What is Lambert-Eaton Myasthenic Syndrome (LEMS)?

Lambert-Eaton myasthenic syndrome, commonly known as LEMS, is a rare autoimmune disorder that affects the connection between the nerves and the muscles. In a healthy body, nerves release a chemical called acetylcholine to tell muscles to contract. In LEMS, the body’s immune system attacks the calcium channels on the nerve endings that are responsible for releasing this chemical. Without enough acetylcholine, the muscles do not receive the signal to move, leading to significant weakness. A unique feature of LEMS is that muscle strength may actually improve temporarily after a few seconds of exercise, which is the opposite of what happens in other similar conditions.

How common is LEMS?

LEMS is a very rare condition, estimated to affect approximately 3 out of every 1 million people. It is much less common than Myasthenia Gravis, which is a related but different neuromuscular disorder. LEMS is usually found in middle-aged and older adults. Interestingly, about 50% to 60% of LEMS cases are associated with an underlying cancer, most commonly small-cell lung cancer. In these cases, the condition is often the first sign that a tumor is present, sometimes appearing months or years before the cancer is detected by other means.

What are the symptoms of LEMS?

The symptoms of LEMS typically develop slowly, unlike those of many other neurological conditions. The weakness usually starts in the lower body and moves upward. Common signs include:

• Leg Weakness: Difficulty walking, climbing stairs, or rising from a chair. The legs often feel heavy.
• The Gowers Sign: Needing to use the hands to push off the thighs to stand up.
• Autonomic Symptoms: Many patients experience a dry mouth, constipation, or blurred vision because the nerve-muscle communication issue also affects the involuntary nervous system.
• Aching Muscles: A dull ache in the thighs and hips is common.
• Decreased Reflexes: When a doctor taps the knee with a reflex hammer, there is often little to no response.
• Temporary Improvement with Exercise: A patient might find that after a brief period of muscle use, their strength briefly returns before fading again.
• Drooping Eyelids: Though less common than in Myasthenia Gravis, some patients may experience mild eyelid drooping or double vision.

What causes LEMS?

LEMS is caused by an autoimmune attack on the voltage-gated calcium channels at the neuromuscular junction. The cause of this attack generally falls into two categories:

1. Paraneoplastic (Cancer-related): In many patients, particularly those with a history of smoking, the immune system creates antibodies to fight a lung cancer tumor. Because the surface of these cancer cells looks similar to the calcium channels on nerve endings, the immune system mistakenly attacks the nerves as well.
2. Primary Autoimmune: In other patients, there is no underlying cancer. Instead, the immune system malfunctions due to a combination of genetic predisposition and unknown environmental triggers.

What are the complications of LEMS?

The most significant complication of LEMS is the potential for respiratory failure, though this is rare compared to other neuromuscular diseases. Other complications include:

• Increased Risk of Falls: Due to profound leg weakness.
• Delayed Cancer Diagnosis: If the neurological symptoms are ignored, an underlying lung tumor may grow undetected.
• Drug Sensitivity: Patients with LEMS can have dangerous reactions to certain types of anesthesia and antibiotics, which can lead to sudden, severe muscle paralysis.

How do doctors diagnose LEMS?

Diagnosis involves a combination of clinical exams and specialized testing:

• Repetitive Nerve Stimulation (RNS): This is a specific type of EMG test. In LEMS, the muscle’s electrical response is initially very low but increases significantly after the patient exercises the muscle for 10 seconds. This is a classic diagnostic sign.
• Blood Tests: Testing for the presence of P/Q-type voltage-gated calcium channel antibodies, which are found in about 85% to 90% of patients.
• Cancer Screening: Because of the strong link to lung cancer, every person diagnosed with LEMS must undergo a chest CT scan or a PET scan to look for hidden tumors.
• Neurological Examination: Assessing muscle strength and checking for diminished tendon reflexes.

How is LEMS treated?

Treatment focuses on improving muscle strength and addressing any underlying malignancy.

• Amifampridine (3,4-DAP): This is often the first-line medication. It works by blocking potassium channels, which keeps the calcium channels open longer, allowing more acetylcholine to be released.
• Cholinesterase Inhibitors: Medications like pyridostigmine can help keep acetylcholine active at the muscle site for a longer time.
• Immunotherapy: Treatments like IVIG, plasma exchange, or steroids are used to lower the level of harmful antibodies in the blood.
• Tumor Treatment: If cancer is found, treating it with chemotherapy, radiation, or surgery often leads to a major improvement in muscle strength.

What can I expect if I have LEMS?

The outlook for LEMS depends largely on whether it is associated with cancer. If no cancer is found, most patients respond well to treatment and can maintain a high level of physical function for many years. For those with cancer, the prognosis is determined by the success of the cancer treatment. In both cases, close coordination between a neurologist and an oncologist is necessary.

Can LEMS be prevented?

There is no known way to prevent the primary autoimmune form of LEMS. However, since the majority of paraneoplastic cases are linked to small-cell lung cancer—which is almost exclusively caused by smoking—avoiding tobacco is the most effective way to reduce the risk of developing this specific form of the disease.

How do I take care of myself?

Patients with LEMS should focus on energy conservation. Planning activities for times when strength is at its peak and taking frequent breaks can help manage daily life. It is crucial to inform any surgeon or dentist about a LEMS diagnosis, as certain medications used in surgery can be life-threatening for these patients. A healthy diet and avoiding infections can also help keep the immune system stable.

Why choose Tender Palm Super-Speciality Hospital for Lambert-Eaton Myasthenic Syndrome (LEMS) Treatment in Lucknow, India?

Tender Palm Super-Speciality Hospital offers advanced Lambert-Eaton Myasthenic Syndrome (LEMS) treatment in Lucknow, India, at an affordable cost. We have a team of experienced neurologists who provide accurate diagnosis and treatment options including immunotherapy, symptomatic medication management, and comprehensive neuromuscular rehabilitation procedures. Our Neurology and Neuromuscular Disorder Care team has decades of experience in successfully treating Lambert-Eaton Myasthenic Syndrome (LEMS) in Lucknow, India.

To seek an Expert Consultation for for Lambert-Eaton Myasthenic Syndrome (LEMS) Treatment in Lucknow, India:

Call us at +91-9076972161
Email at care@tenderpalm.com

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