Time Course of EMG/NCS Findings
Topic: Pharmacology
Created on Tuesday, January 16 2007 by
Last modified on Thursday, January 25 2007.
Sadly, you suffer from a compound fracture of your left 5th toe. Your diabolical surgeon recommends general anesthesia for an open reduction.
When you awaken, he proudly announces, "Congratulations! I have successfully severed your median nerve at its origin off the brachial plexus!"
You are understandably dumbfounded.
On needle EMG, when might you expect to see long, large, polyphasic motor unit action potentials in the affected muscles?
A) Several months B) 10 to 14 days C) 7 to 10 days D) 3 to 4 weeks E) Never
This question was created on January 16, 2007 by .
This question was last modified on January 25, 2007.
ANSWERS AND EXPLANATIONS
A) several months
This answer is correct.
After an injury which causes destruction of a peripheral nerve or root, reinnervation typically takes months to occur. Long, large, polyphasic units are a sign of reinnervation. (
See References)
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B) 10 to 14 days
This answer is incorrect.
After an injury which causes destruction of a peripheral nerve or root, reinnervation typically takes months to occur. Long, large, polyphasic units are a sign of reinnervation. (
See References)
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C) 7 to 10 days
This answer is incorrect.
After an injury which causes destruction of a peripheral nerve or root, reinnervation typically takes months to occur. Long, large, polyphasic units are a sign of reinnervation. (
See References)
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D) 3 to 4 weeks
This answer is incorrect.
After an injury which causes destruction of a peripheral nerve or root, reinnervation typically takes months to occur. Long, large, polyphasic units are a sign of reinnervation. (
See References)
|
| | |
| | |
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E) never
This answer is incorrect.
After an injury which causes destruction of a peripheral nerve or root, reinnervation typically takes months to occur. Long, large, polyphasic units are a sign of reinnervation. (
See References)
|
| | |
| | |
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References:
1. Preston, D.C., and Shapiro, B.E. (2005). Electromyography and Neuromuscular Disorders: Clinical-Electrophysiologic Correlations, 2nd Edition. Elsevier, Philadelphia. | |
2. Guarantors of Brain. (2000). Aids to the Examination of the Peripheral Nervous System, fourth edition. W.B. Saunders, Edinburgh. | |
3. Moore, K.L. (1992). Clinical Oriented Anatomy, 3rd Edition. Williams & Wilkins, Baltimore. | |
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pharmacology
Time Course of EMG/NCS Findings
Question ID: 01160700
Question written by . (C) FrontalCortex.com 2006-2009, all rights reserved.
Created: 01/16/2007
Modified: 01/25/2007
Estimated Permutations: 0