Vascular corticobasal syndrome caused by unilateral internal carotid artery occlusion.

A 65-year-old man developed progressive worsening of right-sided limb-kinetic apraxia and extrapyramidal dysfunction. His left internal carotid artery was found to be occluded, and there was general atrophy and severely decreased cerebral blood flow in the left hemisphere. He had experienced an acute infarction in the left watershed area before superficial temporal artery to middle cerebral artery bypass surgery. After surgery, the cerebral blood flow in the left hemisphere was remarkably improved. Unilateral internal carotid artery occlusion may result in clinical manifestations similar to corticobasal degeneration.