Role of Demographic and Clinical Factors in Cognitive Functioning of Persons with Relapsing-Remitting and Progressive Multiple Sclerosis

Background: Age and time post-diagnosis can significantly impact cognitive and motor functions in multiple sclerosis (MS); however, studies often fail to account for these factors when assessing differences between disease courses. Objectives: Examine differences between relapsing-remitting and progressive MS in cognition, motor function, and everyday activities, controlling for age, education, and time post-diagnosis. Methods: Twenty-one persons with relapsing-remitting MS (RRMS group), 21 with progressive MS (PMS group), and 21 healthy participants (HCs), matched on age, education, and time post-diagnosis, completed tests of cognitive abilities, motor functions, and everyday functional activities. Results: The two groups with MS did not differ on cognitive performance. Poorer performance in processing speed was noted in both MS groups in comparison with the HC group. Motor function was worse for the PMS group compared with the HC and RRMS groups. The RRMS group showed poorer upper limb functioning compared to the HC group. The PMS group had more difficulty with everyday activities as compared with both the RRMS and HC group. Conclusions: When comparing differences in functioning between MS disease courses, attention should be paid to the demographic characteristics of the samples.