Myasthenia gravis

Symptoms:

• vision changes:
  • double vision
  • difficulty maintaining steady gaze
  • eyelid drooping

• swallowing difficulty, frequent gagging or choking
• weakness or paralysis that worsens with exertion later in the day
• drooping head
• poor posture
• difficulty climbing stairs
• difficulty lifting objects
• need to use hands to arise from sitting or recumbent positions
• difficulty talking
• difficulty chewing
• weakness or paralysis improves with rest
  • muscle function best after rest
  • muscle function worst at the end of the day

• hypotonia

Additional symptoms that may be associated with this disease:

• swelling, overall
• muscle atrophy
• hoarseness or changing voice
• fatigue
• facial paralysis
• drooling
• breathing, absent temporarily
• breathing difficulty

Signs and tests:

Examination may be normal or may show muscle weakness that progressively worsens as the muscle is used. Reflexes and sensation are normal. Weakness may affect the arms; legs; the muscles for breathing, swallowing, talking, or any muscle group. Facial involvement is usually early. Eyelids may droop.

• EMG results vary.
• Repetitive stimulation nerve conduction studies are more productive (studies of nerve impulse conduction, performed as the nerve supplying the muscles is repeatedly stimulated).
• Acetylcholine receptor antibodies may be present in the blood.
• A Tensilon test is positive in most cases. A baseline muscle strength evaluation is performed. After Tensilon (edrophonium; a medication that blocks the action of the enzyme that breaks down the transmitter acetylcholine) is given, muscle function improves noticeably.

This disease may also alter the results of the following tests:

• creatinine - urine
• creatinine