Acute effects of thalamotomy and pallidotomy on regional cerebral metabolism, evaluated by PET

The subacute effect of thalamotomy and pallidotomy on regional cerebral met abolism was studied by means of Positron Emission Tomography (PET). In this way we aimed to identify the pattern of functional deafferentiation follow ing a specific lesion in the basal ganglia. The cerebral distribution of 2- [18F]fluoro 2-deoxy-D-glucose (FDG) uptake at 1-2 weeks after operation was compared with the uptake before operation. Analysis of the changes was don e by statistical parametric mapping (SPM). Thalamotomy resulted in a reduct ion of FDG uptake in predominantly the lateral prefrontal- and the parietal cortex, whereas pallidotomy affected only uptake in the (pre)frontal corte x. The absence of change in the primary sensory-motor cortex after either s urgical procedure may suggest that, in man, the motor portions of the thala mus exert a predominantly indirect influence on the human motor cortex. (C) 2000 Elsevier Science B.V. All rights reserved.