Diagnosis of Myasthenia Gravis

A diagnosis of Myasthenia Gravis requires an initial physical exam as well as a complete neurological exam to check for muscle weakness and any abnormalities in the muscle reflexes and feeling. Unfortunately, the chances of a delayed diagnosis or a misdiagnosis are high in the case of myasthenia gravis. This is because symptoms of the condition can be confused for symptoms of other illnesses.

In many cases, symptoms are mild enough to remain unnoticed for a while as well. After reviewing your past medical history, if your doctor suspects a diagnosis of myasthenia gravis, he may prescribe the following tests:

  • CT scan or MRI scans to rule out any tumor or an abnormal thymus gland
  • Nerve conduction studies to check for muscle fatigue
  • EMG or Single Fiber Electromyography can also detect abnormalities in nerve to muscle transmission
  • Acetylcholine receptor antibodies test (blood test) can confirm general myasthenia gravis. In cases of ocular myasthenia gravis (that affects only the eye muscles), levels of these antibodies are not elevated abnormally
  • An edrophonium test will indicate the presence of ocular myasthenia gravis
  • Pulmonary function tests to measure breathing strength. This also helps the doctor predict if the condition will result in severe respiratory problems - known as a myasthenia crisis