The objective of this study is to test the safety and preliminary efficacy of staged bilateral subthalamotomy performed using the ExAblate Transcranial System for the treatment of Parkinson's disease (PD) motor features

The objective of this study is to evaluate the incidence and severity of adverse events (AE/AEs) associated with ExAblate Transcranial Magnetic Resonance Guided Focused Ultrasound (MRgFUS) bilateral staged subthalamotomy for the treatment of PD motor features. To determine the effectiveness of the ExAblate Transcranial staged bilateral subthalamotomy to treat cardinal motor features of subjects with PD.

Inclusion Criteria:

1. Male or Female age 30 years or older
2. Able and willing to give consent and able to attend all study visits
3. A confirmed diagnosis of Parkinsons Disease
4. Subjects that have received unilateral subthalamotomy at least 6 month before the inclusion in bilateral subthalamotomy and present parkinsonian symptoms
5. Able to localize subthalamic nucleus on MRI for treatment
6. Able to communicate sensations during the ExAblate MRgFUS procedure

Exclusion Criteria:

1. Hoehn and Yahr stage in the ON medication state of 2.5 or greater
2. Presence of severe dyskinesia as noted by MDS-UPDRS scores
3. Presence of other central neurodegenerative disease
4. Parkinsonian symptoms are a side effect from neuroleptic medications
5. Subjects exhibiting any behavior(s) consistent with ethanol or substance abuse
6. History of a bleeding disorder or receiving anticoagulant
7. Subjects with advanced kidney disease or on dialysis
8. Subjects with known intolerance or allergies to the MRI contrast agents.
9. Presence of unknown or MRI unsafe devices anywhere in the body.
10. History of multiple strokes, or a stroke within past 6 months
11. Subjects with a history of seizures within the past year
12. Subjects with malignant brain tumors
13. Women who are pregnant or nursing