title: Somatosensory-evoked potential modulation by quadripulse transcranial magnetic stimulation in patients with benign myoclonus epilepsy.
abstract: OBJECTIVE
  In patients with benign myoclonus epilepsy (ME), giant sensory-evoked potential (SEP) reflects the hyperexcitability of the sensory cortex. The aim of this study was to compare the effect of quadripulse transcranial magnetic stimulation (QPS) on the median nerve SEP between ME patients and healthy subjects.
  
  
  METHODS
  Ten healthy volunteers and six ME patients with giant SEP participated in this study. QPSs at interpulse intervals (IPIs) of 5, 30, 50, 100, 500 and 1250 ms were applied over the left primary motor cortex (M1) for 30 min. The peak-to-peak amplitudes of N20 to P25 (N20-P25) and P25 to N33 (P25-N33) components were measured at the left somatosensory cortex.
  
  
  RESULTS
  In healthy participants, the P25-N33 was bidirectionally modulated by QPS over M1, following the Bienenstock-Cooper-Munro (BCM) theory. The N20-P25 was not affected by any QPSs. In ME patients, the giant P25-N33 was potentiated after any QPSs. Furthermore, the N20-P25 was also potentiated after QPS at IPIs of 5, 30, 50 100 or 500 ms.
  
  
  CONCLUSIONS
  In ME patients, the cascade for long-term depression-like effects may be impaired.
  
  
  CONCLUSIONS
  The giant SEP was furthermore enhanced by QPS.
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: setsu-tky@umin.ac.jp.
authors.forename: Setsu
authors.initials: S
authors.lastname: Nakatani-Enomoto
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Neurology, Kitasato University School of Medicine, Kanagawa, Japan. Electronic address: hanajima-tky@umin.ac.jp.
authors.forename: Ritstuko
authors.initials: R
authors.lastname: Hanajima
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: mhamada-tky@umin.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Hamada
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: saccade@hotmail.co.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terao
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: hideyukimatsumoto.jp@gmail.com.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Research Fellow of the Japan Society for the Promotion of Science, Japan Society for the Promotion of Science, Tokyo, Japan. Electronic address: you_shirota@yahoo.co.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Shirota
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: oominami-tky@umin.ac.jp.
authors.forename: Shinya
authors.initials: S
authors.lastname: Ohminami
authors.affiliation: Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: okabes@hotmail.com.
authors.forename: Shingo
authors.initials: S
authors.lastname: Okabe
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan. Electronic address: masakihirose1977@yahoo.co.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Hirose
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan. Electronic address: knaka0325@yahoo.co.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Rehabilitation, Tohoku Bunka Gakuen University, Miyagi, Japan. Electronic address: furu@rehab.tbgu.ac.jp.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Furubayashi
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Neurology - Center for Movement Disorders and Neuromodulation, Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany. Electronic address: StefanJun.Groiss@med.uni-duesseldorf.de.
authors.forename: Stefan Jun
authors.initials: SJ
authors.lastname: Groiss
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan. Electronic address: skoba-tky@umin.ac.jp.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan. Electronic address: mochizuki-h@umin.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mochizuki
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan. Electronic address: enomoto-tky@umin.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Enomoto
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan; Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; JST, Research Seeds Program, Fukushima, Japan. Electronic address: ugawa-tky@umin.net.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ugawa
mesh_terms: D000328:Adult; D000368:Aged; D004831:Epilepsies, Myoclonic / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013003:Somatosensory Cortex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Benign myoclonus epilepsy; Long-term depression (LTD); Long-term potentiation (LTP); Quadripulse transcranial magnetic stimulation (QPS); Somatosensory-evoked potential (SEP)