Association between myasthenia gravis and cognitive disorders: a PRISMA-compliant meta-analysis

Objective This meta-analysis assessed the association between myasthenia gravis (MG) and cognitive disorders.Methods The PubMed, Web of Science, OVID, EMBASE, CNKI and Wanfang electronic databases were comprehensively searched from inception to October 2020 for relevant studies. The primary outcomes were scores of the cognitive function battery. A random effects model was used to evaluate the cognitive function of patients with MG.Results Eight cross-sectional studies containing 381 patients and 220 healthy controls were included in this meta-analysis. In relation to global cognitive function, patients with MG performed significantly worse than healthy individuals (SMD = −0.4, 95% CI = −0.63 to −0.16, p < 0.001, I2 = 10%). Specifically, the impaired cognitive domains included language, visuospatial function, information processing, verbal immediate and delayed recall memory, visual immediate recall memory, and response fluency, while attention, executive function, and visual delayed recall memory were unimpaired. The patients with early-onset (SMD= −0.527, 95% CI = −0.855 to −0.199, p = 0.002) and generalized MG (SMD= −0.577, 95% CI = −1.047 to −0.107, p = 0.016) had poorer global cognitive performance than the healthy population.Conclusions Patients with MG may have cognitive disorders, including those associated with the domains of language, visuospatial function, information processing, verbal immediate and delayed recall memory, visual immediate recall memory and response fluency. Furthermore, the age of onset and disease severity may be associated with cognitive disorders in patients with MG.