What is Lambert-Eaton myasthenic syndrome

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder that affects the neuromuscular junction, the connection between nerves and muscles. It is characterized by muscle weakness and fatigue, particularly in the limbs. LEMS is caused by the immune system mistakenly attacking the voltage-gated calcium channels (VGCCs) in the nerve cells, which disrupts the release of neurotransmitters that signal muscle contractions.

The most common symptoms of LEMS include muscle weakness, especially in the legs and hips, difficulty in walking, climbing stairs, and lifting objects. Other symptoms may include dry mouth, blurred vision, difficulty swallowing, and autonomic dysfunction. LEMS is often associated with an underlying malignancy, particularly small cell lung cancer.

Diagnosis of LEMS involves a combination of clinical evaluation, electromyography (EMG) to measure muscle response, and blood tests to detect the presence of antibodies against VGCCs. Imaging tests may also be conducted to identify any associated tumors.

Treatment for LEMS focuses on managing symptoms and addressing the underlying cause. Medications such as calcium channel blockers, immunosuppressants, and cholinesterase inhibitors are commonly prescribed to improve muscle strength and function. In cases where LEMS is associated with cancer, treating the underlying malignancy is crucial.

While LEMS is a chronic condition, with proper management and treatment, individuals with LEMS can experience significant improvement in their muscle strength and overall quality of life.