What mechanism commonly causes an epidural hematoma after head trauma?

• A. Rupture of the middle meningeal artery often associated with a temporal bone fracture
• B. Rupture of bridging veins
• C. Rupture of the dural venous sinus
• D. Aneurysm rupture of the posterior communicating artery

Answer: (A)

An epidural hematoma is most often produced by rupture of the middle meningeal artery, which runs between the skull and the dura. When the temporal bone is fractured, this artery is commonly torn, allowing arterial blood to rapidly accumulate in the epidural space. The high-pressure arterial bleed leads to quick expansion of the hematoma, causing rapid brain compression and potential deterioration after an initial period of seeming improvement.

Rupture of bridging veins causes a subdural hematoma, which is a slower venous bleed between the dura and arachnoid and tends to accumulate more gradually. Rupture of the dural venous sinus can also lead to bleeding but is not the typical mechanism for an epidural. An aneurysm rupture of the posterior communicating artery results in a subarachnoid hemorrhage, not an epidural collection.