title: Paediatric acquired demyelinating syndromes: incidence, clinical and magnetic resonance imaging features.
abstract: OBJECTIVE
  Changing trends in multiple sclerosis (MS) epidemiology may first be apparent in the childhood population affected with first onset acquired demyelinating syndromes (ADSs). We aimed to determine the incidence, clinical, investigative and magnetic resonance imaging (MRI) features of childhood central nervous system ADSs in the British Isles for the first time.
  
  
  METHODS
  We conducted a population active surveillance study. All paediatricians, and ophthalmologists (n = 4095) were sent monthly reporting cards (September 2009-September 2010). International Paediatric MS Study Group 2007 definitions and McDonald 2010 MS imaging criteria were used for acute disseminated encephalomyelitis (ADEM), clinically isolated syndrome (CIS) and neuromyelitis optica (NMO). Clinicians completed a standard questionnaire and provided an MRI copy for review.
  
  
  RESULTS
  Card return rates were 90%, with information available for 200/222 positive notifications (90%). After exclusion of cases, 125 remained (age range 1.3-15.9), with CIS in 66.4%, ADEM in 32.0% and NMO in 1.6%. The female-to-male ratio in children older than 10 years (n = 63) was 1.52:1 (p = 0.045). The incidence of first onset ADS in children aged 1-15 years old was 9.83 per million children per year (95% confidence interval [CI] 8.18-11.71). A trend towards higher incidence rates of ADS in children of South Asian and Black ethnicity was observed compared with White children. Importantly, a number of MRI characteristics distinguished ADEM from CIS cases. Of CIS cases with contrast imaging, 26% fulfilled McDonald 2010 MS diagnostic criteria.
  
  
  CONCLUSIONS
  We report the highest surveillance incidence rates of childhood ADS. Paediatric MS diagnosis at first ADS presentation has implications for clinical practice and clinical trial design.
authors.affiliation: School of Health and Population Sciences, University of Birmingham, Birmingham, UK. michaelabsoud@childdemyelination.org.uk
authors.forename: Michael
authors.initials: M
authors.lastname: Absoud
authors.forename: Ming J
authors.initials: MJ
authors.lastname: Lim
authors.forename: Wui K
authors.initials: WK
authors.lastname: Chong
authors.forename: Christian G
authors.initials: CG
authors.lastname: De Goede
authors.forename: Katharine
authors.initials: K
authors.lastname: Foster
authors.forename: Roxana
authors.initials: R
authors.lastname: Gunny
authors.forename: Cheryl
authors.initials: C
authors.lastname: Hemingway
authors.forename: Philip E
authors.initials: PE
authors.lastname: Jardine
authors.forename: Rachel
authors.initials: R
authors.lastname: Kneen
authors.forename: Marcus
authors.initials: M
authors.lastname: Likeman
authors.forename: Ken K
authors.initials: KK
authors.lastname: Nischal
authors.forename: Michael G
authors.initials: MG
authors.lastname: Pike
authors.forename: Naomi A
authors.initials: NA
authors.lastname: Sibtain
authors.forename: William P
authors.initials: WP
authors.lastname: Whitehouse
authors.forename: Carole
authors.initials: C
authors.lastname: Cummins
authors.forename: Evangeline
authors.initials: E
authors.lastname: Wassmer
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D020278:Demyelinating Autoimmune Diseases, CNS / Q000453:epidemiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male