A subdural hematoma is a collection of blood on the surface of the brain.
Causes
Subdural hematomas are usually the result of a serious head injury. When they occur in this way, it is called an "acute" subdural hematoma. Acute subdural hematomas are among the deadliest of all head injuries. The bleeding fills the brain area very rapidly, leaving little room for the brain, and are associated with brain injury.
Subdural hematomas can also after a very minor head injury, especially in the elderly. These go unnoticed for many days to many weeks, and are called "chronic" subdural hematomas. During a subdural hematoma, tiny veins between the surface of the brain and its outer covering (the dura) stretch and tear, allowing blood to collect. In the elderly, the veins are often already stretched because of brain atrophy (shrinkage).
Some subdural hematomas occur without cause (spontaneously).
The following increase your risk for a subdural hematoma:
- Head injury
- Very young or very old age
- Anticoagulant medication (blood thinners)
- Long term abuse of alcohol
Symptoms
- Recent head injury
- Loss of consciousness after head injury
- Headache
- Weakness
- Numbness
- Can't speak
- Slurred speech
- Nausea and vomiting
- Lethargy
- Seizures
Exams and Tests
Always get medical help after a head injury. Older persons should receive medical care if they shows signs of memory problems or mental decline. An exam should include a complete neurologic exam.
Your doctor may order a brain imaging study if you have any of the following symptoms:
- Weakness
- Numbness
- Inability to speak
- Slurred speech
- Persistent headache
- Abnormal level of consciousness
- Recent cognitive decline in an elderly person, even without of head injury
A CT scan or MRI scan would likely be done to evaluate for the presence of a subdural hematoma.
Treatment
A subdural hematoma is an emergency condition!
Emergency surgery may be needed to reduce pressure within the brain. This may involve drilling a small hole in the skull, which relieves pressure and allows the hematoma to drain. Large hematomas or solid blood clots may need to be removed through a procedure called a craniotomy, which creates a larger opening in the skull.
Medicines used to treat a subdural hematoma depend on the type of subdural hematoma, the severity of symptoms, and how much brain damage there is. Diuretics may be used to reduce swelling. Anti-convulsant medications such as phenytoin may be used to control or prevent seizures.
Outlook (Prognosis)
The outlook following a subdural hematoma varies widely depending on the type of head injury, the size of the blood collection, and how quickly treatment is obtained.
Acute subdural hematomas present the largest challenge, with high rates of death and injury. Subacute and chronic subdural hematomas have good outcomes in most cases, with symptoms going away after the blood collection is drained.
There is a high frequency of seizures following a subdural hematoma, but these are usually well controlled with medication.
Possible Complications
- Temporary or permanent weakness, numbness, difficulty speaking
- Seizures
- Brain herniation
- Persistent symptoms such as memory loss, dizziness, headache, anxiety, and difficulty concentrating
When to Contact a Medical Professional
A subdural hematoma requires emergency medical attention. Call 911 or your local emergency number, or go immediately to an emergency room.
Spinal injuries often occur with head injuries, so try to keep the person's neck still if you must move him or her before help arrives.
Prevention
Always use safety equipment at work and play to reduce your risk of a head injury. For example, use hard hats, bicycle or motorcycle helmets, and seat belts.
For more information about the NeuroTexas Institute’s Vascular-Stroke Center, click here.
Information from the National Institutes of Health, February, 2009
