II. Epidemiology
- Ages 2 to 60 years
- Dura matter adheres more tightly to skull outside these age ranges, and prevents blood accumulation
III. Pathophysiology
- Epidural Hematoma results from Hemorrhage and blood accumulation between the skull and Dura Mater
- Associated with a Temporal Bone or parietal bone Skull Fracture in most cases
- Hemorrhage is typically from the meningeal arteries (85%), but may also arise from venous sinuses
- Middle Meningeal Artery rupture
IV. Symptoms
- Timing of presentation depends on bleeding source (most present <24 hours)
- Arterial Epidural Hematomas (e.g. middle meningeal artery) develop rapidly (within hours)
- Dural Sinus Epidural Hematomas develop more slowly
- Headache
- Nausea and Vomiting
- Nuchal Rigidity
V. Signs: Pathognomonic Presentation
- Classic presentation occurs in only 20% of patients
- Loss of consciousness
- Period of lucency interspersed between 2 distinct periods of LOC
- Variably present and variable timing
- Absent in most cases, in which patient remains comatose without period of lucidity
- Loss of consciousness
VI. Signs: Transtentorial bleed findings
- Contralateral Hemiparesis
- Loss of consciousness eventually occurs
- Ipsilateral fixed and dilated pupil (Cranial Nerve III palsy) in 85% of cases
- Heralds impending Cerebral Herniation
VII. Imaging: CT Head
- Focal bleeding in territory of middle meningeal artery (contrast with subdural which can extend fully anterior to posterior)
- Convex "lens" (biconvex) appearance on CT (contrast with concave crescent in Subdural Hematoma)
- Outside the dura, and therefore follows the inner skull surface
- Blood dissects between the skull and the tightly adherent dura
VIII. Precautions
- Epidural Hemorrhage may be rapidly fatal
- Mortality is 5 fold higher in delayed diagnosis
IX. Evaluation
- See Trauma Evaluation
- See Head Injury
X. Management
- See ABC Management
- See Management of Severe Head Injury
- See Increased Intracranial Pressure in Closed Head Injury
- Rapid assessment and management is key
- Emergent Neurosurgical Consultation
- Emergent decompression in the Emergency Department
- Indicated in imminent Cerebral Herniation (Ipsilateral fixed and dilated pupil) and delay to neurosurgery
- See Skull Trephination
- Neurosurgical decompression indications
- Epidural Hematoma width >15 mm
- Epidural Hematoma volume >30 ml (cm^3)
- Midline shift >5 mm
- Poor mental status (GCS <8)
- Impending brain Herniation
- Bullock (2006) Neurosurgery 58(3 suppl): S7-15 [PubMed]
XI. References
- Abuguyan (2024) Crit Dec Emerg Med 38(7): 4-11
- Dreis (2020) Crit Dec Emerg Med 34(7):3-21