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  #1  
Old 07-18-2012
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Neuro Clinical Clue to Uncal Herniation!

this was q regarding uncal herniation in uworld.

A 23-year-old male is found at the scene of a motor vehicle accident with bilateral lower extremity fractures. You also note extensive abdominal bruising and scalp lacerations. At the scene, the patient's blood pressure is 80/60 mmHg and his heart rate is 120/min. He is given 2 liters of IV fluids wide open. On the way to the hospital he becomes progressively drowsy, and he develops progressive weakness on the right side of his body. This patient is also likely to show deficits in the functioning of which of the following nerves?

A. Abducens
B. Oculomotor
C. Glossopharyngeal
D. Trigeminal
E. Accessory

what is the clue patient is having uncal herniation ?
i cannot figure it out. :-(
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Old 07-18-2012
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Uncal herniation occurs in the setting of intracranial hemorrhage usually an epidural hematoma.

Progressive neurological deterioration following trauma is indicative of brain parenchymal compression and highly suspicious for intracranial hemorrhage (possibly an epidural since he was initially ok?...lucid interval!!).

Herniation syndromes follow such rapid intracranial accumulation of blood.

The clue to uncal herniation is what is called KERNOHAN's NOTCH phenomenon (please do look it up and u will understand why the patient has right-sided paralysis).

The cranial nerve commonly associated with it is the 3rd cranial nerve...they also present with a dilated pupil (parasympathetic division) and a down and out pupil (motor division to extraocular muscles)...

Typically the Parasympathetic fibres are the first affected before the motor...This is due to the fact that the fibres of cranial nerve 3 are arranged with peripheral fibres=parasympathetic
and central fibres= motor control

The last bit of information is in FA 2011 step 1 page 423!!!
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  #3  
Old 07-18-2012
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I can xplain right side hemiparesis based on raised intracranial tension and focal deficits. si ?


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Old 07-18-2012
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In this question they are obviuosly targeting the phenomenon KERNOHANS notch due to uncal herniation causing the right sided paralysis...not just simple raised intracranial pressure!!...and that is why they also added "what other nerve deficits can be seen!!?"

If it was just a simple raised intracranial pressure giving focal neurological problems...then virtually any nerve deficits can be seen...or would u say in meningitis with raised intracranial pressure, one would get a cranial nerve 3 deficit before a cranial nerve 8 deficit?

Remember the commonest cranial nerve deficit in meningitis is CN 8!!

The concept here is the epidural hemorrhage (an arterial bleed which can give this rapid onset of deterioration following trauma) causing the herniation leading to hemiplegia... unlike an acute subdural hemorrhage (a venous bleed, deterioration wont be this rapid!!)
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Old 07-19-2012
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i know the uncal herniation manifestations.

Quote:
If it was just a simple raised intracranial pressure giving focal neurological problems...then virtually any nerve deficits can be seen...or would u say in meningitis with raised intracranial pressure, one would get a cranial nerve 3 deficit before a cranial nerve 8 deficit?

Remember the commonest cranial nerve deficit in meningitis is CN 8!!
i picked answer as 6 th cranial nerve as this is most common nerve to get affected in raised ICT.
8th nerve palsy is chronic complication in meningitis due to inflammatory response- so dont know if we can directly relate that to raised ICT.

as of now,
**why this question is not of raised ICT?*** may be his BP is not up ...
still dont know


***does question of uncal herniation comes in context of epidural hematomas as this one? so i can keep this fact in back of mind to ans cranial nerve 3 and not 6

this question is hurting me ALOTTTTTTTTTT
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Old 10-10-2012
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Oculomotor is the first nerve to be affected starting with pupillary dilation & progressing to deviated eye downward and out (ipsilateral or contralateral eye could be affected as uncal herniation doesn't localize because sometimes it croses)
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Old 02-28-2013
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Default uncal herniation

i have problem with uncal herniation,,is there any cvs problems?like increase bp?reduce puls rate?
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