Cognitive function characteristics in patients with myasthenia gravis

Abstract

Objective To evaluate the cognitive function characteristics in patients with myasthenia gravis(MG). Methods The cognitive function of 83 MG patients and 39 healthy controls (HC) were evaluated by MMSE, California verbal learning test( CVLT), brief visuospatial memory test revised(BVMT-R), symbol digit modalities test(SDMT), benton judgment of line orientation test(BJLOT), paced auditory serial addition Test(PASAT) and verbal fluency test(VFT). The depression state was assessed by beck depression inventory (BDI). The results were compared between MG and HC groups.The effect of clinical characteristics such as disease type, comorbidities, course of disease, disease severity, and drug treatment on cognitive impairment in MG group was further analysed. Results The scale scores of MMSE(28(26, 29), 29(28, 30)), CVLT, BVMT-R, SDMT((37.06±12.18), (47.54±14.91)) and PASAT((32.86±10.23), (37.00±8.82)) in MG were significantly lower than those in control group (P 0.05). Spearman correlation analysis showed that QMG scores were negatively correlated with SDMT scores(r=-0.234, P<0.05). MG-ADL scores were inversely correlated with total BVMT-R scores of three trials(r=-0.283, P<0.05). Conclusion Patients with MG suffered from cognitive impairment, mainly in memory, attention, processing speed and visual memory, which supported the hypothesis of CNS involvement in MG.Dysfunction in some cognitive domains may be related to the disease severity.Clinicians need take morce attention to early assessment, developing long-term follow-ups and appropriate intervention. Key words: Myasthenia gravis; Neuropsychology; Cognitive function; Depression