Epidural Hemorrhage
Epidural hemorrhage is an accumulation of blood between the skull and the dura mater of the brain. It can lead to an accumulation of blood in this space leading to increases in intracranial pressure and formation of hematomas (blood clotting). This condition is considered a medical emergency. Acceleration-deceleration forces or shear forces can cause epidural hemorrhage. It is most commonly caused by blows to the side of the head that rupture the arteries. This type of bleeding is very rapid because it usually occurs from torn arteries, which have a much higher blood pressure than veins. Symptoms of an epidural bleed will occur much more rapidly and they include intense headaches, abnormal posture, abnormal pupilary reflexes, and loss of consciousness. The patient that looses consciousness can have a period of time where they regain consciousness, though after this period they will slip into unconsciousness and rapidly decline. Computed tomography (CT) and magnetic resonance imaging (MRI) scans are used to diagnose this type of hemorrhage and surgical intervention is necessary to correct the damage. The blood can be aspirated via a burr hole in the skull or a craniotomy (skull is opened and the blood clot is removed).
References:
http://www.ecureme.com/emyhealth/data/Epidural_Hemorrhage.asp
http://en.wikipedia.org/wiki/Epidural_hemorrhage