Cognitive Impairment Features in Patients With Multiple Sclerosis

Introduction : Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system accompanied by neurodegeneration contributing to cognitive dysfunction. Cognitive impairment occurs in 40%-65% of patients with MS and can manifest even in the early stages of the disease. Objective : To evaluate cognitive dysfunction features in patients with MS. Materials and methods : The study included patients with MS (n=30; age, 40.8±9.74 years; disease duration, 9.67±6.96 years; Expanded Disability Status Scale [EDSS] score, 4.76±2.11) and healthy individuals (n=30; age, 40.3±12.24 years). Cognitive impairment was assessed using the Montreal Cognitive Assessment Scale (MoCA) and the Paced Auditory Serial Addition Test (PASAT). Results : Cognitive impairment in the group of MS patients was found in 73.3% of the cases. The mean MoCA, PASAT-3, and PASAT-2 scores of MS patients were 13.56%, 24.31%, and 29.48% lower than those in the control group, respectively. In women, the cognitive level in MS patients remains higher than in men. Analysis of the PASAT-3 and PASAT-2 results in MS patients did not reveal any statistically significant differences between the groups of patients aged 18-35 years and those aged 36-44 years and the groups of patients aged 18-35 years and those aged 45-59 years. The results of the MoCA and hearing tests in patients with higher and secondary education were not statistically significant. We found an inverse relationship between EDSS and PASAT-2 (R= −0.49; P< .05), EDSS and PASAT-3 (R= −0.37; P< .05). The most severe cognitive impairment was observed with high EDSS (7.5-9). Conclusions : We have identified features of cognitive functions in MS. Follow-up and therapy of MS patients require cognitive dysfunction assessment using appropriate scales.