Subthalamic stimulation in Parkinson disease: behavior and social adaptation

Bilateral subthalamic high-frequency stimulation significantly improves motor functions in patients with advanced forms of Parkinson disease (PD). This favorable effect contrasts with a growing number of reports that the treatment may result in psychiatric complications.

To analyze the presence of behavioral disorders and social maladjustment in PD patients successfully treated with continuous bilateral subthalamic stimulation.

Prospective study.

University hospital.

Twenty PD patients underwent prospective evaluation for behavioral and personality changes, quality of life, and social functioning, 6 and 24 months after surgery to implant bilateral stimulating electrodes within the subthalamic nucleus.

At 6 and 24 months after surgery, parkinsonian motor disability (on-stimulation/off-medication) was improved by 81% and 67%, respectively, and the severity of levodopa-related motor complications was improved by 84% and 70%, respectively. Levodopa-equivalent dosage was decreased by 79% and 66%, respectively; severity of depression was improved by 21% and 33%, respectively; and severity of anxiety was improved by 43% and 64%, respectively. The patients' personality traits were unmodified. Twenty-four months after surgery, the global score for quality of life was improved by 28%, whereas scores for social adjustment remained stable.

Provided that patients with PD are rigorously selected for neurosurgery, subthalamic stimulation (1) improves mood, anxiety, and quality of life; (2) does not result in severe permanent psychiatric disorders or modify patients' personality; and (3) does not ameliorate social adaptation.