Ultrasound Neuromodulation in Essential Tremor

ConditionsEssential Tremor Neuromodulation

Trial statusRecruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age18+

SponsorUniversity of California, San Francisco

About this trial

This study is being done to test whether low-intensity focused ultrasound (LIFU) (low energy sound waves) cause temporary changes in brain activity and behavior when directed at particular parts of the brain. By targeting LIFU to the parts of the brain thought to be responsible for essential tremor (ET), and measuring any associated improvement in tremor, the investigators hope to show that LIFU can be a useful tool for studying the brain circuits responsible for tremor and other brain disorders.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Patients with medically refractory tremor scheduled to undergo MR-guided high-intensity focused ultrasound (HIFU) thalamotomy to treat their tremor at UCSF.

Disqualifiers

Due to the logistical complexity of performing MRI in patients with MR-conditional pacemakers (need for device and patient monitoring), patients with pacemakers will be excluded from enrollment. All other patients undergoing HIFU thalamotomy for tremor will be eligible for enrollment.

Trial design

Design model

Single group

Treatments tested in this trial

Focused Ultrasound Neuromodulation - Sham Control
Device
Each ultrasound stimulation protocol will last for 60 seconds, consisting of 4 pulse trains of 5 seconds duration separated by 10 second intervals without stimulation. Across successive stimulation protocols (up to 25/patient) investigators will systematically vary pulse repetition frequency, duty cycle, and acoustic intensity to determine how these parameters contribute to the behavioral effect (transient tremor reduction). Parameters will be shuffled to control for group-level carry over effects. A defocusing lens will be in place during the session to test the difference between focused and unfoucused ultrasound while controlling for non-specific auditory and somatosensory confounds.
Focused ultrasound neuromodulation
Device
Each ultrasound stimulation protocol will last for 60 seconds, consisting of 4 pulse trains of 5 seconds duration separated by 10 second intervals without stimulation. Across successive stimulation protocols (up to 25/patient) investigators will systematically vary pulse repetition frequency, duty cycle, and acoustic intensity to determine how these parameters contribute to the behavioral effect (transient tremor reduction) in each patient. Parameters will be shuffled to control for group-level carry over effects and will include sham (unfocused or off-target stimulation) conditions to control for non-specific auditory confounds.

Treatment groups

60 Participants

are divided into 2 treatment groups

Group A: To determine the most effective stimulation parameters for DRTT LIFU neuromodulation.Experimental treatment 2 interventions

Group B: Defocusing lensSham comparator 1 intervention

Trial outcomes

Primary outcomes

Reduction in tremor

The investigators will screen ultrasound parameters through repeated sonications within the same session (up to 25, depending on patient response) to determine which parameter set is most effective at reducing tremor in each participant as measured by wrist accelerometers (reduction in tremor power from baseline in the characteristic ET range of 4-12 Hz). Stimulation protocols will consist of 5 seconds of active stimulation followed by 10 seconds of no stimulation repeated four times (total 60 s). After each 60-s stimulation, there will be a delay of 3 minutes, during which the investigators will monitor tremor severity every 60 seconds through quantitative accelerometer recordings. If a change in tremor severity greater than 50% is found in the post-LIFU period compared to the pre-LIFU baseline, the investigators will wait until tremor returns to a level comparable to baseline before proceeding with additional stimulations.

Time frame

For 3 minutes immediately after the application of each sonication protocol

Secondary outcomes

Increases or decreases in functional connectivity of brain networks

The investigators will record resting state fMRI (rs-fMRI) immediately after DRTT LIFU neuromodulation with the parameters most effective at reducing tremor in each patient. The investigators hypothesize that LIFU neuromodulation will result in systematic changes in functional connectivity in motor-related brain networks between pre-LIFU (baseline) imaging and immediate post-LIFU imaging. These changes will additionally be compared to those observed between baseline imaging and post-HIFU imaging.

Time frame

20-30 minute MRI scan at the end of the 3-4 hour experimental session

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

University of California, San Francisco

Lead sponsor

Focused Ultrasound Foundation

Collaborator

Source ClinicalTrials.gov

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