High-frequency EEG activity in epileptic encephalopathy with suppression-burst

Yoshihiro Toda, Katsuhiro Kobayashi, Yumiko Hayashi, Takushi Inoue, Makio Oka, Fumika Endoh, Harumi Yoshinaga, Yoko Ohtsuka

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Objective: We explored high-frequency activity in the suppression-burst (SB) pattern of interictal electroencephalogram (EEG) in early infantile epileptic encephalopathy including Ohtahara syndrome (OS) and early myoclonic encephalopathy (EME) to investigate the pathophysiological characteristics of SB. Methods: Subjects included six patients with the SB EEG pattern related to OS or EME (Group SB). The results were evaluated in comparison to tracé alternant (TA) observed during the neonatal period in nine patients to rule out possible nonspecific relationships between high-frequency activity and periodic EEG patterns (Group TA). EEG was digitally recorded with a sampling rate of 500. Hz and the analysis was performed in each of the particular bipolar channel-pairs. We visually selected 20 typical consecutive burst sections and 160 inter-burst sections for comparison from the sleep record of each patient and performed the time-frequency analysis. We investigated the maximum frequencies of power enhancement in each derivation in both groups. Results: In Group SB, a significant increase in power at a frequency of 80-150. Hz was observed in association with the bursts, particularly in the bilateral parieto-occipital derivations, in all patients. In Group TA, on the contrary, no significant increase in high-frequency power was found. The maximum frequencies of power enhancement were significantly higher in Group SB than in Group TA ( p<. 0.001 by repeated-measures ANOVA). Conclusion: Interictal high frequencies of up to 150. Hz were detected in the suppression-burst EEG patterns in epileptic encephalopathy in early infancy. Further studies will be necessary to identify the role of the interictal high-frequency activity in the pathophysiology of such early epileptic encephalopathy.

Original languageEnglish
Pages (from-to)230-236
Number of pages7
JournalBrain and Development
Issue number2
Publication statusPublished - Feb 1 2015


  • Early myoclonic encephalopathy
  • High-frequency oscillations
  • Ohtahara syndrome
  • Time-frequency analysis
  • Tracé alternant

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Developmental Neuroscience
  • Clinical Neurology


Dive into the research topics of 'High-frequency EEG activity in epileptic encephalopathy with suppression-burst'. Together they form a unique fingerprint.

Cite this