The Effects of Arterial Carbon Dioxide Tension on Cerebral Blood Flow and on Cerebral Function in "Moyamoya" disease

The cerebrovascular effects of arterial carbon dioxide tension were studied in 12 children (4-11 years old) with moyamoya disease confirmed by cerebral angiography. The cerebral blood flow (CBF) mesurements with argon washout technique were undertaken in cerebral cortex and in whole brain respectively under normocapnia during fentanyl-diazepam anesthesia. Cortical CBF and whole brain CBF were 38.0±8.5ml/100g•min and 39.2±7.9ml/100g•min respectively. Cerebral metabolic rate was also determined by oxygen content difference between arterial blood and transverse and/or superficial sagittal sinus blood. The electroencephalography frequency and ampli-tude analysis were achieved by a zero-crossing methed (Datex-100). CBF equivalent was determined by changing the alveolar ventilation. Hypercapnia (PaCO2 53.0±4.2mmHg) increased insignificantly CBF equivalent by 12% in the cerebral cortex and by 32% in whole brain respectively. Hypocapnia (PaCO2 33.1±2.9mmHg) decreased CBF equivalent significantly (P