Newly Diagnosed: Taking the First Step on Your Journey

Becoming educated is a good place to start on your journey with Lambert-Eaton myasthenic syndrome (LEMS). Whether you are a patient or a caregiver, knowing as much as possible about the disease will help you be a more active participant in your or your loved one’s healthcare. Learn more below about LEMS and its causes, symptoms, and diagnosis.


LEMS is a rare autoimmune disease that mainly affects muscles in the lower limbs. It is named after Edward Lambert and Lee Eaton, neurologists at the Mayo Clinic in Rochester, Minnesota, who described the syndrome in the 1950s and ’60s.

The disease is characterized by muscle weakness that starts in the lower limbs, making walking and climbing stairs more difficult. As the disease progresses, the arms and shoulders are also affected, and everyday tasks can become a challenge.

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LEMS primarily affects the voluntary muscles — the group of muscles in the body that can be moved at will. But the autonomic nervous system also may be mildly affected.

The primary symptom of LEMS is a weakness in the leg and arm muscles, which can affect mobility. Patients also may experience frequent muscle pain and cramps. As the condition progresses, the shoulder muscles, throat muscles that support speech and swallowing, and muscles in the eyes also may be affected.

To learn more about the symptoms of LEMS, click the links below.

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LEMS can be associated with cancer or can occur spontaneously. It is caused by antibodies produced by the immune cells that mistakenly attack the neuromuscular junction, the point where nerve and muscle cells meet, disrupting the communication between the nervous and muscular systems. This results in weakening of the muscles because they do not receive constant signals from the nervous system to contract or relax.

To learn more about the causes of LEMS, click the links below.

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Diagnosing LEMS is a multi-step approach that involves a thorough assessment of the symptoms. Multiple diagnostic tests are essential, as the symptoms of LEMS often overlap with those of another autoimmune disease, myasthenia gravis.

The first step in the diagnostic process is a physical examination where the neurologist will look for signs of weakness in the arms and legs, which can be indicative of the disease.

To learn more about how LEMS is diagnosed, click on the links below.

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Your LEMS Community

A great way to get more information is directly from those in the LEMS community. Visit the Lambert-Eaton News forums to discuss issues, ask questions, and share your experiences with others.

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