A systematic review on multifocal non-invasive brain stimulation on motor function enhancement

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Neuromodulation

Background:

• Multifocal non-invasive brain stimulation (NIBS) is a promising technique for modulating motor functions by stimulating multiple brain areas simultaneously.
• However, the precise effectiveness and underlying mechanisms of multifocal NIBS remain incompletely understood.
• This systematic review addresses the current state of knowledge regarding multifocal NIBS for motor recovery.

Purpose of the Study:

• To systematically evaluate the effectiveness of multifocal non-invasive brain stimulation (NIBS) in enhancing motor recovery.
• To analyze the impact of targeted brain regions and stimulation protocols on outcomes.
• To assess both behavioral and neurophysiological results of multifocal NIBS interventions.

Main Methods:

• A systematic literature search was conducted across major databases (PubMed, EMBASE, Cochrane Library, Scopus, Web of Science) up to February 10, 2025.
• Included studies involved human participants receiving concurrent dual-site or multifocal NIBS with pre- and post-intervention behavioral assessments.
• Studies employing deep brain stimulation, sequential stimulation, or case reports were excluded, following PRISMA 2020 guidelines.

Main Results:

• Nine studies met the inclusion criteria, primarily targeting the dorsolateral prefrontal cortex and primary motor cortex.
• Neurophysiological data (EEG, fMRI) suggested network-level modulations.
• Behavioral outcomes were variable, with some studies reporting improvements in response inhibition and motor learning, while others showed no significant difference compared to sham stimulation.

Conclusions:

• Multifocal NIBS demonstrates potential as a therapeutic strategy for motor function, but its efficacy is not yet definitively established.
• Inconsistent results, small sample sizes, and varied study designs limit current conclusions.
• Future research should prioritize larger, multi-arm trials incorporating neurophysiological biomarkers to clarify the therapeutic potential of multifocal NIBS.