This study investigates the motor and non-motor effects of Low-Intensity Focused Ultrasound (LIFU) as a non-invasive neuromodulation technique in patients with essential tremor (ET) and refractory tremor. LIFU is a non-thermal, non-ablative form of transcranial focused ultrasound that modulates neural activity through mechanical mechanisms, including direct effects on neuronal membranes, alterations in membrane excitability, and modulation of synaptic transmission. Unlike high-intensity focused ultrasound (HIFU), which produces tissue ablation, LIFU induces reversible effects with a favorable safety profile, making it a promising candidate for non-invasive neuromodulation in movement disorders.
In this randomized, double-blind, sham-controlled, crossover trial, 20 patients with ET and refractory tremor will receive active LIFU targeting the ventral intermediate nucleus (VIM) of the thalamus and sham stimulation in separate sessions, separated by a washout period of at least 12 weeks. Clinical assessments using standardized and validated neurological scales will be performed before and after each session to evaluate changes in motor symptoms, tremor severity, quality of life, and non-motor features.
The primary outcome is the change in the Fahn-Tolosa-Marín Tremor Rating Scale (FTMTRS) and the Essential Tremor Rating Assessment Scale (TETRAS©). Secondary outcomes include the Patient Global Impression of Change (PGIC) and monitoring of adverse events.
This study is being conducted at the Movement Disorders Center of Hospital das Clínicas, University of São Paulo (HC-FMUSP), São Paulo, Brazil, and has been approved by the institutional ethics committee (CAPPesq; approval number 7.406.027).
Diagnosis of essencial Tremor.
Presence of clinically relevant tremor despite optimized pharmacological treatment.3. Age 18-80 years.4. Ability and willingness to provide written informed consent.5. Availability to attend all scheduled study visits at HC-FMUSP.6. Availability of a brain MRI suitable for neuronavigation planning
None
Crossover
Low-Intensity Focused Ultrasound (LIFU) - NeuroFUS PRO
DeviceNon-invasive transcranial neuromodulation using a focused ultrasound transducer (NeuroFUS PRO, Brainbox Ltd., UK) operating at 500 kHz. Pulsed ultrasound is delivered in two 10-minute applications separated by a 20-minute interval, targeting the VIM of the thalamus under MRI-based neuronavigation. Parameters: 5 ms pulse width, 10 Hz PRF, 5% duty cycle, ISPPA 30 W/cm².
Low-Intensity Focused Ultrasound (LIFU) - NeuroFUS PRO
DeviceNon-invasive transcranial neuromodulation using a focused ultrasound transducer (NeuroFUS PRO, Brainbox Ltd., UK) operating at 500 kHz. Pulsed ultrasound is delivered in two 10-minute applications separated by a 20-minute interval, targeting the VIM of the thalamus under MRI-based neuronavigation. Parameters: 5 ms pulse width, 10 Hz PRF, 5% duty cycle, ISPPA 30 W/cm²
Change in the Fahn-Tolosa-Marín Tremor Rating Scale (FTMTRS) and the Essential Tremor Rating Assessment Scale (TETRAS©).
Fahn-Tolosa-Marín (FTM) Tremor Rating Scale Total Score is a validated scale assessing tremor severity, including tremor amplitude, functional disability, and impact on activities of daily living across multiple body regions. The total score ranges from 0 to 144, with higher scores indicating greater tremor severity. Essential Tremor Rating Assessment Scale (TETRAS) Total Score is a validated scale designed specifically for Essential Tremor, assessing tremor severity and functional disability. Higher scores indicate greater tremor severity. The total score ranges from 0 to 112, with with higher scores indicating greater tremor severity.
Application of the Patient Global Impression of Change (PGIC) and assessment of the number and type of adverse events
Application of the Patient Global Impression of Change to assess the participant's overall perception of improvement or worsening of tremor symptoms following the intervention and assessment of the number and type of adverse events occurring during the study period to evaluate the safety of the intervention.
Click on the lead sponsor to view all of their trials.
This trial is not recruiting at the moment. You can still explore other options:
