Subdural hematomas form when a head injury causes blood to accumulate within the brain or between the brain and the skull and can be acute or chronic. Rapid bleeding after a severe head injury can cause acute subdural hematomas. Acute subdural hematomas are among the deadliest of all head injuries. The bleeding fills the brain area very rapidly and compresses brain tissue. This often results in brain injury or death. Subdural hematomas can also occur after minor head injuries, especially in the elderly. These may go unnoticed for long periods of time. These are called chronic subdural hematomas. Chronic subdural hematomas can develop over weeks, months, or even years. By the time symptoms occur, a hematoma may be very large.
The following increase your risk for a subdural hematoma:
• Anticoagulant medication (blood thinners, including aspirin)
• Long-term abuse of alcohol
• Medical conditions that make your blood clot poorly
• Recurrent falls
• Repeated head injury
• Very young or very old age
Chronic subdural hematomas are more common among people with alcoholism, or older people who are relatively prone to falls as well as bleeding. These injuries can lead to small subdural hematomas that may become chronic.
What are the Symptoms of Subdural Hematoma?
Symptoms may occur depending on which area of the brain is damaged.
Chronic subdural hematomas are more difficult to diagnose because of the length of time between the injury and the development of symptoms. They often cause gradual confusion and memory loss, symptoms similar to those of dementia.
Other symptoms may include:
• Confused speech
• Difficulty with balance or walking
• Nausea and vomiting
• Slurred speech
• Increased sleepiness or lethargy
• Persistent vomiting
• Loss of consciousness
• Visual disturbance
After a head injury a medical exam should include a complete neurologic exam. A CT or MRI scan can evaluate the presence of a subdural hematoma. Treatment depends on the type and size of the hematoma, as well as how much pressure has built up in the brain.
Acute subdural hematomas have high rates of death and injury. Only about 50 percent of people who are treated for a large acute subdural hematoma survive.
Chronic subdural hematomas have better outcomes in most cases. People who are treated for a chronic subdural hematoma usually improve.
Often, small subdural hematomas in adults do not require treatment because the blood is absorbed on its own. If a subdural hematoma is large, however, and is causing symptoms, doctors usually operate. Symptoms often go away after the blood collection is drained.
Following surgery, a period of rehabilitation is sometimes needed to assist the person back to his or her usual level of functioning.
Possible long-term complications may include:
• Memory loss
• Difficulty concentrating
• Difficulty speaking