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

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.