Frontiers in Human Neuroscience (Feb 2019)

Impaired Modulation of Corticospinal Excitability in Drug-Free Patients With Major Depressive Disorder: A Theta-Burst Stimulation Study

  • Philippe Vignaud,
  • Philippe Vignaud,
  • Caroline Damasceno,
  • Caroline Damasceno,
  • Emmanuel Poulet,
  • Emmanuel Poulet,
  • Emmanuel Poulet,
  • Jérôme Brunelin,
  • Jérôme Brunelin

DOI
https://doi.org/10.3389/fnhum.2019.00072
Journal volume & issue
Vol. 13

Abstract

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Impaired neural plasticity may be an important mechanism in the pathophysiology of major depressive disorder (MDD). Coupled with electromyography (EMG), repetitive transcranial magnetic stimulation (rTMS) is a useful tool to evaluate corticospinal excitability and cortical neuroplasticity in living humans. The goal of this study was to compare rTMS-induced cortical plasticity changes in patients with MDD and in healthy volunteers. In this single-blind controlled study, 11 drug-free patients with MDD and 11 matched healthy controls were analyzed. Cortical excitability, measured by the amplitude of motor evoked potentials (MEPs) evoked by single-pulse TMS, was assessed before and repeatedly after (for 30 min) participants received a single session of intermittent theta-burst stimulation (iTBS) and continuous TBS (cTBS). rTMS was applied over the left motor cortex using a neuronavigation system. Intensity was set at 80% of the active motor threshold (AMT). A large interindividual variability was observed after both iTBS and cTBS in the two groups. At the group level, we observed impaired iTBS-induced neuroplasticity in patients with MDD compared to that in controls. No differences were observed between the groups regarding cTBS-induced neuroplasticity. Our results suggest impaired long-term potentiation (LTP)-like mechanisms in MDD.Clinical Trial Registration: www.Clinicaltrials.gov, identifier #NCT02438163.

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