title: Diffusion tensor analysis of pediatric multiple sclerosis and clinically isolated syndromes.
abstract: OBJECTIVE
  DTI has shown focal and diffuse white matter abnormalities in adults and children with MS. Here we explore whether DTI abnormalities are present at the time of a first attack or CIS in children and whether early DTI features can predict the development of MS.
  
  
  METHODS
  We assessed region-of-interest and tract-based mean ADC and mean FA values for 3 major white matter pathways and NAWM in 20 children with MS, 27 children with forms of CIS, and controls. Tracts were selected by using standard region-of-interest placements on color FA maps. Identical ROIs were placed in the NAWM on b = 0 T2-weighted images to ensure that both ROIs and resulting tracts passed through NAWM. Conventional MR imaging characteristics were assessed by visual inspection. Statistical analysis compared FA and ADC values between groups by a t test. Logistic regression assessed the predictive value of DTI measures and published conventional MR imaging measures for conversion from CIS to MS.
  
  
  RESULTS
  In pediatric patients with MS, all white matter pathways and analysis confined to the NAWM demonstrated higher mean ADC values and lower mean FA than in controls. In contrast, there were no significant differences in mean ADC and mean FA of white matter pathways in all CIS cohorts compared with controls. In the CIS cohort, none of the DTI measures in white matter pathways or in NAWM were significantly associated with conversion to RRMS in univariate or multivariate models (P > .05 in all models).
  
  
  CONCLUSIONS
  There are significant anisotropic abnormalities in the NAWM of major tracts in children with MS. In contrast, there were no significant changes in pediatric patients with CIS compared with controls at baseline. DTI measures did not predict conversion to MS. The period between CIS and conversion to pediatric MS may represent a window of opportunity for the prevention of diffuse damage in the CNS and potentially progressive disability.
authors.affiliation: Partners Pediatric Multiple Sclerosis Center, Massachusetts General Hospital for Children, Boston, Massachusetts 02114, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Vishwas
authors.forename: B C
authors.initials: BC
authors.lastname: Healy
authors.forename: R
authors.initials: R
authors.lastname: Pienaar
authors.forename: M P
authors.initials: MP
authors.lastname: Gorman
authors.forename: P E
authors.initials: PE
authors.lastname: Grant
authors.forename: T
authors.initials: T
authors.lastname: Chitnis
mesh_terms: D000293:Adolescent; D016880:Anisotropy; D002648:Child; D002675:Child, Preschool; D056324:Diffusion Tensor Imaging; D018450:Disease Progression; D004673:Encephalomyelitis, Acute Disseminated / Q000473:pathology*; D005260:Female; D006801:Humans; D056784:Leukoencephalopathies / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*; D015999:Multivariate Analysis; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013577:Syndrome