title: Neuromyelitis optica spectrum disorders in Algeria: A preliminary study in the region of Tizi Ouzou.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) is a disabling inflammatory condition that targets astrocytes in the optic nerves and spinal cord. Recent advances led to the individualization of a set of conditions now referred as NMO spectrum disorder (NMOSD).
  
  
  OBJECTIVE
  To describe the prevalence and characteristics of NMO SD in north Algeria.
  
  
  METHODS
  The present study is a retrospective and descriptive work which took place in Nedir Mohamed teaching hospital, Tizi-Ouzou, Algeria. 938 Medical files of patients with CNS inflammatory demyelinating diseases were reviewed then patients with optic neuritis and/or myelitis were preselected. Patients who met the 2015 neuromyelitis optica spectrum disorders criteria were selected and analyzed
  
  
  RESULTS
  08 Patients (3.4%) met the 2015 criteria for neuromyelitis optica spectrum disorders, 3/8 (37.5%) were positive to AQ4-IgG and 5/8 (62.5%) were negative. Mean age of onset was 29 years, female to male ratio was 3:1, cerebral MRI was normal in 75% of cases and longitudinally extensive transverse myelitis was present in 75% of cases. 37/232 Patients (15.9%) were considered at high risk of neuromyelitis optica spectrum disorders
  
  
  CONCLUSIONS
  The present study suggests that the spectrum of NMO disorders is a rare entity among patients with optic nerve and spinal cord demyelinating lesions in north Algeria. However, the lack of accurate AQ4-IgG test certainly underestimates its real prevalence.
authors.affiliation: Department of Neurology, Centre Hospitalo-universitaire Nedir Mohamed, Tizi-Ouzou, Algeria.
authors.forename: Smail
authors.initials: S
authors.lastname: Daoudi
authors.affiliation: Department of Neurology, Centre Hospitalo-universitaire Nedir Mohamed, Tizi-Ouzou, Algeria. Electronic address: bouzarmelissa1@gmail.com.
authors.forename: Melissa
authors.initials: M
authors.lastname: Bouzar
mesh_terms: D000328:Adult; D017668:Age of Onset; D000462:Algeria / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging / Q000453:epidemiology; D009471:Neuromyelitis Optica / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D012737:Sex Factors
keywords: AQP4 IgG; Algeria; Demyelinating diseases; IPND 2015 criteria; Myelitis; NMOSD; Optic neuritis