Associations between cognitive impairment at onset and disability accrual in young people with multiple sclerosis

Differently from the adult multiple sclerosis (MS) population, the predictive value of cognitive impairment in early-onset MS is still unknown. We aim to evaluate whether cognitive performances at disease onset predict disease progression in young people with MS. This is a retrospective study on early onset (<25 years) MS patients, who had a baseline cognitive evaluation at disease onset. Demographic and longitudinal clinical data were collected up to 7 years follow up. Cognitive abilities were assessed at baseline through the Brief Repeatable Battery. Associations between cognitive abilities and clinical outcomes (occurrence of a relapse, and 1-point EDSS progression) were evaluated with stepwise logistic and Cox regression models. We included 51 patients (26 females), with a mean age at MS onset of 17.2 ± 3.9 years, and an EDSS of 2.5 (1.0-6.0). Over the follow-up, twenty-five patients had at least one relapse, and 7 patients had 1-point EDSS progression. Relapse occurrence was associated with lower 10/36 SPART scores (HR = 0.92; p = 0.002) and higher WLG scores (HR = 1.05; p = 0.01). EDSS progression was associated with lower SDMT score (OR: 0.70; p = 0.04). Worse visual memory and attention/information processing were associated with relapses and with increased motor disability after up to 7-years follow-up. Therefor, specific cognitive subdomains might better predict clinical outcomes than the overall cognitive impairment in early-onset MS.