ROLE OF VASCULAR RISK-FACTORS IN LACUNAR AND UNEXPLAINED STROKES IN YOUNG-ADULTS - A CASE-CONTROL STUDY

Atherosclerosis is often considered the cause of stroke in young adult s with vascular risk factors and no other obvious cause, even without evidence of atheroma. In a consecutive series of 260 young adult (less than or equal to 45 years old) ischemic stroke patients, the cause of stroke remained unknown in 70 despite investigation including at leas t CT/MR, echocardiogram and duplex + TC Doppler or angiography. Twenty -five presented with classical lacunar syndromes. No differences were found in the distribution of risk factors between cases with lacunar a nd nonlacunar symptoms. The vascular risk factors of these 70 patients were compared with (a) 44 strokes in young adults with evidence of la rge-vessel intracranial or extracranial atheroma; (b) sex- and age-mat ched community controls from the list of a general practitioner. Large -vessel atheromatous strokes included more diabetics than strokes of ' unknown cause' (difference betweem proportions: 23%; 95% CI = 7-39 and 'lacunar infarction' (difference between proportions: 26%; 95% CI = 1 0-42). In conditional regression analysis, hypertension was significan tly more frequent in strokes of 'unknown cause' (odds ratio = 17; 95% CI = 2.7-117), and in 'lacunar infarction' (odds ratio = 10; 95%; CI = 1.4-442) than in controls. Hypertensive single-perforator disease is the most plausible cause of young-adult lacunar infarction. Although y oung-adult strokes of 'unknown cause' are a heterogeneous group, their risk factors are different from both large-vessel atheromatous stroke patients and community controls, and many appear to be related to hyp ertensive single-perforator disease.