Stroke is a multi-factorial disease occurs due to the combination of risk-factors. Pathogenic mechanism of intracranial atherosclerosis (ICAS) and extracranial atherosclerosis (ECAS) vary, hence exploring the risk factors of these subtypes is essential for targeting preventive therapy and to influence choice of management. 

100 patients presenting with acute ischemic stroke with clinically significant atherosclerosis in intra-cranial/extra-cranial arteries were compared with respect to their risk factors, presentation, progression and outcomes.

There were 35 ICAS, 52 ECAS and 13 with both ICAS & ECAS. Mean age of the patients, gender, body mass index was not associated with their stroke type. Medical history of IHD and CKD was more common in patients with ICAS. Median (IQR) NIHSS of our study cohort was 12.97 (4.23) at 3 months. It was significantly higher in ICAS group (median = 16.26) as compared to that in the ECAS group (median = 10.92). Anterior circulation strokes were observed in 78% of patients, more commonly occurring in ECAS stroke group. Median (IQR) mRS score of the study cohort at 3 months was 1 (1.00), four patients died (mRS = 6) three of ICAS and one patients with both ICAS & ECAS. ECAS group had significantly more proportion of patients with favorable mRS as compared to ICAS group. After adjusting for all possible confounders, only increasing NIHSS at admission was significantly associated with poor outcomes at 3 months. Stroke type did not significantly affect the the clinical outcome at 3 months.

Although ICAS and ECAS shared similar risk factors, differences still existed between them as far as clinical outcomes are concerned. With higher NIHSS at admission, ICAS patients are at an increased risk for poor clinical outcome.