Exam 4 Myasthenia Gravis Flashcards Preview

Q4 Clin Med III (GI) > Exam 4 Myasthenia Gravis > Flashcards

Flashcards in Exam 4 Myasthenia Gravis Deck (11)
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1
Q

Myasthenia Gravis is?

A

Autoimmune dis of myoneural jxn

2
Q

Myasthenia Gravis pathophys?

A

Ab’s attack acetylcholine receptors (AChR) on post gang membrane of NMJ
Thymus abn in most

3
Q

Myasthenia Gravis basic defect?

Add’l defect?

A

↓ # of AChR on postsynap mm membrane

Postsynap folds flatten ->
↓ efficiency of transmission
ACh released normally but fails to trigger mm APs

4
Q

Myasthenia Gravis presentation? (6)

A
Proximal Skeletal mm weak/fatigue
Eyelid and EOM weak
Weak chewing, speaking, swallow
Weak respiratory mm
DTR normal
Worse w/ activity, better w/ rest
5
Q

Myasthenia Gravis tests? (4)

A

Repetitive mm activities = reproduce sxs

Tensilon Test = Anticholinesterase -> ↓ACh breakdown -> ↑stim of limited AChRs = improved mm strength

ACh receptor Ab test:
+ = diagnostic,
- result does not r/o

EMG = decremental response to stim

CT/MRI of thorax for thymoma

6
Q

Lambert-Eaton Myasthenic Synd is?

Presentation?

A

Impaired presynap release of ACh
U from CA-caused immune response

↓ or no DTRs
Dry mouth, Impotence
Nerve stim = incremental response

7
Q

Drug-induced Myasthenia U from?

A

Aminoglycoside ABX

Procainamide (antiarrhy)

8
Q

Neurasthenia presentation?

A

Weakness/fatigue
MM testing = jerky release
EMG = normal
Tensilon Test = negative

9
Q

Thyroid dysfxn and MG?

A

Hyper or hypo can produce mm weakness

10
Q

Progressive External Ophthalmoplegia is?

A

Rare disorder of EOM w/ proximal mm weakness

11
Q

MG tx? (5)

A

Anticholinesterase (Pyridostigmine): ↑ mm strength
Thymectomy: remission
Immunosupp: if AChE doesn’t work
Plasmapheresis: for acute exacerb, crisis, refractory
IVIG