II. Lesions in Meninges and Ventricular System
A. Epidural Hemorrhage
Epidural hemorrhage results in most cases from tearing of the middle meningeal artery (less often may occur from tearing of other vascular branches or venous sinuses). This event is usually associated with skull fracture, often of the temporal bone
Epidural hemorrhage is a rapidly expanding space occupying lesion and death may occur 2-12 hours after injury (bleeding is slower if the middle meningeal artery is not involved). The hematoma often causes uncal herniation and/or downward displacement of brainstem structures.
The classical clinical picture involves initial unconsciousness due to concussion, a lucid interval (seconds to hours) and progression to coma. However, the lucid interval does not occur in many cases. Symptoms include focal signs and indications of increased intracranial pressure.
Pathological examination shows a fresh epidural clot at autopsy.