The behavioral complications of pallidal stimulation: A case report

We report a case of recurrent manic episodes associated with chronic deep b rain stimulation (DBS targeting globus pallidus (GP) in the treatment of Pa rkinson's disease (PD). Cardinal PD symptoms and dyskinesia improved with D BS, and neuropsychological testing found improvements in visuospatial measu res associated with left DBS and in verbal memory with right DBS when compa red to the patient's preoperative baseline. Under conditions of right, left , and bilateral DBS, the patient experienced bouts of mania and hypomania l asting several days at a time. Positron emission tomography (PET) with O-15 -labeled water was performed after his first manic episode under four condi tions: no stimulation, right DBS, left DBS, and bilateral DBS. Although no manic switch occurred during the course of the PET study, all three DBS con ditions were associated with decreases in regional flow in the left parahip pocampus and hippocampus and right mid-cingulate gyrus. Increases in Row in left inferior frontal area, bilateral insula, dorsolateral prefrontal cort ex, and cuneus were common to all DBS conditions. GP stimulation in PD may be associated with behavioral and cognitive effects. Distributed blood flow changes observed with pallidal DBS support a role for the pallidum in cogn ition and affective regulation. (C) 2000 Academic Press.