Comment on “Alemtuzumab improves cognitive processing speed in active multiple sclerosis – a longitudinal observational study”

Abstract

LETTER TO THE EDITORDear Editor, An interesting article was recently read about the effect of alemtuzumab on cognitive impairment (CI) in multiple sclerosis (MS) 1 . This brings up the question whether other highly efficacious treatments can impact CI? If the answer is positive, is it permissible to select an escalation approach?MS is a debilitating disease of central nervous system (CNS), which is common among young adults with noticeable economic consequences on the government 2 . Due to widespread distribution of lesions, MS manifests a broad range of the symptoms. CI is one of the most critical symptoms, with prevalence rate ranging from 43 to 70% 3 , embracing all types of clinical courses and disease stages 4 . The evidence suggests that neuropsychological scores are better in relapsing-remitting (RR) patients compared to secondary-progressive (SP) and primary-progressive (PP) cases 5 . Cognitive impairment is more severe in SP patients than in PP patients 6 . Unfortunately, the effect of disease-modifying therapy (DMTs) on cognition is not well known. There is less evidence that DMTs are beneficial to improve the cognition 1 . However, there is still no clear answer to this question: Do high potent DMTs significantly impact CI by slowing and stabilizing the course compared with low potent drugs? Clarification of this issue seems to make a significant change in treating MS patients.Studies showed a link between CI and brain atrophy. Brain atrophy can be seen in the early stages of MS, which is associated with a decrease in brain volume and function. It was found that the higher the severity of cognition impairment in the patients, the higher the severity of brain atrophy 7,8 . Previously, the prevention of relapses was an important goal for treating MS patients 9 . However, this approach has changed, and improving the patients' clinical condition and remission was considered a goal in advancements of the treatments and using new drugs. Therefore, in MS, as in many diseases, such as cancer and rheumatoid arthritis, the term "no evidence of disease activity" (NEDA) is used. NEDA is used as a criterion to