What is a Subdural Hemorrhage?

A subdural hemorrhage (SDH), also known as a subdural hematoma, is a condition in which blood collects underneath the skull between the membrane that covers the brain — the dura — and the brain itself. This is a very serious medical emergency that can result in brain damage or death in a short period of time. The build-up of blood puts pressure on the brain and can injure it severely. There is effective treatment if a person suffering from a subdural hematoma gets to a medical facility quickly.

There basically are two types of subdural hemorrhage: acute or chronic. Acute subdural hemorrhage usually occurs after major head trauma, and bleeding is heavy and rapid. This can quickly become deadly. Chronic subdural hemorrhage may occur after even a minor head injury and can sometimes go unnoticed for days or weeks. This condition is particularly common in elderly people because the veins in the subdural area are more easily damaged in people over the age of 60. Anyone who has the symptoms of this condition, particularly after any head trauma, should be medically evaluated.

The symptoms of subdural hemorrhage include loss or partial loss of consciousness, confusion and drowsiness, sudden headache, personality changes, or impaired vision, speech, or mobility. The hemorrhage can be confirmed using a brain imaging scan, such as a cranial computed tomography (CT) scan or a magnetic resonance imaging (MRI) scan. The elderly, infants, alcoholics, people who use aspirin or other blood thinners regularly, people with blood disorders, and people who have suffered repeated head injuries are at increased risk for subdural hemorrhage.

The treatment for this condition involves drilling small holes in the skull to let the blood out of the subdural area and reduce the pressure on the brain. A craniotomy, which involves removing a portion of the skull, may be necessary for large or heavily clotted hematomas. Any ongoing bleeding will need to be stopped, and anti-inflammatory medication may be prescribed to reduce swelling around the brain. Some chronic hematomas may not need surgery if the blood flow is very slow and light, but any patient who has suffered this type of hemorrhage must be closely observed for worsening of the condition.

If treated quickly and the brain itself has not been injured, patients who have sustained a subdural hemorrhage can recover fully with no permanent brain damage. Some patients do continue to experience headaches, memory problems, seizures, or other symptoms ranging widely in severity. The prognosis is better for a chronic subdural hematoma because there is less pressure on the brain with slower blood build-up; in both types, however, the outlook becomes poorer the longer the condition goes untreated.