Epidemiology of Stroke Subtypes and Aetiologies Among Sri Lankan Stroke Patients

Abstract

INTRODUCTION AND OBJECTIVES: Epidemiology of stroke subtypes in Asian countries is different from western countries. Data on stroke subtypes and aetiologies are limited from Sri Lanka. Therefore, we aimed to describe the same in Sri Lankans stroke patients. METHODS: We analyzed all the acute stroke admissions to Colombo North stroke unit over 5 years from 2013-2018 using the stroke registry. Data were collected prospectively using an interviewer-administered questionnaire and perusing medical records. Ischaemic strokes were classified into clinical subtypes using Oxfordshire Community Stroke Project (OCSP) and aetiological subtypes using Trial of Org 10172 in Acute Stroke Treatment (TOAST) classifications. RESULTS: 891 patients were admitted over 5 years; 765(85.5%) ischaemic strokes and 129 (14.5%) intracerebral haemorrhages (ICH). Of the ischemic strokes, 16(1.8%) were total anterior circulation, 253(29.0%) partial anterior circulation, 543(62.3%) lacunar, 59(6.8%) posterior circulation infarcts on OCSP classification. 542 ischaemic stroke patients who had complete investigations for TOAST classification were studied for aetiology of stroke. 17(3.1%) were of large artery atherosclerosis, 369(68.1%) small vessel occlusion, 11(2.0%) cardioembolic and 145(26.8%) of undermined aetiology. CONCLUSIONS: Prevalence of ischaemic strokes and ICH were not different from western statistics but ischemic stroke subtypes and aetiologies were different in Sri Lankans. Total anterior circulation strokes were significantly lower and lacunar strokes were significantly higher among Sri Lankans compared to Western populations. Small vessel disease was the commonest cause of ischemic strokes and cardio-embolic and large artery strokes were less common compared to White Caucasians.