title: Magnetic lumbosacral motor root stimulation with a flat, large round coil.
abstract: OBJECTIVE
  The aim of this paper is to develop a reliable method for supramaximal magnetic spinal motor root stimulation (MRS) for lower limb muscles using a specially devised coil.
  
  
  METHODS
  For this study, 42 healthy subjects were recruited. A 20-cm diameter coil designated as a Magnetic Augmented Translumbosacral Stimulation (MATS) coil was used. Compound muscle action potentials (CMAPs) were recorded from the abductor hallucis muscle. Their CMAPs were compared with those obtained by MRS using a conventional round or double coil and with those obtained using high-voltage electrical stimulation.
  
  
  RESULTS
  The MATS coil evoked CMAPs to supramaximal stimulation in 80 of 84 muscles, although round and double coils elicited supramaximal CMAPs in only 15 and 18 of 84 muscles, respectively. The CMAP size to the MATS coil stimulation was the same as that to high-voltage electrical motor root stimulation.
  
  
  CONCLUSIONS
  MATS coil achieved supramaximal stimulation of the lumbosacral spinal nerves.
  
  
  CONCLUSIONS
  The CMAPs to supramaximal stimulation are necessary for measurement of the amplitude and area for the detection of conduction blocks. The MATS coil stimulation of lumbosacral motor roots is a reliable method for measuring the CMAP size from lower limb muscles in spinal motor root stimulation.
authors.affiliation: Department of Neurology, Division of Neuroscience, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. hideyukimatsumoto@mail.goo.ne.jp
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Fitri
authors.initials: F
authors.lastname: Octaviana
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Hanajima
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terao
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yugeta
authors.forename: Masashi
authors.initials: M
authors.lastname: Hamada
authors.forename: Satomi
authors.initials: S
authors.lastname: Inomata-Terada
authors.forename: Setsu
authors.initials: S
authors.lastname: Nakatani-Enomoto
authors.forename: Shoji
authors.initials: S
authors.lastname: Tsuji
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ugawa
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001703:Biophysics; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods*; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008161:Lumbosacral Region; D008280:Magnetics / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation; D012680:Sensitivity and Specificity; D013116:Spinal Cord / Q000502:physiology; D013126:Spinal Nerve Roots / Q000502:physiology*; D055815:Young Adult