Epidural Hematoma

Summary

Epidural hematomas are brain bleeds occurring in the confined space between the dura mater and the skull. They usually occur due to a skull fracture involving the pterion, which lies underneath the middle meningeal artery, which branches off the maxillary artery. Patients will lose consciousness at the time of the injury, recover briefly in a lucid interval, then become comatose due to the intracranial expansion of the hematoma. The increased intracranial pressure from an epidural hematoma can contribute to uncal herniation, which is often seen with oculomotor palsy, as well as the cushing reflex. A CT scan is used to diagnose epidural hematomas, and will reveal a hyperdense, biconvex lens-shaped collection of blood. 

Key Points

• Epidural Hematoma
  • Cause
    • Bleeding into confined space (hematoma) above dura mater (epi = above, dural = dural mater) but below skull bones
    • Due to rupture of middle meningeal artery
      • This artery is a branch of the maxillary artery
    • Usually caused by skull fracture involving the pterion
  • Presentation
    • Transient loss of consciousness
    • Followed by brief period of recovery (“lucid interval”)
    • Later devolves into coma
      • Due to intracranial expansion of hematoma (which is bleeding out under arterial pressure), causing compression of adjacent brain (increased intracranial pressure or ICP)
      • Increased ICP can cause
        • Uncal herniation (transtentorial)
          • Often with Oculomotor Nerve (CN III) palsy
        • Cushing reflex/response
  • Diagnosis
    • CT Head without Contrast
      • Biconvex lens-shaped (lentiform), hyperdense blood collection
      • Does NOT cross suture lines
  • Treatment
    • Emergent Craniotomy/Hematoma evacuation