title: Somatosensory evoked high-frequency oscillations in migraine patients.
abstract: OBJECTIVE
  To explore additional evidence concerning generators of somatosensory evoked high-frequency oscillations (HFOs).
  
  
  METHODS
  We recorded HFOs in migraine patients. Subjects were 19 healthy normal subjects and 19 migraineurs. Electrical stimuli were delivered alternately to the right and left median nerves at their wrists. EEGs were recorded from C3'-Fz, C4'-Fz, Erb1-Erb2, Erb2-Erb1 and Cv6-Fz using a 0.3 Hz low-frequency filter and a 3000 Hz high-frequency filter. Responses to 5000 stimuli were averaged. For separation of HFOs from underlying N20, the digitized wide-band signals were digitally bandpass filtered (400-800 Hz) and averaged.
  
  
  RESULTS
  There were no significant differences in peak latencies and amplitudes for N9, N13, N20 and P25 components between normal controls and migraineurs. Root-mean-square amplitudes for HFOs in migraineurs were significantly diminished compared with normal controls.
  
  
  CONCLUSIONS
  A diminished inhibitory mechanism in the somatosensory system may exist in migraineurs. It remains to determine what cell populations contribute to generating HFOs.
  
  
  CONCLUSIONS
  This indicates that there is a dysfunction in cortical information processing in the somatosensory cortex of migraineurs.
authors.affiliation: Section of Environment and Health Science, Department of Biological Regulation, School of Health Sciences, Faculty of Medicine, Tottori University, 86 Nishimachi, Yonago, Japan. neurol@smile.ocn.ne.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakuma
authors.forename: Takao
authors.initials: T
authors.lastname: Takeshima
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ishizaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakashima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D004558:Electric Stimulation / Q000379:methods; D004569:Electroencephalography / Q000379:methods*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000503:physiopathology*; D013003:Somatosensory Cortex / Q000502:physiology*