[Neuropsychological performance in patients with myasthenia gravis]

Myasthenia gravis is a chronic autoimmune disease that affects the neuromuscular transmission. Controversial findings had been reported about cognitive impairment in this disease. The aim of this study was to investigate the cognitive pattern of patients with myasthenia gravis. There were enrolled 24 patients with myasthenia gravis, anti-acetylcholine receptor antibodies (ACRA) positive, and 24 healthy controls.

Patients: age 43.9 ± 14.8, years of education 10.9 ± 3.3.

Controls: age 44.5 ± 15.4, years of education 11.5 ± 3.3. The following areas were evaluated: verbal memory: (long-term storage, retrieval, delayed recall) of the Selective Remained Test; attention: Paced Auditory Serial Addition Task (PASAT 2 and 3 seconds); executive functions: analogies and numbers-letters sequence. Also, it was administered the Beck Depression Inventory II (BDI II). About 33.3% of patients obtained abnormal performance in two or more cognitive tests. 37.5% showed deterioration in attention; 33.3% in verbal memory; 29.2% in executive functions. Significant differences between patients and healthy controls were found in long-term storage (p = 0.001); retrieval (p = 0.007); delayed recall (p = 0.000); PASAT 3 (p = 0.009); PASAT 2 (p = 0.009) and analogies (p = 0.003). Evidence of depression was found: mild in 4.2% of patients; moderate in 25% and severe in 29.2%. Neuropsychological performance declines in patients with myasthenia gravis: attention was more affected than other cognitive areas.