title: Discriminating long myelitis of neuromyelitis optica from sarcoidosis.
abstract: OBJECTIVE
  To compare longitudinally extensive myelitis in neuromyelitis optica spectrum disorders (NMOSD) and spinal cord sarcoidosis (SCS).
  
  
  METHODS
  We identified adult patients evaluated between 1996 and 2015 with SCS or NMOSD whose first myelitis episode was accompanied by a spinal cord lesion spanning ≥3 vertebral segments. All NMOSD patients were positive for aquaporin-4-immunoglobulin G, and all sarcoidosis cases were pathologically confirmed. Clinical characteristics were evaluated. Spine magnetic resonance imaging was reviewed by 2 neuroradiologists.
  
  
  RESULTS
  We studied 71 patients (NMOSD, 37; SCS, 34). Sixteen (47%) SCS cases were initially diagnosed as NMOSD or idiopathic transverse myelitis. Median delay to diagnosis was longer for SCS than NMOSD (5 vs 1.5 months, p < 0.01). NMOSD myelitis patients were more commonly women, had concurrent or prior optic neuritis or intractable vomiting episodes more frequently, had shorter time to maximum deficit, and had systemic autoimmunity more often than SCS (p < 0.05). SCS patients had constitutional symptoms, cerebrospinal fluid (CSF) pleocytosis, and hilar adenopathy more frequently than NMOSD (p < 0.05); CSF hypoglycorrhachia (11%, p = 0.25) and elevated angiotensin-converting enzyme (18%, p = 0.30) were exclusive to SCS. Dorsal cord subpial gadolinium enhancement extending ≥2 vertebral segments and persistent enhancement >2 months favored SCS, and ringlike enhancement favored NMOSD (p < 0.05). Maximum disability was similar in both disorders.
  
  
  CONCLUSIONS
  SCS is an under-recognized cause of longitudinally extensive myelitis that commonly mimics NMOSD. We identified clinical, laboratory, systemic, and radiologic features that, taken together, help discriminate SCS from NMOSD.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.
authors.forename: Eoin P
authors.initials: EP
authors.lastname: Flanagan
authors.affiliation: Radiology, Mayo Clinic, Rochester, MN.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kaufmann
authors.affiliation: Radiology, Mayo Clinic, Rochester, MN.
authors.forename: Karl N
authors.initials: KN
authors.lastname: Krecke
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Aksamit
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.|Laboratory Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Pittock
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.
authors.forename: B Mark
authors.initials: BM
authors.lastname: Keegan
authors.affiliation: Anatomic Pathology, Mayo Clinic, Rochester, MN.
authors.forename: Caterina
authors.initials: C
authors.lastname: Giannini
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.
authors.forename: Brian G
authors.initials: BG
authors.lastname: Weinshenker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000175:diagnosis*; D015203:Reproducibility of Results; D012507:Sarcoidosis / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013118:Spinal Cord Diseases / Q000175:diagnosis*; D063189:Symptom Assessment / Q000379:methods; D055815:Young Adult