Summary
This open-label pilot study will evaluate the safety, tolerability, feasibility, and preliminary efficacy of repeated low-intensity focused ultrasound pulsation (LIFUP) targeting the ventral intermediate nucleus (Vim) of the thalamus in patients with Essential Tremor (ET). Twelve adults with clinically diagnosed ET will undergo six LIFUP treatment sessions over approximately two weeks using the BrainSonix BX Pulsar 1002 system. Tremor severity will be assessed using clinician-rated scales (TETRAS and FTM), patient-reported quality-of-life measures (QUEST), and objective accelerometry before and after treatment sessions, with additional follow-up visits at one and three months post-treatment. MRI scans will be performed at baseline and after the final treatment session to monitor safety. The study aims to characterize whether non-ablative focused ultrasound can safely and transiently modulate tremor-related thalamic circuits and provide preliminary evidence supporting future controlled trials of LIFUP for ET.
Eligibility Criteria
Age Range: 18 years to 90 years
Inclusion Criteria:
1. Confirmed clinical diagnosis of ET
2. Isolated tremor syndrome, at least 3 years duration
3. Subjective complaint of tremor assessed and validated by physician
4. Must be willing to comply with the study protocol
5. English Proficiency
6. At least 18 years of age
7. At most 90 years of age
Exclusion Criteria:
1. Severe microvascular disease or structural brain lesions equivalent to Fazekas scale of 3 or higher in the periventicular or deep white matter.
2. Subjects on blood thinning medications (e.g. Eliquis)
3. Recent stroke (within the last 6 months)
4. Implanted electrodes (e.g. DBS) in brain
5. History of aneurysm
6. History of cranial trauma resulting in fracture or traumatic brain injury
7. Subjects who are unable to cooperate with the testing.
8. Subjects who lack capacity to consent
9. Subjects with severe cardiac disease, increased intracranial pressure, or using a transcutaneous electrical nerve stimulation (TENS) unit.
10. Severe cardiac disease will be defined as any of the following:
i) History of myocardial infarction within the past 6 months ii) Diagnosis of congestive heart failure with NYHA Class III or IV symptoms iii) History of unstable angina, life-threatening arrhythmias, or use of an implantable cardioverter-defibrillator (ICD) iv) Uncontrolled hypertension (SBP \>180 mmHg or DBP \>110 mmHg) despite medication v) Any condition judged by the study physician to place the subject at increased risk from study participation
11. Subjects with implanted medical devices
12. Subjects with a history of seizure disorder.
13. Subjects with contraindications to enter MRI environment
14. Subjects with a history of substance abuse.
15. Subjects who are currently pregnant. This will be verified by a urine test prior to beginning the study.