Epidural Hematoma

Description

• Direct skull trauma
• Inward bending of calvarium causes bleeding when dura separates from skull:
  • Middle meningeal artery is involved in bleed >50% of time
  • Meningeal vein is involved in 1/3
• Skull fracture is associated in 75% of cases, less commonly in children
• >50% have epidural hematoma (EDH) as isolated head injury:
  • Most commonly associated with subdural hematoma (SDH) and cerebral contusion
• Classic CT finding is lenticular, unilateral convexity, usually in temporal region
• It usually does not cross suture lines, but may cross midline

Etiology

• Accounts for 1.5% of traumatic brain injury (TBI)
• Male/female incidence is 3:1
• Peak incidence is from second to third decades of life
• Motor vehicle accidents (MVAs), assault, and falls are most common causes:
  • Of all blunt mechanisms, assault has highest association with intracranial injury requiring neurosurgical intervention
• Uncommon in very young (<5 yr) or elderly patients
• Mortality is 10% for adults, lower for children and is related to preoperative condition
• Worse prognosis for low presenting GCS score, abnormal pupil, older patients, increased ICP preoperatively, midline shift >10 mm on CT, mixed density lesion, presence of concomitant intracranial lesion, volume of bleed >30 cc

• Head injury is the most common cause of death and acquired disability in childhood
• PECARN rules may be used to help stratify risk:
  • Children with one of the following variables are at low risk and do not require head CT:
    • LOC ≥5 s
    • Vomiting (in age ≥2)
    • Severe headache (in age ≥2)
    • Acting abnormally to parents
    • Severe mechanism
    • Abnormal mental status
    • Skull fracture
    • GCS <15
    • Scalp hematoma; nonfrontal
• Falls, pedestrian-struck bicycle accidents are most common causes:
  • Most severe head injuries in children are from MVA
  • Always consider possibility of nonaccidental trauma
• <50% have altered level of consciousness (LOC):
  • If EDH in differential diagnosis (DD), CT should be obtained
• Bleeding is more likely to be venous
• Good outcome in 95% of children <5 yr