Correlation between Optic Nerve Sheath Diameter and Marshall Scale in Acute Traumatic Brain Injury

Background: Imaging plays integral role in the evaluation of patients with acute traumatic brain injury (TBI), with computerized tomography (CT) being the modality of the choice and the most commonly utilized imaging tool. One of the important determinants of TBI severity is raised intracranial pressure (ICP). Optic nerve sheath diameter (ONSD) was considered as a reliable indirect surrogate for the raised ICP, however, studies assessing role of CT-derived ONSD in evaluation of patients with raised ICP or brain injury are limited. Aim of the study: To assess the correlation between ONSD measured by CT scan and the severity of TBI according to Marshall scale. Patients and methods: A cross-sectional analytic study was conducted on 60 adult patients (52 males, 8 females) presented with acute TBI and referred for brain CT examination. After initial general evaluation of brain CT images, the score of TBI was assessed according to Marshal's scale (I to VI). The transverse ONSD was manually measured on axial CT image at 3 mm distance behind eye globe. The correlation between the grade of TBI and ONSD was subjected to statistical analysis. The study was approved by the Institutional Ethical Review Committee. Results: The means of all, right-sided and left-sided ONSD were 4.695 mm, 4.606 mm and 4.785 mm respectively. There was positive, linear and statistically significant correlation (p value