Ancylostoma
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I thought this was interesting, for some reason it kinda stuped me a little. I think the answer in kaplan is a little unexplanatory even though I now have a pretty good guess. Lets see what you guys figure out.
A parient suffers a stroke and presents with weak right limbs, a mandible that deviates to the right on protursion, and anesthesia of the face and scalp. Where is the lesion?
A pons
b tirgeminal Nerve
c Posterior limb of the internal capsule
d medulla
E Paracentral lobule
Edited by Ancylostoma on 12/16/06 - 07:36 PM
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| johnnyu041
Forum Junior
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I say D. Medulla but after the corticospinal tract crosses over since it seems both the Trigeminal n. and the pyrimidal system are involved.....is that right or am i completley wrong?
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| Ancylostoma
Forum Guru
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At the moment you completely wrong, you must remember that the motor nucleus and principle sensory nucleus of the trigeminal nerve are in the pons , The spinal nucleus in in the medulla Try again I found this questions a little funny too.
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| johnnyu041
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Okay well then im completly confused...not sure if its paracentral lobule cause i dont know where that is....i dont think its the other ones though cause the corticospinal tract crosses at the medulla and they are all above that so the weakness would be contralateral....can you explain the answer?
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| Ancylostoma
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Ok jonny, the reason this question is tough is because its a atypical presentation or kaplan screwed up. Either way. you must use the process of elimination. Eliminate the trigeminal nerve because ti would not cause the weakness in the upperlimbs, the post limb of the capsule because whie it could cause the weakness in the upperlimbs it cant cause cn 5 paralysis. Cn nuclie recieve bilateral innevation via corticobulbar fibers, a posterior lim lesion can only cause the contralater lower half to the face to be paralysed(cn7). Medulla has nothing to do with the cn5 , and finally paracentral lobule I believe controls urintation and lwer led on the upper medial surface of the hemisphere. It has to be the pons. Normally the pos would present with a facial pralysis on one side and contralater body paralysis. So this lesion seem to be unusual. Possible a kaplan mistake. Either way the question is still answerable .
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| johnnyu041
Forum Junior
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Thanks! good explanation too it helped a lot, hey when are you taking the exam?
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| Ancylostoma
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Tsking the exam on the 30th, but I fear the sucker. I think I might postpone. My problem is I have to teach myself to slow down and think out problems and of it, I would like to get in a lot more studying. We will see how it goes though.
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| macTT
Forum Senior
Topics: 32
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Ancylostoma,
I agree with you too.....question stem is rather vague....however, I would still go wtih Pons A because it is very similar to that of lateral pontine sydrome. I am taking my exam on the 30th too.....sucks that we don't have Xmas off....wish you best of luck (same for me too)
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| Ancylostoma
Forum Guru
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Good luck to you mactt, make sure you know that in lateral pontine syndrom thre would be a contralateral los of pain and temp from the body. Here both are ipsilateral. Still, the only possble answer would be a lesion somewhere in the pons.
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