Cognitive changes in multiple sclerosis and factors of their development: association with taking disease-modifying therapies

Currently, there is an increase in the life expectancy of patients with multiple sclerosis (MS) due to the improvement of their medical care and the use of disease-modifying therapies (DMTs). Due to the increase in life expectancy, the problem of cognitive impairment (CI) in MS patients becomes relevant. It has been shown that the risk of developing Alzheimer's disease in MS patients aged 45 to 64 years is 4–6 times higher than in the general population. The main non-modifiable risk factors for CI in MS are carriage of HLA-DRB1*15:01, PSEN1, PSEN2, APP, APOE ε4 genes, old age (60 years and older), male gender, prolonged course of the disease, high degree of disability according to EDSS. Modifiable risk factors for CI in MS patients are high levels of anxiety and depression, presence of diabetes mellitus, vascular risk factors, smoking, and drug use. The protective factors for MS include the use of DMTs, high cognitive reserve, high level of physical and social activity.