Background: Patients with risk factors for atherosclerosis is prone to develop carotid plaque or increased intima-media thickness (IMT). We explored the association of carotid plaque, atherosclerotic risk factors, frequency of large artery atherosclerosis (LAA) stroke mechanism, and IMT in acute ischemic stroke patients. Methods: From November 2005 to March 2008, total 633 acute ischemic stroke patients, who were examined with a carotid sonography, were enrolled. The atherosclerotic risk factors and number of plaque, maximum plaque size, and maximum IMT were compared. Results: Of the 633 patients, 496 (78.3%) had one or more carotid plaques [median 2, interquartile range (IQR) 2-5]. Patients with carotid plaques were older (p<0.001), male predominance (p=0.014), more frequent history of hypertension (p<0.001), diabetes (p<0.001), higher Framingham Stroke Risk Score (14.1±4.5 vs. 10.3±4.6, p<0.001), and increased IMT (0.99±0.16 vs. 0.87±0.24, p<0.001) than patients without carotid plaque. Comparing other subtypes of stroke classification, LAA were more frequently found in higher quartiles of number of plaques (p=0.005), or maximum plaque size (p=0.016) but IMT had no significant difference (p=0.214). Conclusions: Carotid plaques were associated with atherosclerotic risk factors, and LAA of stroke classification. Either carotid plaque distribution (number) or severity (maximal thickness) in carotid sonography might be used as a predictor of atherothrombotic infarction in patients with acute ischemic stroke. Journal of Neurosonology 2(1):19-26, 2010

Key Words: Carotid plaque, Intima-media thickness, Carotid sonography, Atherosclerosis, Ischemic stroke