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

A Continued Access Study to Evaluate the Effectiveness and Safety of ExAblate Transcranial MRgFUS Thalamotomy Treatment of Medication Refractory Essential Tremor Subjects

The objective of this prospective, multi site, single-arm study is to capture the efficacy of treatment using the ExAblate Transcranial System and to further demonstrate safety in medication-refractory tremor in patients with essential tremor (ET).

This study is evaluating a new technique for performing Thalamotomy for tremor control. While current techniques have possible invasive or radiation effects, the use of ExAblate if totally non-invasive and without any radiation. After informed consent and screening, eligible subjects will be undergo an ExAblate treatment. All subjects will be followed at 1 day, 1 week, 1, 3, 6 and 12 months and for up to 5 years as directed by their doctor.

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