title: Electroencephalographic features of patients with SCN1A-positive Dravet syndrome.
abstract: OBJECTIVE
  The aim of this study was to characterize the awake EEG features of patients with SCN1A-positive Dravet syndrome.
  
  
  METHODS
  Between January 2002 and December 2012, clinical data of 37 SCN1A-positive Dravet syndrome patients were collected. The first interictal awake EEG features, hot water bath test induced ictal seizure patterns and the concomitant EEG results, as well as follow-up interictal awake EEG recordings were analyzed.
  
  
  RESULTS
  Thirty-seven interictal awake EEG recordings showed 43.2% had normal features, 43.2% had nonspecific findings, and 13.5% had abnormal epileptiform discharges. Ictal pleomorphic seizure types with a median number of three were recorded in 26 patients. In total, 42.3% exhibited myoclonic seizures as their first recognizable seizure type with simultaneous EEG findings characterized by generalized or focal spikes, generalized 2-3.5Hz spike and wave discharges, or generalized 2-3Hz high voltage slow waves, and 30.8% manifested atypical absence seizures with concomitant EEG results showing generalized or focal spikes. Fifteen patients had 45 follow-up interictal awake EEGs during a period of six years. The follow-up awake EEG recordings revealed 42.2% had normal features, 42.2% showed nonspecific findings, and 15.6% disclosed epileptiform discharges.
  
  
  CONCLUSIONS
  The initial and follow-up interictal awake EEG recordings showed normal results and nonspecific features in the majority of SCN1A-positive Dravet syndrome patients. Ictal electroencephalographic seizure types and concomitant EEG pictures were quite diverse and polymorphous. A low detection rate of interictal epileptiform abnormalities at awake stage might make patient management more challenging.
authors.affiliation: Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan; School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Hsiu-Fen
authors.initials: HF
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Taichung, Taiwan; School of Medicine, Chung Shan Medical University, Taichung, Taiwan. Electronic address: chi-cs@hotmail.com.
authors.forename: Ching-Shiang
authors.initials: CS
authors.lastname: Chi
authors.affiliation: Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Chi-Ren
authors.initials: CR
authors.lastname: Tsai
authors.affiliation: Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Chin-Hsuan
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, Tungs' Taichung Metroharbor Hospital, Taichung, Taiwan.
authors.forename: Chi-Chao
authors.initials: CC
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004831:Epilepsies, Myoclonic / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D062550:NAV1.1 Voltage-Gated Sodium Channel / Q000235:genetics*; D055815:Young Adult
chemical_list: D062550:NAV1.1 Voltage-Gated Sodium Channel; C568242:SCN1A protein, human
keywords: Dravet syndrome; EEG; SCN1A