title: Distinguishing optic neuritis in neuromyelitis optica spectrum disease from multiple sclerosis: a novel magnetic resonance imaging scoring system.
abstract: BACKGROUND
  The management of acute optic neuritis differs according to the underlying etiology and techniques which may help with early differential diagnosis are therefore of considerable value.
  
  
  OBJECTIVE
  We wanted to determine if multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) could be differentiated on the basis of neuroimaging abnormalities of the anterior visual pathways following an episode of optic neuritis.
  
  
  METHODS
  Magnetic resonance imaging (MRI) findings of 27 patients diagnosed with MS (n = 15) or NMOSD (n = 12), who presented with acute isolated optic neuritis over a 3-year period, were reviewed retrospectively. The extent and location of inflammation along the anterior visual pathways were analyzed. A novel scoring system was devised, based upon the number of anatomical segments involved.
  
  
  RESULTS
  Patients with NMOSD had a relative risk of 7.5 (confidence interval: 0.3-17.3) of having a score of 4 or more. Only NMOSD patients were found to have a score of 6 or higher. A trend for more posterior involvement of the anterior visual pathways was noted in the NMOSD group.
  
  
  CONCLUSIONS
  This pilot study suggests that the MRI-based scoring system described here may aid in distinguishing patients with optic neuritis who have MS vs NMOSD. Visual pathway inflammation in NMOSD patients appears to be more extensive than in MS, mirroring the longitudinally extensive spinal cord lesions found in neuromyelitis optica.
authors.affiliation: Department of Neuro-Ophthalmology, Moorfields Eye Hospital, London, United Kingdom.
authors.forename: Mithu
authors.initials: M
authors.lastname: Storoni
authors.forename: Indran
authors.initials: I
authors.lastname: Davagnanam
authors.forename: Mark
authors.initials: M
authors.lastname: Radon
authors.forename: Ata
authors.initials: A
authors.lastname: Siddiqui
authors.forename: Gordon T
authors.initials: GT
authors.lastname: Plant
mesh_terms: D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D009103:Multiple Sclerosis / Q000150:complications*; D009471:Neuromyelitis Optica / Q000175:diagnosis* / Q000209:etiology*; D009902:Optic Neuritis / Q000175:diagnosis* / Q000209:etiology*; D010865:Pilot Projects; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014795:Visual Pathways / Q000503:physiopathology