Serial Monitoring of Optic Nerve Sheath Diameter for Prediction of Functional Outcome in Acute Ischaemic Stroke: A Diagnostic Accuracy Study

Background Increased intracranial pressure (ICP) can be reliably detected at the bedside using the optic nerve sheath diameter (ONSD). The functional outcome in stroke patients can be predicted with the use of acute-phase ONSD dynamics. Objectives To determine the predictive accuracy of ONSD on days 0, one, and three for the prognosis of ischemic stroke patients presented to emergency medicine as measured by Modified Rankin Scale (mRS) score. Methods The study involved the enrollment of patients who presented to the emergency department with clinical and radiological diagnosis of ischemic stroke within 24 hours of onset of symptoms. On the day of the incident, day one and day three, the optic nerve sheath diameter was measured transorbitally, 3 mm behind the optic disc. On days 28 and 90, the patient's functional outcome was evaluated using the mRS score. An mRS score of ≤ 3 is considered a good functional outcome, and > 3 is considered a poor functional outcome. Results Study participants were sixty-six people who had experienced an acute ischemic stroke. Mean age was 55.30 ± 13.99, and 56.1% of patients were male. The mean ONSD at all time points during serial monitoring differed significantly between the poor and good functional outcomes. The change in ONSD over time, i.e., from day 0 to day three, was statistically significant in poor functional outcome (Friedman Test: χ2 = 25.6, p < 0.001) for day 28, as well as day 90 (Friedman Test: χ2 = 27.3, p < 0.001). In good functional outcome patients, the change in ONSD for the above-mentioned period was not statistically significant on day 28, as well as on day 90. Cut off ONSD 0.47 cm on day 0 can predict poor functional outcome with 100% specificity and 61% sensitivity for day 28 and 73% sensitivity for day 90. Conclusion Measurement of ONSD with ultrasound had a moderate potential to predict poor functional outcome (mRS > 3) on day 90 in individuals presenting to the emergency room. The trend of ONSD on days 0 to three can assist in predicting functional prognosis in acute ischemic stroke.