The purpose of this study is to see if the MR-guided focused ultrasound (MRgFUS) thalamotomy procedure can be performed on both sides of the brain safely and effectively to reduce bilateral tremor.

Inclusion Criteria:

1. Men and women age 22 years or older
2. Diagnosis of medication-refractory Essential Tremor
3. Has previously underwent an Exablate index procedure in a clinical trial or in a commercial setting at least 9 months prior to enrolling in this trial
4. Able to communicate sensations during the Exablate thalamotomy procedure

Exclusion Criteria:

1. Has experienced any non-transient neurological event or worsening following the Exablate index procedure
2. Presence of unknown or MR unsafe devices anywhere in the body
3. Non-transient hemiparesis as determined by physical examination
4. Clinically significant abnormal speech function as determined by a speech pathologist
5. Pregnant or breastfeeding
6. Unstable cardiac status
7. Behavior(s) consistent with ethanol or substance abuse
8. History of bleeding disorder
9. Has received anticoagulants within one month of Exablate procedure
10. Cerebrovascular disease
11. Intracranial tumor
12. Active or suspected acute or chronic uncontrolled infection
13. Has previously had deep brain stimulation or a prior stereotactic ablation of the basal ganglia or thalamus
14. Implanted objects in the skull or the brain
15. Currently in a clinical trial involving an investigational product or non-approved use of a drug or device or in any other type of medical research
16. Unable to communicate with the investigator and staff