Asymptomatic Stroke Research Articles

Prevalence and determinants of carotid atherosclerosis in a general population.

The aim of this study was to assess the prevalence of asymptomatic carotid atherosclerotic lesions and their relation to principal risk factors. The importance of the relation between asymptomatic carotid atherosclerotic lesions, stroke, and coronary atherosclerosis has been widely discussed, but there are few transversal and longitudinal studies on a general population. A noninvasive examination was carried out using high-resolution B-mode ultrasonography, which has been shown to be a reliable tool for epidemiological studies. We examined 630 men and 718 women aged 18-99 years (participation rate, 74.9%). The global prevalence of carotid atherosclerosis was 25.4% in men and 26.4% in women. Intimal-medial thickening was found in 9.4% of men and 11.7% of women. Plaque prevalence was 13.3% in men and 13.4% in women; prevalence of stenotic plaques was 2.7% and 1.5%, respectively. Subjects aged < or = 39 years showed a very low prevalence of any asymptomatic carotid atherosclerotic lesions. In the multiple logistic regression, the analysis of subjects aged > or = 40 years showed a positive significant association between the severity of carotid atherosclerotic lesions (plaques and stenosis) and age (p < 0.001), systolic blood pressure (p < 0.01), cigarette smoking (p < 0.0001), and the protective effect of high density lipoprotein cholesterol (p < 0.037). This analysis did not provide evidence of a clear-cut association between risk factors and intimal-medial thickening. This population study shows the high prevalence of asymptomatic carotid atherosclerotic lesions in a general population (approximately 25% of adults) and its relation with the classic risk factors. It emphasizes the value of ultrasonography in the detection of early atherosclerotic lesions.

The Influence of Contralateral Disease on the Natural History of Nonoperated Significant Carotid Stenosis

The influence of contralateral disease on the natural history of ipsilateral nonoperated carotid stenosis greater than 50% was analyzed in 90 carotid arteries imaged by contrast arteriography or duplex scanning with a mean follow-up of 23.6 months. Ipsilateral stenosis was greater than 80% in 24 arteries and 50-79% in 66 arteries. Contralateral disease was present in 30 (Group I) and absent in 60 (Group II) patients. In Group I, the contralateral disease consisted of total occlusion in nine (30%), greater than 80% stenosis in five (17%), 50-79% stenosis in 12 (40%) with a mean of 78.6%. No significant difference existed in the incidence of initially asymptomatic vessels (57% versus 67%), stroke (13% versus 2%), or transient ischemic attack (17% each) between Groups I and II on the ipsilateral side (p greater than .05). New ipsilateral neurologic events occurred significantly more often in arteries with greater than 80% ipsilateral stenosis than those with 50-79% stenosis (p less than .02). The incidence of subsequent ipsilateral neurologic events (37% versus 22%), strokes, or transient ischemic attacks (20% versus 13%) was no different in Groups I and II, respectively (p greater than .05). Combined ipsilateral and contralateral neurologic events occurred significantly more often in patients with contralateral disease (p less than .05). Whereas in Group I, new ipsilateral symptoms were significantly more common in initially symptomatic vessels compared to asymptomatic ones (61.5% versus 17.6%, p less than .04), no such difference existed in Group II.