title: Changes in cognitive performance over a 1-year period in children and adolescents with multiple sclerosis.
abstract: OBJECTIVE
  Cognitive impairment is a core symptom of pediatric-onset multiple sclerosis (MS), although relatively little is known regarding the rate of cognitive decline. This study examined the extent, pattern, and correlates of change in cognitive functioning in youth with MS.
  
  
  METHODS
  Changes in cognitive performance in 28 patients with pediatric-onset MS and 26 age-matched controls were ascertained through repeat comprehensive neuropsychological assessment conducted over a 1-year period. Change was evaluated by using a mixed factorial design with repeated measures to determine the interaction between group and time and using the Reliable Change Index (RCI) to determine individual differences on test scores over time. Participants were classified as showing "decline" or "improvement" if change scores exceeded the RCI on three or more tests.
  
  
  RESULTS
  The pattern of change over time differed by group. At the group level, healthy controls were more likely to show improvement across multiple domains of function relative to the MS group. Using the RCI, 7 of 28 patients (25%) showed cognitive deterioration compared with only 1 of 26 controls (3.8%; p < .05). Performance on measures of attention and processing speed, visuomotor integration, verbal fluency, visual memory, and calculation and spelling ability were most responsive to deterioration in functioning over time. Longer disease duration was associated with greater deterioration in visuomotor integration. Increased lesion volume was associated with slower psychomotor speed over time.
  
  
  CONCLUSIONS
  Lower rates of improvement in the pediatric MS group may be suggestive of a lack of age-appropriate cognitive development and warrant further evaluation over time.
authors.affiliation: Department of Psychology, York University and The Hospital for Sick Children, Toronto, Ontario, Canada. ctill@yorku.ca
authors.forename: Christine
authors.initials: C
authors.lastname: Till
authors.forename: Nicole
authors.initials: N
authors.lastname: Racine
authors.forename: David
authors.initials: D
authors.lastname: Araujo
authors.forename: Sridar
authors.initials: S
authors.lastname: Narayanan
authors.forename: D Louis
authors.initials: DL
authors.lastname: Collins
authors.forename: Berengere
authors.initials: B
authors.lastname: Aubert-Broche
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Arnold
authors.forename: Brenda
authors.initials: B
authors.lastname: Banwell
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D003072:Cognition Disorders / Q000209:etiology*; D002658:Developmental Disabilities / Q000503:physiopathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007206:Individuality; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications* / Q000473:pathology; D009483:Neuropsychological Tests; D012189:Retrospective Studies; D013223:Statistics as Topic