title: Diffusion tensor magnetic resonance imaging in very early onset pediatric multiple sclerosis.
abstract: OBJECTIVE
  Active myelination during childhood may influence the impact of multiple sclerosis (MS) on brain structural integrity. We studied normal-appearing white matter (NAWM) in children with MS onset before age 12 years using diffusion tensor (DT) magnetic resonance imaging (MRI).
  
  
  METHODS
  DT MRI scans were obtained from 22 MS children with their first attack before age 12 years, and 31 healthy controls from two referral centers. Using probabilistic tractography, brain tissue integrity within interhemispheric, intrahemispheric, and projection tracts was compared between patients and site-matched controls. The impact of disease and age at MRI on tract NAWM fractional anisotropy (FA) and mean diffusivity (MD) values was evaluated using linear models.
  
  
  RESULTS
  Compared to controls, pediatric MS patients had reduced FA and increased MD of the bilateral superior longitudinal fasciculus and corpus callosum (CC), without center-by-group interaction. CC NAWM average FA was correlated with brain T2 lesion volume. In controls, the majority of the tracts analyzed showed a significant increase of FA and decrease of MD with age. Such a linear correlation was lost in patients.
  
  
  CONCLUSIONS
  In very young pediatric MS patients, DT MRI abnormalities affect brain WM tracts differentially, and are only partially correlated with focal WM lesions. Impaired maturation of WM tracts with age may be an additional factor contributing to these findings.
authors.affiliation: Neuroimaging Research Unit, San Raffaele Scientific Institute, 'Vita-Salute' San Raffaele University, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Rocca
authors.affiliation: Research Institute, The Hospital for Sick Children, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Sonkin
authors.affiliation: IRCCS-Ospedale Casa Sollievo della Sofferenza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Copetti
authors.affiliation: Neuroimaging Research Unit, San Raffaele Scientific Institute, 'Vita-Salute' San Raffaele University, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Pagani
authors.affiliation: McConnell Brain Imaging Center, Montreal Neurological Institute, Canada.
authors.forename: D L
authors.initials: DL
authors.lastname: Arnold
authors.affiliation: McConnell Brain Imaging Center, Montreal Neurological Institute, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Narayanan
authors.affiliation: Research Institute, The Hospital for Sick Children, Canada.
authors.forename: J G
authors.initials: JG
authors.lastname: Sled
authors.affiliation: Research Institute, The Hospital for Sick Children, Canada/The Children's Hospital of Philadelphia, USA.
authors.forename: B
authors.initials: B
authors.lastname: Banwell
authors.affiliation: Neuroimaging Research Unit, San Raffaele Scientific Institute, 'Vita-Salute' San Raffaele University, Italy filippi.massimo@hsr.it.
authors.forename: M
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D016880:Anisotropy; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000000981:diagnostic imaging; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging*; D066127:White Matter / Q000000981:diagnostic imaging
keywords: Magnetic resonance imaging; demyelination; diffusion tensor; pediatric