[Cerebral blood flow in moyamoya disease]

Regional cerebral blood flow in forty cases of moyamoya disease was investigated by intravenous 133Xe injection method. Twenty-one cases were children and other nineteen were adults. No or only slight neurological deficit were found at the CBF studies. CBF was calculated by initial slope index. For investigation of the relation between hemispheric blood flow and age, the regression curve was calculated and that with highest correlation was chosen. In normal group, the relationship between hemispheric CBF and age was correlated to following equation: y = 146.5-58.4 log x (r = -0.903). In contrast, in moyamoya disease, it was correlated to following equation: log y = 2.04-0.23 log x (r = -0.730). It can be said that CBF of the whole brain in moyamoya disease is below normal. The distribution of the rCBF was characteristic in moyamoya disease. There are low CBF values in the frontal and temporal lobes and relatively high values in the occipital lobes as compared with normal CBF distribution. These results are thought to indicate the importance of blood circulation to the brain from the vertebro-basilar arterial system. Moreover a comparison of these CBF results with the six stages of basal moyamoya seen angiographically was investigated in child cases. As the stage of moyamoya disease progressed, the hemispheric CBF decreased gradually and the distribution of blood flow gradually changed from a predominance of flow to the frontal lobes to a predominance of flow to the occipital lobes.