Epidural Hematoma, Classic

KEY FACTS

TERMINOLOGY

• Blood collection between skull and dura

IMAGING

• NECT

○ Hyperdense, biconvex, extraaxial collection

○ > 95% unilateral, supratentorial

○ Does not cross sutures unless venous or sutural

diastasis/fracture is present

○ Compresses/displaces underlying brain, subarachnoid

space

○ Low-density swirl sign: Active/rapid bleeding with

unretracted clot

○ 1/3-1/2 have other significant lesions

• Bone CT

○ Skull fracture in 90-95%

TOP DIFFERENTIAL DIAGNOSES

• Subdural hematoma

• Neoplasm

• Infection/inflammation

• Extramedullary hematopoiesis

PATHOLOGY

• Arterial (90-95%)

○ Arterial epidural hematoma (EDH) is most often near

middle meningeal artery groove fracture

• Venous EDH (5-10%)

○ Fracture is adjacent to dural sinus

○ Common sites: Vertex, anterior middle cranial fossa

CLINICAL ISSUES

• Classic "lucid interval"

○ ~ 50% of cases

• Good outcome if promptly recognized and treated

• Some EDHs < 1 cm may be managed nonoperatively

○ Anterior middle fossa epidural hematoma is usually

venous, benign

(Left) Coronal graphic

illustrates swirling acute

hemorrhage from a laceration

of the middle meningeal

artery by an overlying skull

fracture. The epidural

hematoma displaces the dura

inward as it expands. (Right)

Axial NECT scan in a 47-yearold man with head trauma

shows a classic biconvex

(lentiform) uniformly

hyperdense epidural

hematoma (EDH) ſt in the

right middle fossa. Bone CT

(not shown) disclosed a

nondisplaced skull fracture

underlying the hematoma.

(Left) Coronal scan

reformatted from the axial

date nicely demonstrates the

classic middle cranial fossa

acute EDH ſt. (Right) Sagittal

NECT scan reformatted from

the axial source date in the

same patient shows that the

classic biconvex configuration

of the acute middle fossa EDH

ſt is present in all 3 major

imaging planes.

Trauma, and Stroke

Brain: Pathology-Based Diagnoses: Malformations,

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