Study on Optic Nerve Sheath Diameter Measurements in Prolonged Pediatric Seizures

Overview

A total of 88 postictal children with generalized or focal seizures were included in the study. The ONSD and ONSD/ETD ratio was measured independently by a pediatric neurologist and pediatric emergency expert, three times in both eyes using non-contrasted computed tomography taken within one hour after the seizure. The characteristics of seizures (duration, etiology, initiated treatment, and frequency) were recorded. Non-traumatic patients with normal head computed tomography findings at the hospital admission were considered as the control group (n=109).

This was a prospective observational case-control study. The study included children aged 1 to 18 years who had undergone cranial CT scans in accordance with the Pediatric Emergency Care Applied Research Network (PECARN) guidelines between September 2020 and December 2022. The seizures only observed by a health worker or directly with home videos were taken into consideration. The definition of prolonged seizures proposed by the ILAE Task Force on Classification of Status Epilepticus was employed: those lasting more than five minutes for focal seizures and more than ten minutes for generalized seizures. Children admitted to the emergency department and having head CT without space-occupying/incidental lesions were determined as a control group. The participants were divided into two groups: postictal children (n=88) and healthy controls (n=109). Furthermore, the postictal children were divided into two groups, namely those with focal (n=56) and generalized (n=32) seizures. The following variables were recorded from the medical records: patients' demographic characteristics (age, sex, body mass index), type of seizures (focal or generalized), the duration of seizures, seizure frequency, type of medication initiated, and the etiology of the seizures. To ensure the highest standards of care, the pediatric head CTs were independently reviewed by a pediatric neurologist and a pediatric emergency expert. The investigators measured Optic Nerve Sheath Diameter as a thickness at a distance of 3 mm from the optic disc. The investigators measured the Eyeball Transverse Diameter via axial images, using the widest diameter of each eyeball from retina to retina. The data were presented in the form of frequencies and percentiles for categorical variables and means with standard deviations (SDs) or medians with interquartile ranges for continuous variables. The Mann-Whitney U tests were employed to ascertain the significance of the differences in ONSD and ONSD/ETD ratio observed between the independent groups. A receiver operating curve (ROC) was constructed and the area under the curve (AUC) was measured in order to evaluate the discrimination ability.