Evaluation of cerebral blood flow and metabolism in childhood moyamoya disease: an investigation into re-build-up on EEG by positron CT

The cerebral blood flow and cerebral metabolic rate of oxygen (CBF and CMRO2) of three cases of childhood moyamoya disease were examined by positron-emission-computed tomography for the purpose of investigating the mechanism of the "re-build-up" phenomenon on EEG. Decrease in both CBF and CMRO2 were observed following hyperventilation. However, dissociation between the decrease in CBF and CMRO2 was also observed. Arterial blood-gas analysis disclosed hypocapnea during hyperventilation and hypoxia following hyperventilation. These results clearly indicate that the re-build-up seen on EEG is the manifestation not only of ischemic hypoxia but also of hypoxic hypoxia characteristically seen in moyamoya disease.