Behavioral changes associated with deep brain stimulation surgery for Parkinson's disease.

Evaluation for psychiatric and cognitive dysfunction is a crucial part of preoperative assessment for deep brain stimulation (DBS) surgery. All candidates for DBS should be treated for active psychiatric disorders, and the treatment team should also screen for past psychiatric history, which may predispose to postoperative psychiatric illness. A wide range of behavioral symptoms have been seen following DBS, including depression, hallucinations or true psychosis, mania, and impulsivity. Suicidal ideation should be treated aggressively. Cognitive changes may occur, but data are currently too limited to make predictions regarding subtle effects on cognition. However, patients with dementia may experience further decline in cognitive function following DBS.