Chronic Effects of DBS in Parkinson's Disease and Dystonia

Inclusion Criteria(both groups):

• Ability to give informed consent for the study
• Movement disorder symptoms that are sufficiently severe, in spite of best medical therapy, to warrant surgical implantation of deep brain stimulators according to standard clinical criteria

Inclusion criteria (Isolated dystonia):

• Age 22-75
• Isolated dystonia that is generalized or segmental, that must affect one or - Stable doses of anti-dystonia medications (such as Artane, Baclofen, or Clonopin) for at least 30 days prior to baseline assessment
• For patients with craniofacial involvement, prior treatment with botulinum toxin with failure to adequately control dystonia symptoms.

Inclusion criteria (PD):

• Age 30-75
• Bilateral disease (Hoehn and Yahr stage 2 or greater)
• Has been treated with levodopa/carbidopa, and with a dopamine agonist, at the maximal tolerated doses as determined by a movement disorders neurologist
• Stable doses of antiParkinsonian medications for at least 30 days prior to their baseline assessment
• Significant disability in the setting of optimal medical management by a movement disorders neurologist. Disability may be due to tremor that is unresponsive to medications, or to motor fluctuations
• UPDRS-III score off medication between 20 and 60
• Improvement of at least 30% in the baseline UPDRS-III on medication score, compared to the baseline off-medication score.

Exclusion Criteria (both groups):

• Pregnancy or breast feeding
• MRI showing cortical atrophy out of proportion to age
• MRI showing focal brain lesions that could indicate a non-idiopathic movement disorder,
• Major comorbidity increasing the risk of surgery (prior stroke, severe hypertension, severe diabetes, or need for chronic anticoagulation other than aspirin)
• Inability to comply with study follow-up visits
• Any prior intracranial surgery
• Mood depression with a Beck depression inventory score of > 17 on baseline screening
• Significant cognitive impairment (MoCA<25).
• History of seizures
• Immunocompromised
• Has an active infection
• Requires diathermy, electroconvulsive therapy (ECT) or transcranial magnetic - Has an implanted electronic device such as a neurostimulator, cardiac pacemaker or medication pump.