Class 9 - Motor Endplate Disorders Flashcards
What is the most common disorder of neuromuscular transmission?
myasthenia gravis
Myasthenia is __ common in women than men, with incidence peaking in the ages of __ to __ in women and __ in men
twice as common
20s-30s in women, 50s-60s in men
75% of people with myasthenia gravis have an abnormal ___ gland.
thymus
Risk factors for myasthenia gravis include…
hyperthyroidism
thymic tumor
thyrotoxicosis/hyperthyroidism
immune disorders, such as RA
Myasthenia gravis is exacerbated:
before menstruation
after pregnancy
with chronic infections
What kind of antibodies are seen with myasthenia gravis?
Anti-ACh antibodies that can block ACh receptors or damage postsynaptic mm membrane
What is the pathogenesis of MG?
number of ACh receptors decreases, the remaining are flattened and there is decreased efficiency of neuromuscular transmission
What is a myasthenia crisis?
severe form of MG - lifethreatening, respiratory breathing can become very weak, causing severe breathing problems and leading to lung failure
What are the 4 categories of MG?
- Ocular
- Mild generalized
- Acute fulminating
- Late severe
What is the most common category of MG?
mild generalized (85%)
Ocular MG will see…
ptosis and diplopia
After 15-20 years of MG, weakness becomes __ and involved muscles usually become ___
fixed (permanent), atrophic
How is MG diagnosed?
history, observation, test for Anti ACh antibodies in serum
What is CRPS?
a systemic condition involving the pns, cns and immune system
Type 1 CRPS is different from type 2 in that…
1: trauma did not directly damage the nerves
2: trauma involves a major nerve (causalgia)
