The Eaton-Lambert myasthenic syndrome and long-term treatment with prednisolone

A 34-year-old women with the Eaton-Lambert myasthenic syndrome was treated with prednisolone for over a year. Proximal muscle weakness and breathing difficulty due to weakness in the respiratory muscles showed improvements after long-term administration of prednisolone. Electrophysiological studies before treatment revealed decreased amplitudes of the compound muscle action potential (CMAP), a decrement in CMAP to low frequency nerve stimulation, an increment on high frequency stimulation and posttetanic facilitation over 300%. Following administration of prednisolone, these electrophysiological parameters became almost normal. This case suggests that immunosuppressive drugs such as prednisolone may have a place in the management of the patients with myasthenic syndrome, especially of those who has no evidence of malignant tumor.