A subdural hematoma is a pooling of blood inside the protective membranes (meninges) surrounding the brain. Blood collects underneath the outermost layer called the dura and above the arachnoid, hence the name subdural hematoma. The brain itself does not bleed. The pool of blood is called a hematoma, or blood clot, and can grow large enough to compress brain tissue. The resulting injury can cause brain damage or even death.
Definition & Facts
Subdural hematomas can be divided into acute or chronic. Acute subdural hematomas have symptoms that come on suddenly. They are considered to be serious and potentially life-threatening. Symptoms in chronic subdural hematoma are slower to appear, sometimes taking weeks to present themselves.
The elderly are considered at higher risk for subdural hematomas, especially chronic subdural hematomas. Individuals on blood thinning medication are also at higher risk. No matter if the symptoms of a subdural hematoma come on quickly or slowly, it is considered a medical emergency.
Symptoms & Complaints
Sudden symptoms may include loss of consciousness. More mild symptoms may not appear for several days after the initial injury. A person may appear confused or sleepy. This situation is more common in the elderly. Subdural hematoma symptoms in adults include:
- Nausea and vomiting
- Lethargy or excessive drowsiness
- Unequal pupil size
- Slurred speech
- Changes in blood pressure
- Vision problems
- Loss of balance
Symptoms in infants include:
- Bulging fontanelles (fontanelles are the "soft spots" of the baby's skull)
- Separated sutures (the areas where growing skull bones join)
- Increased head circumference
- Feeding difficulties
- Seizures (in one limb or generalized all over the body)
- High-pitched cry
- Increased sleepiness or lethargy
- Infant irritability
- Persistent vomiting
Acute subdural hematomas are typically caused by some kind of traumatic brain injury resulting from a fall or accident such as those that occur during high impact sports. Acute subdural hematomas are life-threatening. Falls are the leading cause of subdural hematomas in the elderly. The sudden blow to the head causes blood vessels near the protective layers of the brain to tear and bleed.
People taking blood thinners or people with blood clotting disorders are more susceptible to bleeding. Those that abuse alcohol are also at higher risk. The elderly are at higher risk for chronic subdural hematomas because of brain shrinkage. The atrophy of the brain tissue that can come with old age causes the blood vessels to stretch and tear more easily. Even a minor injury can cause a subdural hematoma in the elderly.
Diagnosis & Tests
Anyone with symptoms of a subdural hematoma should go to a hospital emergency room. A quick diagnosis is key to successful treatment. The standard test to check for subdural hematoma is a CT scan of the head. A CT scan is a type of high powered X-ray that can take an image of the brain anatomy and detect abnormal bleeding.
An individual may also get an MRI of the brain. This test can also detect bleeding; however it takes longer and may not be as widely available. A complete neurological examination should also be performed.
Treatment & Therapy
Treatment for subdural hematomas includes surgery, medication and watchful waiting. Subdural hematomas causing severe symptoms can be surgically removed. A brain surgeon can place a burr hole, a surgically created hole in the skull, to suction out the collected blood. The surgeon may also opt to perform a craniotomy. In this procedure, a part of the skull is surgically removed, the blood is cleared from under the dura and the skull bone is surgically put back into place. Careful monitoring of neurological status in the hospital is required after these procedures.
For less serious subdural hematomas, watchful waiting may be appropriate. Individuals will have their neurological status monitored and CT scans may be repeated every few days or weeks. These individuals may be able to recover at home if their symptoms are mild to moderate. People with severe neurological injury, especially those that need ventilator assisted breathing, may need to stay in an intensive care unit until they recover.
Medications can also be used to treat subdural hematomas. Vitamin K or fresh frozen plasma may be administered to reverse the effects of blood thinners in an emergency situation. Individuals may also be prescribed steroids and diuretics to reduce brain swelling. Anticonvulsants may be prescribed, sometimes long term, if an individual is at risk for seizures. Meanwhile, blood thinners such as aspirin or warfarin will be stopped until the subdural hematoma is resolved. If the person is at risk for another subdural hematoma then blood thinners may not be restarted.
Therapy may be prescribed longer term for individuals with brain injury resulting from a subdural hematoma. The prognosis varies with some people making a complete recovery and others needing lifelong help. Physical therapy, occupational therapy, speech therapy and help with activities of daily living are typical therapies offered. Individuals may also need emotional support.
Prevention & Prophylaxis
Older adults should focus on preventing falls in their home by removing clutter and throw rugs. The elderly should also use particular caution when walking outside in snow or rain. Blood thinners should be prescribed responsibly and taken only as prescribed. Individuals at high risk for falls should carefully consider the risks of taking blood thinners.