[102]. The DSM-5 criteria are designed to ensure that the diagnosis is based on the presence of characteristic symptoms and the exclusion of other medical conditions that could explain these symptoms[114]. The first criterion requires the presence of at least one symptom that involves altered voluntary motor or sensory function. These symptoms can manifest in various ways, including motor symptoms (e.g., weakness, tremors, abnormal gait), sensory symptoms (e.g., numbness, loss of vision), or seizure-like episodes (e.g., NES)[115]. The second criterion emphasizes that any recognized neurological or medical condition must not fully explain the observed symptoms. This means that the symptom presentation does not align with known anatomical pathways or physiological mechanisms, and there is no identifiable organic cause for the symptoms[3]. The third criterion requires that the symptoms cause significant distress to the individual or result in impairment in social, occupational, or other important areas of functioning. This may manifest as difficulties in school performance, social interactions, or daily activities in pediatric patients. The fourth criterion ensures that the symptoms cannot be better explained by another medical condition, mental disorder, or substance use[4]. This requires careful assessment to rule out other potential causes, such as neurological disorders, psychiatric conditions, or substance-induced symptoms. The DSM-5 criteria also specify that the symptoms are not intentionally produced or feigned, distinguishing FND from malingering or factitious disorder. Patients with FND are not consciously producing their symptoms, and they genuinely experience the physical manifestations of the disorder[116,117].

Specifiers in DSM-5 for FND

The DSM-5 allows for further specifying the type of symptoms the patient presents[118,119]. These specifiers help to categorize the disorder more precisely:

With weakness or paralysis: Symptoms primarily involve motor deficits, such as weakness or paralysis of a limb.

With abnormal movement: Symptoms include tremors, dystonia, gait disturbance, or other involuntary movements.

With swallowing symptoms: The main symptoms involve difficulty swallowing or a sensation of a lump in the throat (Globus sensation).

With speech symptoms: Symptoms include issues like dysphonia, aphonia, or slurred speech.

With attacks or seizures: This involves seizure-like episodes that are not due to epilepsy (NES).

With anesthesia or sensory loss: Sensory symptoms such as numbness, tingling, or loss of sensory modalities (e.g., vision, hearing).

With mixed symptoms: A combination of motor, sensory, and other functional symptoms.

These criteria are essential for accurate diagnosis and effective management in pediatric patients. They guide clinicians in distinguishing FND from other neurological and psychiatric disorders. Using specifiers allows for a more nuanced understanding of the disorder, aiding in developing tailored treatment plans[120].

Key diagnostic features of FND in pediatrics

Diagnosing FND in pediatric patients requires careful consideration of several key clinical features, as the presentation of this disorder in children and adolescents can be complex and multifaceted. One of the most notable features of pediatric FND is the sudden onset of symptoms[8]. These symptoms often appear abruptly, sometimes following a stressful event or illness, and may seem disproportionate to any identifiable medical cause. This sudden emergence is typically without a preceding history of neurological disorders, making it particularly striking to clinicians and caregivers. Another hallmark of FND in children is the inconsistency in symptom presentation[5]. Symptoms often do not align with known anatomical or physiological pathways, which is particularly evident in motor weakness or sensory loss cases. Additionally, these symptoms vary in intensity and may fluctuate throughout the day, a pattern that contrasts sharply with the more consistent symptomology seen in organic neurological diseases[121].

The presence of positive clinical signs specific to the disorder also characterizes pediatric FND. For instance, Hoover’s sign can be positive in cases of functional leg weakness, indicating a discrepancy in muscle effort that does not match the expected physiological response[80]. Similarly, “give-way weakness” where a child suddenly loses strength in a muscle group under resistance, is another positive sign that helps differentiate FND from other conditions[84]. The exacerbation of symptoms by psychological stressors is a crucial diagnostic feature. Symptoms often worsen during periods of psychological stress or after emotional trauma, with recent life stressors like bullying, family conflict, or academic pressures frequently playing a significant role in the onset or exacerbation of FND symptoms[122]. Finally, a defining characteristic of FND in pediatrics is the lack of corresponding organic findings[123]. Despite the significant symptoms experienced by the child, diagnostic tests such as magnetic resonance imaging (MRI), computed tomography (CT) scans, and EEGs typically return normal results or findings that do not explain the clinical presentation. This absence of organic pathology often necessitates a referral to a psychologist or psychiatrist to explore underlying psychological or emotional factors contributing to the disorder[124].

Triggers and exacerbating factors in pediatric FND

Pediatric FND is often triggered or exacerbated by psychological stress, trauma, and environmental or social factors, which can initiate or worsen symptoms[2]. Understanding these triggers is essential for effective management.

Psychological stress: Acute stress from academic pressures, such as exams, or social stressors like bullying, can lead to sudden onset of FND symptoms like NES or functional weakness[125]. Chronic stress, from family conflicts or pressure to conform, often causes gradual symptom onset, leading to persistent issues like chronic pain or functional movement disorders[126].

Psychological trauma: Acute trauma, such as a car accident or loss of a loved one, can trigger abrupt FND symptoms, including functional paralysis or mutism[43]. Chronic trauma, like abuse or neglect, increases the risk of persistent FND symptoms as a defense mechanism against emotional distress[127].

Environmental and social stressors: Changes in the environment, such as moving homes or schools, can exacerbate FND symptoms, particularly functional weakness or sensory disturbances, due to the anxiety of adjusting to new surroundings[4,60]. Social influences like peer pressure, cyberbullying, and the pressure to conform to social media expectations can also trigger FND, especially in children with underlying vulnerabilities[128].

Physical health and medical procedures: Children with a history of chronic illness or previous injuries, including brain trauma, may develop FND symptoms as a response to the ongoing stress of their medical condition[129]. This includes symptoms like NES or chronic pain, which are aggravated by physical health stressors.

Cognitive and emotional factors: Underlying anxiety, depression, and negative cognitive patterns can speed up the onset of FND. Children with anxiety or those prone to catastrophizing are more likely to experience functional symptoms that fluctuate with their emotional state[130].

Table 3 summarizes the various triggers and exacerbating factors for pediatric FND, highlighting psychological, environmental, and physical influences. Understanding and addressing these triggers are crucial for effective diagnosis and management, improving the child’s symptoms and overall well-being.

Comorbidities in pediatric FND

Comorbidities, both mental health-related and other medical conditions, are frequently observed in children with FND. The presence of comorbidities can complicate the diagnosis, treatment, and overall management of FND, often contributing to the persistence and severity of functional symptoms[19]. Mental health comorbidities may include anxiety disorders such as generalized anxiety disorder (GAD) and panic disorders, depressive disorders such as major depressive disorder or dysthymia, somatic symptom disorder such as somatization, and obsessive-compulsive disorder (OCD)[131]. Medical comorbidities may include chronic pain syndromes such as fibromyalgia and chronic fatigue syndrome, gastrointestinal disorders such as irritable bowel syndrome (IBS) and functional dyspepsia, and neurological disorders such as migraine or epilepsy[132].

Mental health comorbidities

Anxiety disorders: Anxiety disorders are among the most common mental health conditions seen in children with FND. GAD, characterized by excessive worry and fear, can exacerbate FND symptoms, such as tremors, functional gait disturbances, and NES[133]. The relationship between anxiety and FND is bidirectional, with anxiety both contributing to and resulting from the functional symptoms. Children with panic disorder who experience sudden and intense episodes of fear or discomfort may develop functional symptoms as a physical manifestation of their panic attacks. These may include chest pain, dizziness, or functional motor symptoms, such as shaking or paralysis during a panic attack[134].

Depression: Depression is another common comorbidity in children with FND. Symptoms of depression, such as fatigue, loss of interest, and feelings of hopelessness, can overlap with FND symptoms, making it challenging to distinguish between the two. Depression can also exacerbate FND, leading to more persistent and severe functional symptoms, such as chronic pain, fatigue, or NES[135]. Chronic, low-grade depression, or dysthymia, can also be present in children with FND, leading to a long-term experience of both mood disturbances and functional symptoms. The chronic nature of dysthymia can result in prolonged episodes of FND symptoms, making recovery more difficult[136].

Somatic symptom disorder (somatization): Somatic symptom disorder (somatization) involves the experience of physical symptoms that are distressing and cannot be fully explained by medical conditions. Children with this disorder may present with multiple unexplained physical complaints, such as pain, fatigue, or gastrointestinal issues, that coexist with FND[137]. The overlap between somatic symptom disorder and FND can complicate the diagnostic process, as both conditions involve significant physical symptoms that lack a clear organic cause.

OCD: OCD is characterized by persistent, intrusive thoughts (obsessions) and repetitive behaviors (compulsions). In some children with FND, the stress and anxiety related to OCD can trigger or worsen functional symptoms, such as NES or functional paralysis. For example, a child with OCD may develop functional symptoms as a way to cope with the overwhelming anxiety related to their obsessive thoughts[138].

Other medical comorbidities

Children with chronic pain syndromes, such as fibromyalgia, which involves widespread musculoskeletal pain, often experience overlapping FND symptoms. The presence of chronic pain can exacerbate functional symptoms, such as functional weakness or gait disturbances, as the child's body becomes more sensitive to pain and physical stress[139].

Chronic fatigue Syndrome: Chronic fatigue Syndrome, characterized by extreme fatigue not relieved by rest, can co-occur with FND. The fatigue and exhaustion associated with Chronic fatigue syndrome can worsen FND symptoms, leading to more significant disability and a more prolonged course of illness[140].

IBS: IBS a common functional gastrointestinal disorder, is frequently seen in children with FND. Symptoms such as abdominal pain, bloating, and altered bowel habits may overlap with or exacerbate FND symptoms. The stress and anxiety associated with IBS can also contribute to the development or worsening of FND symptoms, such as functional abdominal pain or NES[141]. Another gastrointestinal condition, functional dyspepsia, involves persistent or recurrent pain or discomfort in the upper abdomen. Children with functional dyspepsia may develop FND symptoms as a response to the chronic discomfort and stress related to their gastrointestinal condition[142].

Children with a history of migraines may be more susceptible to developing FND symptoms, particularly functional headache syndromes or NES. The neurological and sensory disturbances associated with migraines can overlap with or trigger functional symptoms, making the clinical presentation more complex[143]. In some cases, children with epilepsy may also present with NES as part of their FND. Distinguishing between epileptic and NES can be challenging but is essential for appropriate management. The coexistence of epilepsy and FND can lead to more frequent and severe seizure-like episodes, requiring careful coordination of care[54].

Importance of a thorough clinical assessment in FND

A thorough clinical assessment is crucial in diagnosing and managing FND, particularly pediatric patients (Figure 4). Given the complexity of FND, where symptoms often mimic those of organic neurological conditions, a detailed evaluation is essential to distinguish FND from other potential causes[144]. A comprehensive clinical assessment helps ensure an accurate diagnosis by carefully evaluating the patient's symptoms, onset, and progression. Since FND symptoms often do not align with known neurological pathways or physiological patterns, a thorough examination can identify inconsistencies characteristic of FND, such as variability in symptoms or positive clinical signs specific to the disorder[145].

Figure 4 Importance of a thorough clinical assessment in functional neurogenic disorders.

One of the primary goals of a thorough clinical assessment is to rule out organic causes of the symptoms. This involves a detailed neurological examination, appropriate imaging studies, and other diagnostic tests. By systematically excluding other potential diagnoses, clinicians can be more confident in identifying FND[146]. A comprehensive assessment goes beyond just the physical symptoms. It also includes an exploration of the patient's psychosocial background, including any recent stressors, family dynamics, and psychological factors that may be contributing to the symptoms. Understanding these elements is crucial for developing a holistic treatment plan that addresses both the physical and psychological aspects of FND[147].

The information gathered during a thorough clinical assessment guides treatment decisions. By understanding the full scope of the patient's symptoms, including any comorbidities or triggering factors, clinicians can tailor interventions to meet the patient's specific needs[148]. This might include a combination of physical therapy, CBT, and family counseling. A thorough clinical assessment also helps build trust between the patient, their family, and the healthcare team. When patients and families see that the clinician is taking the time to understand the condition fully, they are more likely to engage in the treatment process and adhere to recommended interventions. Finally, a detailed initial assessment provides a baseline that can be used to monitor the patient's progress over time. By regularly reassessing the patient, clinicians can adjust treatment plans as needed and ensure that the patient is moving toward recovery[149].

Comparison between pediatric and adult FND

FND presents differently in pediatric and adult populations. Understanding these differences is crucial for accurate diagnosis and effective management. Table 1 compares the key clinical aspects of FND in pediatric and adult patients.

Diagnostic challenges and pitfalls in FND

Diagnosing FND presents several challenges and potential pitfalls, especially in pediatric patients. These challenges can complicate the diagnostic process and lead to delays in appropriate treatment if not carefully navigated. One of the most significant challenges in diagnosing FND is the overlap between its symptoms and those of organic neurological conditions[150]. Symptoms such as weakness, tremors, and sensory disturbances can mimic those of diseases like MS, epilepsy, or stroke. This similarity can lead to misdiagnosis or unnecessary investigations and treatments for other neurological conditions[5]. FND is characterized by symptoms that often do not follow known anatomical or physiological pathways, which can vary in intensity and location over time. This inconsistency can be misleading, as it may be interpreted as malingering or a lack of effort by the patient rather than being recognized as a feature of FND[151].

The strong association between FND and psychological stressors can sometimes lead to the misconception that the symptoms are "all in the patient’s head" or that they are feigned. This misunderstanding can result in the stigmatization of the patient and a failure to appreciate the genuine distress and disability caused by FND. It can also lead to overlooking the importance of addressing the psychological and emotional components of the disorder in treatment[152]. While imaging and other diagnostic tests are essential to rule out organic causes, the lack of abnormal findings in these tests can create a diagnostic pitfall. Some clinicians may mistakenly conclude that if the tests are normal, the symptoms must be fabricated or not worth further investigation, overlooking the diagnosis of FND[153]. The diagnosis of FND requires a high level of clinical expertise and familiarity with the disorder. However, not all clinicians have the same level of experience with FND, which can lead to diagnostic delays or errors. For example, positive clinical signs specific to FND, such as Hoover’s sign or give-way weakness, may be missed or misinterpreted by less experienced practitioners[154].

In pediatric patients, additional challenges include the difficulty of obtaining a reliable history, especially in younger children who may not be able to articulate their symptoms or psychological stressors clearly[155]. Furthermore, the presentation of FND in children may be mistaken for developmental or behavioral disorders, leading to misdiagnosis. Patients with FND often have comorbid psychiatric or medical conditions, such as anxiety, depression, or chronic pain syndromes[43]. Focusing solely on the neurological symptoms may result in overlooking these comorbidities, significantly impacting the patient's overall health and complicating the treatment approach. Due to the complexities of FND and the potential for misdiagnosis, there can be a significant delay in reaching the correct diagnosis[156]. This delay can prolong the patient’s suffering and increase the risk of chronic symptoms, which are more challenging to treat. Effective communication is crucial in FND, but explaining the diagnosis understandably and acceptably to patients and their families can be challenging. Miscommunication can lead to confusion, mistrust, and non-compliance with treatment[157].

Differential diagnosis of FND in pediatrics

The differential diagnosis of FND in children is complex and requires careful consideration of various potential conditions. It involves distinguishing FND from both organic neurological disorders and psychiatric conditions that may present with similar symptoms.

Organic neurological disorders: FND can present with NES, which resemble epileptic seizures but lack the characteristic EEG findings. Both conditions may involve convulsions, altered consciousness, or other seizure-like activity[158]. A key differentiator is that NES typically lacks the electrical changes on an EEG that are seen in true epilepsy. Additionally, NES may be triggered by psychological stressors and can often be interrupted by distraction, unlike epileptic seizures[76]. MS may have symptoms such as weakness and sensory disturbances (e.g., numbness, tingling), and visual changes that can mimic those seen in FND. In pediatric MS, symptoms may also fluctuate, complicating the differentiation from FND. MS is typically associated with characteristic findings on MRI, such as lesions in the brain or spinal cord. Additionally, the presence of oligoclonal bands in cerebrospinal fluid can help differentiate MS from FND. In contrast, FND usually presents with normal imaging and no specific laboratory abnormalities[159].

Migraine with aura can cause visual disturbances, sensory changes, and even motor symptoms like hemiplegia, which may be confused with FND. Migraines are typically episodic, with a clear pattern of triggers and resolution. The presence of accompanying headache and a family history of migraines may aid in differentiation[160]. Neurological examination between episodes is typically normal in migraines, while FND may have more variable symptoms. Guillain-Barré Syndrome (GBS) can present with sudden-onset weakness and sensory changes, which might be mistaken for FND, especially in its early stages. GBS typically involves ascending weakness and areflexia, along with abnormal findings in nerve conduction studies and elevated protein in cerebrospinal fluid. These findings are absent in FND[161].

Psychiatric conditions: Some pediatric psychiatric disorders may have common symptoms with FND. For example, anxiety can manifest with physical symptoms such as tremors, dizziness, and palpitations, which may be misinterpreted as neurological symptoms of FND. In anxiety disorders, the physical symptoms are typically linked to excessive worry or panic and may improve with anxiolytic treatment or during calm periods[2]. FND symptoms, however, are often more persistent and may not always correlate directly with anxiety levels. Depression in children and adolescents can present with psychomotor retardation, fatigue, or other somatic symptoms that could be mistaken for neurological issues. Depressive symptoms are usually accompanied by pervasive low mood, anhedonia, and other cognitive symptoms. While FND can co-occur with depression, the neurological symptoms in FND are typically more prominent and less directly tied to mood[162].

Somatic symptom disorder involves excessive preoccupation with physical symptoms, which may overlap with the presentation of FND. In Somatic Symptom Disorder, the focus is often on the distress or anxiety caused by the symptoms. In contrast, in FND, the neurological symptoms themselves are the primary focus, with less emphasis on the distress they cause[163]. Historically, conversion disorder and FND were often considered synonymous, as both involve neurological symptoms not explained by organic pathology. However, FND is now understood as a broader category that includes conversion disorder. Conversion disorder refers explicitly to symptoms that arise following psychological conflict, while FND can have various psychological and biological underpinnings. Both require careful psychiatric assessment to differentiate from purely organic conditions[164]. When viewed as a subtype of FND, conversion disorder specifically involves a clear temporal link to psychological trauma or conflict[165]. The broader FND diagnosis encompasses a wider range of triggers and presentations. Some children with ADHD may present with tics or other motor disturbances that could be confused with FND. ADHD is characterized by symptoms of inattention, hyperactivity, and impulsivity that are present across multiple settings (e.g., home and school)[166]. FND-related symptoms, in contrast, do not typically fit this behavioral pattern and may vary more widely in their presentation[1].

Due to symptom overlap, differentiating FND from other neurological and psychiatric conditions in pediatric patients is challenging. A careful and comprehensive clinical assessment, including history, physical examination, and appropriate diagnostic testing, is essential to accurately distinguish FND from these other conditions (Table 4). This ensures that the patient receives the correct diagnosis and appropriate treatment.

Laboratory and imaging studies role in diagnosing FND

The diagnosis of FND, particularly in pediatric patients, relies heavily on clinical assessment. However, laboratory and imaging studies also play a crucial role in the diagnostic process[3]. While these tests are not used to diagnose FND directly, they are essential for ruling out other potential neurological or medical conditions that may present with similar symptoms. The normal findings in the context of significant symptoms support the diagnosis of FND, emphasizing the importance of a thorough clinical assessment and the selective use of diagnostic testing[166].

Basic blood tests, including complete blood count, electrolytes, and metabolic panels, are conducted to rule out metabolic or systemic causes of neurological symptoms, such as electrolyte imbalances, infections, or endocrine disorders[167]. In FND, routine blood tests usually return normal results, supporting excluding other medical conditions but offering no specific diagnostic information for FND. Tests for autoimmune markers (e.g., anti-nuclear antibodies, anti-dsDNA, etc.) or markers of inflammation (e.g., erythrocyte sedimentation rate, C-reactive protein) are sometimes performed when there is a suspicion of autoimmune or inflammatory neurological conditions[168]. These tests are generally negative in FND, helping to rule out conditions like lupus, MS, or vasculitis. The absence of such markers is consistent with a diagnosis of FND[169]. In cases where there is a family history of neurological or genetic disorders or when symptoms suggest a possible inherited condition, genetic testing might be considered. Genetic testing in FND typically does not reveal abnormalities linked to the disorder, helping to exclude genetic conditions that might explain the neurological symptoms[170].

MRI is often performed to exclude structural brain abnormalities, such as tumors, demyelinating diseases (e.g., MS), or vascular lesions that could explain the patient's symptoms. In patients with FND, MRI typically reveals normal findings or abnormalities detected are often incidental and unrelated to the clinical presentation[171]. The lack of structural pathology supports the diagnosis of FND but does not confirm it. CT scans are used primarily in acute settings, such as when there is a concern for stroke, hemorrhage, or head trauma, which might present with sudden neurological symptoms[172]. Similar to MRI, CT scans in FND patients usually do not show any acute abnormalities, helping to rule out other conditions but not directly diagnosing FND[1]. Although functional MRI and positron emission tomography are not commonly used in routine clinical practice, these techniques can be employed in research settings to study brain activity and connectivity patterns in FND patients. Research studies have shown altered connectivity in brain networks involved in motor control, emotion regulation, and attention in FND patients[173]. For example, Voon et al[174] found right temporoparietal junction hypoactivity and lower functional sensorimotor regions and limbic regions in individuals with conversion tremors than in individuals with voluntary tremors[174]. However, these findings are not yet widely used for clinical diagnosis due to variability and lack of standardization.

EEG is particularly useful when differentiating between epileptic seizures and NES, which are a common manifestation of FND. In patients with FND, particularly those with NES, EEG typically does not show the epileptiform activity seen in epilepsy. Normal EEG during a seizure-like episode strongly suggests NES rather than true epilepsy[175]. Electromyography (EMG) and nerve conduction studies are used to assess the integrity of the peripheral nervous system and muscle function, particularly when there is weakness or motor symptoms. In FND, EMG and nerve conduction studies are usually normal or show findings inconsistent with the clinical presentation, such as normal muscle activation in the presence of reported weakness, which can help differentiate FND from conditions like myopathy or neuropathy[176].

Management of pediatric FND

The management of FND in children requires a comprehensive and multidisciplinary approach. Given the complex interplay of neurological, psychological, and social factors involved in FND, treatment is most effective when it involves collaboration across various healthcare professionals[59].

Multidisciplinary approach to treatment: The management of pediatric FND requires a coordinated, multidisciplinary approach involving pediatricians, neurologists, psychiatrists, psychologists, physical therapists, and occupational therapists. Each professional brings a unique perspective and set of skills to the treatment team, ensuring that the child’s physical, psychological, and functional needs are comprehensively addressed. This collaborative approach is essential for improving outcomes and helping children with FND achieve the best possible quality of life[177]. Pediatricians often serve as the primary point of contact for children with FND. Their role includes early identification of symptoms, coordination of care, and ensuring that the child receives appropriate referrals to specialists. Pediatricians are responsible for ruling out organic causes of the symptoms through initial evaluations, including history taking, physical examinations, and basic laboratory or imaging tests. They also play a crucial role in ongoing care, monitoring the child’s progress, and managing any comorbid medical conditions. Pediatricians work closely with families to educate them about FND, helping dispel misconceptions and reassuring them about the condition’s nature[178]. Neurologists are critical in the diagnosis and management of FND, particularly in ruling out other neurological conditions that may present with similar symptoms. They perform detailed neurological assessments, including neuroimaging and neurophysiological testing, to exclude conditions like epilepsy, MS, or other structural brain abnormalities[43]. Neurologists also contribute to developing a treatment plan, often focusing on non-pharmacological interventions such as physiotherapy or CBT. They may also manage any neurological comorbidities that might complicate the FND presentation[4].

Psychiatrists play a vital role in the management of FND, especially when psychological stressors, trauma, or psychiatric comorbidities like anxiety or depression are involved. They are responsible for diagnosing and treating these psychiatric conditions, which can significantly impact the course and severity of FND. Psychiatric treatment may include pharmacotherapy, particularly when there is a need to manage severe anxiety, depression, or other mood disorders. Psychiatrists also provide psychotherapy, which can help patients process trauma, manage stress, and develop coping strategies[177]. Psychologists, particularly those specializing in pediatric psychology, are essential in providing non-pharmacological therapies for FND. CBT is a cornerstone of FND management, helping patients understand the relationship between their thoughts, emotions, and physical symptoms[179]. Psychologists work with children to develop skills to manage symptoms, reduce stress, and cope with any underlying psychological issues. Family therapy is also an important aspect of their work, as it helps address family dynamics and educates parents on how to support their children effectively[180].

Physical therapy is crucial in managing motor symptoms associated with FND, such as weakness, tremors, or gait disturbances. Physical therapists work with children through targeted exercises to improve mobility, strength, and coordination[181]. Therapy sessions often focus on retraining the nervous system and encouraging normal movement patterns. Physical therapists also provide strategies to manage fatigue and pain, which can be associated with FND. Occupational therapists help children with FND improve their ability to perform daily activities and participate in school, sports, and other social activities[182]. They assess the child’s functional limitations and design interventions to enhance independence and quality of life. This might include strategies to improve fine motor skills, adaptive techniques for challenging tasks due to FND symptoms, and environmental modifications to support the child’s functioning at home and school[183].

Education and communication with patients and families

Education and communication are fundamental to managing FND in pediatric patients (Figure 5). Ensuring that the patient and their family are well-informed about the nature of FND is critical to the success of any treatment plan. One of the first steps in management is to ensure that the patient and their family understand what FND is and what it is not[59]. This includes explaining that FND is a genuine and treatable neurological condition, not a sign of malingering, psychological weakness, or an incurable disease. Clarification of these aspects helps in reducing fear, anxiety, and stigma associated with the diagnosis. Many families may initially believe a serious, undiscovered medical condition causes the symptoms. It’s important to communicate that while the symptoms are real and distressing, they are not due to structural brain damage or a degenerative disease but rather due to functional changes in how the brain processes information[184]. Educating families about the interplay between psychological stressors and neurological symptoms is essential. This involves explaining how stress, trauma, or psychological factors can manifest as physical symptoms and how these symptoms are very real, even if they don’t have a clear structural cause[185]. Helping families understand that FND is a common condition that affects many children and adults can be reassuring. Normalizing the experience reduces the stigma and promotes acceptance of the diagnosis, making it easier for families to engage in the recommended treatment [178].

Figure 5 Pillars of education and communication with patients and families in pediatric functional neurogenic disorders.

Open and empathetic communication is key to building a therapeutic alliance with the patient and family. It’s essential to listen to their concerns, validate their experiences, and involve them in decision-making processes. This collaborative approach helps build trust and ensures the patient and family feel supported throughout the treatment process[186]. Clear communication about the treatment plan, including the roles of different healthcare providers, the expected therapy duration, and potential challenges, helps set realistic expectations. Families should be informed that recovery may take time and that progress may be gradual, with occasional setbacks[187].

As the child progresses through treatment, ongoing education is important to address new questions or concerns that may arise. Providing resources, such as written materials or referrals to support groups, can help families feel more informed and less isolated. Encouraging the child and family to actively participate in therapy, follow through with recommendations, and maintain a positive attitude toward recovery is crucial[188]. Continuous reassurance that improvement is possible with persistence and appropriate treatment can motivate the family to stay engaged. By providing clear, compassionate, and ongoing information about the condition, healthcare providers can reduce anxiety, foster understanding, and empower families to actively participate in the treatment process. This, in turn, enhances adherence to therapy, supports the therapeutic alliance, and ultimately contributes to better outcomes for the child[189].

Psychological and psychotherapeutic interventions

Psychological and psychotherapeutic interventions are central to managing FND in pediatric patients. These therapies address the underlying psychological factors that contribute to the disorder and help patients develop coping strategies to manage their symptoms. The most widely used and evidence-based interventions include CBT and other therapeutic modalities, such as family therapy and mindfulness practices.

CBT: CBT focuses on identifying and challenging negative thought patterns and behaviors that exacerbate FND symptoms. By changing these patterns, patients can reduce the frequency and severity of their symptoms. CBT teaches patients specific skills to manage stress, anxiety, and other psychological factors that may trigger or worsen FND symptoms. Techniques such as relaxation exercises, cognitive restructuring, and problem-solving are commonly used[190]. CBT is particularly effective in helping patients understand the connection between their thoughts, emotions, and physical symptoms. For example, a child might learn how their fear of a certain situation triggers physical symptoms, and through CBT, they can develop strategies to manage this fear and reduce symptoms[177]. For children with FND, especially those with motor symptoms or reduced activity levels, CBT can include behavioral activation, encouraging gradual increases in activity levels to counteract avoidance behaviors and improve physical functioning. Research supports using CBT to reduce FND symptoms and improve overall functioning in pediatric patients. Studies have shown that CBT can significantly improve quality of life, symptom reduction, and psychological well-being[191].

Family therapy: Family dynamics can play a significant role in the development and maintenance of FND symptoms. Family therapy addresses these dynamics by helping family members understand the disorder, improve communication, and support the child’s treatment. FND can place considerable stress on the family unit. Family therapy reduces this stress by fostering a supportive environment, educating family members about the condition, and encouraging healthy interactions that support the child’s recovery[191,192].

Mindfulness and stress-reduction techniques: Mindfulness-based therapies teach patients to focus on the present moment, helping them reduce anxiety and stress. Techniques such as deep breathing, progressive muscle relaxation, and guided imagery can help manage FND symptoms by promoting relaxation and reducing the physiological arousal that may trigger symptoms. By integrating mindfulness and relaxation techniques into daily routines, patients can learn to manage the stressors that exacerbate FND symptoms. These practices also help children develop a greater awareness of their bodily sensations and how they relate to their emotional states[193].

Acceptance and commitment therapy: Acceptance and commitment therapy encourages patients to accept their symptoms without judgment and commit to behaviors that align with their values, even in the presence of symptoms. This approach helps reduce the impact of FND on the patient’s life by shifting the focus from symptom elimination to living a meaningful life despite the symptoms[194].

Dialectical behavior therapy: Dialectical behavior therapy combines cognitive-behavioral techniques with mindfulness practices and is particularly useful for patients with severe emotional dysregulation. It helps patients manage intense emotions that might trigger or worsen FND symptoms, promoting greater emotional stability and resilience. A tailored, multidisciplinary approach that integrates these psychological therapies can lead to significant improvements in the lives of children with FND and their families[195].

Physical and occupational therapy for motor symptoms

Physical and occupational therapy are essential in managing motor symptoms in pediatric patients with FND. These therapies aim to improve physical functioning, enhance daily living skills, and address the specific motor difficulties experienced by children with FND, such as weakness, tremors, and gait disturbances[182].

Physical therapy: Physical therapy is often the first line of treatment for motor symptoms in FND. The primary goal is to restore normal movement patterns and improve mobility. Therapists use various techniques to help patients regain strength, coordination, and balance[180]. Tailored exercise programs are designed to target specific areas of weakness or dysfunction. These programs might include strength training, stretching, and exercises to improve coordination and balance. Physical therapists work closely with patients to perform exercises correctly and safely[196]. Many patients with FND develop avoidance behaviors due to fear of symptom exacerbation. Physical therapists use graded exposure techniques to gradually reintroduce patients to activities they have been avoiding. This approach helps to reduce fear and improve confidence in movement. Physical therapists may use desensitization techniques for patients experiencing heightened sensitivity to specific movements or sensations to help normalize these sensations and reduce discomfort[197]. Physical therapy for FND leverages the concept of neuroplasticity, the brain's ability to reorganize itself by forming new neural connections. Physical therapy can help retrain the brain to produce more typical motor outputs by encouraging repeated practice of normal movement patterns. Enhancing proprioception, or the body’s ability to sense its position in space, is another key component. Exercises that improve proprioception can help patients better control their movements and reduce symptoms like tremors or gait disturbances[198].

Occupational therapy: Occupational therapists assess the impact of FND on a child’s ability to perform daily activities, such as dressing, eating, writing, and participating in school or play. This assessment is crucial for developing targeted interventions addressing the child’s needs[199]. When certain tasks are difficult due to motor symptoms, occupational therapists introduce adaptive techniques or tools to help the child complete these tasks more easily, such as modified utensils for eating or writing aids for schoolwork[200]. Occupational therapy often involves task-oriented exercises that integrate cognitive and motor skills. This approach helps children improve their ability to perform complex tasks that require coordination, planning, and problem-solving[201]. Similar to physical therapy, occupational therapists use activity grading, gradually increasing the difficulty of tasks to match the child’s improving abilities. This helps build confidence and encourages the child to engage more fully in daily activities[202]. Occupational therapists work with schools to implement accommodations that support the child’s participation in academic activities. This might include adjustments to the classroom environment, modified assignments, or the use of assistive technology[203]. Since FND can affect a child’s social interactions, occupational therapy may also include social skills training. This helps children develop the skills needed to interact with peers, participate in group activities, and build positive relationships. Together, these therapies help children with FND improve their physical functioning and quality of life, enabling them to engage more fully in everyday activities and reach their developmental potential[202].

Pharmacotherapy: Indications and options

Pharmacotherapy is not typically the first-line treatment for FND in pediatric patients. However, it may be considered when specific symptoms, comorbid conditions, or treatment-resistant cases warrant pharmacological intervention. Many children with FND have comorbid psychiatric conditions such as anxiety or depression. In these cases, pharmacotherapy may be indicated to manage these conditions, which can exacerbate FND symptoms[204]. SSRIs or SNRIs are often prescribed to alleviate symptoms of anxiety and depression. If a child with FND also presents with OCD, medications like SSRIs may be beneficial in managing both the OCD and potentially reducing FND symptoms[205].

For pediatric patients with FND who experience severe and disabling pain, pharmacotherapy might be considered as part of a broader pain management strategy. Medications such as gabapentin or pregabalin may be used to manage neuropathic pain. In some cases of NES, particularly when they are frequent and disabling, medications like benzodiazepines might be temporarily used to help manage acute episodes[206]. However, this is generally not a long-term solution due to the risk of dependency. If sleep disturbances are significantly affecting the child’s functioning or exacerbating FND symptoms, sleep aids such as melatonin or, in more severe cases, sedative-hypnotics may be prescribed to improve sleep quality[207]. Table 5 summarizes the most common drugs used in managing children with FND.

School and social support

School and social support are critical components of the management strategy for children with FND. These supports help ensure that the child can participate in educational activities, maintain social connections, and achieve a sense of normalcy despite their condition. Effective management in these areas involves collaboration between healthcare providers, educators, and families to create a supportive environment that addresses the child's academic and social needs[208].

School support: Children with FND may require specific accommodations to succeed in school. An individualized education plan or a 504 plan can outline these accommodations, including modified assignments, extended time on tests, or access to a quiet room for breaks. These plans are developed collaboratively between the school, healthcare providers, and the child’s family to ensure that the child’s educational needs are met. The accommodations must be reviewed regularly and adjusted as needed to reflect the child’s current condition. Flexibility in these plans allows for modifications based on the child’s progress or changes in their symptoms[209]. Educating teachers and school staff about FND is crucial for creating a supportive school environment. Staff should be informed about the nature of FND, its symptoms, and the potential triggers that could exacerbate the condition. This understanding helps reduce stigma and ensures that staff can respond appropriately to the child’s needs[208]. Schools should have clear plans in place to manage any crises that may arise due to FND symptoms, such as NES or sudden motor disturbances. These plans should include steps for ensuring the child’s safety and minimizing disruption to the school day[203]. Children with FND may benefit from additional academic support, such as tutoring or help with specific subjects where they are struggling due to their symptoms. This support can be provided within the school or through external resources. Despite their challenges, children with FND must be encouraged to participate in all aspects of school life, including extracurricular activities. This participation helps foster a sense of belonging and normalcy[178].

Social support: Children with FND may face difficulties in maintaining social relationships due to their symptoms. Schools and families can work together to create opportunities for the child to interact with peers in a supportive setting. This might include structured social activities or playdates arranged with understanding friends[181]. In some cases, children with FND may benefit from social skills training to help them navigate social interactions more effectively. School counselors or external therapists can provide this training, which may involve role-playing scenarios, group therapy, or other interventions designed to build social competence[210]. Family support is essential for children with FND. Parents and siblings can play a crucial role in reinforcing positive behaviors, encouraging participation in social activities, and providing emotional support. Family therapy may also be beneficial in addressing any stress or conflict related to the child’s condition[211]. Involvement in community activities, such as sports teams, clubs, or youth groups, can provide additional social support for children with FND. These activities offer opportunities for the child to build self-esteem, make new friends, and develop a sense of belonging outside of the school environment[212]. Reducing stigma around FND involves promoting awareness and understanding within the child’s social circles, including peers, teachers, and community members. Education about the condition can help to dispel misconceptions and foster a more inclusive environment[213]. Ensuring that the child remains socially connected is crucial in preventing feelings of isolation or loneliness. Schools, families, and healthcare providers should work together to identify signs of social withdrawal and intervene early to provide support. A collaborative approach involving educators, healthcare providers, families, and community resources is essential to creating a supportive environment that addresses the unique challenges children with FND face[214].

Long-term follow-up and monitoring

Long-term follow-up and monitoring are critical components in managing pediatric FND. Given its chronic and often fluctuating nature, continuous assessment and support are essential to ensure optimal outcomes and prevent relapses. This process involves regular medical evaluations, psychological support, and the adjustment of treatment strategies as the child grows and their needs evolve[150]. Regular follow-up appointments with pediatricians, neurologists, and other healthcare providers are essential to monitor the child’s progress. The frequency of these visits may vary depending on the severity of the symptoms, the effectiveness of the treatment plan, and the presence of any comorbid conditions[215]. These appointments assess symptom changes, treatment adherence, and overall well-being. FND can present with new symptoms or changes in symptom patterns over time. Regular evaluations allow for the early detection of new or worsening symptoms, enabling timely adjustments to the treatment plan. This proactive approach helps manage the disorder more effectively and reduces the risk of complications[1].

Continuous monitoring helps assess the effectiveness of various pharmacological, psychological, or physical interventions. If specific treatments are not yielding the expected results, they can be modified or replaced with alternative approaches. This ensures that the child receives the most appropriate and effective care[216]. Regular follow-ups also help monitor for any side effects of medications or complications arising from the treatment. This is particularly important in pediatric patients, where the side effects of drugs can significantly impact development and quality of life[217]. Children with FND often have comorbid psychiatric conditions such as anxiety, depression, or post-traumatic stress disorder (PTSD). Regular mental health evaluations are crucial to monitor the status of these conditions and to adjust therapeutic interventions accordingly[4]. Continuous psychological support can also help in managing stressors that may exacerbate FND symptoms. As the child progresses, the need for adjustments in behavioral therapies, such as CBT, may arise. Regular sessions with a psychologist or therapist ensure that the therapeutic approaches remain relevant and effective[176].

The impact of FND on the family unit is significant, and ongoing monitoring of family dynamics is essential. If the family is experiencing stress or conflict related to the child’s condition, family therapy or counseling may be recommended. This support helps maintain a healthy environment that promotes the child’s recovery[191]. Continuous monitoring of the child’s interactions at school and with peers is vital. Ensuring that the child remains socially engaged and supported at school helps prevent isolation and promote a sense of normalcy. Any issues identified in these areas should be addressed promptly through collaboration between healthcare providers, educators, and the family[218]. As the child grows, their treatment needs may change. For example, as they approach adolescence, they may encounter new psychological or social challenges that require adjustments in therapy or support. Regular follow-ups allow the treatment plan to be dynamic and responsive to these changes[219]. As pediatric patients with FND approach adulthood, a transition plan should be developed to move them from pediatric to adult healthcare services. This transition should be gradual and well-coordinated to ensure continuity of care and support[220]. Long-term monitoring helps identify early warning signs of relapse or worsening symptoms. Educating the child and their family about these signs allows for early intervention, which can prevent a full relapse and maintain the child’s stability. Ongoing support and follow-up help sustain the progress made through treatment. Reinforcement of positive behaviors continued therapy participation, and regular medical evaluations are all crucial in maintaining long-term improvement. Through a coordinated approach involving healthcare providers, the family, and the school, long-term follow-up ensures that children with FND can thrive in all aspects of their lives[59].

Prognosis of FND

Factors influencing the prognosis of pediatric FND: The prognosis of pediatric FND can vary widely depending on several key factors. Understanding these factors is crucial for predicting outcomes and tailoring treatment strategies to improve the child’s long-term well-being. Early identification of FND is one of the most critical factors influencing prognosis. Prompt diagnosis allows for the early initiation of appropriate treatment strategies, which can prevent the condition from becoming chronic[18]. Children diagnosed early are more likely to respond positively to treatment and have a better long-term outcome. Intervening early with CBT, physical therapy, and educational support can significantly improve outcomes. Early intervention helps reduce symptom severity, improve coping mechanisms, and prevent symptom escalation[221]. The longer the duration of symptoms before diagnosis and treatment, the more challenging it can be to manage the disorder. Children with long-standing symptoms may develop more entrenched patterns of behavior and physical dysfunction, making treatment less effective and the prognosis less favorable[59]. The initial severity of the symptoms also plays a role in the prognosis. Children with milder symptoms tend to have a better prognosis, especially when combined with early and appropriate treatment. Severe symptoms, particularly those resistant to treatment, can lead to a more protracted course and poorer outcomes[1].

The presence of comorbid psychiatric conditions, such as anxiety, depression, or PTSD, can complicate the management of FND and negatively impact prognosis. These conditions can exacerbate FND symptoms, making them more difficult to treat, and can contribute to a more complex clinical picture[19]. Addressing comorbid psychiatric conditions through an integrated care approach that includes mental health professionals is essential for improving prognosis. Successful management of these conditions can lead to better overall outcomes for the child[222]. Strong family support is crucial in the management of pediatric FND. A supportive and understanding family environment can significantly improve the child’s prognosis. Families who are engaged in the treatment process, adhere to therapeutic recommendations and provide emotional support help foster better outcomes[223]. A child’s social environment, including peer relationships and school support, also influences prognosis. Positive social interactions and a supportive school environment can enhance the child’s ability to cope with FND and improve their overall prognosis. Conversely, a lack of social support or negative social interactions can hinder progress and worsen outcomes[224].

Adherence to the prescribed treatment plan is a key determinant of prognosis. Children who consistently engage in therapy sessions, follow medical advice, and participate in recommended physical and psychological interventions are more likely to experience improvement[225]. Non-compliance or inconsistency in following the treatment plan can lead to suboptimal outcomes and a poorer prognosis. Family involvement in ensuring treatment adherence, attending therapy sessions, and providing encouragement is vital. The more the family is involved and committed to the treatment process, the better the chances of a positive outcome[226]. Chronic stress, ongoing trauma, or exposure to triggering events can negatively affect the prognosis of FND. Children who continue to face significant stressors may experience more frequent exacerbations of their symptoms, making it difficult to achieve sustained improvement[227]. Identifying and managing stressors and triggers is important to the treatment process. Successful management of these factors can lead to fewer symptom flare-ups and a more stable disorder course. A holistic approach that addresses these factors through early intervention, integrated care, and robust support systems can significantly improve the prognosis for children with FND[228].

Short-term vs long-term outcomes

The prognosis of pediatric FND can vary significantly in the short term vs the long term, with different factors influencing outcomes over these time frames.

Short-term outcomes: In the short term, some children with FND may experience rapid improvement in symptoms, especially if the disorder is identified early and appropriate treatment is initiated. Short-term outcomes are often more favorable when interventions such as CBT, physical therapy, and family support are promptly provided. Some children may experience partial remission of symptoms, where certain symptoms improve, but others persist or fluctuate. These children may still require ongoing treatment and monitoring to prevent relapse[59]. The immediate effectiveness of interventions heavily influences short-term outcomes. For example, children who respond well to initial therapeutic approaches may have a better prognosis in the short term, with fewer symptoms and improved functioning. The child’s ability to psychologically adjust to the diagnosis and treatment process also affects short-term outcomes. A positive adjustment can lead to more immediate improvements in both physical and emotional well-being[227]. Some children may initially resist or struggle with treatment, particularly if they have difficulty accepting the diagnosis or if the symptoms are severe. This can lead to a slower response and less favorable short-term outcomes. The presence of ongoing stressors, such as family conflict, school challenges, or social isolation, can negatively impact short-term outcomes by exacerbating symptoms and hindering progress[229].

Long-term outcomes: In the long term, FND can become a chronic condition with the potential for symptom relapses. Long-term outcomes depend on sustaining symptom management and preventing relapses through continued treatment and support. Children who achieve long-term stability often show sustained improvements in functionality, including better academic performance, social interactions, and participation in daily activities. Long-term stability is more likely when there is consistent adherence to treatment and a supportive environment[230]. Over the long term, FND can have an impact on a child’s development, particularly if the disorder persists into adolescence. The presence of ongoing symptoms can affect the ability to navigate developmental milestones, such as independence and social relationships. Long-term psychosocial outcomes are influenced by the child’s ability to adapt to living with a chronic condition. Successful adaptation can promote positive self-esteem, resilience, and healthy coping mechanisms. However, poor adaptation can result in ongoing mental health challenges, such as anxiety or depression, which may complicate the long-term prognosis[38,231].

For children with persistent FND symptoms, transitioning to adult care becomes an essential consideration in the long term. A well-coordinated transition can ensure continuity of care and support, improving long-term outcomes. Continuous monitoring and periodic reassessment are crucial in managing FND over the long term. As the child grows and their needs change, adjustments to treatment plans help maintain progress and prevent regression[232]. The long-term prognosis for pediatric FND is highly variable, with some children achieving complete resolution of symptoms while others may continue to experience chronic symptoms that require ongoing management. The variability in outcomes is influenced by factors such as the initial severity of symptoms, the presence of comorbid conditions, and the level of support from family and healthcare providers[233]. Despite the challenges, many children with FND have the potential for full recovery, particularly with early and comprehensive treatment. Long-term positive outcomes are more likely when interventions are sustained, and the child receives consistent support. The variability in prognosis highlights the importance of individualized care, continuous monitoring, and a multidisciplinary approach to treatment[234].

Predictors of favourable and unfavourable outcomes

Various factors can influence the prognosis of pediatric FND, serving as predictors of favorable or unfavorable outcomes. Understanding these predictors can guide treatment planning and help set realistic patient and family expectations[235].

Predictors of favorable outcomes in pediatric FND include several key factors. Early diagnosis and treatment are critical, with timely intervention often leading to symptom resolution or significant improvement, mainly when initiated within the first few months of symptom onset[236]. Access to specialized care, such as a multidisciplinary team comprising pediatric neurologists, psychologists, and physical therapists, further enhances the likelihood of a favorable prognosis through comprehensive and coordinated treatment. Children who present with mild symptoms at the onset of FND typically have better outcomes, as these symptoms are more responsive to treatment and less likely to become chronic[237]. A shorter duration of symptoms before diagnosis and treatment also contributes to more favorable outcomes, reducing the risk of entrenched dysfunction. Strong family and social support play a crucial role in recovery, with active family involvement, emotional support, and a positive environment significantly contributing to better outcomes[18]. A supportive social environment, including understanding peers and teachers, helps reduce stressors and encourages the child’s participation in normal activities, further improving the prognosis[238]. The absence of comorbid psychiatric conditions, such as anxiety or depression, is another positive predictor, as it reduces the complexity of the clinical picture and allows for more focused treatment of FND. Finally, treatment adherence is vital; children who consistently follow their treatment plans, including therapies and medications, are more likely to achieve symptom improvement and long-term stability[59].

Predictors of unfavorable outcomes in pediatric FND include several factors that can complicate treatment and hinder recovery. Delayed diagnosis and prolonged symptom duration are significant concerns; late diagnosis, particularly when symptoms have persisted for an extended period, is associated with poorer outcomes, as chronic symptoms are often more challenging to treat and may become resistant to intervention[235]. Children who experience symptoms for a long duration before receiving treatment are at a higher risk of developing chronic FND, leading to less favorable outcomes. Severe initial symptoms also contribute to a more challenging prognosis. Children who present with high symptom severity, such as persistent motor dysfunction, frequent NES, or significant sensory loss, may require more intensive treatment, and the presence of multiple, widespread symptoms affecting various aspects of functioning (e.g., motor, sensory, cognitive) can complicate treatment and negatively impact prognosis[6]. The presence of comorbid psychiatric conditions, such as anxiety, depression, or PTSD, further complicates treatment and is associated with less favorable outcomes, as these conditions may exacerbate FND symptoms and hinder the effectiveness of standard treatment approaches[31]. Additionally, psychological resistance, where children have difficulty accepting the diagnosis or resist psychological interventions, may result in slower progress and a higher risk of persistent symptoms. A lack of family and social support can be detrimental to a child’s recovery; inadequate family support or a stressful home environment, including family conflicts, lack of understanding, or inconsistent support, can exacerbate symptoms and hinder treatment efforts[238]. A negative social environment, characterized by social isolation, bullying, or lack of support from peers and teachers, can contribute to unfavorable outcomes by increasing the child’s stress levels and reducing their motivation to engage in treatment[239]. Finally, non-adherence to treatment is a strong predictor of unfavorable outcomes; poor compliance with treatment plans, whether due to the child’s resistance, family challenges, or other factors, can lead to chronic symptoms and reduced quality of life[240]. Understanding these predictors can help healthcare providers tailor interventions to maximize the chances of recovery and long-term stability for children with FND. Table 6 summarizes the prognostic factors for FND.

Early diagnosis and intervention play a crucial role in improving the prognosis for pediatric FND. Timely identification of FND, especially within the initial months of symptom onset, significantly enhances the likelihood of achieving favorable outcomes[241]. Early diagnosis allows for prompt initiation of targeted therapies, preventing symptoms' progression and reducing the risk of chronicity. Intervening early helps to mitigate the development of entrenched patterns of dysfunction and can lead to quicker symptom resolution or substantial improvement[242]. This proactive approach effectively addresses the symptoms and supports the child’s overall developmental trajectory. Furthermore, early intervention often involves comprehensive care from a multidisciplinary team, including pediatric neurologists, psychologists, and physical therapists. This coordinated care approach ensures that all aspects of the disorder are addressed, which can further enhance recovery and stability[243].

Challenges in diagnosis and management

Variability in symptom presentation: One of the significant challenges in diagnosing and managing Pediatric FND is the variability in symptom presentation. FND symptoms can range widely, from motor dysfunctions like weakness and tremors to sensory disturbances and seizure-like episodes. This variability can complicate the diagnostic process, as symptoms may overlap with those of other neurological or psychiatric conditions, leading to potential misdiagnoses[244]. Developmental stages and individual differences can further influence the range of symptoms in pediatric patients. For instance, younger children might present with more generalized or less specific symptoms, making it harder to pinpoint FND, among other conditions. Moreover, the fluctuating nature of symptoms, with periods of improvement and exacerbation, can add to the diagnostic complexity[66].

This variability also poses challenges for management. Treatment plans must be highly individualized to address the specific symptom profile of each patient. A one-size-fits-all approach is unlikely to be effective, and clinicians must continuously adjust interventions based on the evolving presentation of symptoms[245]. Furthermore, the need for a multidisciplinary team approach becomes evident, as different specialists may be required to address the diverse aspects of the disorder. Clinicians must navigate these challenges by employing a comprehensive, flexible approach to effectively address the wide range of symptoms and their impact on the patient’s quality of life[246].

Stigma and misconceptions about FND: Stigma and misconceptions surrounding FND present significant challenges in both diagnosis and management. Despite being a legitimate medical condition, FND often suffers from a lack of understanding and negative perceptions. This stigma can lead to a range of issues, including delays in diagnosis, inadequate treatment, and additional psychological stress for patients and their families[247]. Misconceptions, such as the belief that FND symptoms are deliberately produced or indicative of psychological weakness, can undermine the validity of the diagnosis and the seriousness with which it is treated. This can result in patients being dismissed or not taken seriously, exacerbating frustration and isolation. The misconception that FND is a "catch-all" diagnosis for unexplained symptoms can also lead to skepticism among healthcare providers, potentially resulting in misdiagnosis or inadequate management[248].

The stigma associated with FND can further impact the treatment process. Patients may experience reluctance to seek help due to fears of judgment or disbelief. This can lead to delays in receiving appropriate care and reduce the likelihood of engaging in necessary treatments. Moreover, the societal and familial misunderstanding of FND may lead to a lack of support, further complicating the management of the disorder[249]. Addressing these challenges requires a concerted effort to educate the public and healthcare professionals about the nature of FND. Improving awareness and understanding can help reduce stigma, encourage timely diagnosis, and promote a more empathetic and effective approach to treatment. By fostering an environment where FND is recognized and respected as a genuine medical condition, patients are more likely to receive the support and care they need for successful management[250].

Barriers to accessing specialized care

Barriers to accessing specialized care pose significant challenges in diagnosing and managing FND. These barriers can impede timely and effective treatment, impacting patient outcomes and overall quality of care. These barriers could be geographical, financial, systemic, psychological barriers, and difficulties related to knowledge, awareness, and communications[251]. In many regions, specialized care for FND may be concentrated in urban areas or large medical centers, making it difficult for patients in rural or underserved areas to access appropriate services. Traveling to specialized centers can be costly and time-consuming, exacerbating the challenge for families. The cost of specialized care, including consultations with pediatric neurologists, psychologists, and physical therapists, can be prohibitive for some families. Insurance coverage may not always extend to all aspects of FND management, leading to financial strain and limited access to necessary treatments[252].

Healthcare systems may lack integrated, multidisciplinary approaches required for comprehensive FND care. This fragmentation can lead to difficulties in coordinating between various specialists, resulting in delays or gaps in treatment. Additionally, long wait times for appointments with specialized practitioners can further delay diagnosis and intervention[253]. Limited awareness of FND among general practitioners and other frontline healthcare providers can delay referrals to specialists. Without adequate knowledge about the disorder, primary care providers may not recognize the need for specialized evaluation, leading to delayed or inappropriate management[254]. Stigma and misconceptions about FND can contribute to reluctance in seeking specialized care. Families and patients may be hesitant to pursue further evaluation or treatment due to fears of being judged or not being taken seriously. Effective management of FND often requires close communication between different healthcare providers, patients, and families[255]. Language barriers, difficulties understanding medical terminology, and inadequate support for non-English speaking families can hinder care coordination. Addressing these barriers involves improving access to specialized care through enhanced awareness, better insurance coverage, and more integrated healthcare services[256]. Efforts to provide financial assistance, reduce travel burdens, and foster better communication can help ensure that all patients with FND receive the comprehensive care they need[16].

The need for pediatric-specific diagnostic tools and criteria

One of the significant challenges in diagnosing and managing Pediatric FND is the lack of pediatric-specific diagnostic tools and criteria. The symptoms and presentation of FND in children can differ considerably from those in adults, necessitating tailored diagnostic approaches and criteria[118]. Developmental differences are crucial; children’s cognitive, emotional, and physical development stages impact how symptoms manifest and are recognized. For instance, younger children might not have the verbal skills or cognitive maturity to articulate their symptoms accurately, making assessment and diagnosis more challenging with adult-oriented tools and criteria[257]. Age-related variability also complicates diagnosis. The presentation of FND can vary significantly across different age groups, and symptoms common in adults may present differently in children[1]. Standard diagnostic criteria may not fully capture these pediatric experiences. Furthermore, the absence of pediatric-specific diagnostic criteria means that existing frameworks, primarily designed for adults, may not fully apply to younger patients, potentially leading to misdiagnosis or delays in identifying the disorder[258].

Many diagnostic tools and assessment scales used for FND are not validated for pediatric populations. This gap highlights the need for customized tools or new, validated instruments appropriate for children, such as age-appropriate symptom checklists, developmental assessments, and neuropsychological evaluations[259]. Effective diagnosis and management often require interdisciplinary collaboration among pediatric neurologists, psychologists, and developmental specialists. The lack of standardized, interdisciplinary diagnostic protocols can hinder a comprehensive approach to evaluation and treatment[260]. Addressing these challenges involves ongoing research and the development of pediatric-specific diagnostic tools and criteria. Creating and validating frameworks that reflect the unique presentations of FND in children will improve diagnostic accuracy, facilitate early intervention, and ensure that pediatric patients receive appropriate and effective care[234].

Future directions and research needs

The field of pediatric FND is evolving, yet several critical gaps in knowledge and understanding remain. Addressing these gaps is essential for improving diagnosis, treatment, and overall patient outcomes. A significant challenge is the limited research focusing specifically on pediatric FND, as much of the existing literature is derived from adult models. These adult-based frameworks may not fully capture the developmental, neurological, and psychosocial nuances of pediatric cases, potentially leading to misdiagnosis or suboptimal treatment approaches[176]. One major research priority is the deepening of our understanding of pediatric FND pathophysiology. While adult FND has been linked to maladaptive brain network functioning, altered connectivity, and dysregulated sensorimotor integration, the mechanisms underlying pediatric FND remain poorly defined. The developing brain exhibits significant neuroplasticity, which may influence symptom manifestation, recovery trajectories, and treatment responsiveness differently than in adults. Emerging research into pediatric-specific neurobiological mechanisms—including functional connectivity alterations, neurotransmitter imbalances, and autonomic nervous system dysfunction—holds promise for advancing diagnostic precision and therapeutic strategies. However, more targeted studies are needed to elucidate these mechanisms and how they evolve across different developmental stages in children[4].

Another pressing issue is the lack of standardized, pediatric-specific diagnostic criteria. Current FND diagnostic frameworks were primarily developed for adults and may not fully accommodate the unique presentations seen in children, who often exhibit a wider range of symptom variability influenced by cognitive, emotional, and social development. Developing and validating pediatric-specific guidelines is critical for ensuring accurate and early diagnosis, as well as for facilitating timely intervention. These guidelines should incorporate age-related symptom variations, differences in coping mechanisms, and developmental factors that influence symptom expression and persistence[156]. In terms of treatment, further research is needed to evaluate the effectiveness of different therapeutic modalities. Psychological interventions, particularly CBT, have shown promise in treating pediatric FND, but more robust studies are necessary to determine optimal treatment duration, delivery methods (e.g., individual vs group therapy), and the role of parent involvement in therapy. Additionally, the integration of physical therapy, occupational therapy, and neurorehabilitation approaches needs further exploration to optimize functional recovery. Pharmacotherapy remains a debated area in pediatric FND management, with limited evidence supporting its use. Investigating the role of medications, particularly in cases with significant psychiatric comorbidities, is crucial for developing a more comprehensive treatment framework. Personalized treatment approaches tailored to specific FND subtypes, symptom severity, and individual patient needs are an important area for future research[261].

Longitudinal studies are also imperative to understanding the long-term outcomes of pediatric FND. Current research is limited in tracking patients over extended periods to assess symptom persistence, recurrence, and functional recovery. Identifying factors that influence prognosis—such as early intervention, family dynamics, and psychosocial support—will help refine treatment strategies and improve long-term patient care. Additionally, studying the transition of pediatric FND patients into adulthood can provide insights into how the disorder evolves over time and whether early intervention can prevent chronicity. Establishing large-scale, multi-center cohort studies will be instrumental in answering these critical questions and guiding clinical practice[262]. Finally, interdisciplinary and collaborative research efforts are essential for advancing the field. The integration of pediatric neurology, psychiatry, psychology, and rehabilitation medicine will provide a more comprehensive understanding of FND and facilitate the development of innovative therapeutic approaches. Expanding awareness and education among healthcare providers, educators, and families is also necessary to reduce diagnostic delays, stigma, and mismanagement. By addressing these research gaps and fostering collaboration, significant strides can be made toward improving outcomes for children with FND[263].

Recommendations

Several key recommendations should be addressed to enhance the management and outcomes of FND. Firstly, developing and implementing pediatric-specific diagnostic criteria is crucial. This involves creating and validating diagnostic tools tailored to the unique presentations of FND in children, with input from multidisciplinary teams, including pediatric neurologists, psychologists, and developmental specialists. Early diagnosis and intervention are vital; thus, healthcare providers should be trained to recognize early signs of FND and initiate prompt treatment. Increasing awareness and education about FND among pediatricians and general practitioners can facilitate earlier referrals to specialists. Additionally, research should focus on the neurobiological mechanisms underlying pediatric FND to inform targeted therapies and improve diagnostic accuracy. Evaluating and refining treatment modalities through ongoing research will help identify the most effective interventions, including psychological therapies, physical therapy, and pharmacotherapy. Long-term follow-up and monitoring are essential to track patient progress, assess the natural history of the disorder, and adjust treatment plans as needed.

Addressing barriers to specialized care is also important, including geographic, financial, and resource-related constraints. Efforts should be made to ensure that all patients have access to comprehensive care. Increasing family and social support is critical; families should be engaged in the treatment process, receive education and support, and foster a positive home environment. Schools and communities should also provide support to reduce stressors and encourage the child’s participation in normal activities. Finally, fostering interdisciplinary collaboration among pediatric neurologists, psychologists, physical therapists, and other specialists is necessary for providing integrated and comprehensive care. By implementing these recommendations, the management of Pediatric FND can be significantly improved, leading to better outcomes for children and their families.

The current study on pediatric FND has several limitations that must be acknowledged. Firstly, the variability in symptom presentation among pediatric patients can make generalizing findings across the entire population challenging. As FND symptoms can vary widely, the study’s results may not fully capture the diverse clinical presentations encountered in practice. Another limitation is the reliance on existing literature and secondary data, which may not always reflect the most current or comprehensive understanding of FND. Studies included in the review may have limitations related to sample size, study design, or methodological approaches that could impact the validity of the findings. Additionally, the heterogeneity of study populations and diagnostic criteria used across different studies can introduce variability and affect the consistency of the results.

The study also faces constraints related to the limited amount of pediatric-specific research available on FND. Much of the current literature is based on adult populations, and translating these findings to pediatric cases may not always be straightforward. The lack of pediatric-specific studies means that some recommendations and conclusions may be extrapolated from adult data, which may not fully account for developmental differences in children. Furthermore, the study may be influenced by publication bias, as positive or significant findings are more likely to be published than negative or inconclusive results. This bias can skew the overall understanding of FND and its management in pediatric patients. Finally, the dynamic nature of FND research means that new findings and advancements may emerge after this study's completion. As such, the conclusions drawn here may need to be updated as the field evolves and new evidence becomes available. Continuous research and the inclusion of more recent data are essential for refining and improving the understanding and management of pediatric FND.

CONCLUSION

Pediatric FND is a complex and multifaceted disorder characterized by diverse symptomatology and variability in clinical presentation. This review highlights the critical role of early diagnosis and intervention in improving patient outcomes. Developing and implementing pediatric-specific diagnostic criteria and a multidisciplinary treatment approach are essential to optimizing care. Findings emphasize that early and accurate diagnosis, access to specialized care, and a supportive family and social environment significantly enhance prognosis. Conversely, delayed diagnosis, severe symptoms, comorbid psychiatric conditions, and lack of support contribute to poorer outcomes. Despite progress in understanding FND, significant gaps remain. The reliance on adult-focused research, variability in symptom expression, and the lack of standardized diagnostic guidelines pose challenges to clinical management. Future research should prioritize elucidating the neurobiological mechanisms of pediatric FND, developing age-specific diagnostic tools, and conducting longitudinal studies to evaluate treatment efficacy. Collaborative, interdisciplinary approaches will be crucial in refining diagnostic frameworks and therapeutic interventions. By addressing these gaps, healthcare providers can improve the recognition, diagnosis, and management of pediatric FND, ultimately enhancing the quality of life for affected children. Advancing research and fostering interdisciplinary collaboration will be essential in optimizing outcomes and refining treatment strategies for this challenging disorder.