Lambert-Eaton syndrome

• Alternative Names

  Myasthenic syndrome; Eaton-Lambert syndrome

• Causes, incidence, and risk factors

  Lambert-Eaton syndrome occurs when nerves cells do not release enough of a chemical called acetylcholine, which transmits impulses between nerves and muscles.

  The result is muscle weakness and other symptoms similar to myasthenia gravis. However, as the muscles continue to contract, the chemical (acetylcholine) can build up in sufficient quantities for strength to get slightly better.

  Lambert-Eaton syndrome may be associated with cancers such as small-cell lung cancer and autoimmune disorders.

• Symptoms
  • Weakness or loss of movement that varies in severity, such as:
    • Difficulty chewing
    • Difficulty climbing stairs
    • Difficulty lifting objects
    • Difficulty talking
    • Drooping head
    • Need to use hands to arise from sitting or lying positions
  • Swallowing difficulty, gagging, or choking
  • Vision changes such as:
    • Blurry vision
    • Double vision
    • Problems maintaining a steady gaze

  Additional symptoms that may be associated with this disease:

  • Blood pressure changes
  • Dizziness upon standing
  • Dry mouth
• Signs and tests

  A physical examination shows weakness or paralysis that gets slightly better with activity. Reflexes may be decreased. There may be loss of muscle tissue.

  Tests to help diagnose and confirm the condition may include:

  • EMG
  • Nerve conduction velocity
  • Tensilon test
• Treatment

  The main goal of treatment is to identify and treat any underlying disorders.

  A method called plasmapheresis may improve symptoms. Plasmapheresis involves removing blood plasma from the body and replaced it with fluid, protein, or donated plasma. This helps to make sure that any harmful proteins (antibodies) that are interfering with nerve function are removed from the body.

  Medications that suppress the immune response, such as prednisone, may improve symptoms in some cases. Medications may also include:

  • Anticholinesterase medications such as Neostigmine or Pyridostigmine
  • 3, 4-diaminopyridine, which increase the release of acetylcholine from nerve cells
• Expectations (prognosis)

  The symptoms of Lambert Eaton syndrome may improve with treatment of the underlying disease or by suppressing the immune system. However, not all people respond well to treatment.

• Complications
  • Difficulty breathing
  • Difficulty swallowing
• Calling your health care provider

  Call your health care provider if symptoms of this condition develop.

Review Date: 9/16/2008

Reviewed By: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.