Repetitive Peripheral Magnetic Stimulation Combined with Motor Imagery Changes Resting-State EEG Activity: A Randomized Controlled Trial

Abstract

Repetitive peripheral magnetic stimulation is a novel non-invasive technique for applying repetitive magnetic stimulation to the peripheral nerves and muscles. Contrarily, a person imagines that he/she is exercising during motor imagery. Resting-state electroencephalography can evaluate the ability of motor imagery; however, the effects of motor imagery and repetitive peripheral magnetic stimulation on resting-state electroencephalography are unknown. We examined the effects of motor imagery and repetitive peripheral magnetic stimulation on the vividness of motor imagery and resting-state electroencephalography. The participants were divided into a motor imagery group and motor imagery and repetitive peripheral magnetic stimulation group. They performed 60 motor imagery tasks involving wrist dorsiflexion movement. In the motor imagery and repetitive peripheral magnetic stimulation group, we applied repetitive peripheral magnetic stimulation to the extensor carpi radialis longus muscle during motor imagery. We measured the vividness of motor imagery and resting-state electroencephalography before and after the task. Both groups displayed a significant increase in the vividness of motor imagery. The motor imagery and repetitive peripheral magnetic stimulation group exhibited increased β activity in the anterior cingulate cortex by source localization for electroencephalography. Hence, combined motor imagery and repetitive peripheral magnetic stimulation changes the resting-state electroencephalography activity and may promote motor imagery.

Effects of neurofeedback training combined with transcranial direct current stimulation on motor imagery: A randomized controlled trial

“…Repeated MI improves the vividness of MI (Iso et al, 2021). Nevertheless, studies of MI with simultaneous action observation (Ono et al, 2013) and repetitive peripheral magnetic stimulation (Sawai et al, 2022) reported no difference in the improvement of MI vividness between groups compared to that in MI alone. Similarly, in this study, there was no difference between the NFB and the NFB + tDCS groups.…”

“…Participants rated the vividness by making a mark on a 100-mm horizontal line, where 0 equaled "not at all" and 100 equaled "very vivid image." MI vividness correlates with cortical excitability (Moriuchi et al, 2020) and has been used in MI studies involving healthy participants as a simple and subjective MI assessment (Iso et al, 2021;Sawai et al, 2022).…”

“…In the training phase, three sets of 20 imagery tasks were performed. Several MI studies consisted of short repetitions of the imagery and rest periods (Xie et al, 2021;Sawai et al, 2022); we followed a similar protocol. The degree of MI improves with its repetition (Pineda et al, 2003); therefore, few trials may erase the effect of tDCS.…”

“…Conversely, numerous trials can cause mental fatigue, which may reduce the degree of MI (Nakashima et al, 2021). Therefore, we set the number of trials at 60, which has been used in previous studies (Maghsoudi and Shalbaf, 2022;Sawai et al, 2022).…”

Motor Imagery-based Neurofeedback in Physiotherapy Practice

“…Motor imagery is known to improve performance [29] and has a motor-learning effect [30] even when the participant does not actually exercise. In addition, motor imagery has been supported from a neurological aspect, as there are areas where brain activity similar to that of actual exercise is observed [31], and resting EEG is altered by motor imagery [32]. On the basis of these background characteristics, motor imagery has been used in sports training for athletes [33] and in rehabilitation for stroke patients [34,35].…”