title: F-wave suppression induced by suprathreshold high-frequency repetitive trascranial magnetic stimulation in poststroke patients with increased spasticity.
abstract: OBJECTIVE
  High-intensity and high-frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex was carried out in poststroke patients with increased spasticity, and the changes in F-wave parameters in comparison with M-wave parameters induced by rTMS were examined.
  
  
  METHODS
  Ten-hertz rTMS pulses were delivered to the primary motor cortex of the lesion side at 110% intensity of the resting motor threshold, and F-waves were obtained from the first dorsal interosseous muscle. F-waves were recorded before (pre-stim) and immediately after the end of rTMS (post-stim) in poststroke patients.
  
  
  RESULTS
  F-wave persistence and F/M Amp.Ratio increased significantly in patients with lesions in upper motor tract as compared with healthy subjects (Wilcoxon rank sum test, p = 0.00023 and p = 0.0073, respectively). After the rTMS application, both F-wave persistence and F/M Amp.Ratio decreased significantly (paired t-test, p = 0.0095 and p = 0.037, respectively). However, the F-wave amplitude did not show a statistically significant variance in poststroke patients.
  
  
  CONCLUSIONS
  High-frequency suprathreshold rTMS may suppress the F-waves by enhancing the inhibitory effect on spinal excitability through the corticospinal tract, and F-wave persistence and F/M Amp.Ratio can be used to determine the effect of rTMS on patients with increased spasticity.
authors.affiliation: Division of Applied System Neuroscience, Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Sidikejiang
authors.initials: S
authors.lastname: Wupuer
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Katayama
authors.forename: Hara
authors.initials: H
authors.lastname: Motohiko
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sekiguchi
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Toshiki
authors.initials: T
authors.lastname: Obuchi
authors.forename: Chikashi
authors.initials: C
authors.lastname: Fukaya
mesh_terms: D000328:Adult; D000368:Aged; D055592:Biophysical Phenomena / Q000502:physiology*; D001703:Biophysics; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009128:Muscle Spasticity / Q000209:etiology / Q000473:pathology*; D020521:Stroke / Q000150:complications; D050781:Transcranial Magnetic Stimulation