Lambert-Eaton Myasthenic Syndrome (LEMS)

Lambert-Eaton syndrome, also known as Lambert-Eaton myasthenic syndrome, is a condition in which the immune system attacks the neuromuscular junctions — the areas where your nerves and muscles connect. Normally, your nerve cells pass signals along to your muscle cells. These signals help your muscles move. Because Lambert-Eaton syndrome affects the way your nerves and muscles communicate, making it difficult to move your muscles as you normally would.

This condition is often associated with a certain type of cancer called small cell lung cancer. This syndrome may result from your body's efforts to fight the underlying cancer.

In some of the remaining cases, Lambert-Eaton syndrome develops following another autoimmune disease. Sometimes the cause is not known.

These are possible symptoms of Lambert-Eaton syndrome:

• Weak muscles—weakness is often relieved temporarily after exercise or exertion.

• Trouble walking.

• Tingling sensation in the hands or feet.

• Eyelid drooping.

• Fatigue.

• Dry mouth.

• Trouble speaking and swallowing.

• Trouble breathing.

• Bladder and bowel changes.

• Erectile dysfunction.

Your healthcare provider will review your symptoms with you and do a physical exam. A special blood test may show that you have this condition. You may also undergo a test called electromyography, which shows how well your muscles are working. Because Lambert-Eaton syndrome is associated with lung cancer, your provider may order X-rays or a CT scan of your lungs. Another condition called myasthenia gravis has symptoms that are very similar to Lambert-Eaton syndrome. Your healthcare provider will use the results of the electromyography and other tests to tell the difference between the conditions.

If your healthcare provider finds that you have this condition, you'll be checked for lung cancer and other cancers, such as lymphoma. If cancer isn’t found at first, you may need regular check-ups to keep looking for an underlying cancer, as Lambert-Eaton syndrome may appear as much as 3 years before a cancer diagnosis.

If you have cancer, your healthcare provider may treat it with surgery, radiation, or chemotherapy. If you have cancer and respond well to treatment, your Lambert-Eaton syndrome is more likely to get better. Your provider may also prescribe medicines to suppress your immune system or to help improve the signals between your nerve and muscle cells.

You may also undergo a treatment called plasmapheresis. This involves replacing the plasma in your blood. This removes harmful immune system proteins from your blood that may be involved in the condition.

Because the exact cause of Lambert-Eaton syndrome isn’t fully understood, it’s not entirely clear how to prevent the disease. The best way to reduce your risk for lung cancer, often associated with Lambert-Eaton syndrome, is not to smoke. Other steps that may help lower your risk for lung cancer include:

• Avoid exposure to tobacco smoke.

• Eat more fruits and vegetables.

• Have your home checked for radon.

Symptoms of Lambert-Eaton Syndrome may become worse when you're warm or have a fever. As a result, avoid taking hot showers or baths and contact your healthcare provider if you start developing signs of a cold or the flu. Exercising on a regular basis and getting enough sleep may also help you manage your symptoms.