OBJECTIVES: Chronic high frequency electrostimulation of the globus pallidus internus mimics pallidotomy and improves clinical symptoms in @entity191 . The aim of this study was to investigate the cognitive consequences of unilateral deep brain stimulation. METHODS: Twenty non-demented @entity1 with @entity191 (age range 38-70 years) were neuropsychologically assessed 2 months before and 3 months after unilateral pallidal stimulation. The cognitive assessment included measures of memory, spatial behaviour, and executive and psychomotor function. In addition to group analysis of @entity73 , a @entity73 index (CII) was calculated for each individual @entity1 representing the percentage of cognitive measures that fell more than 1 SD below the mean of a corresponding normative sample. RESULTS: Neurological assessment with the Hoehn and Yahr scale and the unified @entity191 rating scale disclosed a significant postoperative reduction in average clinical @entity191 symptomatology (p<0.001). Repeated measures multivariate analysis of variance (using right/left side of stimulation as a between subjects factor) showed no significant postoperative change in cognitive performance for the total @entity1 group (main effect of operation). The side of stimulation did not show a significant differential effect on cognitive performance (main effect of lateralisation). There was no significant operation by lateralisation interaction effect. Although the @entity1 experienced significant motor symptom relief after pallidal stimulation, they remained mildly depressed after surgery. Analysis of the individual CII changes showed a postoperative @entity73 in 30% of the @entity1 . These @entity1 were significantly older and took higher preoperative doses of levodopa than @entity1 showing no change or a postoperative cognitive improvement. CONCLUSIONS: Left or right pallidal stimulation for the relief of motor symptoms in @entity191 seems relatively safe, although older @entity1 and @entity1 needing high preoperative doses of levodopa seem to be more vulnerable for @entity73 after deep brain stimulation.

Cognitive outcome after unilateral pallidal stimulation in XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive impairment', 'cognitive change', 'cognitive decline'] @entity191 :: ('MESH:D010300', 'Disease') :: ["Parkinson's disease"]
@entity191 :: (MESH:D010300,Disease) :: ['Parkinson's disease']
