Pathophysiology of myasthenia gravis

Patient Profile

S.D., a 58-year-old African American male, was diagnosed with myasthenia gravis several years ago. He has been taking pyridostigmine and prednisone since then and has had few symptoms. Today, while visiting his daughter, he had a choking episode followed by the onset of severe weakness in his arms and legs along with respiratory distress. She drove him immediately to the emergency department.

Subjective Data

• Reports difficulty “getting enough air”
• Says food “got stuck in my throat”
• Having difficulty speaking clearly

Physical Examination

• Blood pressure 172/90, pulse 102, respirations 24 and shallow, temperature 99.9° F
• Oxygen saturation 91% on room air
• Symmetric muscle weakness involving all four limbs and jaw muscles
• One episode of bladder incontinence since arrival
• Tense and anxious
• Diaphoretic

Discussion Questions

1. Explain what is the pathophysiology of myasthenia gravis (MG) and what complication of myasthenia gravis is S.D. experiencing?
2. His daughter asks what may have caused her father to get worse. What would you tell her?