ACETAZOLAMIDE TEST IN DETECTING REDUCED CEREBRAL PERFUSION RESERVE AND PREDICTING LONG-TERM PROGNOSIS IN PATIENTS WITH INTERNAL CAROTID-ARTERY OCCLUSION

IN A SERIES of 32 patients with internal carotid artery occlusion, reg ional cerebral blood flow (rCBF) and regional cerebral vasoreactivity (rCVR) were measured by xenon-133 single photon emission computed tomo graphy and the acetazolamide test. We evaluated its usefulness in dete cting the reduced cerebral perfusion reserve and predicting long-term prognosis. All Type 1 patients (normal rCBF and rCVR) were medically t reated and experienced no recurrent ischemic attack. Cerebral hemodyna mics remained unchanged. Type 2, 3, and 4 patients underwent superfici al temporal artery-middle cerebral artery double anastomosis, if they consented to surgery. All Type 2 (normal rCBF and reduced rCVR) and Ty pe 3 (reduced rCBF and rCVR) patients, who underwent surgery, showed n o further ischemic attacks, as well as long-term normalization of rCVR , although long-term rCBF normalization was obtained in only three of seven Type 3 patients. Cerebral hemodynamics remained unchanged in Typ e 4 patients after surgery. In follow-up periods, major completed stro ke occurred in all 3 Type 2 and Type 3 patients who were medically tre ated. These results suggest that the acetazolamide test is valuable in assessing the cerebral perfusion reserve and predicting long-term pro gnosis in patients with internal carotid artery occlusion, although fu rther long-term or randomized studies are needed.