title: High-frequency oscillations in idiopathic partial epilepsy of childhood.
abstract: OBJECTIVE
  We explored high-frequency oscillations (HFOs) in scalp sleep electroencephalography (EEG) studies of patients with idiopathic partial epilepsy (IPE) of childhood in order to obtain a better understanding of the pathologic mechanisms underlying IPE.
  
  
  METHODS
  The subjects were 45 patients, including 32 with benign childhood epilepsy with centrotemporal spikes (BCECTS) and 13 with Panayiotopoulos syndrome (PS). A total of 136 EEG records were investigated through temporal expansion and filtering of traces and time-frequency spectral analysis.
  
  
  RESULTS
  HFOs with frequency of 93.8-152.3 Hz (mean 126.2 ± 13.6 Hz) in the band of ripples were detected in association with spikes in 97 records (71.3%). Time from last seizure to the EEG recording was significantly shorter in those with spike-related HFOs than in the EEG recordings with spikes without HFOs (p = 0.006). Although time from last seizure reflects age, age at the time of recording was not significantly different between EEG studies with and without HFOs. Peak-power values of the high-frequency spots in time-frequency spectra were significantly negatively correlated with time from last seizure (R(2) = 0.122, p < 0.001) but not with age at the time of recording. Peak frequencies of the high-frequency spectral spots were not significantly correlated with age at the time of recording or with time from last seizure.
  
  
  CONCLUSIONS
  The close relationship between the generation of spike-related HFOs and the period of active seizure occurrence indicated that HFOs may tell us more about epileptogenicity in IPE than the spikes themselves. Because there is a spectrum of pediatric epileptic disorders extending from the benign end of BCECTS to the encephalopathic end of epilepsy with continuous spike-waves during slow-wave sleep (CSWS), and HFOs that have already been detected in association with CSWS were more prominent than HFOs in IPE, intense spike-related HFOs may indicate poor prognosis.
authors.affiliation: Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan. k_koba@md.okayama-u.ac.jp
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Harumi
authors.initials: H
authors.lastname: Yoshinaga
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Toda
authors.forename: Takushi
authors.initials: T
authors.lastname: Inoue
authors.forename: Makio
authors.initials: M
authors.lastname: Oka
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ohtsuka
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001921:Brain / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic