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

Subjects who sign informed consent and pass all eligibility criteria will be randomized to a treatment assignment. During treatment, the assigned treatment (ExAblate Transcranial or Sham ExAblate Transcranial)will be delivered. Subjects are followed in a blinded fashion for three (3) months. After the 3-month assessment, subjects will be unblinded and told their treatment assignment. Subjects receiving Sham ExAblate Transcranial treatment who still meet criteria will be crossed over and receive an active ExAblate Transcranial treatment. Subjects will be followed for up to two (2) years. Follow-up at 1 week, 1 month, 3 months, 6 months, 9 months, 12 months and up to two (2) years includes Unified Parkinson's Disease Rating Scale (UPDRS) scoring, mental and cognitive functional testing and questionnaires.