title: Prevalence and Characteristics of Vaccination Triggered Seizures in Dravet Syndrome in Hong Kong: A Retrospective Study.
abstract: Dravet syndrome is a rare epileptic encephalopathy characterized by treatment-resistant polymorphic seizures. Seizure onset usually occurs during the first year of life, and seizures are often associated with heat-related triggering factors (e.g., fever, photosensitivity, or hot bath). It has been reported that children with Dravet syndrome often present with recurrent febrile seizures and vaccination-related seizures.
  
  
  
  We analyzed the occurrence of vaccination-related seizures (defined as the development of a seizure within 48 hours post vaccination) in 54 patients with Dravet syndrome. Patients were divided into two groups according to whether seizures occurred within 48 hours of vaccination (i.e., vaccination-proximate group) or not (vaccination-distant group).
  
  
  
  There was no significant difference in the vaccination-proximate group and vaccination-distant group for the presence of SCN1A mutation. In our Dravet syndrome cohort, the vaccination-proximate group consisted of 17 (31.5%) patients with Dravet syndrome. Thus vaccination-related seizures are a common triggering factor in Dravet syndrome, reported in up to one third of our patients.
  
  
  
  Vaccination-related seizures may act as the triggering factor for the onset of seizures in children with Dravet syndrome, especially before the definitive diagnosis of Dravet syndrome can be made within the first year of life. We suggest further study of guidelines and protocols for the prevention and management of vaccination-related seizures in children with recurrent febrile seizures pending a definitive diagnosis of Dravet syndrome in the first 12 months of life.
authors.affiliation: Division of Paediatric Neurology/Developmental Behavioural Paediatrics/Neuro Habilitation, Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Polly Tsz Yan
authors.initials: PT
authors.lastname: Wong
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. Electronic address: vcnwong@hku.hk.
authors.forename: Virginia Chun-Nei
authors.initials: VC
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004831:Epilepsies, Myoclonic / Q000150:complications* / Q000453:epidemiology / Q000235:genetics / Q000276:immunology; D005260:Female; D006723:Hong Kong; D006801:Humans; D007223:Infant; D008297:Male; D062550:NAV1.1 Voltage-Gated Sodium Channel / Q000235:genetics; D015995:Prevalence; D012189:Retrospective Studies; D012640:Seizures / Q000453:epidemiology* / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D014611:Vaccination / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D062550:NAV1.1 Voltage-Gated Sodium Channel; C568242:SCN1A protein, human
keywords: Dravet syndrome; children; seizure; vaccination