Cerebral hemodynamics in moyamoya disease

Rebuild-up phenomenon, an electroencephalographic pathological finding in moyamoya disease, was evaluated in the context of dynamic changes in cerebral circulation after hyperventilation. Sequential functional angiography after hyperventilation, measurement of cerebral blood flow (CBF) by the outflow method, and Kr-81m single photon emission tomography were employed for clarification of the sequential dynamic changes in cerebral circulation after hyperventilation. In most cases there was a persistent decrease in CBF even after arterial carbon dioxide tension (PaCO2) had been normalized, which suggests that the response of the cerebral circulation to the changes in PaCO2 is delayed. Moreover, this feature was most prominent in the superficial layer of the cerebrum. For the most part, coincidence and synchronization were documented between rebuild-up and the delayed response of the cerebral circulation. These findings indicate that the delayed CBF response to hyperventilation contributes pathogenetically to rebuild-up in moyamoya disease. (author)