How Does SDH Work?
Subdural Hematoma
Subdural hematoma (SDH) is a hemorrhage that occurs beneath the membrane that covers the brain and spinal column (dura). It is often caused by head injury but can occur without obvious cause. The bleeding in the brain area can cause brain injury by compressing brain tissue, and surgical intervention is often required. Symptoms include loss of consciousness, dizziness, numbness, slurred speech and seizures.
Causes
Besides head injury, anything that breaks the veins between the brain and the dura allowing blood to collect can cause SDH. A serious injury can produce "acute" SDH, a rapid filling of the brain area with blood. Acute SDH is a very deadly condition and must be dealt with immediately.
Loss of brain tissue due to age or disease can cause SDH because of the increase in the space between the dura and the brain, which allows fluid to collect. Small SDHs, sometimes called "chronic" SDH, can go undetected for days, but can still be quite dangerous.
The use of anticoagulants may contribute to SDH in some cases.
Treatment
Treatment is based on the severity of the SDH, which is classified based on its size, location and especially its age. An acute SDH is less than 72 hours old and appears denser than the brain (hyperdense) on a CAT scan. A subacute SDH is 3 to 20 days old and appears to have the same or less density than the brain (isodense or hypodense) on a CAT scan. Chronic SDH is 3 weeks or older and is hypodense when compared to the brain on a CAT scan.
The definitive treatment of SDH is surgical evacuation of the hemorrhage. The surgical procedure can consist of drilling one or more small holes (burr holes) in the skull to relieve pressure on the brain. The burr holes are normally positioned to make conversion to a larger hole (craniotomy) convenient; a craniotomy may be needed to remove larger hemorrhages and/or solid blood clots and to stop any active subdural bleeding. Depending on the individual circumstances, patients may also receive blood plasma transfusions and/or hyperventilation.
After surgery the patient should be hydrated to aid in the re-expansion of the compressed areas of the brain. Resting in bed with the head on the same plane with the rest of the body will increase the blood pressure in the veins of the compressed area (intracranial venous pressure). This will also aid in the re-expansion.
Tags: brain area, brain tissue, burr holes, Does Work, head injury, than brain