Parieto-occipital glucose hypometabolism in Parkinson's disease with autonomic failure

To investigate the characteristics of regional cerebral metabolism in a sub group of patients with Parkinson's disease and autonomic failure, we studie d seven patients with Parkinson's disease with autonomic failure (PA group) , 11 patients with Parkinson's disease without apparent autonomic failure ( PD group), and nine normal controls using fluoro-deoxyglucose positron emis sion tomography (FDG-PET). To determine differences in metabolic distributi on among these groups, regional relative glucose metabolic rates (RGMR), wh ich were normalized with cerebellar values, were calculated and age-adjuste d covariance analyses were done. When compared with that of controls, RGMR in the cerebral cortex of the PA group was markedly reduced in the occipita l cortex (P<0.001), inferior parietal cortex (P<0.005) and superior parieta l cortex (P<0.005), but without a decrease in the sensory motor and medial temporal cortices, putamen and thalamus. In contrast, the PD group did not show significant focal hypometabolic distribution. Our findings raise the p ossibility that Parkinson's disease with autonomic failure may overlap with the features of dementia with Lewy bodies. (C) 1999 Elsevier Science B.V. All rights reserved.