Observational Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Nov 26, 2022; 10(33): 12175-12183
Published online Nov 26, 2022. doi: 10.12998/wjcc.v10.i33.12175
Prognostic values of optic nerve sheath diameter for comatose patients with acute stroke: An observational study
Sha Zhu, Chao Cheng, Liu-Liu Wang, Dian-Jiang Zhao, Yuan-Li Zhao, Xian-Zeng Liu
Sha Zhu, Xian-Zeng Liu, Department of Neurology, Peking university international hospital, Beijing 102206, China
Chao Cheng, Dian-Jiang Zhao, Department of Radiology, Peking University International Hospital, Beijing 102206, China
Liu-Liu Wang, Department of Intensive Care Unit, Peking University International Hospital, Beijing 102206, China
Yuan-Li Zhao, Department of Neurosurgery, China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Beijing 100070, China
Author contributions: Zhu S participated in the design of the study, analysis of the data, and drafting of the manuscript; Cheng C, and Zhao DJ participated in measuring optic nerve sheath diameter and eyeball transverse diameter; Wang LL contributed to the collection of clinical data; Zhao YL contributed to the guidance of the research; Liu XZ contributed to the guidance of the research and review of the manuscript; The author(s) have read and approved the final version of the manuscript.
Institutional review board statement: This retrospective study was approved by the Ethics Committee of Peking University International Hospital [Approval No. 2021-001 (BMR)].
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: If there is a need, you can find the corresponding author to share data at any time.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Xian-Zeng Liu, PhD, Professor, Department of Neurology, Peking University International Hospital, No. 1 Life Science Park Life Road, Changping District, Beijing 102206, China. liuxianzeng@pkuih.edu.cn
Received: July 24, 2022
Peer-review started: July 24, 2022
First decision: August 22, 2022
Revised: September 13, 2022
Accepted: October 26, 2022
Article in press: October 26, 2022
Published online: November 26, 2022
ARTICLE HIGHLIGHTS
Research background

Stroke is mainly accompanied by an increased intracranial pressure (ICP), leading to more severe brain damage via secondary cerebral ischemia and hernia. A sudden rise of ICP is typically observed in comatose patients with acute stroke. Measuring optic nerve sheath diameter (ONSD) is noninvasive and convenient in comatose patients. Previous studies have shown that computed tomography (CT) can be used to accurately measure ONSD. The strong correlation between ICP and ONSD has been generally identified.

Research motivation

However, the ONSD of normal and sick individuals mainly varies noticeably. The ONSD/ETD ratio slightly varies. Therefore, the ONSD/ETD ratio has a smaller variability and a higher stability, and it may be more appropriate for ICP monitoring. To date, several studies have shown that the ONSD/ETD ratio is more related to ICP than the ONSD. Therefore, it is reasonable to speculate that the ONSD/ETD ratio has a higher value in predicting the prognosis of neurological function.

Research objectives

In the current study, unenhanced cranial CT scan was used to measure the ONSD and ETD, and the prognostic values of the ONSD and ONSD/ETD ratio in comatose patients with acute stroke were compared. the area under the curve (AUC) values of the ONSD and ONSD/ETD ratio for predicting the prognosis of comatose patients with acute stroke were 0.760 (95%CI: 0.637-0.882) and 0.808 (95%CI: 0.696-0.920), respectively. Although there was no significant difference in the performance of the two parameters in predicting the prognosis, the AUC of the ONSD/ETD ratio seemed to be higher than that of the ONSD. This study confirmed that ONSD/ETD can better predict neurological outcomes, and the variation is small, which provides a reference for non-invasive ICP monitoring and prediction of neurological outcomes in the future.

Research methods

A total of 67 comatose patients with acute stroke were retrospectively recruited. The ONSD and ETD were measured by cranial computed tomography (CT) scan. The ONSD was measured vertically at 3 mm behind the eyeball. ETD was measured from one side of the retina behind the lens to the other side for the maximum diameter. All patients underwent cranial CT scan within 24 h after coma onset. Patients' baseline clinical data were collected, including age, gender, body weight, body mass index, mean arterial pressure (MAP), stroke type, glasgow coma scale (GCS) scores, surgery during hospitalization (e.g., clearance of hematoma and decompressive craniectomy). Patients were divided into death group and survival group according to their survival status at discharge. The differences of the ONSD and ONSD/ETD ratio between the two groups and their prognostic values were compared by MedCalc software.

Research results

In this study, 42 (62.7%) patients died, while 25 (37.3%) patients survived at discharge. there were significant differences in the GCS score (χ2 = 49.809, P < 0.0001), stroke type (χ2 = 11.981, P = 0.003), ONSD (t = 4.078, P < 0.0001), ONSD/ETD ratio (t = 4.625, P < 0.0001), and surgery (χ2 = 4.803, P = 0.048) between the two groups. The ONSD and ONSD/ETD ratio were included in the logistic regression model for multivariate analysis, respectively. After adjusting for age, MAP, GCS score, stroke type, and surgery, the associations among the ONSD (P = 0.04), ONSD/ETD ratio (P = 0.036), and mortality were still significant.

The AUC of the ONSD was 0.760 (95%CI: 0.637-0.882, P < 0.0001), with a sensitivity of 81.0% and a specificity of 64.0% at a cut-off value of 5.7 mm. The AUC of the ONSD/ETD ratio was 0.808 (95%CI: 0.696-0.920, P < 0.0001), with a sensitivity of 92.9% and a specificity of 68.0% at a cut-off value of 0.25. The AUC values of the receiver operating characteristic (ROC) curves of the ONSD and ONSD/ETD ratio were compared. There was no significant difference in the AUC values of the two indices (Z = 1.333, P = 0.1826).

The results of this study provide a reference for noninvasive ICP monitoring and prediction of neurological outcomes in the future.

In the future, we need to expand the sample size to determine the value of ONSD/ETD ratio in predicting increased ICP and poor prognosis.

Research conclusions

In this study, the area under the ROC curve of ONSD and ONSD/ETD ratio was compared by MedCalc for the first time. Although there was no significant statistical difference in P value, the area under the ROC curve of ONSD/ETD ratio tended to increase compared with ONSD, and the degree of variation was smaller. Therefore, ONSD/ETD ratio is more recommended for ICP monitoring and predicting prognosis.

Research perspectives

This study compared and evaluated the prognostic value of ONSD and ONSD/ETD ratio in comatose patients with stroke. The mortality increased in comatose patients with acute stroke when the ONSD was > 5.7 mm or the ONSD/ETD ratio was > 0.25. In addition, ONSD/ETD ratio was more reliable than ONSD. However, it is necessary to expand the sample size to study single etiology.