Summary

Extradural Haemorrhage (EDH) is an arterial bleed (Most commonly from the Middle Meningeal Artery) located between the skull and the dura mater. It typically follows trauma (Blow to the temporal region – Pterion). The haematoma does NOT cross suture lines (Dura is adherent). On CT, it appears as a biconvex ("Lemon-shaped") hyperdense collection. The classic presentation is the "Lucid Interval" – Initial loss of consciousness -> Apparent recovery -> Rapid deterioration and death as the haematoma expands and causes uncal herniation (Compression of CN III leading to ipsilateral dilated pupil, then brainstem compression). This is a neurosurgical emergency; emergency craniotomy and evacuation is life-saving. Prognosis is excellent if treated before herniation ("Talk and Die" syndrome occurs when recognition is delayed).

Key Facts

• Location: Between Skull and Dura Mater.
• Aetiology: Trauma to Pterion (Temporoparietal).
• Vessel: Middle Meningeal Artery (Most common). Venous (Rarer, often posterior fossa).
• CT Appearance: Biconvex (Lemon-shaped). Hyperdense. Does NOT cross suture lines.
• Lucid Interval: "Talk and Die" – Initial LOC -> Recovery -> Deterioration.
• Herniation Signs: Ipsilateral Fixed Dilated Pupil (CN III), Contralateral Hemiparesis, Cushing's Triad.
• Treatment: Emergency Craniotomy and Evacuation.

Clinical Pearls

"Lemon Shape = Extradural": Biconvex. Subdural is crescent-shaped.

"Lucid Interval = High Index of Suspicion": Patient who was knocked out, wakes up, then deteriorates rapidly.

"Blown Pupil = Ipsilateral to Lesion": CN III compressed against tentorium.

"Does NOT Cross Sutures": Dura is adherent at suture lines.

Why This Matters Clinically

EDH is one of the most treatable neurosurgical emergencies. Prompt recognition and surgery can result in complete recovery; delay leads to death.

Pterion

Middle Meningeal Artery (MMA)

Haematoma Formation

• Stripping of dura from skull as blood accumulates.
• Dura adherent at suture lines -> Biconvex shape. Does NOT cross sutures.
• Volume increases rapidly (Arterial).
• Mass effect -> Raised ICP -> Herniation.

Uncal Herniation

Cushing's Triad (Late Sign of Raised ICP)

Key Guidelines

Scenario 1:

• Stem: A young man is hit on the side of the head. He was briefly unconscious, then fully recovered (Lucid interval), then suddenly becomes unresponsive with a fixed dilated left pupil. CT shows a biconvex hyperdense lesion. What is the diagnosis and immediate management?
• Answer: Extradural Haemorrhage. Emergency Craniotomy and Evacuation.

Scenario 2:

• Stem: What vessel is most commonly injured in EDH?
• Answer: Middle Meningeal Artery.

Scenario 3:

• Stem: What is the CT appearance of an EDH, and why does it NOT cross suture lines?
• Answer: Biconvex (Lemon-shaped) collection. Does NOT cross sutures because the dura is adherent to the skull at suture lines.

What is an Extradural Haemorrhage?

An extradural haemorrhage is bleeding between the skull and the brain's covering (dura) after a head injury. It is usually caused by damage to a blood vessel in the temple area.

Why is it dangerous?

Blood builds up quickly and presses on the brain. This can cause unconsciousness, brain damage, and death if not treated urgently.

What is the "Lucid Interval"?

Someone may be knocked out briefly, wake up and seem fine, then suddenly get much worse as the bleeding expands. This is a warning sign – seek help immediately if this occurs.

How is it treated?

• Emergency surgery to remove the blood and stop the bleeding.

Key Counselling Points (Post-Operative)

1. Follow-Up: "You will need monitoring and follow-up imaging."
2. Warning Signs: "Report any new headaches, confusion, or weakness."
3. Recovery: "With prompt treatment, most people make a full recovery."

• William Macewen (1879): Pioneer of surgical evacuation for intracranial haematomas.
• Harvey Cushing: Advanced understanding of raised ICP and herniation syndromes.