3.14 Ch. 12.3 Flashcards
What does MG damage?
ACh receptors at the NMJ
What happens during MG?
repeated use of muscle leads to increasing weakness
What does botulism interfere with?
release of ACh from motor axon
What happens with botulism?
- produces acute, progressive weakness
- loss of stretch reflexes
- sensation remains intact
myopathy
disorder intrinsic to muscles
myopathy: sensation and autonomic function
- sensation intact
- autonomics intact
*because nervous system is not affected by myopathy
Later stages of myopaty
Coordination, muscle tone, and reflexes are unaffected until muscle atrophy becomes so severe that muscle activity cannot be elicited.
What are the benefits of using electrodiagnostic studies?
reveals pathologic location and are often diagnostic
nerve conduction studies can be used to differentiate among these:
- primarily myelinopathy and axonopathy processes
- UMN and LMN paresis
- mononeuropathy and polyneuropathy
- local conduction block and Wallerian degeneration
3 clinical signs of peripheral neuropathy are revealed in:
- ≥ 50 yo
- presence of 2-3 s/s
*correlate with highly electrodiagnostic evidence of peripheral neuropathy
3 clinical signs of peripheral neuropathy
- Absence of ankle jerk reflex despite facilitation
- Impaired vibration
- Impaired position sense of the great toe
evaluation of polyneuropathy: What increases along with severity of neuropathy?
reports of pins and needles sensations
evaluation of polyneuropathy: signs of damage result from
hypoactivity or hyperactivity of neurons
Important thing when evaluating for polyneuropathy
distinction between PNS and CNS dysfunction is vital**
What guides treatment decisions for polyneuropathy?
- sensory
- MMT
- EMG/NCV
