Depression, anxiety and impulse control disorders are among the most prominent neuropsychiatric symptoms in Parkinson's disease (PD) that greatly impact patients' and caregivers' quality of life. However, the neural correlate underlying these symptoms is still largely unknown preventing the development of comprehensive treatment for these symptoms.~The aims of this study are to 1) Determine the neural correlates of non-motor symptoms, 2) Determine how cortical stimulation can reduce these symptoms and normalize the abnormal brain signals, 3) Develop closed-loop stimulation paradigms and 4) Teach patients how to voluntarily modulate the abnormal brain signals.~Ten PD patients undergoing deep brain surgery (DBS) implantation and diagnosed with mild to moderate mood disorder and/or impulsive behavior will be enrolled in this study. In addition to the standard therapeutic DBS electrode used to treat motor symptoms, a flexible electrode will be placed over the prefrontal cortex. Both electrodes will be attached to the Medtronic Activa PC+S pulse generator (and Medtronic Summit RC+S pulse generator as replacements), investigational devices that allows therapeutic stimulation and chronic brain recordings. At multiple time points, up to 2 years post-implantation, in our clinic or patient's home, brain signals will be recorded while patients are resting or performing emotion/cognition tasks. Symptoms will be assessed using validated questionnaires and tasks to allow identification of neurophysiological correlates of non-motor symptoms. There is also an optional sleep study included for better understanding of the brain's physiology. The investigators will then investigate the effect of cortical stimulation on both symptoms severity and brain signals that may be related to symptom expression. These signals will then be used to implement closed-loop controlled cortical stimulation and neuro-feedback controlled strategies.
This study will investigate cortical stimulation to treat mood and behavioral symptoms in Parkinson's disease patients.