Background: Although carotid plaque may be associated with development of an ischemic stroke, a few studies have examined carotid plaque in the aspect of etiologic classification. The present study was aimed at investigating the utility of ultrasound for etiologic grouping among ischemic stroke subtypes by comparing various plaque thickness measurements of the carotid arteries. Methods: We retrospectively analyzed medical and sonographic records of acute stroke patients who were admitted to the neurology department between July, 2004 and June, 2006. Plaque score, the sum of all plaque thicknesses, and maximum plaque thickness (MPT) of the carotid arteries were compared among the subgroups classified by Trial of Org 10172 in Acute Stroke Treatment classification. Results: Among 848 patients with acute ischemic stroke, 511 patients, evaluated by cerebral angiography and carotid sonography, were enrolled and grouped into the following categories: large artery atherosclerosis (LAA; n=190), cardioembolism (CE; n=59), small artery disease (SA; n=95), or negative evaluation (NEG; n=167). Plaque scores and MPT of the carotid arteries were significantly increased in LAA compared with others (p<0.01). The median values of the plaque scores were 5.8mm in LAA, 2.4 mm in CE, 2.7 mm in SA, and 3.3 mm in NEG. The median values of MPT were 2.8mm in LAA, 1.7 mm in CE, 2.0 mm in SA, and 2.0 mm in NEG. Conclusions: Acute stroke patients with large artery atherosclerosis had severer atherosclerotic plaques in the carotid arteries. In patients with acute cerebral infarction, a carotid plaque evaluation by ultrasound may be helpful for etiologic classification. Journal of Neurosonology 1(1):35-38, 2009

Key Words: Carotid artery plaque, Cerebral infarction, Atherosclerosis