Immune System

Recently Answered

• QWhat is the best way to eat if I have myasthenia gravis?

  1 Answer

  A

  

  A Reston Hospital Center answered

  If you have myasthenia gravis, the muscles that you use for chewing may become fatigued very easily. To prevent this, you may want to eat smaller meals more frequently throughout the day. Avoiding sticky and hard foods and replacing them with foods that are easier to chew may also be helpful.

• QWhat are the symptoms of lymphedema?

  2 Answers

  A

  

  A Dr. Sheldon Feldman, MD , Surgery, answered on behalf of Columbia University Department of Surgery

  Lymphedema can vary greatly in severity and is classified as subclinical, mild, moderate or severe. Most cases are subclinical, meaning that symptoms are so mild that people are unaware it is occurring. Mild or moderate cases might involve minor swelling of the arm, hand or even a single finger. The more severe it becomes, however, the more debilitating lymphedema can be. Swelling can become severe, people may lose motion in the limb, and the pressure of the extra fluid can cause chronic skin damage, leading to serious infections such as lymphangitis and cellulitis.

  See All 2 Answers
• QCan myasthenia gravis be prevented?

  1 Answer

  A

  

  A Reston Hospital Center answered

  Since the cause of myasthenia gravis is unclear, it is not believed to be preventable at this time. What may be prevented, however, is the worsening of your symptoms. To deal with the muscle weakness of myasthenia gravis, take measures to conserve your energy as much as possible. You can accomplish this by taking rest breaks following periods of activity. If possible, avoid stress and extreme heat. Certain drugs-quinine, calcium channel blockers, beta blockers, and certain antibiotics-should be avoided, as they can also worsen symptoms.

• QHow can doctors test for lymphedema?

  1 Answer

  A

  

  A Dr. Sheldon Feldman, MD , Surgery, answered on behalf of Columbia University Department of Surgery

  The development of lymphedema can be detected using a testing method called bioimpedance spectroscopy, which measures extracellular fluid in the limbs by passing low-dose electric current through the limb, to detect the way the body responds to fluid changes. The test is painless, fast (five minutes), noninvasive and portable.
• QHow is myasthenia gravis diagnosed?

  2 Answers

  A

  

  A Donna Hill Howes, RN , Family Medicine, answered

  Unfortunately, a delay of one or two years in diagnosis is not unusual in cases of myasthenia gravis. Because weakness is a common symptom of many other disorders, the diagnosis is often missed in people who experience mild weakness or in those individuals whose weakness is restricted to only a few muscles.

  The first steps in diagnosing myasthenia gravis include a review of the individual's medical history and physical and neurological examinations. The signs a physician must look for are impairment of eye movements or muscle weakness without any changes in the individual's ability to feel things. If the physician suspects myasthenia gravis, several tests are available to confirm the diagnosis.

  A special blood test can detect the presence of immune molecules or acetylcholine receptor antibodies. Most patients with myasthenia gravis have abnormally elevated levels of these antibodies. However, antibodies may not be detected in patients with only ocular forms of the disease.

  Another test is called the edrophonium test. This approach requires the intravenous administration of edrophonium chloride, or Tensilon (r), a drug that blocks the degradation of acetylcholine and temporarily increases the levels of acetylcholine at the neuromuscular junction. In people with myasthenia gravis involving the eye muscles, edrophonium chloride will briefly relieve weakness. Other methods of confirming the diagnosis include a version of nerve conduction study that tests for specific muscle fatigue by repetitive nerve stimulation. This test records weakening muscle responses when nerves are repetitively stimulated. Repetitive stimulation of a nerve during a nerve conduction study may demonstrate decrements of the muscle action potential due to impaired nerve-to-muscle transmission.

  A different test called single-fiber electromyography (EMG), in which single muscle fibers are stimulated by electrical impulses, can also detect impaired nerve-to-muscle transmission. Computed tomography may be used to identify an abnormal thymus gland or the presence of a thymoma.

  A special examination called pulmonary function testing, which measures breathing strength helps to predict whether respiration may fail and lead to a myasthenic crisis.

  This answer is based on source information from the National Institute of Neurological Disorders and Stroke.

  See All 2 Answers
• QWhat tests are used to diagnose myasthenia gravis?

  1 Answer

  A

  

  A Brigham and Women's Hospital answered

  There are several tests that taken together are almost certain for myasthenia gravis (an autoimmune neuromuscular disorder that leads to fluctuating muscle weakness and fatigue). Sometimes, the tests must be repeated several times, and even then, a very small number of cases remain uncertain. Most neuromuscular clinics can perform these tests -- some are blood tests, others related to electromyogram (EMG), and it can be useful to inject a drug called neostigmine, which improves myasthenia symptoms. There are several diseases that can imitate myasthenia, so a careful examination is required.
• QWhat are complications of myasthenia gravis?

  1 Answer

  A

  

  A Reston Hospital Center answered

  A serious-but treatable-complication of myasthenia gravis, is a myasthenic crisis. When a myasthenic crisis occurs, the muscles that control your breathing become too weak for proper ventilation. This medical emergency requires use of a ventilator until medications and blood filtering treatments can enable you to breathe on your own again. Possible triggers for a myasthenic crisis include fever, infection, or an adverse drug reaction.

• QHow does myasthenia gravis affect the body?

  1 Answer

  A

  

  A Reston Hospital Center answered

  In myasthenia gravis, a disruption in the communication between your nerves and muscles makes your muscles feel weak. For some, the weakness is localized to a specific muscle group. For others, the weakness is more general and can affect several muscle groups. Your weakness will become worse after periods of activity and improve after rest.

• QWhy does lymphedema occur in some women after surgery for breast cancer?

  1 Answer

  A

  

  A Dr. Sheldon Feldman, MD , Surgery, answered on behalf of Columbia University Department of Surgery

  If breast cancer cells are detected in the lymph nodes under the arm, the lymph nodes may be removed in order to prevent recurrence of the cancer (called lymph node dissection). When the normal pathway of lymph drainage is removed, sometimes the lymph fluid is unable to find another adequate path, causing the fluid to back up in the arm.
• QWho is at risk for developing lymphedema?

  1 Answer

  A

  

  A Dr. Sheldon Feldman, MD , Surgery, answered on behalf of Columbia University Department of Surgery

  Lymphedema develops in about 19% of women who have axillary lymph node dissection. Among those who have lymph node biopsy only, the rate of lymphedema is about 6%. The use of radiation after surgery increases the risk significantly, because radiation often closes collateral channels of fluid removal: among women who have lymph node dissection and radiation, the incidence of lymphedema may be as high as 40%. Other risk factors include being overweight, fluid retention due to weight or other causes, and limited range of motion in the arms due to chronic bursitis, trauma, or other causes.