NBME5 Question

[SCME500]

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75-year-old female is brought to the er semicomatose 24 hrs after hitting the back of her head in a fall. No symptoms after the fall, but she developed blurred vision and weakness of the extremities 18hours after the fall. Examination shows left hemiparesis; the right pupil is dilated and unresponsive to light. A CT scan without contrast shows a diffuse extra-axial hemorrhage over the right cerebral hemisphere.

subdural: no symptoms after the fall; age; onset of symptoms 18 hrs; location;
epidural: cn3 involvement; ?? (a guy who got >275 thinks it is epidural, so i dont know...)

what do you guys think?

 

[Myxedema]

Left hemiparesis: Right CST is affected.
Right mydriasis: Right CN III palsy.
Right cerebral hemorrhage: Right PCA is affected.

These three findings are seen in uncal herniation. Uncal herniation can be caused by any space-occupying lesion, such as intracranial hemorrhage and tumors.Given the patient's age and clinical presentation, subdural hemorrhage is more likely.

You can't differentiate between epidural and subdural hematoma based on which tract is affected and which is not, so in this situation, involvement of CN III only tells you that right side of midbrain is affected.

 

[SCME500]

Left hemiparesis: Right CST is affected.
Right mydriasis: Right CN III palsy.
Right cerebral hemorrhage: Right PCA is affected.

These three findings are seen in uncal herniation. Uncal herniation can be caused by any space-occupying lesion, such as intracranial hemorrhage and tumors.Given the patient's age and clinical presentation, subdural hemorrhage is more likely.

You can't differentiate between epidural and subdural hematoma based on which tract is affected and which is not, so in this situation, involvement of CN III only tells you that right side of midbrain is affected.

I surfed the web (just a little) and did not find any info on a subdural resulting in cn3 paresis. mind you, i too initially thought that it is a subdural hematoma. form my fleeting review of what's out there i am now beginning to think this is actually an epidural because a subdural would not stay localized to one hemisphere! anyone else out there? mind you, i was not kidding that a friend who got 275+ thinks it is an epidural, so keep coming. thanks.

 

[Myxedema]

"Neurosurgery in the elderly: brain tumors and subdural hematomas." Clin Geriatr Med. 2006 Aug;22(3):623-44.

An acute SDH (subdural hematoma) usually induces variable amounts of midline shift, depending on the amount of brain atrophy. This shift also may induce a subfalcine or uncal herniation, with resulting brainstem, cranial nerve, or vascular compressions. Clinically, this manifests itself as unilateral or bilateral posturing (decerebration or decortication), pupillary dilatation, changes in autonomic regulation, and respiratory depression.

How the epidural and subdural act depends on the patient. A chronic subdural hematoma can present with chronic, more generalized sign and symptoms (as its name implies), such as headache, confusion, etc. Whereas an acute subdural may act more similar to an epidural hematoma.

"An elderly patient falling with no lucid interval" is a more typical of scenario for subdural hematoma. Could it be epidural? Sure - you can't eliminate epidural just the patient's elderly or there's no lucid interval. CT scan results is ambiguous as well. So, while both epidural and subdural hemorrhages are possible, given the patient's age, and lack of lucid interval, I would still go with subdural hematoma.

One last thing I'd like to add: It's not possible to differentiate the etiology simply based neurological signs.

 

[SCME500]

"Neurosurgery in the elderly: brain tumors and subdural hematomas." Clin Geriatr Med. 2006 Aug;22(3):623-44.


How the epidural and subdural act depends on the patient. A chronic subdural hematoma can present with chronic, more generalized sign and symptoms (as its name implies), such as headache, confusion, etc. Whereas an acute subdural may act more similar to an epidural hematoma.

"An elderly patient falling with no lucid interval" is a more typical of scenario for subdural hematoma. Could it be epidural? Sure - you can't eliminate epidural just the patient's elderly or there's no lucid interval. CT scan results is ambiguous as well. So, while both epidural and subdural hemorrhages are possible, given the patient's age, and lack of lucid interval, I would still go with subdural hematoma.

One last thing I'd like to add: It's not possible to differentiate the etiology simply based neurological signs.

i totally agree regarding the age and no lucid interval and besides the middle meningeal runs under the parietal bone. i think the main question i would love to clarify is whether a subacute (18 hrs) subdural cause a UNILATERAL brain compression resulting in cn3 paresis within 6 hours of initial presentation?

 

[Myxedema]

i totally agree regarding the age and no lucid interval and besides the middle meningeal runs under the parietal bone. i think the main question i would love to clarify is whether a subacute (18 hrs) subdural cause a UNILATERAL brain compression resulting in cn3 paresis within 6 hours of initial presentation?

Yes, that would be an acute subdural hematoma.

 

[SCME500]

Yes, that would be an acute subdural hematoma.

http://emedicine.medscape.com/article/1137207-overview

"Generally, acute subdural hematomas are less than 72 hours old and are hyperdense compared with the brain on computed tomography scans. The subacute phase begins 3-7 days after acute injury; the surgical literature favors 3 days, whereas the radiological literature favors 7. Subacute subdural hematomas are isodense or hypodense compared with the brain.

Chronic subdural hematomas are 21 days (3 wk) or older and are hypodense compared with the brain. However, subdural hematomas may be mixed in nature, such as when acute bleeding has occurred into a chronic subdural hematoma."

which leads me to believe, once again that the dude was right. it is an epidural.

 

[Boardz]

http://emedicine.medscape.com/article/1137207-overview

"Generally, acute subdural hematomas are less than 72 hours old and are hyperdense compared with the brain on computed tomography scans. The subacute phase begins 3-7 days after acute injury; the surgical literature favors 3 days, whereas the radiological literature favors 7. Subacute subdural hematomas are isodense or hypodense compared with the brain.

Chronic subdural hematomas are 21 days (3 wk) or older and are hypodense compared with the brain. However, subdural hematomas may be mixed in nature, such as when acute bleeding has occurred into a chronic subdural hematoma."

which leads me to believe, once again that the dude was right. it is an epidural.

subdural. your 'friend' doesn't exist and if he does he really got a 228.

 

[SCME500]

subdural. your 'friend' doesn't exist and if he does he really got a 228.

? dude this is a middle school forum. i do not feel the need to have an imaginary friend who i attribute some questionable answers to in order to avoid responsibility. especially given that the forum is anonymous, you may rethink your approach to posting here. thanks.

your personal opinion on what this hematoma is does not count. if you have an opinion, you must be able to cite why you think one way or the other. this is a very difficult question. and just so that you know: i also asked a senior attending this very question as a case and his answer came before he even heard about the CN3 compression - rupture of middle meningeal artery.

 

[SCME500]

http://emedicine.medscape.com/article/1137207-overview

"Generally, acute subdural hematomas are less than 72 hours old and are hyperdense compared with the brain on computed tomography scans. The subacute phase begins 3-7 days after acute injury; the surgical literature favors 3 days, whereas the radiological literature favors 7. Subacute subdural hematomas are isodense or hypodense compared with the brain.

Chronic subdural hematomas are 21 days (3 wk) or older and are hypodense compared with the brain. However, subdural hematomas may be mixed in nature, such as when acute bleeding has occurred into a chronic subdural hematoma."

which leads me to believe, once again that the dude was right. it is an epidural.

anyone else care to join the discussion and prove me wrong? i am 99.9 % sure, but still open to suggestion. myxedema, i was wondering what you thought about my emedicine post. wouldn't you agree that it now seems more like an epidural?

also (wiki): A lucid interval is especially indicative of an epidural hematoma. An estimated 20 to 50% of patients with epidural hematoma experience such a lucid
interval.http://en.wikipedia.org/wiki/Lucid_interval

thanx.

 

[Boardz]

? dude this is a middle school forum. i do not feel the need to have an imaginary friend who i attribute some questionable answers to in order to avoid responsibility. especially given that the forum is anonymous, you may rethink your approach to posting here. thanks.

your personal opinion on what this hematoma is does not count. if you have an opinion, you must be able to cite why you think one way or the other. this is a very difficult question. and just so that you know: i also asked a senior attending this very question as a case and his answer came before he even heard about the CN3 compression - rupture of middle meningeal artery.

This question is _very_ easy. you have an imaginary friend who got 270+ and an attendee who's absolutely incompetent. I hope you just left out details when giving him the question. honestly... where do you go to school? North korea?

 

[Myxedema]

myxedema, i was wondering what you thought about my emedicine post. wouldn't you agree that it now seems more like an epidural?
thanx.

I've read it, but given the same clinical and CT findings, I still think that a subdural hematoma is more likely. Since this is an NBME question, do you have the answer choices? I suspect the answer choices will either have epidural or subdural, not both of them.

 

[SCME500]

I've read it, but given the same clinical and CT findings, I still think that a subdural hematoma is more likely. Since this is an NBME question, do you have the answer choices? I suspect the answer choices will either have epidural or subdural, not both of them.

Both, epi + sub. 😡 hahaha I would not be asking otherwise

 

[thehundredthone]

If we really had to get into splitting hairs, perhaps the use of the term 'diffuse extra axial haemorrhage' would support SDH more than EDH? Further scrutinising the question from an exam point of view, hitting the back of your head in a fall is unlikely to be an EDH.

EDH is likely to cause pressure symptoms early on due to the sheer volume of blood, but 18hrs is neither here nor there, so.

 

[Phloston]

I just took NBME5 today and chose laceration of cerebral veins (i.e. subdural hematoma). The question says diffuse extra-axial hemorrhage over the right cerebral hemisphere. Epidurals cannot cross suture lines, so if that were the diagnosis, the hemorrhage wouldn't be diffuse. The fact that it's diffusely confined to the right hemisphere means the hematoma hasn't crossed the falx, which is characteristic of subdural. This is all not to mention, she didn't lose consciousness; epidurals almost always result in the initial blackout period. It's definitely subdural.

 

[thehundredthone]

I wouldn't say they cannot cross suture lines as a rule, since the pressure can build and rupture the periosteal attachment, but yes they generally do not.