MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Neuromuscular & Muscular
Neuromuscular & Muscular

Myasthenia Gravis



  • Precipitants of Myaesthenic Crisis

  • Infection
  • Surgical procedures
  • Drugs - neuromuscular blockers, aminoglycosides, macrolides, beta blockers, calcium channel blockers, corticosteroids
  • Pregnancy


  • Manifestations of Myaesthenia Gravis

  • Fatiguing muscle weakness (worse with use and improved with rest) affecting the eyes, face, oropharynx, trunk and limbs
  • Myaesthenic crisis (respiratory failure)


Patients with myaesthenic syndromes exhibit muscle fatigability, or the inability to maintain contraction of muscles over time.
  • Clinical Signs

  • Skeletal Muscle Fatiguability

  • Simpson's test - ptosis on sustained upward gaze
  • Peek sign - inability to maintain sustained eye closure
  • Bulbar fatiguability - development of nasal speech with reading
  • Proximal muscle fatigability - inability to maintain arms above the head
  • Signs of Management

  • Thymectomy scar


  • Management Options for Myaesthenia Gravis

  • Maintenance

  • Anticholinesterase agents - pyridostigmine, neostigmine
  • Immunosuppression (uncommonly)
  • Thymectomy
  • Myaesthenic Crisis

  • IV immunoglobulin
  • Plasmapheresis
  • Respiratory support
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...