Modulation of spinal cord excitability by subthreshold repetitive transcranial magnetic stimulation of the primary motor cortex in humans

作者：Antoni Valero‐Cabré, Massimiliano Oliveri, Massimo Gangitano, A. Pascual–Leone · 发表于：Neuroreport · 年份：2001 · DOI：10.1097/00001756-200112040-00048 · 被引用次数：79 · 研究领域：Transcranial Magnetic Stimulation Studies、Motor Control and Adaptation、Muscle activation and electromyography studies

Repetitive transcranial magnetic stimulation (rTMS) allows the modulation of intra-cortical excitability and may therefore affect the descending control of spinal excitability. We applied rTMS at subthreshold intensity and 1 Hz frequency for 10 min to the left primary motor cortex representation of the flexor carpi radialis muscle (FCR) in 10 subjects and assessed the H and M responses to median nerve stimulation before and after the rTMS. Following rTMS, H wave thresholds significantly reduced by approximately 20%. Maximal H but not M wave amplitude significantly increased over the baseline, so that H/M amplitude ratio was increased by 41%. Sham stimulation did not induce any noticeable change in M or H waves. Slow rTMS might facilitate monosynaptic spinal cord reflexes by inhibiting the cortico-spinal projections modulating spinal excitability.