Subdural hematoma: What you need to know
One type of internal bleeding in the skull is called subdural hematoma. People should be aware of the signs and symptoms of head trauma and seek treatment immediately if they or someone around them experience a head injury.
What is a subdural hematoma?
Subdural hematomas are the result of head injuries where the blood collects between the surface of the brain and the skull.
A subdural hematoma occurs when a vein located beneath the skull ruptures and starts to bleed. The blood collects between the brain and the skull. As this space begins to fill with blood, the increasing pressure causes some of the symptoms of subdural hematoma.
Subdural hematoma bleeding occurs in one of the layers of tissue between the brain and the skull called the meninges. The outermost layer is called the dura.
If pressure continues to build against the brain, a subdural hematoma may lead to long-term health problems or life-threatening situations. In the worst case scenarios, untreated subdural hematomas can lead to unconsciousness or death.
Subdural hematomas are a result of injury to the head. The severity of the injury determines how the subdural hematoma will be categorized.
There are two types of subdural hematomas: acute and chronic.
Acute subdural hematoma
A subdural hematoma caused by a severe head injury is considered acute. Likely causes may include car accidents or a fall from a height.
Cases of acute subdural hematoma are often harder to treat and more likely to lead to long-term consequences or death. The risk of death from an acute subdural hematoma is more than 50 percent.
Chronic subdural hematoma
Chronic cases of subdural hematoma are either due to repeated or mild head injuries.
Older adults are more likely to develop chronic subdural hematoma due to increased frequency of falls.
Older adults are also at higher risk because a person's brain shrinks as they age, and this shrinkage causes the tiny veins on the surface of the brain to stretch, making them more vulnerable to tearing
While chronic subdural hematomas are easier to treat, there is still the risk of death or long-term health consequences.
The symptoms of subdural hematoma can vary from person to person. Common symptoms include:
- severe headache
- change in mood or behavior
- slurred speech
- loss of consciousness or passing out
- vision problems
Symptoms of an acute subdural hematoma occur quickly following the injury. In cases of chronic subdural hematoma, symptoms are more likely to develop slowly or may not develop at all.
The symptoms occur at different rates due to the speed at which blood starts to pool and put pressure on the brain.
In cases of chronic subdural hematoma, small veins on the outer surface of the brain may tear. The tears cause bleeding in the subdural layer of tissue. In these cases, symptoms may not appear for several days or even weeks.
Other factors may influence a person's symptoms. A person's age or other medical conditions both play a role in how quickly symptoms start to develop.
Warfarin and other blood thinners may increase the chances of developing a subdural hematoma.
The most common cause of a subdural hematoma is a severe injury to the head. Minor head injuries are a less common cause and more typical in older people.
Sometimes, subdural hematomas may occur spontaneously as a result of another medical condition.
Risk factors that increase a person's chances of developing subdural hematoma include:
- blood thinners, such as warfarin or aspirin
- medical conditions that cause blood clotting issues
- long-term alcohol use or abuse
- repeated head injuries, such as from falls or sports
- very young or very old age
It is important to diagnose cases of acute subdural hematoma quickly so treatment can begin immediately. Rapid treatment may minimize the risk of death or long-term effects.
Cases of chronic subdural hematoma may be more difficult to diagnose, as symptoms do not develop rapidly or may not have an obvious cause.
To diagnose subdural hematoma, a doctor will usually use computed tomography (CT), or magnetic resonance imaging (MRI) scans to get a clear picture of the brain. The doctor will examine the scan for signs of bleeding.
If the doctor identifies bleeding, they will determine the source of the bleeding and develop a plan of action to address the issue.
The doctor may also check a person's blood pressure and heart rate, as well as order blood work to get blood cell and platelet counts. These screenings and tests are designed to look for internal bleeding and blood loss.
Surgery is generally carried out to remove the blood clot and any leaked blood.
A person with a subdural hematoma will usually require surgery. For acute cases, the person will likely undergo a craniotomy.
During this procedure, a surgeon first removes a portion of the person's skull near the site of the subdural hematoma. The surgeon will then remove the clot and will then use suction and irrigation techniques to remove any leaked blood.
A craniotomy is a risky procedure. In some circumstances, however, it necessary to save a person's life.
For chronic subdural hematomas or when an acute hematoma is smaller than 1 cm in diameter, a surgeon may use burr hole surgery. During this procedure, the surgeon drills a small hole into the person's skull and inserts a rubber tube to drain the blood.
After surgery, a doctor will usually prescribe anti-seizure medication. A person may need to take the drugs for several months or years. Taking these medications can help prevent a seizure that could cause another subdural hematoma.
Doctors typically prescribe medications to help reduce swelling around the brain, which may help prevent or reduce pressure in the skull in the days following surgery.
Recovery times vary greatly between individuals. The speed of recovery often depends on the extent of damage the subdural hematoma has caused to the brain.
Only between 20 and 30 percent of people can expect to see a full or nearly full recovery of brain functioning.
Often, people treated quickly have the best chances of full recovery. Younger people and people whose swelling is controlled are more likely to see better results during recovery.
Even after treatment, a subdural hematoma has the potential to lead to death or permanent brain damage. A quick medical response and care are essential to give a person the best chance of survival and full recovery.
It is essential for a person to follow all recommendations for post-surgery treatment to increase the chances of a favorable outcome.