The subclavian steal syndrome may occur when either subclavian artery is occluded proximal to the origin of its vertebral artery. If the resultant decrease in the subclavian arterial pressure distal to the occlusion is sufficient to create an arterial pressure gradient, then actual reversal of blood flow takes place in the ipsilateral vertebral artery. Blood is shunted away from the cerebral circulation into the distal subclavian artery and into the arm. This may produce relative cerebral ischemia with neurologic symptoms such as dizziness, blurring of vision, headache, staggering, and occasionally olfactory hallucinations. These symptoms are often initiated or intensified with exercise of the ipsilateral arm.
The disorder was first described by Contorni in 1960,1 and since then more than 180 cases have been reported in the literature.2 An atherosclerotic plaque is the most frequent etiologic condition in the arterial occlusion, especially in the older age group. The recommended