ExAblate Transcranial MR Guided Focused Ultrasound for the Treatment of Parkinson's Disease

Inclusion Criteria: * Men and women, age 30 years and older * Subjects who are able and willing to give informed consent and able to attend all study visits * Subjects with a diagnosis of idiopathic PD as confirmed from clinical history and examination by a movement disorder neurologist at the site * Subject demonstrates a severe resting tremor or postural/action as measured by UPDRS * Subject exhibits a significant disability from their PD tremor despite medical treatment * Subjects should be on a stable dose of all PD medications for 30 days prior to study entry * Subject is able to communicate sensations during the ExAblate Transcranial procedure Exclusion Criteria: * Subjects with unstable cardiac status * Subjects exhibiting any behavior(s) consistent with ethanol or substance abuse * Severe hypertension * Subjects with standard contraindications for MR imaging such as non-MRI compatible implanted metallic devices including cardiac pacemakers, size limitations, etc. * Known intolerance or allergies to the MRI contrast agent including advanced kidney disease or severely impaired renal function * Significant claustrophobia that cannot be managed with mild medication * Current medical condition resulting in abnormal bleeding and/or coagulopathy * Receiving anticoagulant (e.g. warfarin) or antiplatelet (e.g. aspirin) therapy within one week of focused ultrasound procedure or drugs known to increase risk or hemorrhage * History of intracranial hemorrhage * History of multiple strokes, or a stroke within past 6 months * Subjects who are not able or willing to tolerate the required prolonged stationary supine position during treatment * Are participating or have participated in another clinical trial in the last 30 days * Subjects unable to communicate with the investigator and staff * Subjects with a history of seizures within the past year * Subjects with brain tumors * Subjects with intracranial aneurysms requiring treatment or arterial venous malformations (AVMs) requiring treatment * Subjects who have had deep brain stimulation or a prior stereotactic ablation of the basal ganglia