Patient selection for revascularization procedures in adult Moyamoya disease based on dynamic perfusion computerized tomography with acetazolamide challenge (PCTA)

The usefulness of dynamic perfusion computerized tomography for early diagnosis of stroke is well established. However, limited data exists to assess the value of PCT in the evaluation of patients with chronic cerebral ischemia. The purpose of the study was to assess the utility of perfusion computerized tomography with acetazolamide challenge (PCTA) in the evaluation of cerebral perfusion and cerebrovascular reserve (CVR) in adult Moyamoya patients. From 2005-2008, 41 patients with Moyamoya were scrutinized by PCTA. Of these, 22 patients (12 females, ten males, mean age 41 years) with ischemic symptoms from Moyamoya disease were found to have no response or decreased cerebrovascular flow post-acetazolamide indicating compromised CVR. Eight had bilateral symptoms. Based on matching symptoms and decreased CVR on PCTA, those 22 patients underwent 30 superficial temporal artery-to-middle cerebral artery (STA-MCA) by-pass (eight with bilateral abnormal PCTA had bilateral STA-MCA by-pass). After a mean follow-up of 14 months (range, 3-36 months), no new strokes or symptoms were reported. Graft patency, as documented by postoperative computerized tomography angiography at a mean 12 weeks after surgery was 100%. Eight patients had postoperative PCTA documenting improved CVR after STA-MCA by-pass. At latest follow-up, none of the 19 patients with PCTA findings suggestive of normal CVR had any ischemic symptoms. CVR testing by means of PCTA may have a key role in patient selection for revascularization surgery and postoperative follow-up. These promising results warrant further testing of the technique.