ASYMMETRY OF BASAL GANGLIA GLUCOSE-METABOLISM AND DOPA RESPONSIVENESSIN PARKINSONISM

We investigated, by positron emission tomography (PET) with [F-18]fluo ro-2-deoxy-d-glucose (FDG) (FDG-PET), brain glucose metabolism in 19 p atients with parkinsonian features. We compared local pattern of FDG u ptake and asymmetry indexes in patients with therapeutic response to l evodopa (L-dopa) (group 1, presumed Parkinson's disease, n = 9) and pa tients without L-dopa therapeutic response (group 2, presumed striaton igral degeneration, n = 10). Limb dystonia was present in 11% of patie nts in group 1 and in 40% of patients in group 2, Asymmetry in basal g anglia metabolism was distributed differently in the two, groups (anal ysis of variance, p < 0.04). In superior and inferior putamen, superio r and middle caudate, ventral striatum, and inferior thalamus, relativ e reduction in metabolism on the side contralateral to predominant par kinsonian signs was associated with L-dopa unresponsiveness. On the co ntrary, in middle caudate, ventral striatum, and inferior thalamus, a relative increase in metabolism on the side contralateral to the predo minant side, parkinsonian signs were found in L-dopa-responsive patien ts. Our FDG-PET study using simple statistical procedures demonstrates inverse asymmetry of basal ganglia glucose metabolism in parkinsonian patients grouped on the sole basis of L-dopa responsiveness.