A patient presents to the emergency room 6 hours after a temporal head trauma with lucid interval followed by rapid deterioration. CT shows a biconvex (lenticular) hyperdense hematoma. The hematoma is most likely to be between which two layers?

• A Between the dura mater and the inner table of skull ✓
• B Between the dura mater and the arachnoid mater
• C Between the arachnoid mater and the pia mater (subarachnoid space)
• D Between the inner table and the diploe

Explanation

Extradural (epidural) hematoma lies between the dura mater and the inner table of the calvaria. It is most commonly caused by rupture of the anterior branch of the middle meningeal artery, which runs in a groove in the temporal bone (pterion — the thinnest part of the skull where four bones meet: frontal, parietal, temporal, sphenoid). The biconvex shape results from the tight adherence of the dura to the inner table, which limits hematoma spread except at suture lines. The classic lucid interval occurs because the initial brain concussion resolves before arterial bleeding is sufficient to cause mass effect, then rapid expansion causes herniation.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.