Dysplastic vertebral artery with paradoxical infarction.

A rare abnormality of the vertebral artery is described in a 63-year-old male. The right vertebral artery consisted of several minute endothelial lined channels which failed to perfuse at autopsy. The anterior spinal artery showed areas of muscular media dysplasia. These anomalies were associated with large posterior communicating arteries. The terminal event was precipitated by thrombotic occlusion of the left vertebral artery. The embryological aspect of these anomalies are discussed.