The effect of active cognitive reserve on cognitive functions in multiple sclerosis patients

Aim: The etiology of MS related cognitive impairment is not clear. The objective of the research is to examine the impact of active cognitive reserve, the sum of lifetime intellectual activities, on MS-associated cognitive impairment. Secondarily, the impact of clinical-sociodemographic variables including disability level, disease duration, age, depression, anxiety and stress on cognitive performance was investigated. Method: The study sample consisted of 106 MS patients. "Cognitive Reserve Index Questionnaire" utilized to measure active cognitive reserve. "Depression Anxiety Stress Scale-21" administered to measure the emotional state and "EDSS" was used to assess disability. The "Stroop test" administered to measure attention and inhibition function; the "Brief International Cognitive Assessment Battery for MS" administered to evaluate processing speed, verbal and visual memory; the "Paced Auditory Serial Addition Test" was employed to evaluate working memory; and the "Controlled Verbal Recall Test" was used to measure verbal fluency. Mann-Whitney U analysis applied to find whether the cognitive impairment levels of MS patients varied according to active cognitive reserve and clinical-sociodemographic variables; Spearman's Rho correlation and binary logistic regression analysis utilized to find the relationship between these variables and cognitive impairment. Results: Mann-Whitney U analysis indicate a difference between the neuropsychological test performance of patients with high and low active cognitive reserve. Correlation analysis revealed that cognitive reserve and patient age were positively correlated with all tests except Stroop. The binary logistic regression model correctly predicted cognitive impairment 93.8% of the time. The analyses indicated that active cognitive reserve was predicted with MS patients' overall cognitive performance. The findings suggest active cognitive reserve can be used as an important variable when assessing patients' cognitive functioning.