Assessing prognostic value of optic nerve sheath diameter and Marshall computed tomography score in severe traumatic brain injury: A prospective study

Objectives: To study the role of Optic Nerve Sheath Diameter (ONSD) and computed tomography (CT) Marshall Grading in predicting outcome in severe Traumatic Brain Injury (TBI). Methodology: All patients with severe TBI, following inclusion and exclusion criteria, were included. The patients were divided into two groups: the operative and nonoperative groups. Six-hourly ultrasonography (USG)-guided ONSDs were performed in both eyes over 96 hours. Marshall Grading of CT imaging was applied . Results: Twenty-four male patients with severe TBI were part of the study. The AUROC for ONSD of the right side predicting intracranial pressure (ICP) more than 15 was 0.787 (95% CI: 0.727 - 0.847), while for the left side was 0.813 (95% CI: 0.757 - 0.869). The area under the receiver operating characteristic (ROC) curve (AUROC) for ONSD of the right side predicting ICP more than 22 was 0.927 (95% CI: 0.87 - 0.984), while for the left side was 0.939 (95% CI: 0.888 - 0.99). All results were statistically significant ( p <0.001). Combining ONSD >4.5 mm and Marshall grade >3 yielded a sensitivity of 61.5% and a specificity of 90.9% for predicting an ICP >15 mmHg, although the results were not statistically significant. Marshall score did not differ significantly between the discharge (mean 2.75 ± 1.00) and death (mean 3.00 ± 0.93) groups (W = 54.000, p = 0.536). Conclusion: ONSD assessment should be included in routine monitoring of patients with TBI. The initial CT scan findings alone can serve as a valuable predictor of elevated ICP; however, combining with ONSD measurements increases predictive accuracy.