Deep Brain Stimulation-Induced Mania in Parkinson's Disease

Parkinson's Disease is the second most common neurodegenerative disorder, characterized by very debilitating motor and non-motor symptoms. While medication can alleviate the impact of this disease in patient's daily life, not all patients will respond adequately to treatment, its benefits may not be long-lasting and/or incapacitating side-effects may result. For these cases, DBS has been used to improve symptoms and quality of life. Nevertheless, this approach may have clinically significant side-effects. In fact, important neuropsychiatric adverse events can occur as a result of DBS stimulation, including DBS-induced mania. This is a debilitating mood disorder, frequently associated to a decrease in DBS efficacy due to the need to change/alter stimulation parameters or switch off the device entirely with the patient losing the benefits and the improving quality of life associated with the amelioration of his motor (but also non-motor) symptoms provided by DBS-stimulation. However, reliable predictors for its occurrence are lacking and its pathophysiology is still poorly understood. In this project, the investigators aim to clarify if there are specific DBS electrode locations and/or stimulation parameters associated to development of DBS-induced Mania while additionally determining other potential sociodemographic and clinical predictors. The investigators also aim to further explore if DBS-induced mania results from the impact of specific stimulation parameters and/or target locations in functional connectivity networks. The investigators hypothesize that specific stimulation parameters and treatment targets associated with DBS-induced mania stimulation will impact particular subcortical brain regions, alongside other clinical and sociodemographic predictors. Additionally, the investigators hypothesize that such specific pattern of stimulation will be associated to specific dysfunctional brain connectivity networks. To address these hypotheses, the investigators propose three specific aims: 1. To determine if there are specific DBS electrode location and/or stimulation parameters associated to development of DBS-induced Mania; 2. To determine if there are specific sociodemographic and/or clinical predictors for the emergence of DBS-induced Mania; 3. To explore if specific functional connectivity networks are associated to the DBS target location and/or stimulation parameters associated with Mania.