Lambert-Eaton Myasthenic Syndrome (LEMS)

Signs and Symptoms

The first symptoms of LEMS are usually leg weakness and difficulty walking. Oculobulbar weakness (affecting the muscles of the eyes, face and throat) may occur later, causing ptosis (droopy eyelids), speech impairment and swallowing problems.

Unlike weakness in myasthenia gravis, weakness in LEMS temporarily improves after exertion. For more on why this occurs, see Causes/Inheritance.


LEMS symptoms usually begin with leg weakness, often followed by weakness in the muscles of the eyes, face and throat. Sometimes the weakness temporarily improves after exertion.

Lambert-Eaton Myasthenic Syndrome


MDA leads the search for treatments and therapies for Lambert-Eaton myasthenic syndrome (LEMS). The Association also provides comprehensive supports and expert clinical care for those living with LEMS.

In this section, you’ll find up-to-date information about Lamber-Eaton myasthenic syndrome, as well as many helpful resources. This information has been compiled with input from researchers, physicians and people affected by the disease.

MDA Awards $13.5 Million in Research Grants

The Muscular Dystrophy Association has awarded 44 grants totaling $13.5 million to support research efforts aimed at advancing understanding of disease processes and uncovering new strategies for treatments and cures of muscular dystrophy and the more than 40 other diseases in the Association’s program.

The new grants were reviewed by MDA’s Scientific and Medical Advisory Committees, and approved by MDA’s Board of Directors at its December meeting.

Research Briefs: DMD, FA, DM, PM, IBM, MG, LEMS

Duchenne muscular dystrophy