[khanar]

A 25 year old male patient brought to the emergency department after a severe road traffic accident that involved a head injury. Initially the patient had no symptoms but after 16 hours he started to have left lower limb weakness and abnormal light reaction in his right pupil?
What is the mechanism of cerebral injury in this patient?
A- White matter damage due to the accident shear forces
B- Tear of the middle meningeal artery
C- Brain contusion
D- Laceration of the leptomeningeal arteries
E- Laceration of the cerebral bridging veins

 

[khanar]

Correct option is B

This patient had epidural hematoma (note the lucid interval) so the correct answer is tear of the middle meningeal artery.

 

[ohmedk]

Answer?

I think that the answer is E- Laceration of the cerebral bridging veins.

This is because the patient has presented with symptoms of Interhemispheric subdural hematoma which was probably caused by the laceration of the cerebral bridging veins.

The findings include:
1. symptoms manifests itself in a delayed fashion (after 16 hours)
2. falx syndrome-paresis or seizures of the lower extremity contralateral to the hematoma) Note- we can tell that the paresis of the leg are on the contralateral side (left in this case) because there is abnormal light reaction in his right pupil

 

[khanar]

Disagree with ohmedk

I think the answer is middle meningeal artery because the case scenario goes with epidural

Have a look at this thread
http://www.usmle-forums.com/usmle-step-1-bits-pieces/141-subdural-epidural.html

 

[Seetal]

answer E

the most important clue for an epidural hemorrhage is lucid interval, which isnt mentioned here. the scenario never mentioned going in and out of a conscious state (that is lucid interval). lucid interval usually happens 10 to 15 minutes after an accident and the lesion will be on the temporal side.

subdural hemorrhage on the other hand have symptoms that may appear within 24 hrs (definitely longer than epidural hem.) or even a week after traumatic brain injury.

the injured side is prolly somewhere on the right hemisphere due to contralateral leg paresis and ipsilateral eye involvement.

the answer is injured bridging veins - E

 

[khanar]

Seetal is right

Yes, Seetal.
You are absolutely right. I agree with you.
Mary has been caught by the question trap