title: Clinical features of neuromyelitis optica in a large Japanese cohort: comparison between phenotypes.
abstract: OBJECTIVE
  To analyse clinicoepidemiological features of neuromyelitis optica in a large cohort and to compare the differences between onset age, gender and clinical phenotypes.
  
  
  METHODS
  Antiaquaporin-4 antibody (AQP4-ab) levels were tested in 2366 serum samples of patients diagnosed as having central nervous system inflammatory demyelinating disorders by their referring physicians. AQP4-ab was measured by indirect immunofluorescence staining using human AQP4-transfected HEK 293 cells. A blinded analysis was performed and was combined with clinical information.
  
  
  RESULTS
  A total of 583 patients (91.4% women) were AQP4-ab-positive. The average onset age was 42.9±15.9 years. According to MRI studies, spinal-cord lesions were detected in 85.3% of the patients, longitudinally extensive transverse myelitis in 72.7% and cerebral lesions in 51.1%. Unilateral or bilateral blindness was observed in 16.2% of patients, 19.8% were associated with Sjögren syndrome, and 13.6% were associated with thyroid diseases. Myelin basic protein was detected in the cerebrospinal fluid of 57.5% patients. In addition, men presented with an older onset age, a greater number of brainstem MRI lesions and positive myelin basic protein in the cerebrospinal fluid. All child-onset patients (<15 years, n=9) presented with optic neuritis as the first symptom, while older-onset patients presented with myelitis. Twenty patients initially developed limited brain lesions, and seven of these patients did not develop optic or spinal lesions during the 1-5-year follow-up period.
  
  
  CONCLUSIONS
  The clinical characteristics of AQP4-ab-positive patients were similar. However, optic neuritis was more common in paediatric patients, while myelitis was more common in older patients. A small number of patients exhibited only cerebral, brainstem, or cerebellar lesions during the initial several years and lower Extended Disability Status Scale scores.
authors.affiliation: Department of Neurology, Kanazawa Medical University, 11 Daigaku, Uchinadamachi, Kahokugun, Ishikawa, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Nagaishi
authors.forename: Mineo
authors.initials: M
authors.lastname: Takagi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Umemura
authors.forename: Masami
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsui
authors.forename: Masatoyo
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakimura
authors.forename: Keiko
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D017668:Age of Onset; D000906:Antibodies / Q000097:blood; D051401:Aquaporin 4 / Q000276:immunology; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D001921:Brain / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods; D009471:Neuromyelitis Optica / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000453:epidemiology* / Q000276:immunology / Q000473:pathology; D010641:Phenotype; D012727:Sex Characteristics; D013116:Spinal Cord / Q000473:pathology
chemical_list: D000906:Antibodies; D051401:Aquaporin 4; D015415:Biomarkers