BACKGROUND: In patients with myasthenia gravis (MG), poor performance on cognitive tests has been found. Performance on memory tasks has been reported to correlate with disease activity, but memory in MG patients was also recently found to be unimpaired. PATIENTS AND METHODS: Cognitive functioning was examined in 23 patients with MG and 23 healthy controls. The patients were assessed for IQ, memory, attention, and motor performance. Immunoglobulin G antiacetylcholine receptor autoantibody titers were determined. Event-related potentials were generated for patients and controls. RESULTS: Mean IQs of patients were at average. Memory and attention were not more impaired in patients than controls. Event-related potentials were not delayed in either group. Patients with elevated autoantibody concentrations similarly showed unimpaired neurocognitive and motor functioning. CONCLUSION: In this study, no evidence of neuropsychological impairment was found in MG, arguing against the involvement of higher cortical functions. Sleep abnormalities rather than central mechanisms may explain the memory impairments reported by some studies.
BACKGROUND: In patients with myasthenia gravis (MG), poor performance on cognitive tests has been found. Performance on memory tasks has been reported to correlate with disease activity, but memory in MGpatients was also recently found to be unimpaired. PATIENTS AND METHODS: Cognitive functioning was examined in 23 patients with MG and 23 healthy controls. The patients were assessed for IQ, memory, attention, and motor performance. Immunoglobulin G antiacetylcholine receptor autoantibody titers were determined. Event-related potentials were generated for patients and controls. RESULTS: Mean IQs of patients were at average. Memory and attention were not more impaired in patients than controls. Event-related potentials were not delayed in either group. Patients with elevated autoantibody concentrations similarly showed unimpaired neurocognitive and motor functioning. CONCLUSION: In this study, no evidence of neuropsychological impairment was found in MG, arguing against the involvement of higher cortical functions. Sleep abnormalities rather than central mechanisms may explain the memory impairments reported by some studies.