もやもや病に対するSTA-MCA吻合術後・過灌流と一過性神経脱落症状について : IMP SPECTを用いた検討  [in Japanese] Transient Focal Neurological Deficit Due to Hyperperfusion after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis in Patients with Moyamoya Disease  [in Japanese]

Surgical revascularization for moyamoya disease is believed to prevent cerebral ischemic attacks by improving cerebral blood flow (CBF). We investigated how the rapid increase in CBF through the direct bypass affects the ischemic brain. CBF was measured by N-isopropyl-p-[^<123>I] iodoamphetamine single-photon emission computed tomography (^<123>I-IMP-SPECT) within 1 week after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis performed on 27 sides of 22 consecutive patients (male:female=6:16, 2-62 years old) with moyamoya disease from March 2004 to April 2005. Five patients (male:female=1:4, 26-55 years old) suffered delayed transient focal neurological deficit mimicking ischemic attack at 2 to 7 days after surgery. Postoperative SPECT revealed focal intense increase in CBF at the sites of anastomosis in all 5 patients. Postoperative magnetic resonance imaging showed no ischemic changes, and magnetic resonance angiography showed the apparently patent STA-MCA anastomosis as thick high signal intensity sign in all 5 patients. The anatomical location and the temporal profile of hyperperfusion were completely in accordance with the neurological deficits. Strict blood pressure control and administration of a free radical scavenger were instituted. The symptoms were resolved in all patients. In conclusion, transient focal neurological deficit following STA-MCA anastomosis can be caused by focal hyperperfusion in patients with moyamoya disease. Routine CBF measurement is recommended to differentiate hyperperfusion and transient ischemic attack, since the treatments for these conditions are contradictory.