Non-invasive stimulation through temporal interference to modulate essential tremor (TremorTIS (pilot))

Résumé de l'étude

Our pilot project aims to examine the effects of a relatively recent non-invasive brain stimulation technique, transcranial temporal interference stimulation (tTIS), which allows for neuromodulation of deep brain structures. We have chosen to use a relatively simple motor circuit model, that of essential tremor (ET), by targeting the ventral intermediate nucleus (VIM) of the thalamus with tTIS in patients with ET who are candidates for VIM thalamotomy using high-intensity focused ultrasound, guided by MRI (MRgFUS). The goal is to identify whether tTIS stimulation of the VIM can transiently modulate the characteristics of tremor, as measured using accelerometers, as proof of principle for the functioning of tTIS in humans.

(BASEC)

Intervention étudiée

The medical device under investigation is the "Isolated Bipolar Constant Current Simulator DS5" from Digitimer Ltd, which provides transcranial electrical stimulation known as temporal interference stimulation (tTIS). This is based on the administration of two high-frequency currents f1 and f2, in the kHz range, via two pairs of electrodes placed on the participant's scalp at a predefined location. These two frequencies interfere at a focal point, generating an electrical "envelope" based on the difference of the two high-frequency currents (Δf = f2 - f1) that oscillates within a physiological range (typically 1-100 Hz), allowing modulation of neurons. The main advantage of this method is the ability to modulate deep brain structures without training cortical neurons, due to the intrinsic properties of neuronal membranes acting as a "low-pass" filter that effectively filters frequencies f1 and f2. Until now, this medical device has been tested in various deep structures of the human brain (e.g., striatum, hippocampus, globus pallidus); however, the ventral intermediate nucleus (VIM) of the thalamus has never been targeted by tTIS to our knowledge. Our study therefore aims to test the possibility of modulating the VIM using tTIS in patients affected by essential tremor who are candidates for VIM thalamotomy using high-intensity focused ultrasound, guided by MRI (MRgFUS). This relatively simple motor model allows for proof of concept of the tTIS method in human subjects. If such proof is provided, this pilot study opens the possibility of conducting further randomized controlled studies to determine a stimulation protocol that could ultimately simulate the effect of MRgFUS pre-operatively, as well as identify potential post-MRgFUS adverse effects.

(BASEC)

Maladie en cours d'investigation

Essential tremor (ET)

(BASEC)

Sponsor

Prof. Christian Lüscher

(BASEC)

Nom du comité d'éthique approbateur (pour les études multicentriques, uniquement le comité principal)

Commission cantonale d'éthique de Genève

(BASEC)

Date d'approbation du comité d'éthique

30.01.2026

(BASEC)

Résultats de l'essai