Patient case (clinical description): A 60-year-old man comes to the clinic complaining of hand tremor that started few months ago.  It is most bothering when he wants to drink from a glass or pour from a bottle. He does not smoke, but drinks occasionally. He recently started consuming more alcohol as his tremor subsides somewhat when he drinks small amounts of alcohol.  Family history is significant for similar problems in his mother.  Vital signs are normal and the patient has no other medical conditions.  Neurologic examination shows bilateral tremor in the upper extremities. The diagnosis of essential tremor is confirmed.

Patient's own account: I'm only a 60 years old man but I already suffer from shaky hands. It started a few months ago, and it really bothers me when I want to pour myself a glass or even while drinking. I don't smoke, but I drink alcohol from time to time. To be honest, I've been drinking a little more lately since it helps me with the shaking. My mom had the same issue when she was my age. The doctor took my vitals, and they were normal. I don't have any other medical issues. I underwent neurological exams and it showed that I’m shaky from both sides. The doctor diagnosed me with essential tremor.

Clinical trial: Staged Bilateral Exablate Treatment of Medication Refractory Essential Tremor

Eligibility criteria:
Inclusion Criteria:

          1. Subjects who:

               1. previously underwent Exablate thalamotomy for their essential tremor in a
                  clinical study or in a commercial procedure at least 9 months prior to enrolling
                  in this study for contralateral Exablate thalamotomy

               2. Subjects who would benefit from a bilateral treatment for their essential tremor
                  and would want to undergo a staged bilateral thalamotomy

          2. All subjects must have a complete baseline CRST prior from first Exablate thalamotomy

          3. Men and women age 22 years to 75 years of age.

          4. Minimum score of 24 on MoCA or 20 on MMSE

          5. Subjects who are able and willing to give consent and able to attend all study visits

          6. Postural or intention tremor severity score of greater than or equal to 2 in the both
             upper extremities as measured by the CRST rating scale while on stable medication

          7. Thalamus can be targeted by the Exablate device. The region must be apparent on MRI
             such that targeting can be performed.

          8. Able to communicate sensations during the Exablate Thalamotomy treatment

          9. Original (before first Exablate procedure) CRST score of 2 or above in any one of the
             items 16-23 from the Disability subsection of the CRST: speaking, feeding other than
             liquids, bringing liquids to mouth, hygiene, dressing, writing, working, and social
             activities.

         10. Subjects on antidepressant medications must be stable for at least 3 months prior to
             procedure(i.e., no change in medication drug or dosage for 3 months based on
             historical medical records).

         11. Remains eligible for Exablate treatment with no changes to medical history that would
             affect Exablate treatment criteria, (e.g., bleeding/coagulation requirements, or new
             pathology such as infarct, tumor, etc).

        Exclusion Criteria:

          1. Subjects with unstable cardiac status

          2. Subjects exhibiting any behavior(s) consistent with ethanol or substance abuse as
             defined by the criteria outlined in the DSM-IV as manifested by one (or more) of the
             following occurring within a 12 month period:

          3. Subjects with uncontrollable blood pressure (hypertensive with diastolic BP > 100 on
             medication)

          4. History of abnormal bleeding and/or coagulopathy, i.e. subjects with risk factors for
             intraoperative or postoperative bleeding as indicated by: platelet count less than
             100,000 per cubic millimeter, a documented clinical coagulopathy, or INR coagulation
             studies exceeding the institution's laboratory standard

          5. 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
             (e.g. Avastin) within one month of focused ultrasound procedure

          6. Active or suspected acute or chronic uncontrolled infection

          7. Individuals who are not able or willing to tolerate the required prolonged stationary
             supine position during treatment (can be up to 4 hrs of total table time.)

          8. Subjects with life-threatening systemic disease that include but not limited to the
             following will be excluded from the study participation: HIV, Liver Failure, blood
             dyscrasias, etc...

          9. Any clinically significant moderate to severe sensory deficit lasting greater than 30
             days after the first Exablate thalamotomy NOTE: Subjects with clinically significant
             moderate to severe sensory deficit following first Exablate thalamatomy should be
             excluded even if event resolves within a few months of treatment. This may cause new
             first thalamotomy subjects to be ineligible for the bilaterally staged treatment.

         10. Moderate to severe cerebellar disturbance (imbalance or ataxia) or presence of
             moderate or severe hemiparesis NOTE: Subjects with moderate to severe cerebellar
             disturbance (imbalance or ataxia) or presence of moderate or severe hemiparesis
             following first Exablate thalamatomy should be excluded even if event resolves within
             a few months of treatment. This may cause new first thalamotomy subjects to be
             ineligible for the bilaterally staged treatment.

         11. Any persistent dysphasia/dysarthria, language impairment following first Exablate
             thalamotomy.

             NOTE: Subjects with significant impairment following first Exablate thalamotomy should
             be excluded even if event resolves within a few months of treatment. This may cause
             new first thalamotomy subjects to be ineligible for the bilaterally staged treatment.

         12. Significant reduction in cognitive function since the first thalamotomy. NOTE:
             Subjects with significant reduction in cognitive function following first Exablate
             thalamatomy should also be excluded even if event resolves within a few months of
             treatment. This may cause new first thalamotomy subjects to be not eligible for the
             bilaterally staged treatment.

         13. Subject is pregnant or breastfeeding.

         14. Subjects who have an overall Skull Density Ratio of less than 0.40 as calculated at
             screening
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 22 Years old.
Subject must be at most 75 Years

Eligibility (NLI label): Entailment