title: Clinical characteristics of late-onset neuromyelitis optica spectrum disorder: A multicenter retrospective study in Korea.
abstract: BACKGROUND
  There are currently few studies regarding late-onset neuromyelitis optica spectrum disorder (LO-NMOSD).
  
  
  OBJECTIVE
  We aimed to describe the characteristic features of patients with LO-NMOSD in Korea.
  
  
  METHODS
  Anti-aquaporin-4 antibody-positive patients with neuromyelitis optica spectrum disorder (NMOSD) from nine tertiary hospitals were reviewed retrospectively. The patients were divided into two groups based on age of onset: LO-NMOSD (⩾50 years of age at onset) versus early-onset neuromyelitis optica spectrum disorder (EO-NMOSD) (<50 years of age at onset). Clinical, laboratory, and magnetic resonance imaging (MRI) parameters were investigated.
  
  
  RESULTS
  Among a total of 147 patients (125 female; age of onset, 39.4 ± 15.2 years), 45 patients (30.6%) had an age of onset of more than 50 years. Compared to patients with EO-NMOSD, patients with LO-NMOSD had more frequent isolated spinal cord involvement at onset (64.4% vs 37.2%, p = 0.002), less frequent involvement of the optic nerve (40.0% vs 67.7%, p = 0.002), and less frequent brain MRI lesions (31.1% vs 50.0%, p = 0.034). Furthermore, there was a significant positive correlation between age of onset and Expanded Disability Status Scale (EDSS) score at last follow-up ( r = 0.246, p = 0.003).
  
  
  CONCLUSIONS
  Age of onset could be an important predictor of lesion location and clinical course of patients with NMOSD.
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea/Neuroscience Center, Samsung Medical Center, Seoul, Korea.
authors.forename: Jin Myoung
authors.initials: JM
authors.lastname: Seok
authors.affiliation: Department of Neurology, Bucheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Bucheon, Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Cho
authors.affiliation: Department of Neurology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Suk-Won
authors.initials: SW
authors.lastname: Ahn
authors.affiliation: Department of Neurology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea.
authors.forename: Eun Bin
authors.initials: EB
authors.lastname: Cho
authors.affiliation: Department of Neurology, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Min Su
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Neurology, Ajou University College of Medicine, Suwon, Korea.
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Joo
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Shin
authors.affiliation: Department of Neurology, Ulsan University Hospital, College of Medicine, University of Ulsan, Ulsan, Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Neurology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Byung-Jo
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, College of Medicine, Dong-A University, Busan, Korea.
authors.forename: Jong Kuk
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Neurology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
authors.forename: Joong-Yang
authors.initials: JY
authors.lastname: Cho
authors.affiliation: Department of Neurology, College of Medicine, Kosin University, Busan, Korea.
authors.forename: So-Young
authors.initials: SY
authors.lastname: Huh
authors.affiliation: Department of Neurology, School of Medicine, Eulji University, Seoul, Korea.
authors.forename: Ohyun
authors.initials: O
authors.lastname: Kwon
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea/Neuroscience Center, Samsung Medical Center, Seoul, Korea.
authors.forename: Kwang-Ho
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea/Neuroscience Center, Samsung Medical Center, Seoul, Korea.
authors.forename: Byoung Joon
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea/Neuroscience Center, Samsung Medical Center, Seoul, Korea.
authors.forename: Ju-Hong
authors.initials: JH
authors.lastname: Min
mesh_terms: D000328:Adult; D017668:Age of Onset; D051401:Aquaporin 4 / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000097:blood / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D051401:Aquaporin 4; D001323:Autoantibodies
keywords: Neuromyelitis optica (NMO); age of onset; late-onset neuromyelitis optica; neuromyelitis optica spectrum disorder (NMOSD); seropositive neuromyelitis optica spectrum disorder