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A 76 year old woman was brought to the ER semicomatose 24 hours after hitting back of her head in a fall. No symtoms were present during the fall, but she developed blurred vision and weakness of left extremities 18 hours after fall. Examination shows left hemiparesis, right pupil is dilated and unresponsive to light. CT shows diffuse extra-axial hemorrhage over right cerebral hemisphere. What is the mechanism of injury?

A) Contusion of brain
B) Laceration of cerebral bridging vein
C) Laceration of small leptomeningeal blood vessel
D) Laceration of middle meningeal artery
E) Shearing forces damaging white matter

:confused:
 

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This is a difficult question.

The lady was hit on the occiput yet she's having parietal lobe neurological deficits. This must be a countercoup injury.

Countercoup injury is usually due to brain contusion (choice A). However, epidural hemorrhage may also be caused by a countercoup injury.

The lady also had a lucid interval and therefore it goes more with epidural hemorrhage (choice D).

But am not sure :confused:

See this thread also
http://www.usmle-forums.com/usmle-step-1-bits-pieces/141-subdural-epidural.html
 

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Discussion Starter #4
I am not sure too, but there is a question with a similar concept on the CBSSA.

I answered B, but i think it is D. Maybe she lied about falling and hitting the back of her head.:p
 

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Did She lie? What? How is this relevant? The way the History was put 2gether it makes it sound as if what happened 2 her was answer B.

Interesting discussion though.

Thanks a lot 4 keeping me posted
 

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I got that question right when I did the NBME
I remember I answered D
Lucid interval --> Epidural hematoma --> Middle meningeal artery

As Sabio said this is a coutercoup injury and the biggest clue is the lucid interval.
May I ask how do you know that you got it right when you did the NBME?
As far as I can tell there is no expanded feedback version for form 5.
thanks
 

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"Acute subdural hematoma - Following an acute SDH, coma is present from the time of injury in approximately 50 percent of cases. However, approximately 12 to 38 percent of patients have a transient "lucid interval" after the acute injury that is followed by a progressive neurologic decline to coma [2,10]. Posterior fossa SDH, like most space-occupying lesions in this location, presents with symptoms of elevated intracranial pressure including headache, vomiting, anisocoria, dysphagia, cranial nerve palsies, nuchal rigidity, and ataxia."

UpToDate 2011

So, i am with a sub-dural hematoma (i.e B. Laceration of cerebral bridging vein)
 

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"Acute subdural hematoma - Following an acute SDH, coma is present from the time of injury in approximately 50 percent of cases. However, approximately 12 to 38 percent of patients have a transient "lucid interval" after the acute injury that is followed by a progressive neurologic decline to coma [2,10]. Posterior fossa SDH, like most space-occupying lesions in this location, presents with symptoms of elevated intracranial pressure including headache, vomiting, anisocoria, dysphagia, cranial nerve palsies, nuchal rigidity, and ataxia."

UpToDate 2011

So, i am with a sub-dural hematoma (i.e B. Laceration of cerebral bridging vein)
I searched in the website. It should be an NBME question:
look at the following link: http://www.sikhstudentassociation.c...ortable /from desk top/NBME/NBME5/nbme5_1.pdf

I think the correct answer is B. Because
1) I did not find any lucid interval in the patient history.
2) The symptoms happens 18 hours after the fall.
3) CT suggests extra-axial hemorrhage, indicating either epi- or sub-dural hemorrhage.

Any other comment on this question would be appreciated.
 

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As I see it, this question is meant to distinguish subdural hematoma from epidural hematoma.

The compression of cerebral structures causes both the blurred vision and weakness of extremities, however, this can be caused by both subdural and epidural hematomas.

Subdural hematoma (involving bridging veins) presents with increasing headache and confusion. Epidural hematoma (involving the middle meningeal artery) presents with unconsciousness after a lucid interval.

Therefore, I consider she has an epidural hematoma.
 

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I think the answer is B
what i know is that middle meningeal artery has higher blood pressure since it is an artery , so hemorrhage will occur faster. bridging Veins since they are veins they have lower blood pressure and thus need extra time for making a hemorrhage that cause signs and symptoms, since here the symptoms were delayed for 18 hours , then I think the answer is B
 

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It is B laceration of bridging veins causing a subdural hematoma.
It is B because 1. Old age 2. She hit back of her head after a fall. 3. Because it is a venous bleed it takes time to develop as compared to epidural which occurs in hours and usually but not always has a lucid interval. 4. CT also shows DIFFUSE extra axial hemorrhage over left cerebral hemisphere (sounds more like crescent shaped hemorrhage of subdural spread over a larger are as compared to convex lens shaped epidural hematoma not that widely distributed).
 
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