Objective: In sporadic cases of olivopontocerebellar atrophy (OPCA), to determine whether local cerebral blood flow (ICBF) is reduced, whether ICBF is coupled to local cerebral metabolic rate for glucose (ICMRglc), and whether ICBF measurements are potentially useful in diagnosing OPCA. Design: Positron emission tomography was used with [15O]H2O to measure ICBF and with [18F]fluorodeoxyglucose to measure ICMRglc in 17 patients with OPCA and 21 normal control subjects. Results: In OPCA patients, ICBF was significantly decreased in the cerebellum, but not in the cerebral cortex, basal ganglia, thalamus, or brainstem. In the same patients, ICMRglc was significantly decreased in the cerebellum and brainstem, where the largest changes were observed, and also in the cerebral cortex, basal ganglia, and thalamus. The ratio of ICBF to ICMRglc, an indicator of the coupling of blood flow to metabolism, was similar in OPCA patients and normal subjects for all regions except the brainstem, where the ratio was marginally decreased in OPCA patients. Using logistic discriminant analysis to assess the ability of ICBF and ICMRglc to differentiate OPCA patients from normal subjects, we found the cross-validated sensitivity of absolute ICMRglc as a predictor of OPCA was 82% with a corresponding specificity of 71%; the sensitivity of absolute ICBF was 71% and the specificity 76%. Conclusions: In sporadic cases of OPCA, ICBF is reduced in the cerebellum, CBF remains coupled to ICMRglc, and the ICBF pattern is a useful predictor of the diagnosis.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Jul 1995|
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