O205 Motor event-related desynchronization/synchronization (ERD/ERS) is modulated by transcranial static magnetic field stimulation (tSMS)

Abstract

Objectives There is a growing interest about the potential use of non-invasive neuromodulation as treatment for different neurologic and psychiatric conditions. Transcranial static magnetic field stimulation (tSMS) is very simple to use and has shown significant effects on cortical excitability. Our aim was to analyze the effect of tSMS on movement-related cortical oscillatory activity. Methods We performed a randomized parallel sham-controlled study in healthy volunteers to investigate the changes in alpha and beta motor ERD/ERS induced by 30-min tSMS of the motor cortex. We recorded 6 EEG channels from 20 healthy volunteers who performed a minimum of 100 hand ballistic movements, before and after stimulation (tSMS or sham stimulation in two different sessions). ERD/ERS was computed by means of Gabor transforms. Results We observed a reduction of the amplitude of the alpha ERD and alpha ERS after tSMS, that was not observed after sham stimulation. The effect of tSMS lasted for at least 30 min. There was no effect on beta ERD/ERS. Discussion tSMS over the motor cortex has been shown to decrease cortical excitability as measured by motor evoked potentials (MEPs) induced with transcranial magnetic stimulation. Our results show that it also has a selective effect on the oscillatory behaviour of the motor cortex. Conclusions Alpha motor ERD/ERS is modulated by transcranial static magnetic field stimulation, while beta ERD/ERS is not. Significance The changes induced by tSMS in the motor cortex include dynamic modulation of cortical activity.