high yield neuroanatomy errata?

[ENThopeful]

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does this exist?

Pg 35 says that an uncal hemorrhage causes a contralateral hemiparesis due to compression of kernohan's notch.

Shouldn't an uncal hemorrhage on say the right side cause ipsilateral hemiparesis also on the right side because of compression of the left kernohan notch, and therefore the corticospinal tract that decussates further down in the medullary pyramid?

FA seems to agree with me pg. 407 of the 2009 edition..

 

[Mortal_Lessons]

does this exist?

Pg 35 says that an uncal hemorrhage causes a contralateral hemiparesis due to compression of kernohan's notch.

Shouldn't an uncal hemorrhage on say the right side cause ipsilateral hemiparesis also on the right side because of compression of the left kernohan notch, and therefore the corticospinal tract that decussates further down in the medullary pyramid?

FA seems to agree with me pg. 407 of the 2009 edition..

I think you are referring to the false localizing sign of Kernohan's notch. Right-sided uncal hemorrhage will cause transtentorial herniation on the same side, so typically there's palsy of third cranial nerve on the same side (R) and compression of corticospinal tract on same side (R) leading to left-sided motor manifestations. However, with large shifts in the brain stem, you can get compression of contralateral corticospinal tract (L) with ipsilateral (R) weakness, leading to the false localizing sign.

 

[summergirl12]

I think that's not in reference to the herniation, but to the actual lesion of the crus cerebri. So if you had a left uncal herniation, the right crus cerebri would be compressed, presenting as hemiparesis contralateral to the right side (left) and ipsilateral to the herniation, hence the false localizing sign. So you're right, I think HY Neuro just presents it awkwardly.

 

[ENThopeful]

I think you are referring to the false localizing sign of Kernohan's notch. Right-sided uncal hemorrhage will cause transtentorial herniation on the same side, so typically there's palsy of third cranial nerve on the same side (R) and compression of corticospinal tract on same side (R) leading to left-sided motor manifestations. However, with large shifts in the brain stem, you can get compression of contralateral corticospinal tract (L) with ipsilateral (R) weakness, leading to the false localizing sign.

See according to the picture on HY neuroanatomy on page 35, an uncal herniation on the right side would lead to compression of the corticospinal tract on the opposite site. (I would post the picture but admins would jump at my throat). Therefore, there should be ipsilateral hemiparesis/plegia whatever you want to call it. Yet the text says contralateral hemiplegia.

If you look on page 407, it says uncal hemorrhage causes ipsilateral paresis.

I think HY neuroanatomy is simply wrong when it says uncal hernation causes contralateral hemiplegia, it sohuld be ipsilateral. Here is a paper in spanish that seems to also agree:
http://www.ncbi.nlm.nih.gov/pubmed/15368030



Apologies for the long and tedious post, and thanks for the input!

 

[ENThopeful]

I think that's not in reference to the herniation, but to the actual lesion of the crus cerebri. So if you had a left uncal herniation, the right crus cerebri would be compressed, presenting as hemiparesis contralateral to the right side (left) and ipsilateral to the herniation, hence the false localizing sign. So you're right, I think HY Neuro just presents it awkwardly.

I see what you are saying, but I for sure did not infer that when I read it! I agree with you though.