NCT06331052

3-D Tractography FUS Ablation for Essential Tremor

3-D Tractography Focused Ultrasound Ablation for Essential Tremor

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 24 (estimated)
• Sponsor: University of North Carolina, Chapel Hill · Academic / Other
• Sex: All
• Age: 22 Years
• Healthy volunteers: Not accepted

Summary

The investigators propose to advance Vim-FUSA (Ventral Intermediate Nucleus - Focused Ultrasound Ablation) with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. The investigators hypothesize that 3-D tractography Vim-FUSA will improve the Vim ablation compared to standard Vim-FUSA and prove safe and feasible in the clinical setting. The investigators also hypothesize that intraoperative magnetic resonance (i-MR) monitoring will differentiate ablated tissue from immediate perilesional edema and accurately predict the Vim-FUSA clinical outcomes.

Detailed description

Essential tremor (ET) is a common neurological disorder and a leading cause of functional and psychological disabilities that can be difficult to suppress with oral medications, many of which have considerable side effects limiting adequate dosing. As a result, up to 20% of ET patients cannot achieve satisfactory control of their symptoms and must consider interventional options. Focused ultrasound ablation (FUSA) of the ventral intermediate nucleus (Vim) is an FDA-approved and Medicare-reimbursed procedure for ET resistant to medications that can selectively ablate the brain area associated with tremor without the need for surgical incisions or anesthesia. The success of Vim-FUSA depends on the ability to accurately ablate 70% of the Vim volume without lesioning neighboring structures, a goal that is complicated by technical challenges in three critical phases of the procedure: planning (identifying the Vim location and extension); delivery (ablating the Vim volume with adequate accuracy); and monitoring (confirming Vim ablation with reliable intraoperative imaging). The investigators propose to advance Vim-FUSA with the support of 3-D tractography, a neuroimaging technique to visually represent nerve tracts within the brain. The investigators hypothesize that 3-D tractography Vim-FUSA will improve the Vim ablation compared to standard Vim-FUSA and prove safe and feasible in the clinical setting. The investigators also hypothesize that intraoperative magnetic resonance (i-MR) monitoring will differentiate ablated tissue from immediate perilesional edema and accurately predict the Vim-FUSA clinical outcomes. Aim 1. Estimate and characterize the improvement in Vim ablation achieved with 3-D tractography Vim-FUSA vs. standard Vim-FUSA in an experimental controlled animal study. Through an experimental animal study, the investigators will characterize the Vim ablation delivered with 3-D tractography Vim-FUSA in one hemisphere (experimental group) vs. standard Vim-FUSA in the opposite hemisphere (control group). Aim 2. Test safety, feasibility, and preliminary efficacy, and estimate effect size of 3-D tractography Vim-FUSA in a phase-II, two-groups, pre-post interventional human study. In a human study, the investigators will test the safety and feasibility of ablating 70% of the Vim volume while checking for side effects with intraoperative clinical testing. Tremor assessments will be videotaped at baseline and 12 weeks and compared, in a blinded fashion, with age-sex matched controls randomly selected from the video repository of the two FDA-regulated studies of standard Vim-FUSA at baseline and 12 weeks. Aim 3 (Exploratory). Assess the accuracy of i-MR in differentiating tissue ablation from immediate perilesional edema and its utility in predicting Vim-FUSA clinical outcomes. In the experimental animal study, the investigators will estimate and compare the accuracy of conventional and non-conventional i-MR in differentiating tissue necrosis from perilesional edema. In the interventional human study, the investigators will evaluate the utility of i-MR in predicting Vim-FUSA clinical outcomes

Conditions

• Essential Tremor

Interventions

Type	Name	Description
DEVICE	MR-guided Focused Ultrasound Ablation	3-D tractography Vim-FUSA -D tractography Vim-FUSA will be carried out as follows: (a) head shaving and placement of the stereotactic frame (Integra radionics frame, Integra Lifesciences, NJ, USA) secured to the skull with transcutaneous screws; (b) positioning on the procedure table and placement of the ultrasound transducer; (c) acquisition of conventional magnetic resonance (MR) imaging and co-registration with the CT head and 3-D tractography imaging acquired pre-surgically; (d) exploration of the target area with subtherapeutic sonications; (e) intraoperative monitoring with clinical testing of tremor and side effects with a standardized protocol. (f) Therapeutic sonications in the target area to deliver definitive ablation followed by clinical testing of tremor and side effects with a standardized protocol as described in section (e).

Timeline

• Start date: 2024-02-28
• Primary completion: 2028-02-28
• Completion: 2028-02-28
• First posted: 2024-03-26
• Last updated: 2026-01-20

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study