Patients with paediatric-onset multiple sclerosis are at higher risk of cognitive impairment in adulthood: an Italian collaborative study

Background: Patients with paediatric-onset multiple sclerosis (POMS) could be at an increased risk for cognitive impairment (CI), given the potential harmful effects of disease activity in neurodevelopment. However, there is scarce information on their long-term cognitive outcomes. Objective: To compare the prevalence and profile of CI between adults with a history of POMS and those with classic, adult-onset multiple sclerosis (AOMS). Methods: Cognitive performance was assessed through the Brief Repeatable Battery (BRB) and the Stroop Test in consecutive patients referred to six Italian MS centres. CI was defined as impairment in ⩾2 cognitive domains. Results: In all, 119 patients with POMS and 712 with AOMS were included in this analysis. The prevalence of CI was 48.0% in AOMS, 44.5% in POMS; with similar neuropsychological profile between the two groups. However, when adjusting for current age, we found a significantly increased risk for CI (odds ratio (OR) = 1.71; p = 0.02) and for impairment in information processing speed (OR = 1.86; p < 0.01) in patients with POMS. A higher Expanded Disability Status Scale (EDSS) was also identified in POMS (p = 0.03) compared with AOMS patients.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This study was in part financed through an FISM (Italian Federation of Multiple Sclerosis) research grant

VBM results (follow-up > baseline).

<p>The <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131803#pone.0131803.g002" target="_blank">Fig 2</a> represents: A) the significant increase in parahippocampus GM density, B) the increase GM density in dorsolateral prefrontal cortex as revealed by the longitudinal VBM analysis.</p

Mean number of impaired tests in patients starting natalizumab with EDSS>3 or<3.

<p>Columns represent mean (± SD) number of failed cognitive tests in patients starting natalizumab with EDSS ≤3 (black) or >3 (grey). *, <i>p</i><0.005 <i>vs</i>. baseline; #, <i>p</i><0.01 <i>vs</i>. baseline; °, <i>p</i><0.05 <i>vs</i>. EDSS >3.</p

Clinical characteristics of patients at different follow ups.

<p>ARR: annualized relapse rate; EDSS: expanded disability status scale</p><p>Clinical characteristics of patients at different follow ups.</p

Baseline socio-demographic information.

<p>The table reported mean and standard deviation. Age, education and disease duration are expressed in years.</p><p>♀ = female</p><p>♂ = male.</p><p>Baseline socio-demographic information.</p

Neuropsychological tests scores at different follow ups.

<p>See text for tests abbreviation. Repeated measures ANOVA was used to compare tests mean scores at different follow ups. The p value related to the main effect of the within variable Time is reported in this Table.</p><p>Neuropsychological tests scores at different follow ups.</p