title: Acute disseminated encephalomyelitis in China, Singapore and Japan: a comparison with the USA.
abstract: Ethnicity-related differences in the incidence of acute disseminated encephalomyelitis (ADEM) and other demyelinating diseases including multiple sclerosis and neuromyelitis optica spectrum disorders have been reported. Little is reported on the influence of ethnicity and geographical location in ADEM.
  
  
  
  Medical records of patients who presented with ADEM (ICD-9 323.61 and 323.81) at large referral hospitals in China, Singapore and Japan (years 1992-2015) were retrospectively reviewed and data were collected in a centralized database. Presenting features and outcomes of ADEM were compared between this multi-country Asian cohort and a uniformly collected US cohort using risk differences and risk ratios. Both cohorts were standardized to a 35% pediatric population to facilitate the comparison.
  
  
  
  There were 83 Asian patients (48 male, 16 pediatric) followed for a median of 2 (25th-75th percentile 1-10) months. Asian patients exhibited a 26% higher prevalence of spinal cord involvement on magnetic resonance imaging [95% confidence interval (CI) 0-52%; P = 0.05; 63% vs. 37%], a 39% lower prevalence of preceding events (95% CI 12-65%; P < 0.01; 33% vs. 72%) and a 23% lower prevalence of corpus callosum involvement (95% CI 7-39%; P < 0.01; 8% vs. 31%). No difference was observed between the two cohorts in the probability of relapse over the first year after disease onset.
  
  
  
  It is hypothesized that the high proportion of Asian patients with spinal cord lesions relates to genetic vulnerability or the higher incidence of neuromyelitis optica spectrum disorders in Asia or could be a spurious association. ADEM presentations most probably vary across geographical settings or ethnicities.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.|Academic Medical Center - University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: D L H
authors.initials: DL
authors.lastname: Koelman
authors.affiliation: Group in Biostatistics, University of California, Berkeley, Berkeley, CA, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Benkeser
authors.affiliation: Department of Neurology, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore, Singapore.
authors.forename: S X
authors.initials: SX
authors.lastname: Neo
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore, Singapore.
authors.forename: K
authors.initials: K
authors.lastname: Tan
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Katsuno
authors.affiliation: Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Sobue
authors.affiliation: Department of Developmental Disability Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Natsume
authors.affiliation: Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chahin
authors.affiliation: Department of Neurology, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Mar
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: A
authors.initials: A
authors.lastname: Venkatesan
authors.affiliation: Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA.|Department of Pediatric Neurology, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: T
authors.identifier: 0000-0002-9897-4422
authors.initials: T
authors.lastname: Chitnis
authors.affiliation: Department of Neurology, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Hoganson
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Yeshokumar
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: P
authors.initials: P
authors.lastname: Barreras
authors.affiliation: Department of Neurology, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: B
authors.initials: B
authors.lastname: Majmudar
authors.affiliation: Department of Biostatistics, University of Washington, Seattle, WA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Carone
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: F J
authors.initials: FJ
authors.lastname: Mateen
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003337:Corpus Callosum / Q000473:pathology; D016208:Databases, Factual; D004673:Encephalomyelitis, Acute Disseminated / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D012846:Singapore / Q000453:epidemiology; D013116:Spinal Cord / Q000473:pathology; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: acute disseminated encephalomyelitis; cohort studies; demyelination; international comparison; multiple sclerosis; neuromyelitis optica spectrum disorders