Does myasthenia gravis impact cognitive functioning? A systematic review and meta-analysis

Background: Myasthenia Gravis, traditionally known as a purely motor disease, has been recently associated also with non-motor symptoms, including psychological and cognitive symptoms. However, the presence of cognitive impairment in Myasthenia Gravis remains unclear due to limited and heterogeneous findings. This systematic review and meta-analysis aims to clarify the relationship between Myasthenia Gravis and cognitive performances. Methods: Following PRISMA guidelines, we systematically searched PubMed, Web of Science, and SCOPUS for original researches published between January 2000 and December 2024 assessing cognitive functioning in people with MG compared to healthy controls. Pooled standardized mean differences and 95% confidence intervals were calculated for each cognitive domain using random-effects meta-analysis. Results: Six studies comprising 242 Myasthenia Gravis patients and 166 healthy controls met inclusion criteria. Compared to healthy controls, people with Myasthenia Gravis showed significantly lower performance in processing speed (Symbol Digit Modalities Test), phonemic and animal verbal fluency, visuo-spatial memory (visual reproduction), and verbal learning (California Verbal Learning Test). Heterogeneity was low to moderate across most outcomes. Conclusions: This meta-analysis supports the presence of selective cognitive impairments in individuals with Myasthenia Gravis. These findings underscore the need for a multidimensional approach to care in Myasthenia Gravis, that includes cognitive and psychological health.