Epidural Hematoma (EDH)

Risk factors

• Head trauma — usually blunt impact to the temporal region
• Motor vehicle collision, assault, sports injury (boxing, contact sports)
• Falls
• Coagulopathy or anticoagulant use (smaller-impact injuries can produce EDH)

Pathophysiology

A fracture across the pterion (where the temporal bone meets the sphenoid wing) lacerates the middle meningeal artery, causing arterial blood to dissect the dura away from the inner skull. Because the dura is tightly adherent at suture lines, the hematoma cannot cross them, producing the classic lens-shaped (biconvex) appearance. The high-pressure arterial source allows rapid expansion and herniation if not evacuated promptly.

Clinical presentation

Differential diagnosis

• Acute subdural hematoma — Crescent-shaped, crosses sutures, venous source, often more diffuse underlying brain injury
• Subarachnoid hemorrhage (traumatic) — Blood in sulci/cisterns rather than extra-axial collection
• Cerebral contusion — Coup-contrecoup injuries; intra-axial hyperdensities
• Diffuse axonal injury — Often CT-negative initially; MRI shows punctate hemorrhages at gray-white junction; coma out of proportion to CT
• Skull fracture without intracranial injury — Trauma, possible scalp hematoma; head CT confirms absence of intracranial blood

Diagnostic workup

Diagnostic algorithm

flowchart TD
  A[Head trauma<br/>temporal blow] --> B[Initial LOC<br/>then lucid interval]
  B --> C[Rapid deterioration<br/>headache, vomiting, GCS drop]
  C --> D[Non-contrast head CT]
  D --> E{Biconvex hyperdensity<br/>± skull fracture?}
  E -->|Yes| F[Epidural hematoma]
  F --> G{Size >30 mL,<br/>shift >5 mm,<br/>GCS ≤8,<br/>or pupil change?}
  G -->|Yes| H[Emergency<br/>craniotomy evacuation]
  G -->|No| I[ICU observation<br/>serial CT + neuro exam]
  H --> J[Excellent prognosis<br/>if pre-herniation]

Treatment

Complications

• Uncal herniation, brainstem compression, death (if untreated)
• Permanent neurologic deficits despite evacuation
• Seizures (early or late post-traumatic epilepsy)
• Hydrocephalus
• Post-concussive syndrome
• Recurrent or residual hematoma requiring re-operation

PANCE pearls

• Classic boards triad: temporal blow + lucid interval + rapid deterioration. Time-critical: surgery before herniation = good outcome.
• Lens shape that does NOT cross sutures = epidural. Crescent that DOES cross sutures = subdural.
• Middle meningeal artery is the most common source, but venous EDHs (less rapid) occur from dural sinus or diploic vein injury — often in posterior fossa or anterior frontal locations.
• Pediatric EDH is often venous, slower to expand, and may lack lucid interval. Maintain high suspicion.
• Posterior fossa EDH can compress the brainstem rapidly — low threshold for surgery even with smaller volumes.

References

• Brain Trauma Foundation 2017 — Guidelines for the Management of Severe Traumatic Brain Injury (Carney et al., Neurosurgery 2017)
• Surgical Guidelines — Surgical Management of Acute Epidural Hematomas (Bullock et al., Neurosurgery 2006)
• ACS TQIP — ACS TQIP Best Practices in the Management of TBI (American College of Surgeons, 2015)