The impact of disease modifying therapies on cognitive functions typically impaired in multiple sclerosis patients: a clinician’s review

Abstract

ObjectiveOver the last few decades clinicians have become aware that cognitive impairment might be a major cause of disability, loss of employment and poor quality of life in patients suffering from multiple sclerosis [MS].The impact of disease modifying therapies [DMTs] on cognition is still a matter of debate. Theoretically, DMTs could exert a substantial beneficial effect by means of reducing neuroinflammation and brain atrophy, which are established correlates of cognitive dysfunction. The aim of the study was to review the evidence concerning the effect of DMTs on cognitive functions.MethodsPubMed, Scopus, and the European Committee for Treatment and Research in Multiple Sclerosis [ECTRIMS] Library were searched for articles concerning the pediatric and adult populations of patients with multiple sclerosis, including clinical trials and RWD, where psychometric results were analyzed as secondary or exploratory endpoints.ResultsWe reviewed a total of 44 studies that were found by our search strategy, analyzed the psychological tests that were applied, the length of the follow-up, and possible limitations. We pointed out the difficulties associated with assessing of DMTs’ effects on cognitive functions, and pitfalls in cognitive tools used for evaluating of MS patients.ConclusionThere is a need to highlight this aspect of MS therapies, and to collect adequate data to make informed therapeutic decisions, to improve our understanding of MS-related cognitive dysfunction and provide new therapeutic targets.

Risk Factors for Cognitive Impairment in Multiple Sclerosis Patients

“…In more recent trials, follow-up was only 1-2 years short, and thus insufficient to study long-term effects. Limitations regarding the cognitive tests and the small cohorts are also frequently reported [70]. Despite the previously mentioned impediments, a very recent review showed that most DMTs correlate with improved cognitive function [70].…”

“…Limitations regarding the cognitive tests and the small cohorts are also frequently reported [70]. Despite the previously mentioned impediments, a very recent review showed that most DMTs correlate with improved cognitive function [70]. The only two DMTs that showed inconsistent results were glatiramer acetate and fingolimod [71], but extensive real-world studies should be conducted.…”

Predicting clinical progression and cognitive decline in patients with relapsing-remitting multiple sclerosis: a 6-year follow-up study

“…The introduction of effective disease-modifying therapies (DMTs) has markedly reduced the annual relapse rate and radiological progression. Moreover, DMTs also seem to have an impact on reducing the rate of cognitive impairment (CI) and the potential for improving cognitive parameters [5].…”

“…The risk factors associated with the development of CI in MS include older age, greater disability in EDSS scale [6], brain atrophy [7], fewer years of education, and male sex [8], although the data differs despite the studies. Factors that have a protective effect on the development of CI are DMTs [5] and the cognitive reserve [9]. There is little data on biochemical factors as predictors of CI in MS, studies having focused mainly on light neurofilaments, with contradictory results [10,11].…”