title: Distinguishing Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion from Prolonged Febrile Seizures by Acute Phase EEG Spectrum Analysis.
abstract: BACKGROUND
  To differentiate the features of electroencephalography (EEG) after status epileptics in febrile children with final diagnosis of either febrile seizure (FS) or acute encephalopathy for an early diagnosis.
  
  
  METHODS
  We retrospectively collected data from 68 children who had status epilepticus and for whom EEGs were recorded within 120 h. These included subjects with a final diagnosis of FS (n = 20), epileptic status (ES; n = 11), acute encephalopathy with biphasic seizures and late reduced diffusion (AESD; n = 18), mild encephalopathy with a reversible splenial lesion (MERS; n = 7), other febrile encephalopathies (n = 10), hypoxic-ischemic encephalopathy (n = 1), and intracranial bleeding (n = 1). Initially, all EEGs were visually assessed and graded, and correlation with outcome was explored. Representative EEG epochs were then selected for quantitative analyses. Furthermore, data from AESD (n = 7) and FS (n = 16) patients for whom EEG was recorded within 24 h were also compared.
  
  
  RESULTS
  Although milder and most severe grades of EEG correlated with neurological outcome, the outcome of moderate EEG severity group was variable and was not predictable from usual inspection. Frequency band analysis revealed that solid delta power was not significantly different among the five groups (AESD, MERS, FS, ES and control), and that MERS group showed the highest theta band power. The ratios of delta/alpha and (delta + theta)/(alpha + beta) band powers were significantly higher in the AESD group than in other groups. The alpha and beta band powers in EEGs within 24 h from onset were significantly lower in the AESD group. The band powers and their ratios showed earlier improvement towards 24 h in FS than in AESD.
  
  
  CONCLUSIONS
  Sequential EEG recording up to 24 h from onset appeared to be helpful for distinction of AESD from FS before emergence of the second phase of AESD.
authors.affiliation: Department of Child Neurology, Institute of Neurological Science, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Oguri
authors.affiliation: Department of Child Neurology, Institute of Neurological Science, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: †Department of Pathobiological Science and Technology, School of Life Sciences, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Chisako
authors.initials: C
authors.lastname: Fukuda
authors.affiliation: ‡Department of Pediatrics, Shimane University Hospital, Izumo 693-8501, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Kishi
authors.affiliation: Department of Child Neurology, Institute of Neurological Science, Tottori University Faculty of Medicine, Yonago 683-8503, Japan; §Department of Pediatrics, Shimane Prefectural Center Hospital, Izumo 693-8555, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yokoyama
authors.affiliation: ||Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; ¶Department of Critical care Medicine, Fukuoka Children's Hospital, Fukuoka 813-0017, Japan.
authors.forename: Sooyoung
authors.initials: S
authors.lastname: Lee
authors.affiliation: ||Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; *Section of Pediatrics, Department of Medicine, Fukuoka Dental College, Fukuoka 814-0193, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Torisu
authors.affiliation: ††Department of Pediatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Toyoshima
authors.affiliation: ‡‡Department of Pediatrics, Matsue Red-Cross Hospital, Matsue 690-8506, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sejima
authors.affiliation: §§Department of Pediatrics, Tsuyama Chuo Hospital, Tsuyama 708-0841, Japan.
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Kaji
authors.affiliation: ||||Division of Neurology, Saitama Children's Medical Center, Saitama 339-8551, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Hamano
authors.affiliation: ¶¶Division of Child Neurology, Seirei-Hamamatsu General Hospital, Hamamatsu 430-8558, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Okanishi
authors.affiliation: **Department of Laboratory Medicine, Kyoto Min-iren Central Hostpial, Kyoto 604-8453, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tomita
authors.affiliation: Department of Child Neurology, Institute of Neurological Science, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Maegaki
keywords: acute encephalopathy; acute encephalopathy with biphasic seizures and late reduced diffusion (AESD); electroencephalography; febrile seizure; spectrum analysis