title: Clinical course of H1N1-vaccine-related narcolepsy.
abstract: To follow and analyze the clinical course and quality of life of Pandemrix H1N1-vaccine-related narcolepsy (pNT1).
  
  
  
  Twenty-six drug-naïve confirmed pNT1 subjects completed Epworth Sleepiness Scale (ESS), Ullanlinna Narcolepsy Scale (UNS), Swiss Narcolepsy Scale (SNS), Rimon's Brief Depression scale (RDS), and WHO-5 Well-being index questionnaires near the disease onset and in a follow-up a minimum of two years later. The number of cataplexies and body mass index (BMI) were recorded. The effects of hypocretin-1 levels and sleep recording results were analyzed. The findings at the follow-up visit were compared with 25 non-vaccine-related type 1 narcolepsy (NT1) subjects.
  
  
  
  In pNT1, RDS score decreased significantly (mean 10.2, SD 4.7 vs mean 6.7, SD 4.5, p = 0.003). Median of BMI increased from 20.8 kg m(-2) to 23.4 kg m(-2), p <0.001. There were no significant differences in other sleep scores. However, deviation and range in questionnaire scores at the follow-up were wide. Subjects with very low or undetectable hypocretin-1 levels had worse scores in UNS (mean 26.4, SD 6.95 vs mean 19.1, SD 3.83, p = 0.006) and ESS (mean 17.9, SD = 4.29 vs mean 14.1, SD = 3.70, p = 0.047) than those with hypocretin-1 levels of 20-110 pg/mL. Most disabling symptoms were excessive daytime sleepiness and disturbed sleep. There were no significant differences between the scores in pNT1 and NT1.
  
  
  
  Clinical course of pNT1 is heterogeneous but the evolution of pNT1 seems similar to NT1. Lower hypocretin levels in pNT1 are associated with a more severe phenotype.
authors.affiliation: Clinic of Neurology, Central Finland Central Hospital, Jyväskylä, Finland; Helsinki Sleep Clinic, Vitalmed Research Centre, Helsinki, Finland; Department of Neurological Sciences, University of Helsinki, Helsinki, Finland. Electronic address: tomi.sarkanen@ksshp.fi.
authors.forename: Tomi
authors.initials: T
authors.lastname: Sarkanen
authors.affiliation: Helsinki Sleep Clinic, Vitalmed Research Centre, Helsinki, Finland; Department of Neurological Sciences, University of Helsinki, Helsinki, Finland; Department of Clinical Neurophysiology, HUS Medical Imaging Center, Helsinki University Central Hospital, Finland.
authors.forename: Anniina
authors.initials: A
authors.lastname: Alakuijala
authors.affiliation: Helsinki Sleep Clinic, Vitalmed Research Centre, Helsinki, Finland; Department of Neurological Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Partinen
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000009:adverse effects*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control; D008297:Male; D009290:Narcolepsy / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D000068797:Orexins / Q000032:analysis / Q000134:cerebrospinal fluid; D017286:Polysomnography / Q000379:methods; D011795:Surveys and Questionnaires
chemical_list: D007252:Influenza Vaccines; D000068797:Orexins
keywords: Cataplexy; Narcolepsy; Pandemrix; Vaccine