title: Influence of phasic muscle contraction upon the quadripulse stimulation (QPS) aftereffects.
abstract: OBJECTIVE
  Contractions of the target muscle influence the aftereffects of repetitive transcranial magnetic stimulation (rTMS). The aim of this paper is to investigate whether or not voluntary hand movement influences the aftereffects of quadripulse stimulation (QPS) on the hand motor area.
  
  
  METHODS
  Thirteen healthy volunteers participated in this study. After QPS-5 or QPS-50 intervention over the motor hot spot for the right first dorsal interosseous muscle (FDI), the subjects performed voluntary motor tasks (opening-closing right hand movements at 1 Hz for 1 min). We compared the time courses of MEP size between the conditions with and without voluntary movement.
  
  
  RESULTS
  When the subjects moved their hands immediately after QPS, both QPS-5 and QPS-50 aftereffects were abolished. However, if they moved their hands at 20 min after QPS, the long-term aftereffects were preserved.
  
  
  CONCLUSIONS
  Voluntary hand movement applied after intervention influences QPS aftereffects, but the magnitude of the influence depends on the delay between QPS and the voluntary movement.
  
  
  CONCLUSIONS
  In the plasticity induction experiments, we should always be mindful of the fact that voluntary movement, including the target muscle, seriously influences the induced long-term effects of QPS.
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan. Electronic address: skado@fmu.ac.jp.
authors.forename: Suguru
authors.initials: S
authors.lastname: Kadowaki
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Enomoto
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Takenobu
authors.initials: T
authors.lastname: Murakami
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Setsu
authors.initials: S
authors.lastname: Nakatani-Enomoto
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ugawa
mesh_terms: D000328:Adult; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: De-depression; Depotentiation; Metaplasticity; Quadripulse stimulation (QPS); Transcranial magnetic stimulation; Voluntary movement