Lacunar Syndromes (Archived)

Lacunar syndromes are clinical manifestations of lacunar infarctions. The affected arteries arise at sharp angles from major vessels and are prone to constriction and occlusion. These penetrating arteries do not have any collaterals and vary in size between 400 μ to 900 μ in diameter. The term “lacune” was first described in the late 19th and early 20th century and usually designates a small, chronic cavity that represents the healed phase of lacunar infarction. However, some reported cases reveal that a lacune results from an extensive infarct or intracerebral hemorrhage. The anatomic distribution of lacunar syndromes and infarctions is commonly the basal ganglia (globus pallidus, putamen, thalamus, and caudate), the pons, and the subcortical white matter structures (internal capsule and corona radiata). These anatomical sites correspond to lesions at the lenticulostriate arteries, the anterior choroidal artery, thalamoperforating arteries, paramedian branches of the basilar artery, and the recurrent artery of Heubner from the anterior cerebral artery. Lesions at these specific sites account for many of the symptoms of lacunar syndromes. Over 20 lacunar syndromes have been described, but the most common are pure motor hemiparesis, pure sensory stroke, ataxic hemiparesis, sensorimotor stroke, and dysarthria-clumsy hand syndrome.