Lambert-Eaton myasthenic syndrome associated with alemtuzumab administration.

BACKGROUND: Alemtuzumab administration is known to cause secondary autoimmune disease but has not been associated with the development of neurologic autoimmune conditions. Lambert-Eaton myasthenic syndrome (LEMS) is caused by autoantibodies directed against calcium channels on the neuromuscular junction.

CASE REPORT: We report a case of a patient with relapsing-remitting multiple sclerosis (RRMS) treated with alemtuzumab who develop generalized weakness initially attributed to progression of MS but eventually determined to be due to LEMS.

CONCLUSION: Alemtuzumab treatment can result in the development of neurologic autoimmune conditions that could mimic MS progression.