Neurology · Traumatic Brain Injury
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Epidural hematoma is most commonly caused by a skull fracture at the pterion resulting in rupture of the middle meningeal artery.
The classic clinical presentation is a lucid interval following a brief period of loss of consciousness after head trauma.
Patients often present with a fixed and dilated pupil on the side of the lesion due to uncal herniation causing oculomotor nerve (CN III) compression.
Non-contrast head CT reveals a biconvex or lens-shaped hyperdensity that does not cross suture lines.
The rapid expansion of arterial blood leads to a quick rise in intracranial pressure, potentially causing contralateral hemiparesis and ipsilateral pupillary dilation.
Urgent surgical evacuation via craniotomy is the definitive treatment to prevent permanent neurological damage or death.
Epidural hematoma is a neurosurgical emergency that requires immediate consultation and stabilization to prevent brainstem compression.
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A 24-year-old male is brought to the emergency department after being struck in the side of the head with a baseball bat. He initially lost consciousness for one minute, then regained consciousness and appeared completely normal for 30 minutes. He now presents with a rapidly declining level of consciousness, severe headache, and a fixed, dilated pupil on the right side. A non-contrast head CT is performed.
What is the most likely diagnosis and the most appropriate next step in management?
Epidural hematoma; urgent surgical craniotomy.
The patient's presentation of a lucid interval followed by rapid neurological decline is classic for an epidural hematoma caused by middle meningeal artery rupture, requiring immediate surgical decompression.
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Etiology / Epidemiology
Occurs primarily in young adults following temporal bone trauma with rupture of the middle meningeal artery.
Clinical Manifestations
Classic lucid interval followed by rapid neurological deterioration and blown pupil.
Diagnosis
Non-contrast CT head shows a lens-shaped (biconvex) hyperdensity that does not cross suture lines.
Treatment
Urgent surgical evacuation (craniotomy) is mandatory; avoid lumbar puncture.
Prognosis
Excellent if treated before coma; poor if fixed/dilated pupils are present.
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Epidemiology & Etiology
Most common in young males following high-impact trauma, such as sports injuries or motor vehicle accidents. The injury typically involves a temporal bone fracture which lacerates the underlying vasculature. It is a classic neurosurgical emergency requiring immediate recognition.
Pertinent Anatomy
The pterion is the weakest point of the skull where the frontal, parietal, temporal, and sphenoid bones meet. Beneath this lies the middle meningeal artery, which is highly susceptible to shearing forces during blunt trauma.
Pathophysiology
Arterial bleeding creates a high-pressure hematoma between the dura mater and the skull. As the hematoma expands, it causes mass effect and uncal herniation. This leads to compression of the oculomotor nerve (CN III), resulting in ipsilateral pupillary dilation.
Clinical Manifestations
Patients often present with a lucid interval, where consciousness is regained after initial loss before rapidly declining. Red flags include ipsilateral blown pupil, contralateral hemiparesis, and Cushing's triad (hypertension, bradycardia, irregular respirations). Failure to intervene leads to brainstem compression and death.
Diagnosis
Non-contrast CT head is the gold standard for rapid diagnosis. The image reveals a biconvex (lens-shaped) hyperdensity that is constrained by cranial sutures. Unlike subdural hematomas, these do not cross suture lines.
Treatment
Immediate surgical decompression via craniotomy is the definitive treatment. Lumbar puncture is strictly contraindicated due to the risk of precipitating herniation. If surgery is delayed, mannitol or hypertonic saline may be used to temporarily lower intracranial pressure.
Prognosis
Prognosis is excellent if the patient is alert at the time of surgery. Outcomes are significantly worse if the patient presents with fixed, dilated pupils or a GCS < 8 prior to intervention.
Differential Diagnosis
Subdural Hematoma: Crescent-shaped, crosses suture lines, usually venous
Subarachnoid Hemorrhage: Thunderclap headache, blood in cisterns
Intracerebral Hemorrhage: Focal neurological deficits, intraparenchymal blood
Concussion: Normal CT head, transient loss of consciousness
Skull Fracture: Bone disruption without significant intracranial mass effect