FrontalCortex, Inc. is a non-profit corporation dedicated to neurology education.

Upper extremity muscle function and innervation 02

Topic: Anatomy

Created on Monday, August 18 2008 by jdmiles

Last modified on Monday, August 18 2008.

During a needle EMG, you notice a large number of fibrillations in the abductor pollicis brevis muscle while the patient is at rest. From this, you deduce that the patient has a lesion. Of the following options, which lesion is most compatible with the EMG findings?

 
        A) A lesion in the posterior cord
 
        B) A C6 radiculopathy
 
        C) A stroke
 
        D) A lesion in the lower trunk
 
        E) A lesion in the middle trunk
 

 


Back to the question = Go back to the top of the page.
See another question like this one = Reload a different version of this question ().
Click here for a random question = Load a random question from the database.
Clone this question = Use this question as a template to create a totally NEW question.
Rate this question = Enter detailed rating for this question!
Average user rating for this question = 3 = How users like you have rated this question.
This question was created on August 18, 2008 by jdmiles.
This question was last modified on August 18, 2008.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ANSWERS AND EXPLANATIONS




A) a lesion in the posterior cord

This answer is incorrect.


The fibrillations suggest an active peripheral nerve lesion. The abductor pollicis brevis muscle receives innervation from the median nerve, the medial cord, the lower trunk, and the C8 and T1 nerve roots.  (See References)

Back to the questionSee another question like this oneClick here for a random questionClone this question Rate this questionAverage user rating for this question = 3
Please log in if you want to rate questions.

 

 

 

 

 

 

 

 

 




B) a C6 radiculopathy

This answer is incorrect.


The fibrillations suggest an active peripheral nerve lesion. The abductor pollicis brevis muscle receives innervation from the median nerve, the medial cord, the lower trunk, and the C8 and T1 nerve roots.  (See References)

Back to the questionSee another question like this oneClick here for a random questionClone this question Rate this questionAverage user rating for this question = 3
Please log in if you want to rate questions.

 

 

 

 

 

 

 

 

 




C) a stroke

This answer is incorrect.


The fibrillations suggest an active peripheral nerve lesion. The abductor pollicis brevis muscle receives innervation from the median nerve, the medial cord, the lower trunk, and the C8 and T1 nerve roots.  (See References)

Back to the questionSee another question like this oneClick here for a random questionClone this question Rate this questionAverage user rating for this question = 3
Please log in if you want to rate questions.

 

 

 

 

 

 

 

 

 




D) a lesion in the lower trunk

This answer is correct.


The fibrillations suggest an active peripheral nerve lesion. The abductor pollicis brevis muscle receives innervation from the median nerve, the medial cord, the lower trunk, and the C8 and T1 nerve roots.  (See References)

Back to the questionSee another question like this oneClick here for a random questionClone this question Rate this questionAverage user rating for this question = 3
Please log in if you want to rate questions.

 

 

 

 

 

 

 

 

 




E) a lesion in the middle trunk

This answer is incorrect.


The fibrillations suggest an active peripheral nerve lesion. The abductor pollicis brevis muscle receives innervation from the median nerve, the medial cord, the lower trunk, and the C8 and T1 nerve roots.  (See References)

Back to the questionSee another question like this oneClick here for a random questionClone this question Rate this questionAverage user rating for this question = 3
Please log in if you want to rate questions.

 

 

 

 

References:

1. Preston, D.C., and Shapiro, B.E. (2005). Electromyography and Neuromuscular Disorders: Clinical-Electrophysiologic Correlations, 2nd Edition. Elsevier, Philadelphia. (ISBN:075067492X)Advertising:
Back to the questionSee another question like this oneClick here for a random questionClone this question Rate this questionAverage user rating for this question = 3
Please log in if you want to rate questions.

 

FrontalCortex.com -- Neurology Review Questions -- Neurology Boards -- Board Review -- Residency Inservice Training Exam -- RITE Exam Review
anatomy
Upper extremity muscle function and innervation 02
Question ID: 081808096
Question written by J. Douglas Miles, (C) 2006-2009, all rights reserved.
Created: 08/18/2008
Modified: 08/18/2008
Estimated Permutations: 198000

User Comments About This Question:

0 user entries
Please log in if you'd like to add a comment.