II. Pathophysiology
- Middle Meningeal Artery rupture
- Results in blood accumulation between skull and dura
- Associated with a temporal bone Skull Fracture in most cases
IV. Signs: Pathognomonic Presentation
- 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
V. Signs: Transtentorial bleed findings
- Contralateral Hemiparesis
- Ipsilateral fixed and dilated pupil (Cranial Nerve III palsy) in 85% of cases
- Heralds impending Cerebral Herniation
VI. Imaging: CT Head
- Focal bleeding in territory of middle meningeal artery (contrast with subdural which can extend fully anterior to posterior)
- Convex "lens" 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
VII. Precautions
- Epidural Hemorrhage may be rapidly fatal
VIII. Evaluation
- See Trauma Evaluation
- See Head Injury
IX. 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
- Midline shift >5 mm
- Poor mental status (GCS <8)
- Bullock (2006) Neurosurgery 58(3 suppl): S7-15 [PubMed]
X. References
- Dreis (2020) Crit Dec Emerg Med 34(7):3-21