subclavian steal syndrome, a vascular syndrome caused by an occlusion in the subclavian artery proximal to the origin of the vertebral artery. It results in a reversal of the normal blood pressure gradient in the vertebral artery and decreased blood flow distal to the occlusion. It is characterized by episodes of flaccid paralysis of the arm, pain in the mastoid and occipital areas, and a diminished or absent radial pulse on the involved side. Markedly different blood pressure measurements obtained from each arm are sometimes indicative of the condition.
