Changes in cognitive-emotional and physiological symptoms of depression following STN-DBS for the treatment of Parkinson's disease

Abstract

Background and purpose: Subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to have beneficial effects on the motor features of Parkinson's disease (PD), but its impact on non-motor symptoms, most notably mood, has not been fully explored.

Methods: In the first study to independently compare the emotional-cognitive and somatic/physiological symptoms of depression, we examined mood differences in 17 bilateral STN-DBS and 22 matched non-surgical PD patients at baseline and 6 months.

Results: The STN-DBS group reported higher levels of depression at baseline with significant endorsement of physical symptomatology. Postoperatively, no significant between-group differences in physical symptoms of depression were found. In contrast, a significant group by time interaction for cognitive-emotional symptoms of depression was found, with the STN-DBS group reporting an increase in psychological symptoms of distress. The STN-DBS group also reported an increase in anxiety following surgery. The suicide rate of 5% found in our study is consistent with other postoperative studies in PD. The impact of changes in levodopa and psychotropic medication are also explored.

Conclusions: Preliminary results suggest that the motor improvement often observed in patients with PD following bilateral STN-DBS may be partially offset by an increase in affective-cognitive symptoms of depression.