Intracerebral steal phenomenon: a potential mechanism for contralateral stroke after carotid artery stenting.

The "intracerebral steal phenomenon (ISP)" is a paradoxical vasodilatory response that reduces the cerebral blood flow to the impaired perfusion area. This phenomenon has been mainly reported in patients with moyamoya vessels with hyperventilation and with the administration of specific drugs such as acetazolamide. We report a case with contralateral infarction that can be explained by ISP after carotid stenting. This report indicates that ISP should be considered as a potential mechanism for contralateral infarction after carotid stent insertion, particularly in the case of contralateral vessel stenosis.