Prevalence of and risk factors for cognitive impairment in patients with relapsing-remitting multiple sclerosis: Multi-center, controlled trial

Background: Cognitive impairment (CI) is a common problem in multiple sclerosis (MS), may occur either in early or late phase of the disease, and impairs quality of life. Objectives: This study aimed to determine the prevalence of CI and related risk factors in relapsing-remitting MS (RRMS) patients in Turkey. Methods: The present cross-sectional, multi-center, and nationally representative study included RRMS patients. Sociodemographic characteristics, cognitive functions and additional outcomes were compared between patients with and without CI. Results: The analyses included 487 RRMS patients. According to the BRB-N battery results, CI prevalence was 53.7%. There was a negative significant correlation of BRB-N subtests with age, disease duration, and EDSS and MSNQ-patient rated scores. On the logistic regression analysis, increased age, living in village/rural area, high income level, and high EDSS score were significant increasing risk factors in the development of CI. Conclusions: This is the first national cognitive data obtained from MS in Turkey, which is a country between Europe and Asia and thus has characteristics of both continents. The similarity of the results of the present study obtained from Turkey to the Western-based data indicates that CI is universal in MS and the main factors affecting CI have not changed.