A B S T R A C T
Aim: During the past decade, there has been an increasing interest in the evaluation of cognitive function in myasthenia gravis (MG),neuromuscular transmission disorder caused by acetylcholine receptor auto‑antibodies. However, the results of previous studies on cognition and MG are inconsistent and controversial. This study aimed to evaluate cognition in patients with mild/moderate grades of MG. Methods: This study included 20 patients with MG with a mean age of 28.45 ± 8.89 years and duration of illness of 3.52 ± 1.15 years. Cognition was tested using a sensitive battery of psychometric testing (Mini‑mental State Examination [MMSE], Stanford‑Binet Intelligence Scale 4th edition [SBIS] and Wechsler Memory Scale‑Revised [WMS‑R]) and by recording P300
component of event‑related potentials (ERPs), a neurophysiological analog for cognitive function. Results: Compared with healthy subjects (n = 20), patients had lower total scores of cognitive testing (MMSE, SBIS and WMS‑R) (P = 0.001), higher Beck
Depression Inventory 2nd edition scores (P = 0.0001) and prolonged latencies (P = 0.01) and reduced amplitudes (P = 0.001) of P300 component of ERPs. Correlations were identified between total scores of cognitive testing and age (r = -0.470, P = 0.010),
duration of illness (r = -0.788, P = 0.001) and depression scores (r = -0.323, P = 0.045). Using linear regression analysis and after controlling for age and depression scores, a significant correlation was identified between total scores of cognitive testing and duration of illness (β = -0.305, P = 0.045). Conclusion: Patients with mild/moderate MG may have cognitive dysfunction. This is important
to determine prognosis and managing patients.