Till, Christine2018-03-012018-03-012017-07-202018-03-01http://hdl.handle.net/10315/34320In healthy children and adolescents, increased white matter integrity is highly correlated with cognitive and language development. Moreover, higher level of physical activity has been shown to confer positive effects on cognition and is associated with increased white matter microstructure in children. Decreased white matter integrity and impaired cognitive efficiency (i.e., speed of information processing) are consistently observed in pediatric-onset multiple sclerosis (MS) compared to healthy controls. However, the association between physical activity, white matter integrity, and cognition has yet to be fully described in this population. To address this gap in the literature, this study aimed to determine whether level of self-reported strenuous physical activity is associated with white matter integrity and cognitive efficiency in pediatric-onset MS patients. We examined white matter integrity in 24 pediatric-onset MS patients and 34 age- and sex-matched healthy controls via diffusion tensor imaging (DTI) using tract-based spatial statistics (TBSS). Participants also completed a neuropsychological test battery (from which a cognitive efficiency composite score was derived), and a questionnaire examining self-reported strenuous physical activity. Findings demonstrated that patients had significantly lower white matter integrity relative to healthy controls in the entire white matter skeleton (i.e., across the whole brain) and in 21 of 26 interrogated white matter tracts. Cognitive outcomes did not associate with indices of white matter integrity. Self-reported strenuous physical activity also did not associate with white matter integrity; however, it was positively associated with white matter volume in healthy controls, and trended towards a positive association in patients. The results of this study confirm that DTI parameters are sensitive to disease pathology in pediatric-onset MS. While we did not confirm that white matter integrity was associated with cognitive efficiency, this cohort of patients was relatively cognitively preserved, likely masking any relation. No association with self-reported strenuous physical activity was noted; however further investigation of the positive effects of physical activity on white matter in pediatric-onset MS is warranted, as its role in moderating cognitive functioning in this population remains to be elucidated.enAuthor owns copyright, except where explicitly noted. Please contact the author directly with licensing requests.KinesiologyElectronic Thesis or Dissertation2018-03-01Pediatric-onset multiple sclerosisNeuropsychologyCognitive efficiencyWhite matter integrityDiffusion tensor imagingPhysical activity