Objective

The objective of this pilot study is to characterize the abnormal neuronal firing patterns of basal ganglia neurons and those in the premotor cortex in patients with treatment-resistant movement disorders undergoing deep brain stimulation (DBS) surgery.

Study population

Fifteen adult patients with treatment-resistant movement disorders who are undergoing deep brain stimulation surgery at Suburban Hospital, Bethesda, Maryland, will be studied.

Design

This is a physiology study of treatment-resistant movement disorder patients who have been scheduled for implantation of a deep brain stimulation device into the Nucleus accumbens. Prior to surgery, patients will learn a rewarded visual-motor task and undergo magnetoencephalography. The task will be repeated during DBS surgery, with collection of information on electrical activity including single neuronal unit and local field potentials. The task and MEG will be repeated 3-4 months after surgery. The collected data will be analyzed for coherence patterns during rest and rewarded movements.

Outcome measures

We plan to characterize and quantify the oscillatory activity present in motor circuits of treatment-resistant movement disorder patients during rewarded visually guided movements. We hypothesize that during visually guided movements, neuronal coherence will be significantly increased relative to resting periods. Thus, by better understanding the alteration in oscillatory patterns in these patients, we hope to develop better DBS stimulation paradigms in order to better treat this disease in the future.

Objective:

The objective of this pilot study is to characterize the abnormal neuronal firing patterns of basal ganglia and thalamic neurons and those in the premotor cortex in patients with treatment-resistant movement disorders undergoing deep brain stimulation (DBS) surgery. Neuronal activity will be studied in a decision-making task guided by reward. Secondary objectives will involve study of how activity in the brain is modulated in such a task and how DBS can influence the cerebral activity related to decision-making.

Study population:

Fifteen adult patients with treatment-resistant movement disorders (Essential tremor or Parkinson s disease) who are undergoing deep brain stimulation surgery at Suburban Hospital, Bethesda, Maryland, will be studied.

Design:

This is a physiology study of medically refractory patients who have been scheduled for implantation of a deep brain stimulation device into basal ganglia or thalamic structures. Prior to surgery, patients will learn a rewarded visual-motor task and undergo magnetoencephalography (MEG). The task will be repeated during DBS surgery, with collection of information on electrical activity including single neuronal unit and local field potentials. The task and MEG will be repeated 3 and 6 months after surgery.

Outcome measures:

The collected data will be analyzed for coherence patterns during rest and rewarded movements. We plan to characterize and quantify the oscillatory activity present in motor circuits of patients during rewarded visually guided movements. We hypothesize that during visually guided movements, neuronal coherence will be significantly increased relative to resting periods. Activity during surgery will be compared with MEG recordings in the same task both before and after surgery. By understanding the alteration in oscillatory patterns in these patients, we hope to improve DBS stimulation paradigms in order to optimize treatment protocols.

• INCLUSION CRITERIA:

Adult patients (over 18 years of age) with severe treatment-resistant ET or PD who are scheduled for deep brain stimulation surgery at Suburban Hospital

Able to provide Informed Consent

EXCLUSION CRITERIA:

Subjects who are not willing or able to safely tolerate the study procedures

Subjects who have untreated depression or psychiatric disorder

Subjects who use illicit substances

Subjects who are pregnant

Subjects who are claustrophobic

Subjects who have metallic dental fillings.

Subjects who have any of the following: cardiac pacemaker; implanted cardiac defibrillator; aneurysm clip; neuro or bone stimulator; insulin or infusion pump; implanted drug infusion device; cochlear, otologic, or ear implant; prostate radiation seeds; IUD (intrauterine device); transdermal medication patch (Nitro); any type of prosthesis (eye, penile); heart valve prosthesis; shunt (spinal/intraventricular); wire sutures or surgical staples; bone/joint pin, screw, nail, plate; body tattoos or makeup (eyeliner/lip); body piercing(s) (non-removable); breast tissue expander; any metallic implants or objects.