title: Etiologies for seizures around the time of vaccination.
abstract: OBJECTIVE
  This study was an assessment of the incidence, course, and etiology of epilepsy with vaccination-related seizure onset in a population-based cohort of children.
  
  
  METHODS
  The medical data of 990 children with seizures after vaccination in the first 2 years of life, reported to the National Institute for Public Health and Environment in the Netherlands in 1997 through 2006, were reviewed. Follow-up data were obtained of children who were subsequently diagnosed with epilepsy and had had seizure onset within 24 hours after administration of an inactivated vaccine or 5 to 12 days after a live attenuated vaccine.
  
  
  RESULTS
  Follow-up was available for 23 of 26 children (median age: 10.6 years) with epilepsy onset after vaccination. Twelve children developed epileptic encephalopathy, 8 had benign epilepsy, and 3 had encephalopathy before seizure onset. Underlying causes were identified in 15 children (65%) and included SCN1A-related Dravet syndrome (formerly severe myoclonic epilepsy of infancy) or genetic epilepsy with febrile seizures plus syndrome (n = 8 and n = 1, respectively), a protocadherin 19 mutation, a 1qter microdeletion, neuronal migration disorders (n = 2), and other monogenic familial epilepsy (n = 2).
  
  
  CONCLUSIONS
  Our results suggest that in most cases, genetic or structural defects are the underlying cause of epilepsy with onset after vaccination, including both cases with preexistent encephalopathy or benign epilepsy with good outcome. These results have significant added value in counseling of parents of children with vaccination-related first seizures, and they might help to support public faith in vaccination programs.
authors.affiliation: Department of Medical Genetics, and n.verbeek@umcutrecht.nl.
authors.forename: Nienke E
authors.initials: NE
authors.lastname: Verbeek
authors.affiliation: Rudolph Magnus Institute of Neurosciences, Department of Child Neurology, University Medical Centre Utrecht, Utrecht, Netherlands; and.
authors.forename: Floor E
authors.initials: FE
authors.lastname: Jansen
authors.affiliation: National Institute for Public Health and Environment (RIVM), Bilthoven, Netherlands.
authors.forename: Patricia E
authors.initials: PE
authors.lastname: Vermeer-de Bondt
authors.affiliation: Department of Medical Genetics, and.
authors.forename: Carolien G
authors.initials: CG
authors.lastname: de Kovel
authors.affiliation: Department of Medical Genetics, and.
authors.forename: Marjan J A
authors.initials: MJ
authors.lastname: van Kempen
authors.affiliation: Department of Medical Genetics, and.
authors.forename: Dick
authors.initials: D
authors.lastname: Lindhout
authors.affiliation: Department of Medical Genetics, and.
authors.forename: Nine V A M
authors.initials: NV
authors.lastname: Knoers
authors.affiliation: National Institute for Public Health and Environment (RIVM), Bilthoven, Netherlands.
authors.forename: Nicoline A T
authors.initials: NA
authors.lastname: van der Maas
authors.affiliation: Department of Medical Genetics, and.
authors.forename: Eva H
authors.initials: EH
authors.lastname: Brilstra
mesh_terms: D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010375:Pedigree; D012640:Seizures / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics*; D013997:Time Factors; D014611:Vaccination / Q000009:adverse effects*
keywords: Dravet syndrome; PCDH19; SCN1A; epilepsy; etiology; seizure; vaccination