Anterior choroidal artery-territory infarction. Report of cases and review.

Occlusion of the anterior choroidal artery (AChA) can cause infarction in the posterior limb of the internal capsule. Infarction is less frequent in the thalamus, midbrain, temporal lobe, and lateral geniculate body territories of the AChA. The most common clinical sign is hemiparesis. Hemisensory loss is usually transient but may be severe at onset. Homonymous upper-quadrant anopia, hemianopia, or upper- and lower-quadrant sector anopsia can be present. A homonymous defect in the upper and lower visual fields sparing the horizontal meridian is probably diagnostic of a lesion in the lateral geniculate body in the territory of the AChA. The most common stroke mechanism is small-vessel occlusive disease, predominantly found in hypertensive and diabetic patients, but cardiac-origin embolism also can affect the AChA territory. Two of our patients had infarction after temporal lobe resection for epilepsy. Occasionally patients have associated disabilities of higher cortical function that are usually transient. The lesion should be recognizable by computed tomography.