What is Lambert Eaton Myasthenic Syndrome: Causes, Symptoms, Treatment

Lambert-Eaton Myasthenic Syndrome is an extremely rare autoimmune disorder which is characterized by gradual onset of muscle weakness especially of the thigh and pelvic muscles. Lambert-Eaton Myasthenic Syndrome is in most of the cases a precursor for small cell lung cancer and affects individuals mostly with a history of chronic long term smoking. The detection of the lung cancer almost always follows the diagnosis of Lambert-Eaton Myasthenic Syndrome.

This condition is found mostly in the elderly population, although in some cases even if an individual does not have a history of smoking and had no diagnosis of cancer, he or she can be affected at any age with Lambert-Eaton Myasthenic Syndrome.

Lambert-Eaton Myasthenic Syndrome is an autoimmune condition meaning that the defense mechanism of the body mistakenly acts against the healthy tissues of the body taking them to be foreign substances.

Lambert-Eaton Myasthenic Syndrome develops when the immune system of the body damages the calcium channels on the motor nerve membrane. The function of these channels is to induct calcium into the nerves resulting in release of acetylcholine.

Acetylcholine is a chemical which acts as a mediator between the nerve cells and muscles of the body. Due to this damage, less of acetylcholine is produced resulting in gradual muscle weakness especially in the pelvic and thigh region in cases of Lambert-Eaton Myasthenic Syndrome.

The primary presenting feature of Lambert-Eaton Myasthenic Syndrome is persistent muscle weakness and lethargy of the pelvic and thigh muscles. As a result of this disease, the affected individual may not be able to carry out any strenuous type of activity like negotiating stairs or walking for long distances.

The onset of symptoms is gradual and as the condition progresses, symptoms tends to get worse. As the condition advances, multiple muscles of the body start to get affected like the shoulder muscles and muscles of the lower extremities.

The affected individual also starts having problems with speech and tends to have dysphagia as well due to Lambert-Eaton Myasthenic Syndrome. The progression of symptoms is significantly hastened if there is a diagnosis of small cell lung cancer which happens in almost all the cases of Lambert-Eaton Myasthenic Syndrome.

Additionally, the affected individual will tend to have dry mouth, constipation, sexual dysfunction, and decreased sweating. Unintentional weight loss is also a characteristic feature of Lambert-Eaton Myasthenic Syndrome.

The diagnosis of Lambert-Eaton Myasthenic Syndrome is made from the distinct symptoms that is caused by this condition like muscle weakness and fatigue. A history of chronic long term smoking also point towards a diagnosis of Lambert-Eaton Myasthenic Syndrome.

To diagnose muscle weakness, specialized tests in the form of EMG and nerve testing may be done which will clearly delineate muscle weakness. Testing for reduced level of acetylcholine in the body virtually confirms the diagnosis of Lambert-Eaton Myasthenic Syndrome. A screening test for small cell lung cancer should be done for all patients with a known diagnosis of Lambert-Eaton Myasthenic Syndrome.

The treatment for Lambert-Eaton Myasthenic Syndrome depends on various factors including the age and overall health of the individual and the presence or absence of cancer in the patient. If there is presence of cancer then treatment is first directed towards treating the cancer. This may end up relieving some of the symptoms caused by Lambert-Eaton Myasthenic Syndrome also.

To treat Lambert-Eaton Myasthenic Syndrome, immunosuppressants can be of great value especially in extreme cases of Lambert-Eaton Myasthenic Syndrome.

Drugs used in treatment of this disease are prednisone either alone or in combination with azathioprine or cyclosporin which has shown to be quite effective in alleviating the symptoms of Lambert-Eaton Myasthenic Syndrome.