Disrupted Attention as a Mediator of Fatigue-Related Memory Impairment in Myasthenia Gravis: A Cross-Sectional Study

Myasthenia gravis (MG) is a neuromuscular disease characterized by progressive muscle weakness and fatigue. Although its symptoms are primarily physical, emerging evidence suggests a link between MG and specific cognitive impairments. These impairments are hypothesized to arise secondarily from fatigue, emotional symptoms, and poor sleep quality. This study aims to examine the extent to which these neuropsychiatric factors affect memory and attention in MG patients, considering sustained attention as a potential mediating variable.This cross-sectional study included 88 participants: 48 MG patients and 40 healthy controls. A neuropsychological battery assessed verbal memory, attention, processing speed, executive function, working memory, and verbal fluency. Fatigue, anxiety-depression, and sleep quality were measured through standardized self-report instruments.MG patients showed impairments in immediate and delayed verbal memory, sustained attention, and concentration. Hierarchical regression identified concentration as the strongest predictor of memory performance, while physical fatigue significantly predicted concentration. Mediation analysis showed that concentration fully mediated the relationship between fatigue and verbal memory. Among clinical variables, only glucocorticoid treatment was associated with poorer cognitive outcomes.The findings confirm cognitive impairments in MG, influenced by fatigue, emotional symptoms, and sleep quality, highlighting the need for integrated clinical approaches.