Co-existence of Lambert-Eaton myasthenic syndrome and subacute cerebellar degeneration in a patient with rheumatoid arthritis.

A 38 year old woman with rheumatoid arthritis had a rare co-existence of Lambert-Eaton myasthenic syndrome and subacute cerebellar degeneration. She had mild but transient improvement in muscle power following plasmapheresis, which correlated with the degree of increment on high rate repetitive nerve stimulation (RNS). Her cerebellar signs did not improve, however. This differential therapeutic response may be due to different mechanisms of injury and tissue susceptibility.