Which presentation most strongly suggests an arterial epidural hematoma?

• A. Failure to regain consciousness following a head injury
• B. Unconsciousness at the time of injury with a brief lucid interval followed by a decrease in LOC
• C. Nonspecific, nonlocalizing progression of alteration in LOC over weeks
• D. Rapid deterioration of neurologic function within 24 to 48 hours after injury

Answer: (B)

The main concept is that an arterial epidural hematoma often presents with a brief lucid interval after the initial loss of consciousness, followed by rapid neurological decline. This happens because a ruptured artery (usually the middle meningeal artery) bleeds quickly into the epidural space, causing a rapid rise in intracranial pressure.

In this scenario, the patient is unconscious at the time of injury, experiences a short period of regained or normal consciousness (a lucid interval), and then rapidly deteriorates. That sequence—initial loss of consciousness, a transient recovery, then sudden worsening—is the classic clue pointing to an arterial epidural hematoma, since arterial bleeding leads to fast expansion of the hematoma and quick deterioration.

Other patterns are less specific. A general failure to regain consciousness after head trauma isn’t as diagnostic. A slow, weeks-long progression suggests a non-epidural process (like a chronic subdural or other cause). Rapid deterioration within 24 to 48 hours can occur with various acute injuries, but without the lucid interval, it’s not as characteristic of an arterial epidural hematoma.