Measurement of cerebral circulation and metabolism in patients with spinocerebellar degeneration using positron emission tomography and O-15 steady-state method

Ten subjects diagnosed as having spinocerebellar degeneration (SCD) were studied using positron emission tomography and O-15 steady-state method. Regions of interest were acquired for the cerebellar hemisphere, vermis, pons, corpus striata, thalami, and cerebral cortices. Eight normal volunteers served as a control group. Regional cerebral oxygen consumption (rCMRO2) was significantly decreased in the cerebellar hemispheres (reduction of 34.6 % from the control value), vermis (47.4 %) and pons (48.2 %), and cerebral blood flow (rCBF) was also decreased significantly. But regional oxygen extraction fraction (rOEF) was not decreased in those areas. In both thalami (24.6 %) and corpus striata (24.6 %), rCMRO2 and rCBF were mildly but significantly reduced. Cerebral cortices showed no significant reduction in rCMRO2 and rCBF. The decreases of rCBF or rCMRO2 in cerebellar hemispheres, vermis, and pons correlated significantly with the degree of the atrophic changes detected by X-ray CT. These findings suggest that the measurement of cerebral oxygen metabolism and blood flow is useful in the diagnosis of SCD. (author)