Cognitive impairment in multiple sclerosis phenotypes: Neuropsychological assessment in a portuguese sample.

Background: Cognitive impairment affects 40-65% of MS patients, encompassing all disease stages and types of clinical courses. This estimation is based on different instruments used and population normative data.

Objective: This study aims to assess the cognitive function in a hospital-based cohort of Portuguese MS patients, to allow estimating the prevalence of cognitive impairment in different phenotypes.

Methods: Three hundred and thirteen patients with Multiple Sclerosis (MS) underwent neuropsychological assessment with the brief repeatable battery of neuropsychological tests (BRBN-T) and the brief international cognitive assessment for multiple sclerosis (BICAMS).

Results: Differences were observed in the cognitive impairment profile of different disease phenotypes and of the different disease severity stages. RRMS patients performed better in the cognitive test of the BRBN-T and BICAMS than those with progressive disease phenotypes. Relationships between cognitive impairment and disability and professional status were relevant. Although similarities could be observed in the cognitive profile of the MS phenotypes, with predominant involvement of verbal memory, verbal fluency, and information processing speed, the latter was found to be more frequent as the disease progressed.

Conclusion: This study contributes to improve knowledge about the cognitive profile of the different MS phenotypes and understand the cognitive characteristics of Portuguese patients.