Magnetoencephalography (MEG) Pilot Study (MEG)

Network Characteristics in Essential Tremor (ET) Patients Undergoing High-Intensity Focused Ultrasound (HiFU): a Magnetoencephalography (MEG) Pilot Study

The purpose of this research is to learn more about how the brain works in people with essential tremor, and how it changes after treatment with High-Intensity Focused Ultrasound (HiFU). Essential tremor is a movement disorder that causes shaking, usually in the hands, and can make everyday tasks difficult. HiFU is a treatment that uses focused sound waves to target a small area in the brain involved in tremor. In this study, the investigators aim to understand how this treatment affects the brain's networks by using safe, non-invasive tests such as brain imaging, brain wave recordings, and movement assessments.

Study Overview

• Status: Recruiting
• Conditions: Essential Tremor
• Intervention / Treatment: Diagnostic test: MRI and fMRI scans; Diagnostic test: MEG; Diagnostic test: Sensor-based motor assessments; Other: Clinical evaluations; Other: Questionnaires and rating scales that

Detailed Description

Participation in this study will last for approximately eight months. Participants will be asked to attend a total of six study visits. These include a screening visit to see if a potential participant qualifies for the study, an assessment visit before treatment and treatment visits. Prior to and after treatment (one day, six weeks, and six months after treatment), participants will have Magnetoencephalography (MEG), Functional Magnetic Resonance Imaging (fMRI), Sensor-Based Gait and Motor Function Assessments and Self-Report Questionnaires.

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: subeikshanan venkatesan, MBBS; Phone Number: 352-273-9000; Email: subeikshanan.venkatesan@neurology.ufl.edu

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32610
      • Recruiting
      • UF Health
      • Contact: Justin Hilliard, MD; Phone Number: 352-273-9000

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion:

• Age >50 years and <85 years
• Refractory to at least 2 first line tremor medications
• Skull Density Ratio (SDR) > = 0.35

Exclusion:

• MR/MEG incompatible implants and implantable devices (ex: pacemaker)
• Head tremor interfering with MEG recording
• Severe depression and/or anxiety
• Severe cognitive impairment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Essential Tremor refractory to at least 2 first line tremor medications; Eligible patients will have MRI and fMRI scans, MEG recordings, sensor-based motor assessments, clinical evaluations and questionnaires and rating scales before the treatment, right after, and again at 6 weeks and 6 months afterward.

Diagnostic test: MRI and fMRI scans; functional MRI, diffusion tensor imaging, anatomical MRI; Diagnostic test: MEG; non-invasive electrophysiological technology that provides high temporal and spatial resolution to examine large-scale cortical dynamics.; Diagnostic test: Sensor-based motor assessments; research-grade wearable sensors equipped with gyroscopes and accelerometers to precisely and accurately quantify patients' tremors. These sensors will be worn on the wrist or finger, capturing data as patients perform standardized tremor assessment tasks, such as spiral drawing task, writing task, commonly used in essential tremor evaluation. Gait and balance assessments will be conducted by synchronizing multiple sensors placed on the upper and lower extremities as well as the midline. Gait and balance data will be collected during tasks such as the 7-meter walk test, 360-degree turn test, and postural sway.; Other: Clinical evaluations; vital signs, health status review, and neurological exam.; Other: Questionnaires and rating scales that; daily functioning, mood, memory, and tremor

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in brain electrical activity measured by magnetoencephalography (MEG) before and after treatment with focused ultrasound	Brain electrical activity will be recorded using magnetoencephalography (MEG) before treatment and at follow-up visits after treatment. MEG signals are collected as time-series data and processed to derive quantitative measures of functional brain connectivity that inform how interconnected different brain regions are. The primary outcome is the average change in these connectivity measures from pre-treatment baseline to post-treatment follow-up across participants.	baseline to 7 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between change in tremor amplitude and change in MEG connectivity	Pearson correlation coefficient evaluating the correlation between the change in wearable sensor-derived tremor amplitude (acceleration magnitude, m/s2) and the change in MEG connectivity metrics. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change in tremor frequency and change in MEG connectivity	Pearson correlation coefficient evaluating the correlation between the change in wearable sensor-derived tremor frequency (Hz) and the change in MEG connectivity metrics. Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change in gait parameters and change in MEG connectivity	Pearson correlation coefficient evaluating the correlation between the change in wearable sensor-derived gait parameters during a standardized walk test and the change in MEG connectivity metrics. Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change in postural sway and change in MEG connectivity	Pearson correlation coefficient evaluating the correlation between the change in wearable balance sensor-derived postural sway and the change in MEG connectivity metrics. Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change in 360-degree turn performance and change in MEG connectivity	Pearson correlation coefficient evaluating the correlation between the change in 360-degree turn performance (duration and number of steps), obtained from wearable sensors, and the change in MEG connectivity metrics. Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Change from Baseline in MEG-derived Functional Connectivity Strength	Assessment of the longitudinal change in MEG-derived functional connectivity strength over multiple time points. Unitless connectivity coefficient, reported as Z-score difference	Baseline (pre-treatment) to 6 months post-treatment
Change from Baseline in MEG-derived Directed Connectivity	Assessment of the longitudinal change in MEG-derived directed (effective) connectivity over multiple time points. Unitless influence coefficient, reported as Z-score difference	Baseline (pre-treatment) to 6 months post-treatment
Change from Baseline in MEG-derived Oscillatory Band Power	Assessment of the longitudinal change in MEG-derived oscillatory band (delta, theta, alpha, beta, gamma) power over multiple time points. Unit of Measure: fT²/Hz, reported as average of differences	Baseline (pre-treatment) to 6 months post-treatment
Change from Baseline in MEG-derived Network Coherence	Assessment of the longitudinal change in MEG-derived network coherence over multiple time points. Unit of Measure: Unitless coherence index, reported as Z-score difference	Baseline (pre-treatment) to 6 months post-treatment
Correlation between sonication energy and MEG connectivity	Pearson correlation coefficient evaluating the relationship between total sonication energy (Joules, J) and MEG-derived network measures including functional connectivity strength, directed connectivity, oscillatory band power, and network coherence. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Baseline (pre-treatment) to 6 months post-treatment	Pearson correlation coefficient evaluating the relationship between peak intra-procedural temperature (degrees Celsius, °C) and MEG-derived network measures including functional connectivity strength, directed connectivity, oscillatory band power, and network coherence. Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between number of sonications and MEG connectivity	Pearson correlation coefficient evaluating the relationship between the total number of sonications (count) and MEG-derived functional connectivity strength Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between lesion volume and MEG connectivity	Pearson correlation coefficient evaluating the relationship between lesion volume (cubic millimeters, mm³) and MEG-derived functional connectivity strength Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between patient age and MEG connectivity	Pearson correlation coefficient evaluating the relationship between patient age (years) and MEG-derived functional connectivity strength Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between disease duration and MEG connectivity	Pearson correlation coefficient evaluating the relationship between disease duration (years) and MEG-derived functional connectivity strength Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change from baseline in CRST score and MEG connectivity	Pearson correlation coefficient evaluating the relationship between change from baseline in tremor severity as measured by the Clinical Rating Scale for Tremor (CRST score, points) and MEG-derived functional connectivity strength. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change from baseline in tremor amplitude and MEG connectivity	Pearson correlation coefficient evaluating the relationship between change from baseline in wearable sensor-derived tremor amplitude (acceleration magnitude, m/s²) and MEG-derived functional connectivity strength. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change from baseline in tremor frequency and MEG connectivity	Pearson correlation coefficient evaluating the relationship between change from baseline in tremor frequency (Hertz, Hz), measured using a wearable sensor and MEG-derived functional connectivity strength. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change from baseline in gait speed and MEG connectivity	Pearson correlation coefficient evaluating the relationship between change from baseline in gait speed (meters per second, m/s) during a standardized walk test, obtained using wearable sensors and MEG-derived functional connectivity strength. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change from baseline in postural sway and MEG connectivity	Pearson correlation coefficient evaluating the relationship between change from baseline in postural sway (acceleration magnitude, m/s²) from wearable sensors and MEG-derived functional connectivity strength. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment
Correlation between change from baseline in 360-degree turn performance and MEG-derived functional connectivity strength.	Pearson correlation coefficient evaluating the relationship between change from baseline in 360-degree turn duration (seconds) and number of steps (count) from wearable sensors, and MEG-derived network measures. Unit of Measure: Correlation coefficient (r) ranging from -1 to 1	Baseline (pre-treatment) to 6 months post-treatment

Collaborators and Investigators

• Sponsor: University of Florida
• Investigators: Principal Investigator: Justin Hilliard, MD, University of Florida

Study record dates

Study Major Dates

• Study Start (Actual): February 17, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027

Study Registration Dates

• First Submitted: February 6, 2026
• First Submitted That Met QC Criteria: February 25, 2026
• First Posted (Actual): March 3, 2026

Study Record Updates

• Last Update Posted (Actual): May 1, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Essential Tremor; Health Care Quality, Access, and Evaluation; Investigative Techniques; Epidemiologic Methods; Diagnostic Techniques and Procedures; Diagnosis; Data Collection; Health Care Evaluation Mechanisms; Quality of Health Care; Public Health; Environment and Public Health; Tomography; Diagnostic Imaging; Surveys and Questionnaires; Magnetic Resonance Imaging
• Other Study ID Numbers: IRB202500103; OCR48773 (Other Identifier: University of Florida)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No