Summary

Extradural haematoma (EDH) is bleeding between the skull and dura mater, typically from arterial injury (middle meningeal artery) following temporal bone fracture. It is a neurosurgical emergency. The classic presentation is a "lucid interval" - initial loss of consciousness, apparent recovery, then rapid deterioration due to expanding haematoma and brain herniation. CT shows a characteristic biconvex (lens-shaped) hyperdensity limited by cranial sutures. Emergency craniotomy and haematoma evacuation is life-saving. Mortality is 5-10% with prompt surgery but approaches 90% if untreated or delayed.

Key Facts

• Cause: Middle meningeal artery rupture (85%); Dural venous sinuses (15%)
• Mechanism: Usually head trauma with temporal bone fracture
• Classic Sign: Lucid interval (seen in 20-50%)
• CT Appearance: Biconvex (lens-shaped), hyperdense, respects suture lines
• Treatment: Emergency craniotomy and evacuation
• Mortality: 5-10% with surgery; 90% without

Clinical Pearls

"Lucid Interval = Impending Disaster": A patient who was briefly unconscious, wokes up, then deteriorates is classic EDH. Act immediately.

"Lens-Shaped = Extradural": EDH is biconvex (lens) because dura is stripped off skull. SDH is crescent-shaped as blood spreads freely in subdural space.

"Respect the Sutures": EDH is limited by suture lines (dura firmly attached). If blood crosses sutures, think subdural or other pathology.

"Pupil on the Side of the Lesion": A fixed, dilated pupil is ipsilateral to the haematoma (uncal herniation compresses CN III).

Primary Survey

• ABCDE approach
• C-spine immobilisation
• GCS (document trend)

Neurological Examination

Warning Signs Requiring Immediate Action

• GCS drop ≥2 points
• New pupil asymmetry
• New focal neurological deficit
• Posturing

Mortality

Functional Outcomes

• With early surgery: 50-80% make good recovery
• Pre-operative GCS is strongest predictor
• GCS 3: Very poor prognosis even with surgery
• GCS 9-15: Good prognosis with early intervention

Prognostic Factors

Key Guidelines

1. NICE Head Injury Guidelines (CG176, 2014; updated 2017)
2. Brain Trauma Foundation Guidelines (2016)
3. SBNS Standards of Care for Severe Head Injury

Key Evidence

Surgical vs Conservative

• Non-randomised data strongly supports surgery
• Mortality without surgery approaches 90%

Timing of Surgery

• Earlier surgery = Better outcomes
• "Golden hour" concept applies
• Each 30-minute delay increases mortality

What is an Extradural Haematoma?

An extradural haematoma (also called epidural haematoma) is bleeding between the skull and the outer covering of the brain (dura). It's usually caused by a head injury that tears a blood vessel, typically an artery.

Why is it Dangerous?

The bleeding creates a blood clot that presses on the brain. Because the skull is rigid, this pressure can push the brain downwards (herniation), which is life-threatening.

What Are the Warning Signs?

After a head injury, watch for:

• Severe or worsening headache
• Confusion or unusual behaviour
• Vomiting
• Drowsiness or difficulty walking
• One pupil larger than the other
• Weakness in arm or leg

The "Lucid Interval"

Sometimes a person with this injury seems to recover briefly before getting worse. This is called a lucid interval and is a classic warning sign.

How is it Treated?

Emergency surgery is usually needed to remove the blood clot and stop the bleeding. With quick treatment, most people make a good recovery.

When to Seek Help

Call 999 immediately if someone:

• Has had a head injury and becomes increasingly drowsy
• Is confused or their behaviour changes after a head injury
• Has a seizure after a head injury
• Has different-sized pupils