Modulating motor cortical oscillation with coordinated reset multifocal transcranial magnetic stimulation.

Area of Science:

• Neuroscience
• Neuromodulation
• Motor Control

Background:

• The theory of coordinated reset (CR) stimulation suggests that multifocal, randomly ordered bursts can reduce oscillatory power in neural generators.
• Noninvasive neuromodulation techniques offer potential for modulating brain activity and improving motor function.

Purpose of the Study:

• To develop and evaluate a noninvasive coordinated multifocal burst stimulation (COMBS) system based on CR theory.
• To investigate the effects of COMBS on motor cortical excitability and oscillatory power during a finger-tapping task in healthy participants.

Main Methods:

• Developed a COMBS system using three synchronized repetitive transcranial magnetic stimulation (rTMS) devices.
• Recorded electroencephalography (EEG) and electromyography (EMG) in 16 healthy participants during a finger-tapping task before and after COMBS intervention.
• Assessed cortical excitability using measures like resting motor threshold, short-interval intracortical inhibition/facilitation, and cortical silent period in a separate group of 14 participants.

Main Results:

• COMBS did not alter resting oscillatory power at the targeted frequency.
• Significant increases in α-band power were observed during both preparation and movement stages of the finger-tapping task.
• Low β-band power increased during the movement stage, and low β-band event-related desynchronization was reduced.
• No significant changes in reaction time were found, but a trend towards a reduced error rate was observed.
• No significant changes in cortical excitability measures were detected after COMBS.

Conclusions:

• COMBS, a novel application of CR theory with multi-rTMS, can modulate cortical oscillatory power, particularly in the α and low β bands, during specific stages of motor tasks.
• While COMBS did not alter overall cortical excitability, its effects on specific oscillatory bands suggest potential for refining motor control.
• This study provides initial evidence for CR stimulation's capacity to modify motor cortical oscillations in a targeted manner.