Ultrasound Neuromodulation in Essential Tremor

What this Trial Is About

Researchers are investigating whether low-intensity focused ultrasound (LIFU), which uses low energy sound waves, can temporarily change brain activity and improve symptoms in people with essential tremor (ET). This study focuses on targeting LIFU to a specific brain circuit called the dentatorubrothalamic tract (DRTT), which is thought to be responsible for ET. The goal is to find the best ultrasound settings to reduce tremor and to understand how these changes affect brain networks. This research is interventional and uses repeated measures within the same participants. Participants will undergo a single LIFU session lasting about 3 to 4 hours, typically one or two days before their scheduled MR-guided high-intensity focused ultrasound (HIFU) treatment for tremor. During the session, researchers will apply multiple brief ultrasound stimulations with varying settings while measuring tremor using wrist accelerometers. A sham stimulation using unfocused ultrasound will also be done to control for non-specific effects. After the stimulation session, brain scans using resting state functional MRI will assess changes in brain connectivity. Participants will then proceed with their planned HIFU treatment, which includes similar tremor monitoring and MRI evaluations. Throughout the study, participants will have their tremor severity recorded before, during, and after each ultrasound stimulation. The research team will analyze these measurements to identify the stimulation settings that most effectively reduce tremor temporarily. Functional brain changes will be examined through MRI scans taken shortly after the LIFU session. The study monitors safety and treatment effects during the same visit, and participation lasts for the duration of the LIFU session plus follow-up imaging and the subsequent HIFU procedure.

Ultrasound Neuromodulation in Essential Tremor