title: Myelitis: Differences between multiple sclerosis and other aetiologies.
abstract: BACKGROUND
  Myelitis can appear as an initial symptom in the context of demyelinating diseases, systemic inflammatory diseases, and infectious diseases. We aim to analyse the differences between myelitis associated with multiple sclerosis (MS) and myelitis resulting from other aetiologies.
  
  
  METHODS
  Single-centre, retrospective analysis of patients with initial myelitis (2000-2013). Demographic, aetiological, clinical, radiological and prognostic variables were analysed and compared between patients with myelitis from MS and those with myelitis due to other aetiologies.
  
  
  RESULTS
  We included 91 patients; mean follow-up was 7 years. Diagnoses were as follows: MS 57 (63%), idiopathic transverse myelitis 22 (24%), associated systemic diseases 6 (7%), and other diagnoses (6%). Myelitis due to MS was associated with younger age of onset (35 ± 11 vs. 41 ± 13; P = .02), more pronounced sphincter involvement (40.4 vs. 27.3%; P=.05), greater multifocal involvement in spinal MRI (77.2 vs. 26.5%; P=.001), shorter lesion extension (2.4 vs. 1.4 vertebral segments; P=.001), cervical location (82.5 vs. 64.7%; P=.05) and posterior location (89.5 vs. 41.2%; P=.001). Myelitis due to other aetiologies more frequently showed anterior location (47.1 vs. 24.6%; P=.02), and central cord involvement (47.1 vs. 14.1%; P=.001), with better recovery at one year of follow up (EDSS 2.0 vs. 1.5; P=.01). Multivariate analysis showed that multifocal spinal cord involvement (OR 9.38, 95% CI: 2.04-43.1) and posterior cord involvement (OR 2.16, 95% CI: 2.04-2.67) were independently associated with the diagnosis of MS.
  
  
  CONCLUSIONS
  A high percentage of patients with an initial myelitis event will be diagnosed with MS. The presence of multifocal and posterior spinal cord lesions was significantly associated with the diagnosis of MS.
authors.affiliation: Servicio de Neurología, Departamento de Neurociencias, Hospital Universitari Germans Trias i Pujol, Badalona (Barcelona), España. Electronic address: silviapresasro@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Presas-Rodríguez
authors.affiliation: Servicio de Neurología, Departamento de Neurociencias, Hospital Universitari Germans Trias i Pujol, Badalona (Barcelona), España.
authors.forename: L
authors.initials: L
authors.lastname: Grau-López
authors.affiliation: Servicio de Neurología, Departamento de Neurociencias, Hospital Universitari Germans Trias i Pujol, Badalona (Barcelona), España.
authors.forename: J V
authors.initials: JV
authors.lastname: Hervás-García
authors.affiliation: Institut de Diagnòstic per la Imatge, Hospital Universitari Germans Trias i Pujol, Badalona (Barcelona), España.
authors.forename: A
authors.initials: A
authors.lastname: Massuet-Vilamajó
authors.affiliation: Servicio de Neurología, Departamento de Neurociencias, Hospital Universitari Germans Trias i Pujol, Badalona (Barcelona), España.
authors.forename: C
authors.initials: C
authors.lastname: Ramo-Tello
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology; D009187:Myelitis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult
keywords: Enfermedades sistémicas; Esclerosis múltiple; Idiopathic myelitis; Mielitis; Mielitis idiopáticas; Multiple sclerosis; Myelitis; Systemic diseases