Continued Access Protocol: ExAblate Transcranial MR Guided Focused Ultrasound for the Treatment of Essential Tremors

Inclusion Criteria:

   - Men and women, age 22 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 Essential Tremor as confirmed from clinical history and
   examination by a neurologist or neurosurgeon specialized in movement disorder

   - Subject exhibits a significant disability from their ET despite medical treatment

   - Subjects should be on a stable dose of all ET 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

   - 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