Prevalence of Cognitive Disorders in Multiple Sclerosis Patients: A Cross-sectional Study in Semnan in 2019

 Multiple sclerosis (MS) as a chronic inflammatory disease is one of the most common neurological diseases characterized by demyelinating lesions in the brain, spinal cord, and optic nerve. The present study was designed and conducted to investigate the prevalence of cognitive disorders in patients with MS.

In this cross-sectional study, 60 patients with MS referred to Kowsar Semnan Hospital (Semnan, Iran) in 2020 were examined. Two questionnaires, including Beck's Depression Inventory (BDI-II) and Brief International Cognitive Assessment for MS (BICAMS) were used for data collection. Moreover, data was entered and analyzed in STATA software (version 14).

The mean (standard deviation [SD]) age of the patients was 35.33 (7.20) years; 66.7% of them were female, 85% had a university education level, 75% were married, and 16.7% experienced mild depression based on the BDI-II. In terms of the type of MS, 88.3% of patients had relapsing-remitting multiple sclerosis (RRMS) and 58.3% suffered from at least one cognitive disorder, as well as the Auditory/Verbal learning was the most common cognitive disorder with 43.3%. Women were significantly more likely than men to suffer from at least one cognitive disorder (P<0.05), and people with secondary progressive multiple sclerosis (SPMS) were significantly more likely to have at least one cognitive disorder compared to those with RRMS (P<0.05).  Similarly, the symbol digit modalities test (SDMT) scores in individuals with SPMS were significantly higher than those in individuals with RRMS (P<0.05). However, no statistically significant association was observed between the types of cognitive disorders in MS patients and the presence of depression (P>0.05).

A significant proportion of MS patients had at least one of the cognitive disorders, and the prevalence of cognitive disorders in SPMS patients was higher than in RRMS patients.