title: Clinical features of narcolepsy in children vaccinated with AS03 adjuvanted pandemic A/H1N1 2009 influenza vaccine in England.
abstract: OBJECTIVE
  The aim of this study was to investigate whether children in England with narcolepsy who received the ASO3 adjuvanted pandemic A/H1N1 2009 influenza vaccine (Pandemrix) differed clinically from unvaccinated patients.
  
  
  METHODS
  A retrospective review was conducted in children with narcolepsy diagnosed by sleep centres and paediatric neurologists in 16 English hospitals. The inclusion criteria were patient age 4 to 18 years, onset of narcolepsy after January 2008, and diagnosis by the time of the key data-gathering visit in 2011. Clinical data came from hospital notes and general practitioner questionnaires. An expert panel validated the diagnoses.
  
  
  RESULTS
  Seventy-five patients with narcolepsy were identified (43 males, 32 females; mean age at onset 10y 4mo, range 3-18y). Of these patients, 11 received the Pandemrix vaccine before narcolepsy onset. On first presentation, there were more frequent reports of cataplexy, among other features, in vaccinated than in unvaccinated patients (82% vs 55%), but only excessive weight gain (55% vs 20%) was significantly more frequent (p=0.03). Facial hypotonia (p=0.03) and tongue protrusion (p=0.01) were eventually seen more frequently in vaccinated children. When considering patients diagnosed within a year of onset, vaccinated children were not diagnosed more rapidly than unvaccinated children.
  
  
  CONCLUSIONS
  Some symptoms and signs of narcolepsy were more frequently reported in Pandemrix-vaccinated patients. There was no evidence of the more rapid diagnosis in vaccinated patients that has been reported in Finland and Sweden.
authors.affiliation: PIND Research Group, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Winstone
authors.forename: Lesley
authors.initials: L
authors.lastname: Stellitano
authors.forename: Christopher
authors.initials: C
authors.lastname: Verity
authors.forename: Nick
authors.initials: N
authors.lastname: Andrews
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Miller
authors.forename: Julia
authors.initials: J
authors.lastname: Stowe
authors.forename: John
authors.initials: J
authors.lastname: Shneerson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D005152:Facial Muscles; D005260:Female; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects*; D008297:Male; D008499:Medical Records; D009123:Muscle Hypotonia / Q000209:etiology; D009290:Narcolepsy / Q000453:epidemiology* / Q000821:virology*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D014059:Tongue / Q000503:physiopathology; D014611:Vaccination / Q000009:adverse effects*
chemical_list: D007252:Influenza Vaccines; C556153:pandemrix