Optic Nerve Ultrasonography for Differentiating Hemorrhagic and Ischemic Strokes in Emergency Department; A Cross-Sectional Study

Ultrasonography of the optic nerve might help in detecting patients’ high intracerebral pressure. Given the importance of early diagnosis for implementing therapeutic measures, non-invasive methods have received a great deal of attention among researchers, recently. The present study investigated the accuracy of optic nerve ultrasonography in differentiation of ischemic and hemorrhagic strokes in patients with cerebrovascular accident (CVA).

The present study was a descriptive analytical one. Through convenience sampling, 212 patients visiting Imam Hossein, Loghman, and Shohadaye Tajrish hospitals in 2018 were selected. The data gathering tool was a researcher-designed checklist, which consisted of demographics, clinical characteristics of the patients, and information about optic nerve diameter. Data were extracted from medical files and ultrasonography reports of the patients. The results obtained through estimating the diameter of the optic nerve sheath were analyzed in comparison with cerebral computed tomography (CT) scan findings as the golden standard. Finally, using statistical tests, sensitivity, specificity, positive/negative predictive value, and accuracy of ultrasonography in differentiating ischemic and hemorrhagic CVA were calculated.

Among the participants, 163 had ischemic CVA and 56 had hemorrhagic CVA. The mean diameter of optic nerve among the participants was 5.26±0.35 in the ischemic CVA group and 5.80±0.51 in the hemorrhagic CVA group (p=0.001). In addition, sensitivity and specificity were 86.50% (95% CI: 80.28%-91.34%) and 66.07% (52.19%-78.19%), respectively.

The results of the present study showed that in the cut-off point of 5.5, the ultrasonographic diameter of the optic nerve sheath had a sensitivity and specificity of 86.50% and 66.07%, respectively, and a mean accuracy of 81% in differentiation of ischemic and hemorrhagic CVA. Therefore, this method can be used as a non-invasive method in differentiation of ischemic and hemorrhagic CVA.