Relationship between the Oxfordshire Community Stroke Project classification and vascular abnormalities in patients with predominantly intracranial atherosclerosis.

BACKGROUND: The Oxfordshire Community Stroke Project (OCSP) classification is a stroke classification based on clinical features collected at bedside. Previous studies reported good correlation between vascular abnormalities and OCSP mainly in populations not at risk of intracranial atherosclerosis. There have been limited data on the relationship between intracranial atherosclerosis and the OCSP classification.

METHODS: Consecutive Chinese patients admitted to a regional hospital with acute ischemic stroke were studied in Hong Kong. Stroke subtype was classified as total or partial anterior circulation infarct (TACI or PACI), posterior circulation infarct (POCI), or lacunar infarct (LACI), according to the OCSP method. Transcranial Doppler (TCD) was performed whenever possible to evaluate the intracranial arteries as well as the carotid arteries. National Institute of Health Stroke Scale (NIHSS) was used to assess the severity of stroke on admission.

RESULTS: Six hundred and ninety-nine consecutive patients were studied. On admission, 24 patients were classified as TACI (3.4%), 96 PACI (13.7%), 111 POCI (15.9%), and 468 LACI (67.0%). Of the 345 patients who had TCD evidence of intracranial or carotid artery abnormalities, 75% had intracranial involvement only, 5% extracranial involvement only and 20% had both intracranial and extracranial involvement. The frequencies of arterial abnormalities were found in 58% of TACIs, 48% of PACIs, 48% of POCIs and 50% of LACIs. There was no evidence that the frequencies of arterial abnormalities were different between the OCSP groups (P=0.8). Middle cerebral artery velocity was abnormal in 9 TACIs (38%), 32 PACIs (33%), 35 POCIs (32%) and 177 LACIs (38%) (P=0.6). Vertebrobasilar velocities were abnormal in 4 TACIs (17%), 20 PACIs (21%), 29 (26%) and 87 LACIs (19%) (P=0.3). The OCSP subtypes were associated with POCIs the severity of stroke. NIHSS score of > or =9 was found in 83% of TACIs, 18% of PACIs, 9% of POCIs, and 12% of LACIs (P<0.0001).

CONCLUSIONS: OCSP classification is not significantly related to the presence of vascular abnormalities among patients with predominantly intracranial atherosclerosis.