Pathogenesis
Precipitants of Myaesthenic Crisis
- Infection
- Surgical procedures
- Drugs - neuromuscular blockers, aminoglycosides, macrolides, beta blockers, calcium channel blockers, corticosteroids
- Pregnancy
Manifestations
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)
Diagnosis
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
Management Options for Myaesthenia Gravis
Maintenance
- Anticholinesterase agents - pyridostigmine, neostigmine
- Immunosuppression (uncommonly)
- Thymectomy
Myaesthenic Crisis
- IV immunoglobulin
- Plasmapheresis
- Respiratory support
Next Page
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------