Low-frequency rTMS inhibitory effects in the primary motor cortex: Insights from TMS-evoked potentials

6533b871fe1ef96bd12d1bf1

RESEARCH PRODUCT

Low-frequency rTMS inhibitory effects in the primary motor cortex: Insights from TMS-evoked potentials

Demis Basso Elias Paolo Casula Elias Paolo Casula Giorgio Arcara Vincenza Tarantino Giuliana Marino Gianna Toffolo John C. Rothwell Patrizia Ebisiacchi

subject

Adult Male Cognitive Neuroscience medicine.medical_treatment TMS; EEG; Inhibition; TEPs; N100; GABAb Stimulation Electroencephalography Inhibitory postsynaptic potential behavioral disciplines and activities TMS; EEG; inhibition; GABAb; N100 Young Adult medicine Humans EEG N100 Evoked Potentials Inhibition Visual Cortex N100 Settore M-PSI/02 - Psicobiologia E Psicologia Fisiologica medicine.diagnostic_test TEPs musculoskeletal neural and ocular physiology Motor Cortex Electroencephalography Neural Inhibition Transcranial Magnetic Stimulation Transcranial magnetic stimulation TEP Visual cortex medicine.anatomical_structure nervous system Neurology TMS GABAb Female Evoked Potential Primary motor cortex Psychology Neuroscience psychological phenomena and processes Human Motor cortex

description

The neuromodulatory effects of repetitive transcranial magnetic stimulation (rTMS) have been mostly investigated by peripheral motor-evoked potentials (MEPs). New TMS-compatible EEG systems allow a direct investigation of the stimulation effects through the analysis of TMS-evoked potentials (TEPs).We investigated the effects of 1-Hz rTMS over the primary motor cortex (M1) of 15 healthy volunteers on TEP evoked by single pulse TMS over the same area. A second experiment in which rTMS was delivered over the primary visual cortex (V1) of 15 healthy volunteers was conducted to examine the spatial specificity of the effects. Single-pulse TMS evoked four main components: P30, N45, P60 and N100. M1-rTMS resulted in a significant decrease of MEP amplitude and in a significant increase of P60 and N100 amplitude. There was no effect after V1-rTMS.1-Hz rTMS appears to increase the amount of inhibition following a TMS pulse, as demonstrated by the higher N100 and P60, which are thought to originate from GABAb-mediated inhibitory post-synaptic potentials. Our results confirm the reliability of the TMS-evoked N100 as a marker of cortical inhibition and provide insight into the neuromodulatory effects of 1-Hz rTMS. The present finding could be of relevance for therapeutic and diagnostic purposes. © 2014 Elsevier Inc.

year	journal	country	edition	language
2014-01-01	NeuroImage

https://doi.org/10.1016/j.neuroimage.2014.04.065