Individualized Beta Frequency Intermittent Theta Burst Stimulation Enhances Corticospinal Plasticity in Healthy...

Area of Science:

• Neuroscience
• Neurophysiology
• Brain Stimulation

Background:

• Intermittent theta burst stimulation (iTBS) modulates cortical excitability but shows high interindividual variability.
• Individualized beta-band frequency stimulation may enhance cortical plasticity.
• This study explores individualized iTBS for targeted cortical excitability.

Purpose of the Study:

• To investigate if iTBS at an individualized beta-band frequency enhances specific cortical excitability (L2/3 interneurons, L5 pyramidal neurons).
• To determine if individualized iTBS prolongs effects on cortical excitability and reduces interindividual variability.
• To compare individualized iTBS with conventional iTBS and sham stimulation.

Main Methods:

• 30 healthy participants underwent a randomized, cross-over design with individualized iTBS, conventional iTBS, and sham conditions.
• Individualized iTBS used peak beta-band corticomuscular coherence for frequency selection.
• Effects on motor-evoked potentials (MEPs) were assessed immediately and up to 60 minutes post-stimulation.

Main Results:

• Individualized iTBS significantly increased both PA-MEPs and LM-MEPs, with sustained effects up to 50 minutes.
• Conventional iTBS only showed an immediate increase in PA-MEPs and lacked sustained effects.
• The responder rate was higher for individualized iTBS (62.5%) compared to conventional iTBS (37.5%).

Conclusions:

• Individualized beta-band frequency iTBS enhances the duration of corticospinal excitability.
• This personalized approach reduces interindividual variability in response to iTBS.
• Improved specific cortical excitability may underlie the enhanced effects of individualized iTBS.