Abstract
<title>Abstract</title> <p> <bold>Background</bold> Hemorrhagic transformation (HT) is a serious complication of acute ischemic stroke (AIS) and is associated with increased morbidity and mortality. Early identification of patients at risk for HT may facilitate closer monitoring and timely intervention. Optic nerve sheath diameter (ONSD) has emerged as a non-invasive surrogate marker of intracranial pressure. This study aimed to evaluate whether serial changes in CT-derived ONSD could predict hemorrhagic transformation in patients with acute ischemic stroke. <bold>Methods</bold> A prospective observational study was conducted in the Emergency Department of a tertiary care teaching hospital. Consecutive adult patients presenting with acute ischemic stroke were enrolled. ONSD was measured from initial CT brain images and repeated on follow-up CT performed 24 hours later. The primary outcome was the development of hemorrhagic transformation on follow-up imaging. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive performance of ONSD change. <bold>Results</bold> A total of 110 patients with acute ischemic stroke were included. Hemorrhagic transformation occurred in 34 patients (30.9%). Patients who developed HT demonstrated a greater increase in ONSD between baseline and follow-up imaging. ROC analysis showed that change in ONSD predicted hemorrhagic transformation with an area under the curve (AUC) of 0.754. An ONSD change threshold of 0.34 mm demonstrated a sensitivity of 88.2%, specificity of 59.2%, positive predictive value of 49.2%, and negative predictive value of 91.8% for predicting HT. <bold>Conclusions</bold> Serial CT-derived ONSD change is associated with hemorrhagic transformation in acute ischemic stroke. An increase in ONSD of 0.34 mm or greater demonstrated good discriminatory ability and a high negative predictive value, suggesting potential utility as an early imaging biomarker for risk stratification in patients with AIS. Larger multicentre studies are warranted to validate these findings. </p>