Abstract
Regional cerebral blood flow (rCBF) was measured by the 133Xe inhalation method in 19 patients with moyamoya disease aged 5 to 46 and compared with that in 17 healthy volunteers aged 7 to 67.
In healthy volunteers, mean hemispheric flow values (mCBF) in the steady state decreased and cerebrovascular resistance (CVR) increased with advancing age. Most young patients showed low values of mCBF in both hemispheres in comparison with healthy volunteers. A significant difference of mCBF between both hemispheres was observed in eight young patients. The side of lower mCBF corresponded well with clinical manifestations in seven patients. About half of the young patients showed higher values of CVR than young healthy volunteers. Lower mCBF was correlated with lower intelligence quotient values in 10 school children with moyamoya disease.
The distribution of rCBF showed a hyperfrontal pattern in healthy volunteers. However, in the patients, regional distribution of hemispheric flow showed a different pattern with low flow in the upper frontal region and mean flow in the posterotemporal and the occipital regions. Most of the relatively ischemic foci which showed a reduction of more than 15% of mCBF, corresponded to low density lesions in computed tomographic scans, but low density lesions did not always correspond to relatively ischemic foci.
rCBF measurements were carried out during hyperventilation in five healthy volunteers and in one patient, and during 5% CO2 inhalation in one healthy volunteer and two patients. CO2 reactivity was uniformly present in the hemispheres of healthy volunteers. rCBF in both hemispheres was reduced by hyperventilation, more markedly in the patient than in healthy volunteers. On the other hand, in two patients, the flow was increased in the temporooccipital regions and was decreased in the frontal region by 5% CO2 inhalation, and mCBF was slightly increased.
Encephalomyosynangiosis (EMS) or both EMS and superficial temporal-middle cerebral artery anastomosis was performed on 28 sides of 17 patients. Postoperative rCBF measurements in 21 sides of 12 young patients indicated a gradual increase of mCBF in 14 sides of nine patients from 3 months after surgery.
These results indicate that rCBF measurements by the 133Xe inhalation method are useful in determining cerebral hemodynamics in patients with moyamoya disease, especially in children.
