Cortical Stimulation to Treat Mood and Behavioral Symptoms in Parkinson's Disease Patients

Prior treatment

• Major comorbidity increasing the risk of surgery (prior stroke, severe hypertension, severe diabetes, or need for chronic anticoagulation other than aspirin)
• Any prior intracranial surgery except DBS surgery

Other illness

• MRI showing focal brain lesions that could indicate a disorder other than idiopathic PD
• Significant cognitive impairment (MoCA\<20).
• History of seizures
• Has an active infection
• Requires diathermy, electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS) to treat a chronic condition

Age

• MRI showing cortical atrophy out of proportion to age

Other

• Pregnancy or breast feeding
• Immunocompromised
• Inability to comply with study follow-up visits
• Any personality or mood symptoms that study personnel believe will interfere with study requirements.

• Ability to give informed consent for the study
• Age 30-75
• Diagnosis of Parkinson's disease by a movement disorders specialist
• Movement disorder symptoms that are sufficiently severe, in the setting of best medical therapy, to warrant surgical implantation of deep brain stimulators according to standard clinical criteria
• UPDRS-III score off medication between 20 and 80 and an improvement of at least 30% in the baseline UPDRS-III on medication score, compared to the baseline off-medication score.
  • OR Patients with tremor-dominant PD (a tremor score of at least 2 on a UPDRS-III sub-score for tremor), treatment resistant, with significant functional disability despite maximal medical management OR Patients intolerant to medication causing significant functional disability
• Have one or several mild to moderate mood or impulsive behavior as defined by:
  • depression (BDI\>=13)
  • anxiety (BAI \>=7)
  • impulsive behavior as indicated by a positive score on the Questionnaire for Impulsive-Compulsive disorders in Parkinson's Disease (QUIP-A) or as determined by clinical interview or informant report
  • Mood or behavior symptom fluctuations corresponding to minimum 30% improvement in non-motor symptoms when comparing visual analogue scales (VAS) scores in the on versus off medication state
• Stable doses of anti-Parkinsonian medications for at least 30 days prior to their baseline assessment.