Myasthenia Gravis Flashcards
Overview
Produces sporadic, progressive weakness and abnormal fatigue of striated (skeletal) muscles.
Exacerbated by exercise and repeated movement
Improved by anticholinesterase drugs
Usually affects muscles inervated by the CNs (face, lips, tongue, neck), but can affect any muscle group
Unpredictable course of recurring exacerbations and periodic remissions
No known cure
May be life threatening if it involves the respiratory system
Causes/Incidence
May result from an autoimmune response
Ineffective acetylcholine release
Inadequate muscle fiber response to acetylcholine
Affects 3 of every 10, 000 people of any age
More common in young women and older men
20% of neonates born to mothers with MG have transient myasthenia (and occasionally persistent)
Disease may coexist with immunologic & thyroid disorders
Remissions occur in about 25% of patients
Complications
Respiratory distress
Pneumonia
Chewing and swallowing difficulties
Aspiration
S&S
Skeletal muscle weakness
Fatigabilty
Early on fatigue of certain muscles may be all that occurs
Later it may be severe enough to cause paralysis
Muscles usually strongest in am and weaken through day, especially after exercise
Onset may be sudden or insidious
Weak eye closure, ptosis & diplopia may be first signs
Muscle weakness progressive
Blank, expressionless face
Nasal vocal tones
Dx
Fatigue with repeated muscle use over short period of time with improvement with rest
Electromyography may help confirm
Acetylcholine receptor antibodies in the blood is highly specific and fairly sensitive for diagnosis
Tx
Symptomatic
Anticholinesterase drugs
Corticosteroids
Immunosuppressants
Special Considerations
Continuity of care important
Plan activity to make most of energy peaks
Warn patient to avoid strenuous exercise, stress, infection, and needless exposure to the sun or cold.
Myasthenia Gravis Foundation
