Cognitive Impairment in Different MS Subtypes and Clinically Isolated Syndromes

Objective: To investigate the pattern of cognitive impairment in patients with relapsing-remitting (RR), secondary progressive (SP), primary progressive (PP) multiple sclerosis, and patients with clinically isolated syndrome (CIS) suggestive of MS, relative to control participants in the Greek population.

Methods: RR patients (N=75), SP patients (N=29), PP patients (N=23), CIS patients (N=33), and healthy control participants (N=43) were assessed by the Brief Repeatable Battery of Neuropsychological Tests (BRBN).

Results: The overall prevalence of cognitive dysfunction in our patients was 52.8% with CIS patients excluded and 47.5% with CIS patients included. All MS patients differed significantly from controls in all BRBN measures. Similar was the pattern of cognitive dysfunction in patients with CIS suggestive of MS, although verbal learning/memory capacity (as measured by the Selective Reminding Test) remained relatively spared. The comparisons between patient groups revealed some differences in the performance mainly in favor of CIS and RRMS patients. These differences largely disappeared after controlling for physical disability (EDSS).

Conclusion: All MS subtypes patients exhibit a pattern of cognitive impairment running across the studied cognitive domains. The pattern of cognitive dysfunction in patients with CIS is similar with relative sparing of verbal learning.