Epidural hematoma is caused by which mechanism?

• A. Focused blow to head, skull fracture and arterial laceration
• B. Viral infection
• C. Dehydration
• D. Venous sinus thrombosis

Answer: (A)

Epidural hematoma results from arterial bleeding into the space between the skull and dura after a head injury that fractures the skull, typically tearing the middle meningeal artery. Because it's arterial, blood pours in rapidly, creating a quickly expanding hematoma that can cause sudden neurological deterioration after a brief lucid interval. The other options don’t fit: a viral infection affects meninges or brain tissue rather than causing an arterial epidural bleed; dehydration doesn’t produce an epidural hematoma; venous sinus thrombosis involves the venous system and leads to different patterns of hemorrhage, not an acute arterial epidural bleed.