Turning LEMS 
 into strength 

For people affected by Lambert-Eaton myasthenic syndrome (LEMS), understanding the challenges ahead is one key to moving beyond them.


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Information has the power to change lives.

LEMS Aware was created to deliver relevant information, resources, and connections to patients and caregivers who may be living with or affected by LEMS. Wherever you are on your journey—searching for the right doctor, the right diagnosis, or the right treatment—this site can guide you to that next milestone.

Stay Informed

Get to know the many faces of LEMS! Read more about how symptoms present differently and shouldn’t be overlooked.

Get to know the many faces of LEMS! Read more about how symptoms present differently and shouldn’t be overlooked.

What is LEMS?

LEMS is a rare neuromusculara system in the body that includes nerve cells called neurons and the muscles they control disease that can have a profound effect on a person’s mobility and quality of life

Lambert-Eaton myasthenic syndrome, also known as LEMS, disrupts the communication between nerves and muscles. It is named after the two neurologists, Dr. Edward Lambert and Dr. Lee Eaton, who first identified the syndrome at the Mayo Clinic during the 1950s.

LEMS typically causes severe, debilitating, and progressive weaknessgradual worsening in the upper legs and hips, making it difficult for a person to walk or even stand. LEMS can also weaken the muscles of the upper arms and shoulders, making self-care and independence difficult. Some people with LEMS also experience other symptoms, such as dry mouth or problems with vision. You can learn more about all the symptoms of LEMS in the next section.

Is it LEMS?

Learn more about LEMS symptoms and how you can take charge of your health to get the proper diagnosis and treatment you need.


LEMS occurs when the body’s immune system mistakenly attacks a part of the nervous system called the neuromuscular junction, disrupting communication between the nerves and muscles.

In about 50% of people with LEMS, this abnormal immune system attack is associated with the presence of an underlying cancer in the body—most often an aggressive type of lung cancer called small cell lung cancer (SCLC).

Most cases of LEMS and SCLC occur in patients with a history of smoking.

For some patients, LEMS symptoms are an important early warning sign that alerts doctors to screen for cancer and get an earlier start on treatment. Download this helpful Doctor Discussion Guide.

Learn more about how doctors screen LEMS patients for cancer and how it may be treated if there is a co-occurrence.

LEMS AND Pregnancy

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“Pregnancy icon

LEMS Pregnancy Registry: In conjunction with the FDA, Catalyst Pharmaceuticals has created a registry to collect information about the safety of LEMS treatment in the event of pregnancy. Contact the registry as soon as you learn that you are pregnant by calling (855) 212-5856 or visiting www.lemspregnancystudy.com.


While the COVID-19 pandemic created concern and uncertainty for the entire world, the impact on people with chronic medical conditions was even more keenly felt. Patients searched the Internet for information regarding treatment and relied on their physicians for answers.

One online resource that continues to offer the most current and reliable COVID-19 guidance for physicians treating patients with LEMS is the website for the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM).

Click here to find the latest COVID-19 guidance from AANEM

Consult with your doctor regarding specific questions around your current LEMS treatment and COVID-19 vaccination

Be prepared for other medical situations!

Discover simple tips that may help you or your loved one with LEMS manage special circumstances such as surgery, a trip to the dentist, and more. Visit Considerations for When…

Ready to explore and learn more about LEMS?

How LEMS affects the body

Severe muscle weakness is typically the most recognizable sign of LEMS, but it’s not the only one. LEMS also causes other symptoms. Use the LEMS Symptom Map to learn all of the signs that may point to a diagnosis of LEMS.

Doctors who treat LEMS

Still undiagnosed? It may be time to schedule a visit with a specialist in neuromuscular disease. Visit the Diagnosis and Treatment page to learn more about LEMS experts who can put you on the path to feeling better.

Helpful lifestyle tips

Diagnosis and treatment are the most important milestones on the journey to feeling better, but there are other things that you can do to help manage your condition. Learn some helpful tips on the LEMS community page.


Stay informed

More content is on the way for LEMS Aware, including video stories with real patients who are living and thriving with LEMS. Sign up to stay informed about new additions to the website as well as other resources that become available.

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