Quadripulse Stimulation: A Replication Study with A Newly Developed Stimulator

Abstract Quadripulse stimulation (QPS) is a promising patterned repetitive transcranial magnetic stimulation protocol, which allows the modulation of brain activity for over one hour after the stimulation. Recently, Deymed Diagnostic developed a new stimulator specifically designed to deliver QPS (DuoMAG MP-Quad, https://deymed.com/duomag-qps). The properties of the after-effect with this new stimulator were expected to parallel those obtained with another stimulator, the Magstim stimulator, which is currently used in the psychological and clinical research but not commercially available anymore. Nevertheless, experimental validation of DuoMAG MP-Quad was still warranted. We thus studied the QPS after-effect induced by this stimulator. As a result, motor evoked potentials were found to be bidirectionally modulated by the QPS for more than one hour, consistent with previous studies using the Magstim stimulator. Moreover, the degree of the after-effect was comparable to the after-effect induced by the other stimulator. Taken together, we conclude that the newly developed QPS stimulator is as effective as the Magstim stimulator.