REGIONAL CEREBRAL HEMODYNAMICS DURING RE-BUILD UP PHENOMENON IN CHILDHOOD MOYAMOYA DISEASE - AN ANALYSIS USING TC-99M-HMPAO SPECT

We investigated the role of ischemic hypoxia in the appearance of re-b uild-up phenomenon on electroencephalography in childhood moyamoya dis ease using Tc-99m-hexamethyl propyleneamine oxime and single photon em ission computed tomography (Tc-99m-HMPAO SPECT). In the case reported on, critical reduction of regional cerebral blood flow (rCBF) was obse rved during rebuild-up phenomenon in the bilateral parieto-occipital a rea where acetazolamide testing revealed severe impairment of the perf usion reserve. On electroencephalography, the rebuild-up phenomenon or iginated in these areas. In addition, re-build-up phenomenon developed into the entire hemisphere 30 s later, even where the severe ischemia was not observed. These results suggest that rCBF reduction induced b y hyperventilation plays a critical role in the appearance of the re-b uild-up phenomenon, but other factors such as ischemic hypoxia after h yperventilation are also important in the development of this phenomen on.