The Influence of Sleep Quality on Cognitive Performance in Patients With Multiple Sclerosis

Background Cognitive impairments (CI) affect 30-70% of patients with multiple sclerosis (MS) and can occur even in the absence of other deficits. CI are among the most debilitating manifestations, significantly impacting patients' quality of life, hindering their social activity and employment. The article discusses the possible role of sleep disturbances on cognitive performance in patients with MS considering the role of glymphatic system and its activity during sleep. Methods The study included 32 patients with MS without disease-modifying therapy experiencing exacerbations. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), while sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI). Statistical analyses were conducted using Jamovi (version 2.3.28). Mann-Whitney U test and Spearman correlation analysis were employed, with p<0.05 considered statistically significant. Results MoCA total scores, executive functions, short term memory, attention, concentration, and working memory were significantly lower in the CI group compared to the normal cognitive function group. Attention, concentration and working memory decline significantly correlated with later falling asleep time and existence of sleep disturbances. Short term memory component has a significant negative correlation with falling asleep time, sleep duration and sleep efficiency. Spearman test showed significant negative correlation between PSQI total score and MoCA total score, attention concentration and working memory as well as short memory components. Conclusion A moderate negative correlation exists between sleep quality scores and cognitive performance, suggesting that poorer sleep may be associated with reduced cognitive function in patients with MS.