INTRACRANIAL LARGE-ARTERY DISEASE AND LACUNAR INFARCTION

Small 'lacunar' infarcts in the territory of the deep perforators (ITDP) have usually been attributed to small-vessel disease associated with hypertension or diabetes, but recently also to embolism from extracranial large-artery atherosclerosis or heart disease. However, in several cases, the cause of ITDP remains undetermined. Of 1,800 patients with first-ever stroke from the Lausanne Stroke Registry, 320 had ITDP smaller than 1.5 cm on computed tomography or magnetic resonance imaging. In 26 (8%) of them, the etiology of ITDP remained undetermined, because they had no hypertension, diabetes, extracranial large-artery disease or a potential cardiac source of embolism. Angiography was performed prospectively in the last 16 patients with undetermined etiology for ITDP. In 10 of them, intracranial stenosis on the parent large artery (middle cerebral artery in 6, basilar artery in 4) was demonstrated at the presumed site of origin of the deep perforator. Local obstruction of the mouth of deep perforators by intracranial large-artery disease may not be an uncommon cause of ITPD and should be looked for in ITDP of 'undetermined' origin.