Intracranial large artery disease among OCSP subtypes in ethnic South Asian ischemic stroke patients.

The site of vascular stenosis correlates well with the Oxfordshire Community Stroke Project (OCSP) classification among Caucasians, but not among ethnic Chinese patients. We prospectively studied 205 consecutive ethnic South Asian ischemic stroke patients to investigate the prevalence of intracranial large artery disease determined by transcranial color-coded doppler and magnetic resonance angiography among OCSP subtypes. The distribution of OCSP subtypes was 7% total anterior circulation infarction (TACI), 17% partial anterior circulation infarction (PACI), 14% posterior circulation infarction (POCI) and 62% lacunar infarction (LACI). Significant intracranial large artery disease was common among all OCSP subtypes; 79% with TACI, 47% PACI, 65% POCI and 44% LACI. This is similar to ethnic Chinese data and is likely due to the predominance of intracranial disease over extracranial disease. Clinical axioms using OSCP subtypes based on Caucasian data may be misleading if applied to ethnic South Asians.