Suicidal thoughts in patients with Parkinson's disease treated by deep brain stimulation of the subthalamic nuclei: two case reports and review of the literature

Background: Deep brain stimulation (DBS) of the subthalamic nuclei (STN) can result in depression despite the obvious motor improvement. Case presentations: Two patients with serious life-threatening depressive episodes are described. In the first case, the trigger for depression was a slight adjustment of the left stimulating electrode's contact. In the second case, reducing both the dopaminergic therapy and the voltage of DBS resulted in the manifestation of depressive symptoms. Conclusions: DBS-induced depression possibly has pathogenetic differences from ordinary Parkinson's disease depression. The STN region seems to be a sensitive zone that influences emotions.