Motor and nonmotor symptom follow-up in parkinsonian patients after deep brain stimulation of the subthalamic nucleus

OBJECTIVE: To evaluate motor and nonmotor symptoms in patients with Parkinson's disease undergoing bilateral deep brain stimulation of the subthalamic nucleus (STN DBS). METHODS: Thirty-six consecutive patients receiving bilateral STN stimulation implants were evaluated preoperatively as well as 12 and 24 months after surgery. Motor symptoms were assessed through the Unified Parkinson's Disease Rating Scale (UPDRS). Data concerning nonmotor symptoms were collected from items of the UPDRS and 2 additional questions from clinical charts regarding constipation and urological dysfunction. RESULTS: STN DBS was effective in controlling motor symptoms; concerning nonmotor symptoms, sleep quality and constipation improved after surgery as compared to baseline. Salivation, swallowing and sensory complaints were ameliorated to a comparable degree by the medication on state, whether preoperatively or postoperatively. With a lower dose of dopaminergic medication, however, the medication on state appeared to be a much larger percentage of the day postoperatively. No significant variations were detected in intellectual impairment, depression, thought disorders, motivation, falling unrelated to freezing, nausea, orthostatic hypotension and urological dysfunction. CONCLUSIONS: STN DBS effectively controls motor symptoms, while nonmotor features of advanced Parkinson's disease patients are mostly unchanged after surgery, even though some specific aspects, notably sleep complaints and constipation, are ameliorated.