Aging with multiple sclerosis: prevalence and profile of cognitive impairment

Background: The increase in life expectancy of patients with multiple sclerosis (MS) requires a better knowledge of disease features in the older patients group. Objective: To describe the prevalence and profile of cognitive impairment (CI) in older patients with MS and perform a comparison with younger patients. Methods: Patients were consecutively recruited for 6 months. Cognitive performance was assessed through the Brief Repeatable Battery and the Stroop Test. CI was defined as impairment in ≥ 2 cognitive domains. Results: We identified 111 patients older than 55 years (mean age 59.7 years). The prevalence of CI was 77.4%, which was significantly higher than in younger patients (42.8%; p < 0.01). Information processing speed was the most impaired domain (68.8%), followed by verbal learning (49.5%), executive function (47.7%), and visuospatial learning (26.6%). We found no significant differences in the prevalence of impairment in the distinct cognitive domains between older and younger patients with CI. Depression and fatigue were not associated with increased CI among patients in the older age group (p > 0.70). Conclusion: There is a remarkably high frequency of CI in older patients with MS. The similar profile of CI between older and younger patients suggests that CI is mostly directly related to MS itself and not to comorbid age-related disorders.