The Positive Effects of Synchronized 5 Hz Repetitive Transcranial Magnetic Stimulation and Motor Imagery

The bimodal balance-recovery model suggests that intervention strategies should differ based on the competition or vicariation model. Current training methods are predominantly influenced by the competition model, resulting in limited benefits for motor rehabilitation. Transcranial magnetic stimulation (TMS) has the capacity to modulate neural plasticity. Motor imagery (MI) activates the same cortical areas as motor execution. Therefore, we applied 5 Hz repetitive magnetic stimulation (rTMS) synchronously with MI to investigate the combination effects. This study recruited 14 healthy subjects. 5 Hz rTMS was applied on right motor cortex, and MI was left grasping imagery. TMS-evoked electromyography (TMS-EMG) and electroencephalography (TMS-EEG) data were recorded before and after training to assess the effects. The results demonstrated a significant increase in the peak-to-peak value (PPV) of motor evoked potential (MEP) (p = 0.017) and a significant increase in the N15-P30 complex of TMS-evoked potentials (TEP) (p = 0.044) after MI-rTMS training, suggesting the enhancement in motor function. Furthermore, the N100 results of the active group exhibited bilateral suppression of GABAB-mediated inhibition (ROI2: p = 0.029, ROI5: p = 0.007), providing theoretical support for its application under the vicariation model. Correlations between MEP PPV and affected M1 N100 (r = -0.473, p = 0.013), as well as between MEP PPV and contralateral P180 (r = 0.314, p = 0.018), confirmed positive motor effects in both groups. Therefore, MI alone shows the lateralization intervention and MI-rTMS shows bilateral activation. This synchronous integration of rTMS and MI provides a novel motor training method tailored for the vicariation model of motor rehabilitation.Clinical Relevance- This synchronous integration of rTMS and MI provides a novel motor training method tailored for vicariation model of motor rehabilitation.