Lambert-Eaton syndrome is a muscle disease that causes muscle weakness. Lambert-Eaton syndrome has symptoms similar to myasthenia gravis, which is why it is sometimes called myasthenic syndrome. However, the causes of both diseases are different - Lambert-Eaton syndrome most often proves the development of cancer. What are the other causes of Lambert-Eaton syndrome? How do I recognize my symptoms? What is the treatment?

Lambert-Eaton myasthenic syndrome(LEMS, Lambert-Eaton myasthenic syndrome) is a disease that affects muscles making them weaken. It's similar to myasthenia gravis, which is why Lambert-Eaton syndrome is sometimes also called myasthenic syndrome.

Lambert-Eaton syndromeis a disease of the elderly - the average age of people with LEMS is 60 years. The condition is rarely diagnosed in children, but there are a few known cases of its development in people under 17 years of age. In addition, LEMS occurs with an almost equal frequency in men and women.

Lambert-Eaton syndrome - causes

Lambert-Eaton syndrome in most cases (about 85%) is of neoplastic origin, and thus is classified as paraneoplastic syndromes. Lambert-Eaton syndrome is most often (50% of patients) associated with small cell lung cancer. It can also be associated (but less frequently) with cancer of the breast, stomach, colon, prostate, bladder, kidney or gallbladder.

How does cancer contribute to the development of the disease? The cancer-fighting body is also believed to inadvertently attack the nerve endings of the muscles. It's important to know that LEMS symptoms often precede cancer symptoms. In most cases, the onset of cancer occurs within the first 2 years of onset of Lambert-Eaton syndrome.

About 15 percent LEMS is an autoimmune disease, i.e. one in which the immune system produces antibodies against its own cells and tissues - in this case against the so-called calcium channels at the nerve endings that go to the muscles. As a consequence, the ability of the nerve cells to send signals to the muscle cells is disrupted. This, in turn, causes a decrease in muscle strength.

Lambert-Eaton syndrome - symptoms

The predominant symptom is muscle weakness, usuallythe proximal muscles of the legs and arms (that is, thighs and arms). Then it becomes difficult to walk (especially significant difficulties in walking up the stairs are observed) and to raise the arms (the patient cannot, for example, brush his hair). Muscle pains may be an accompanying symptom.

In addition, symptoms may appear, such as:

  • dry mouth
  • sweating disorder
  • tearing reduction
  • male impotence
  • orthostatic hypotension, i.e. a drop in blood pressure (systolic by at least 20 mm Hg, diastolic pressure by 10 mm Hg) after standing - for example, when getting out of bed quickly

Less frequent (about 25% of patients) symptoms of the eye, such as ptosis or double vision. Occasionally, there may be problems talking, chewing or swallowing foods.

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Lambert-Eaton syndrome and myasthenia gravis

Lambert-Eaton syndrome and myasthenia gravis are diseases that share similar symptoms. The difference, however, is that with LEMS, little physical exertion brings improvement (albeit only temporarily). This is different than in the case of myasthenia gravis - despite the physical exertion, the patient's muscles become weaker and weaker. Characteristic for Lambert-Eaton syndrome is also the fact that the patient feels worse in the morning after waking up than in the evening - quite the opposite to myasthenia gravis. In addition, the first symptoms of myasthenia gravis are 65-70 percent. sick drooping eyelids. This symptom is rare in Lambert-Eaton syndrome.

Lambert-Eaton syndrome - diagnosis

If Lambert-Eaton syndrome is suspected, tests such as:

  • blood tests (including immunological tests)
  • electrostimulation boredom test (stimulating the nerve with electrical stimuli)
  • monofilament electromyography (SFEMG)
  • research to look for cancer. As the disease is most often associated with lung cancer, chest X-ray and bronchoscopy are performed. If no lung cancer is found, the tests should be repeated in six months, because, as mentioned, the cancer may appear even several years after the onset of LEMS symptoms

Physicians should rule out conditions such as myasthenia gravis, dermatomyositis / polymyositis, inflammatory demyelinating polyradiculoneuropathy, spinal muscular atrophy, and inclusion myositis.

Lambert-Eaton syndrome - treatment

If the cause of the disease is cancer, oncological treatment is applied. In addition, the patient is administered cholinesterase inhibitors,immunosuppressants (including prednisone and cyclophosphamide), as well as drugs that increase the amount of calcium in nerve endings (diaminopyridine). In periods of worsening of symptoms, plasmapheresis (cleansing the blood of undesirable elements - in this case of antibodies directed against the muscles) or immunoglobulins are administered.