Magnetic Resonance Imaging-Guided Temporal Interference Stimulation of the Cerebellar Fastigial Nucleus in Stroke Patients for Balance

Summary

This protocol describes a standardized, magnetic resonance imaging-guided temporal interference stimulation approach designed to selectively target the cerebellar fastigial nucleus in stroke patients. By enabling anatomically precise and reproducible deep cerebellar neuromodulation, this method seeks to enhance postural control and balance recovery.

Abstract

Lower limb motor and balance impairments are common dysfunctions after stroke. Although non-invasive brain stimulation has shown promise as an adjunct to neurorehabilitation, it remains limited to superficial cortical regions, instead of deep brain targets such as the cerebellar fastigial nucleus, which contributes to posture control and motor coordination. Temporal interference stimulation represents an emerging strategy for non-invasive brain stimulation for targeting deep neural structures. It delivers two high-frequency electric fields with slightly different carrier frequencies through the scalp. Computational models and early experimental studies suggest that temporal interference stimulation may preferentially modulate deep targets while reducing stimulation of superficial tissues. In this study, we introduce a standardized, image-guided protocol for cerebellar fastigial nucleus temporal interference stimulation in stroke patients. The protocol combines high-resolution structural magnetic resonance imaging, individualized electric field modelling, and computational optimization to design subject-specific electrode montages focusing toward the cerebellar fastigial nucleus. This protocol provides a reproducible framework for studying deep cerebellar neuromodulation and may support future mechanistic and rehabilitation studies of post-stroke motor and balance dysfunction.

Introduction

Lower limb motor and balance impairments are among the most common dysfunctions after stroke. These impairments remain major challenges for clinical rehabilitation. Despite advances in conventional rehabilitation strategies, recovery of postural control and gait is often incomplete. Non-invasive brain stimulation (NIBS) has therefore been investigated as a promising approach to stroke recovery. Clinical studies, including randomized controlled trials, suggest that techniques like repetitive transcranial magnetic stimulation (rTMS) can improve lower limb Fugl-Meyer scores and balance scales in chronic stroke patients by modulating neural networks involved in motor cont....

Protocol

Approval for the study protocol was obtained from the Institutional Review Board (IRB) or Ethics Committee. All study procedures involving human participants were conducted in strict compliance with the ethical principles outlined in the Declaration of Helsinki.

1. Participant Screening

1. Review the participant’s medical history to exclude contraindications, including pregnancy, epilepsy, implanted metallic or electronic devices (e.g., intracranial metallic foreign bodies, cardiac pacemakers, cochlear implants, etc.), intracranial hypertension, intracranial tumors, or skin lesions at electrode placement site....

Results

Electric Field Modeling Example
To evaluate whether the individualized MRI-guided workflow could achieve the study objective of steering temporal interference stimulation toward the cerebellar fastigial nucleus (FN), representative results were analyzed in a logical sequence from model generation to field localization. High-resolution T1-weighted MRI data were successfully segmented into six tissue compartments, enabling individualized electric field modeling for subsequent montage optimization

Discussion

Methodological overview and key implementation considerations
This study presents a standardized protocol for the non-invasive modulation of the cerebellar FN using individualized TI stimulation. By integrating high-resolution structural MRI, computational electric field modeling, and a multi-channel stimulation interface, the proposed protocol enables anatomically informed and precise targeting of the FN. This approach establishes a novel methodological framework for investigating the functional contributions of d.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
72-channel Electrode Cap	Suzhou NeuroDome Medical Technology Co., Ltd	Suzhou, China	72-point electrode cap for brain stimulation
Conductive Gel	Not applicable	Not applicable	Gel for enhancing electrode-skin contact
Flexible measuring tape	Not applicable	Not applicable	Used to measure head circumference for electrode cap fitting
NervioWeb software platform	Suzhou NeuroDome Medical Technology Co., Ltd	Suzhou, China	Online brain modulation experimental platform
NervioX-1000 stimulator	Suzhou NeuroDome Medical Technology Co., Ltd	Suzhou, China	Non-invasive deep brain stimulation system
Nuprep skin prep gel	Weaver and Company	Aurora, CO, USA	Abrasive paste for skin cleaning to enhance conductivity