Lambert-Eaton Myasthenic Syndrome

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Lambert-Eaton Myasthenic Syndrome (LEMS) is a rare autoimmune disorder that affects the neuromuscular junction, leading to muscle weakness and fatigue. It is often associated with other symptoms such as dry mouth, difficulty swallowing, constipation, decreased reflexes, blurred vision, drooping eyelids, and difficulty speaking. Understanding the causes, symptoms, and treatment options for LEMS is crucial for individuals diagnosed with this condition.

Causes of Lambert-Eaton Myasthenic Syndrome

LEMS is caused by an autoimmune response where the body’s immune system mistakenly attacks the neuromuscular junction. This junction is responsible for transmitting signals from the nerves to the muscles, allowing them to contract and function properly. In LEMS, the immune system produces antibodies that target specific proteins in the neuromuscular junction, impairing its ability to transmit signals effectively.

Symptoms of Lambert-Eaton Myasthenic Syndrome

Muscle Weakness and Fatigue

One of the primary symptoms of LEMS is muscle weakness, which typically starts in the lower limbs and gradually progresses to other muscle groups. Individuals with LEMS may experience difficulty walking, climbing stairs, or lifting objects. Fatigue is also common, with muscles becoming easily tired even after minimal exertion.

Dry Mouth and Difficulty Swallowing

LEMS can affect the salivary glands, leading to a dry mouth. This can cause discomfort and difficulty in speaking or swallowing. Adequate hydration and the use of saliva substitutes can help alleviate these symptoms.


Due to the involvement of the autonomic nervous system, individuals with LEMS may experience constipation. This occurs when the muscles in the digestive tract do not contract properly, leading to difficulty in passing stools. A high-fiber diet, increased fluid intake, and regular exercise can help manage constipation.

Decreased Reflexes

LEMS can cause a decrease in reflexes, making it harder for individuals to react quickly to stimuli. Reflexes such as the knee-jerk reflex may be diminished or absent. This can impact coordination and balance, increasing the risk of falls.

Blurred Vision and Drooping Eyelids

Some individuals with LEMS may experience blurred vision and drooping eyelids, known as ptosis. This occurs due to the weakness of the muscles responsible for controlling eye movement and eyelid elevation. Eye drops and corrective lenses can help manage these visual disturbances.

Difficulty Speaking

LEMS can affect the muscles involved in speech production, leading to difficulty in articulating words and speaking clearly. Speech therapy and exercises can be beneficial in improving communication for individuals with LEMS.

Treatment Options for Lambert-Eaton Myasthenic Syndrome

While there is no cure for LEMS, various treatment options can help manage the symptoms and improve quality of life for individuals with this condition.

Immunosuppressive Therapy

Immunosuppressive medications, such as corticosteroids and immunosuppressants, can help reduce the autoimmune response and decrease the production of antibodies that target the neuromuscular junction. These medications aim to slow down the progression of LEMS and alleviate symptoms.


Plasmapheresis is a procedure where the plasma, which contains the antibodies responsible for attacking the neuromuscular junction, is removed from the blood. The plasma is then replaced with a substitute, reducing the antibody levels and improving muscle function temporarily.

Intravenous Immunoglobulin (IVIG) Therapy

IVIG therapy involves the infusion of immunoglobulins, which are antibodies derived from donated blood. These immunoglobulins help modulate the immune response and reduce the attack on the neuromuscular junction, providing temporary relief from LEMS symptoms.

Physical Therapy

Physical therapy plays a crucial role in managing LEMS by improving muscle strength, flexibility, and coordination. A physical therapist can design a personalized exercise program to target specific muscle groups and enhance overall mobility.

Supportive Measures

Supportive measures such as assistive devices, mobility aids, and modifications to the living environment can greatly improve the quality of life for individuals with LEMS. These measures aim to compensate for muscle weakness and promote independence.


Lambert-Eaton Myasthenic Syndrome is a rare autoimmune disorder characterized by muscle weakness, fatigue, and various other symptoms. While there is no cure for LEMS, treatment options such as immunosuppressive therapy, plasmapheresis, IVIG therapy, and physical therapy can help manage the symptoms and improve overall well-being. It is essential for individuals with LEMS to work closely with healthcare professionals to develop a comprehensive treatment plan tailored to their specific needs. By understanding the causes, symptoms, and available treatment options, individuals with LEMS can take proactive steps towards managing their condition and living a fulfilling life.

Haroon Rashid, MD
Rate author
Urgent Care Center of Arlington, VA
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