Correlation of optic nerve sheath diameter (ONSD) assessed by computed tomography (CT) with Glasgow coma scale (GCS) in patients with traumatic brain injury in tertiary care hospital of Nepal

Abstract

Introduction: The optic nerve sheath, an extension of the dura mater and subarachnoid space filled with cerebrospinal fluid (CSF), connects to the CSF area around the optic nerve. Increased CSF pressure from brain edema can enlarge the sheath. The diameter of the optic nerve sheath (ONSD) remains consistent across different ages, genders, and anatomical locations. Intracranial injuries can worsen clinical conditions, leading to significant morbidity and mortality if not treated. Neurological conditions can be assessed using the Glasgow Coma Scale (GCS) or imaging techniques like CT or MRI, which have their limitations. Evaluating ONSD is a simple, safe, cost-effective, and non-invasive way to track changes in intracranial pressure (ICP).

Method: This cross-sectional, prospective study was done in Department of Radiology, Patan Hospital, Patan Academy of Health Sciences after obtaining ethical clearance. Computed Tomography of patients referred for head injury between 2025 Feb to 2025 Jun were analyzed. Statistical analysis was performed using SPSS v20.

Result: Out of the 55 patients included in data analysis, 37 were males and 18 were females. Majority (65%) belonged to middle age group (20–50 years), with the mean age of 44 years.  Significant association was observed between baseline ONSD and GCS.

Conclusion: This study found a significant association between ONSD measured by CT and GCS scores in patients with traumatic brain injury. Higher ONSD values were associated with lower GCS scores, indicating that ONSD can serve as a reliable, non-invasive marker for elevated intracranial pressure and severity of brain injury.