title: Tract-based spatial statistics analysis of diffusion-tensor imaging data in pediatric- and adult-onset multiple sclerosis.
abstract: BACKGROUND
  White matter (WM) microstructure may vary significantly in pediatric-onset (PO) and adult-onset (AO) patients with multiple sclerosis (MS), a difference that could be explained by the effects of an inherent plasticity in the affected pediatric brains early in the disease, and a phenomenon that does not occur later in life. This hypothesis would support the observation that disease progression is much slower in POMS compared to AOMS patients.
  
  
  OBJECTIVE
  To examine WM microstructure in the brain of adults with POMS and AOMS, using tract based spatial statistics (TBSS) analysis of diffusion-tensor imaging (DTI).
  
  
  METHODS
  Adults with relapsing-remitting (RR) POMS, who were diagnosed before age of 18 years (n = 16), were compared with age-matched (AOA, n = 23) and disease duration-matched (AOD, n = 22) RR patients who developed MS after the age of 18 years. Scans were analyzed using the FSL software package (Oxford, UK) and statistics were performed using TBSS to evaluate WM microstructure between groups based on the mean fractional anisotropy (FA) values obtained from the DTI.
  
  
  RESULTS
  Widespread cortical and deep WM area differences characterized by increased FA values were seen in the AOAMS compared with POMS group (P < 0.05, TFCE corrected). Significantly increased FA values of posterior WM areas were detected in the AODMS compared with POMS group (P < 0.05, TFCE corrected).
  
  
  CONCLUSIONS
  Increased FA values in WM areas of the AOMS compared with the POMS patients suggest that diffuse WM microstructure changes are more attributable to age of onset than a simple function of disease duration and age.
authors.affiliation: State University of New York at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York; Buffalo Neuroimaging Analysis Center, Buffalo, New York.
authors.forename: Rachel
authors.initials: R
authors.lastname: Aliotta
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Cox
authors.forename: Katelyn
authors.initials: K
authors.lastname: Donohue
authors.forename: Bianca
authors.initials: B
authors.lastname: Weinstock-Guttman
authors.forename: E Ann
authors.initials: EA
authors.lastname: Yeh
authors.forename: Paul
authors.initials: P
authors.lastname: Polak
authors.forename: Michael G
authors.initials: MG
authors.lastname: Dwyer
authors.forename: Robert
authors.initials: R
authors.lastname: Zivadinov
mesh_terms: D000328:Adult; D017668:Age of Onset; D001921:Brain / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology