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* nbme 12 block 1 q 48
 #620702  
  zeus23 - 10/10/11 14:35
 
  It has a spinal cord section,

A 23-year-old man has had progressive weakness and atrophy of the intrensic muscles of the left hand during the past 3 months. The most likely cause is damage to which of the following labeled sites in the corss section of the spinal cord shown?

now i know its lower motor neuron, so i picked the anterior horn, but it was the wrong answer.Can anyone please explain why the answer is the lateral horn?

thanks
 
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* Re:nbme 12 block 1 q 48
#2518346
  samhi08 - 11/06/11 10:02
 
  you have to pick the answer labelling cervical enlargment on left side  
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* Re:nbme 12 block 1 q 48
#2610424
  vera16 - 03/10/12 15:45
 
  "Atrophy" is the motor neuron sign lesion. Hence, the choice has to be a lower motor neuron aka anterior horn. So it is either E or F.

"Primary motor neurons arise in contralateral cortex, decussate at pyramids, then descend in the lateral CST (ignoring trunk stabilizers in the anterior CST) on the same side as the anterior horns on which they synapse. An anterior horn lesion on the same side as the motor deficit would be expected. Thus, left intrinsic hand muscle atrophy implies left LMN lesion. If it's in the spinal cord, I would think that it's the anterior horn."

After taking everything into consideration. The answer is F. Left lower motor neurons/left anterior horns.

Kaplan Neurology has a really good diagram for all of these pathways.
 
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* Re:nbme 12 block 1 q 48
#2639831
  drfuture - 04/11/12 14:44
 
  F is wrong as i chose it it in the online nbme can some body help here  
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* Re:nbme 12 block 1 q 48
#2639832
  tomstong - 04/11/12 14:47
 
  Guys please share your NBME 11 and 12. My e-mail is oyetong@yahoo.com  
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* Re:nbme 12 block 1 q 48
#2639838
  drfuture - 04/11/12 14:57
 
  guys the G is not the intermediate horn cuz this is not the thoracic spinal cord  
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* Re:nbme 12 block 1 q 48
#2717844
  nadia2012 - 08/17/12 11:01
 
  labl on the pecture is r.the let side is the right side ,,we need to call the nbme  
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* Re:nbme 12 block 1 q 48
#2717845
  nadia2012 - 08/17/12 11:05
 
  labl on the pecture is r.the let side is the right side ,,we need to call the nbme  
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* Re:nbme 12 block 1 q 48
#2717849
  nadia2012 - 08/17/12 11:08
 
  please  
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