Symptoms:

Symptoms may include:

• Weakness or loss of movement that can be more or less severe, including:
  • Difficulty chewing
  • Difficulty climbing stairs
  • Difficulty lifting objects
  • Difficulty talking
  • Drooping head
  • Need to use hands to get up from sitting or lying positions
• Swallowing difficulty, gagging, or choking
• Vision changes such as:
  • Blurry vision
  • Double vision
  • Problems keeping a steady gaze

Symptoms related to the autonomic nervous system usually occur, and include:

• Blood pressure changes
• Dizziness upon standing
• Dry mouth

Signs and tests:

A detailed medical history will be taken to determine risk factors, such as a history of certain cancers.

A physical examination shows:

• Decreased reflexes
• Possible loss of muscle tissue
• Weakness or paralysis that gets slightly better with activity

Tests to help diagnose and confirm the condition may include:

• Electromyography (EMG) to test the health of the muscle fibers
• Nerve conduction velocity (NCV) to test the speed of electrical activity along nerves