Impaired frontostriatal cognitive functioning following posteroventral pallidotomy in advanced Parkinson's disease

We investigated the long-term effects of posteroventral pallidotomy on test s sensitive to the functional integrity of frontostriatal neural systems in a sample of 11 patients with advanced Parkinson's disease CPD). Patients w ere assessed within I month prior to surgery and at 12 months following pal lidotomy. Changes in outcome measures were compared to a control sample of equally performing PD patients receiving nonsurgical medical management ass essed over a 12-month period. Measures of cognitive abilities sensitive to frontostriatal functional integrity tested psychomotor processing speed, ex ecutive components of working memory, and reasoning. Additional tests of ge neral mental status and semantic memory ability were utilized to assess the specificity of the effect of pallidotomy on cognitive function Significant declines in performance on all measures sensitive to frontostriatal integr ity were found for the surgery group but not the PD control group. No signi ficant changes in performance were found on the measures of general mental status or semantic memory for either the surgery or PD control samples. The se results suggest that the posteroventral pallidotomy selectively impairs performance on tests of frontostriatal cognitive abilities. (C) 2000 Academ ic Press.