Disabling cerebral transient ischemic attacks.
The surgical management of an emerging clinical entity, namely disabling transient cerebral ischemic attacks, is described. A series of 19 patients treated in a 2-year period (12 with anterior circulation dysfunction and seven with posterior insufficiency) met the following criteria: 1) stereotypical recurrent episodes of transient neurological dysfunction related to the anterior or posterior circulation distribution; 2) failure of maximum medical therapy to control the transient neurological dysfunction; 3) four-vessel cerebral angiography demonstrating an isolated vascular territory corresponding to patient symptoms; 4) inhalation xenon cerebral blood flow studies with at least three of eight probe-pairs showing significant asymmetries in the initial slope index, localizing an area of relative oligemia to the symptomatic hemisphere (anterior circulation only); and 5) severe restriction of lifestyle due to transient ischemic attacks (TIA's). Seventeen patients underwent surgical bypass therapy: deep sylvian superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in nine; surface STA-MCA bypass in three; STA-superior cerebellar artery bypass in three; STA-posterior cerebral artery bypass in one; and aorta-carotid artery bypass in one. There was one perioperative death and four perioperative strokes (two ipsilateral and two contralateral to the operated side). The average follow-up period was 14 months. Of the 16 surviving surgically treated patients, 13 (81%) have had an excellent to good outcome with complete resolution of TIA's and minimal neurological deficits. Three patients had a poor outcome with either a significant persistent neurological deficit or continued TIA's. The two patients not treated surgically continue to have vertebrobasilar insufficiency episodes while receiving oral anticoagulation medication. The overall mortality rate (5.5%) and stroke morbidity rate (22.2%) of surgical therapy for disabling TIA's are high in this neurologically unstable group of patients, but are associated with an 81% excellent to good response. Although the natural history of disabling TIA's is not known, these patients present with significant to total disability due to their symptoms. It is concluded that disabling TIA's respond to surgical revascularization and may represent an indication for cerebral revascularization surgery.