Effects of Deep Brain Stimulation (DBS) Frequency on Neural Synchrony

Recruitment & Eligibility

Inclusion Criteria

A diagnosis of idiopathic Parkinson's disease, with bilateral symptoms at Hoehn and Yahr Stage greater than or equal to II.
Documented improvement in motor signs on versus off dopaminergic medication, with a change in the Unified Parkinson's Disease Rating Scale motor (UPDRS III) score of >= 30% off to on medication.
The presence of complications of medication such as wearing off signs, fluctuating responses and/or dyskinesias, and/or medication refractory tremor, and/or impairment in the quality of life on or off medication due to these factors.
Subjects should be on stable doses of medications, which should remain unchanged until the DBS system is activated. After the DBS system is optimized (during which time the overall medication dose may be reduced to avoid discomfort and complications such as dyskinesias) the medication dose should remain unchanged, if possible, for the duration of the study.
Treatment with carbidopa/levodopa, and with a dopamine agonist at the maximal tolerated doses as determined by a movement disorders neurologist.
Age > 18

Exclusion Criteria

Subjects with significant cognitive impairment and/or dementia as determined by a standardized neuropsychological battery.
Subjects with clinically active depression, defined according to the Diagnostic and Statistical manual of Mental Disorders, Fourth Edition (DSM-IV) criteria and as scored on a validated depression assessment scale.
Subjects with very advanced Parkinson's disease, Hoehn and Yahr stage 5 on medication (non-ambulatory).
Age > 80.
Subjects with an implanted electronic device such as a neurostimulator, cardiac pacemaker/defibrillator or medication pump.
Subjects, who are pregnant, are capable of becoming pregnant, or who are breast feeding.
Patients with cortical atrophy out of proportion to age or focal brain lesions that could indicate a non-idiopathic movement disorder as determined by MRI
Subjects having a major comorbidity increasing the risk of surgery (prior stroke, severe hypertension, severe diabetes, or need for chronic anticoagulation other than aspirin).
Subjects having any prior intracranial surgery.
Subjects with a history of seizures.
Subjects, who are immunocompromised.
Subjects with an active infection.
Subjects, who require diathermy, electroconvulsive therapy (ECT), or transcranial magnetic stimulation (TMS) to treat a chronic condition.
Subjects, who have an inability to comply with study follow-up visits.
Subjects, who are unable to understand or sign the informed consent

Study & Design

Arm && Interventions

Group	Intervention	Description
DBS (Deep Brain Stimulation)	DBS (Deep Brain Stimulation)	DBS ( Deep Brain Stimulation) ( both high and low frequency deep brain stimulation will be applied to the subthalamic nucleus)

Primary Outcome Measures

Name	Time	Method
Low frequency stimulation versus no stimulation	3 years	The changes in neuronal oscillations, measured in power (dB/Hz) and frequency (Hz), that are significantly different between periods of low frequency stimulation and periods of no stimulation - during rest - in people with Parkinson's disease off medications.

Secondary Outcome Measures

Name	Time	Method
Low frequency stimulation versus high frequency stimulation	3 years	To determine if the effects of low frequency stimulation are due to using a lower total power delivered than normal therapeutic high frequency stimulation.

Recruitment & Eligibility