title: Neuromyelitis optica in patients with myasthenia gravis who underwent thymectomy.
abstract: BACKGROUND
  Myasthenia gravis (MG) and neuromyelitis optica (NMO, also known as Devic disease) are rare autoimmune disorders, with upper-limit prevalence estimates in the general population of 15 per 100,000 and 5 per 100,000, respectively. To our knowledge, an association between these diseases has not been previously reported.
  
  
  OBJECTIVE
  To describe 4 patients with MG who developed NMO after thymectomy and to analyze possible causes of apparent increased prevalence of NMO among patients with MG.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Four patients with MG who underwent thymectomy.
  
  
  METHODS
  None.
  
  
  RESULTS
  The prevalence of MG within the published cohort of patients with NMO is more than 150 times higher than that in the general population.
  
  
  CONCLUSIONS
  Dysregulation of B-cell autoimmunity in myasthenia, possibly exacerbated by loss of control over autoreactive cells as a result of thymectomy, may predispose patients to the development of NMO.
authors.affiliation: Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10467, USA.
authors.forename: Ilya
authors.initials: I
authors.lastname: Kister
authors.forename: Sandeep
authors.initials: S
authors.lastname: Gulati
authors.forename: Cavit
authors.initials: C
authors.lastname: Boz
authors.forename: Roberto
authors.initials: R
authors.lastname: Bergamaschi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Piccolo
authors.forename: Guiseppe
authors.initials: G
authors.lastname: Piccolo
authors.forename: Joel
authors.initials: J
authors.lastname: Oger
authors.forename: Michael L
authors.initials: ML
authors.lastname: Swerdlow
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009157:Myasthenia Gravis / Q000150:complications / Q000473:pathology / Q000601:surgery*; D009471:Neuromyelitis Optica / Q000150:complications / Q000473:pathology / Q000601:surgery*; D013934:Thymectomy / Q000379:methods*; D016896:Treatment Outcome