Myasthenia Gravis Flashcards
1
Q
MG is characterized as
A
Weakness as day progresses or with further/repetitive use of muscles
-disorder of NMJ
2
Q
etiology of MG?
A
- AI destruction of post-synaptic NMJ ach receptors
- Ab binds to post synaptic ach receptors so ach cannot bind
3
Q
MCC MG
A
thymoma
4
Q
MC presenting sign of MG?
A
ptosis
5
Q
how to test for MG?
A
- ice pak test, place cold pak over eye for 2 min
- improvement is a positive sign
- neuromuscular transmission improved at lower temps
6
Q
how to distinguish b/w MG and cholinergic crisis?
A
Pts presents with fatigue, SOB, very weak/can’t stand
- If you give edrophonium and it gets worse it is a cholinergic crisis
- if it gets better it is MG crisis
- inhibits achase
7
Q
good lab test to order if you suspect MG?
A
Acetylcholine receptor antibody (AChR)
-if this Ab is present then they have MG
8
Q
if the AChR antibody test is negative, what is another test you can order?
A
MuSK (muscle-specific tyrosine kinase) antibody: 40–50% of AChR-negative patients have antibodies to MuSK
9
Q
what meds to avoid for pts w/MG?
A
fluoroquinolones and aminoglycosides
10
Q
treatment options for MG?
A
- any stigmine which are Achase inhibitors to allow Ach to stay in synapse
- prednisone
- immunosuppresants
