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Acute (subacute) subdural hematoma Causes and Risks:
Subdural means "below the
dura" (the dura mater is the outer membrane covering the brain). Subdural hematoma develops when blood veins that are located between the membranes covering the brain (the
meninges) leak blood after an injury to the head . The head injury could be as obvious as a traumatic accident or as trivial as a minor bump to the head. Blood collects into a mass
(hematoma) that presses on the tissues of the brain. Pressure damages the brain tissue and causes loss of brain function that may progressively worsen as the hematoma enlarges and intracranial pressure (pressure within the head) increases. The injury and the resulting collection of blood cause inflammation of the brain tissues, which leads to swelling (cerebral edema). Cerebral edema further increases the intracranial pressure.
Subdural hematoma often develops as a complication after a head injury. Symptoms of subdural hematoma may develop even after symptoms of the head injury (such as decreased consciousness ) have improved. Acute subdural hematoma progresses rapidly, with symptoms usually appearing within 24 hours of the injury. Rapid deterioration occurs thereafter. Subacute subdural hematoma usually develops symptoms within 2 to 10 days after the injury because of a slightly slower leakage of blood into the subdural area. Typically, symptoms of the original injury improve for a period, followed by development of symptoms of subdural
hematoma.
Risks include head injury, very young or old age, chronic use of aspirin, chronic use of anticoagulant medication (blood thinners), and alcoholism or chronic alcohol use . Other important risk factors include any disorder that may result in a risk of falling, particularly disorders where confusion and cognitive impairment are already present and may mask symptoms of
acute/subacute subdural hematoma.
Subdural hematoma occurs in people of all ages.
Acute/subacute subdural hematoma is less common, but more often fatal, than chronic subdural hematoma . Chronic subdural hematoma occurs in about 1 out of 10,000 people.
Prevention:
Acute /subacute subdural hematoma may not be preventable once a head injury has occurred.
Minimize the risk of head injury by using appropriate safety equipment and safety precautions in sports or recreation and work. For example, use hard hats, bicycle or motorcycle helmets, and seat belts. Do not dive into water if the depth of water is unknown or if rocks may be present under the surface of the water.
Symptoms:
- recent injury or trauma to the head
- loss of consciousness after original injury
- drowsiness
- headache , steady or fluctuating
- impaired vision
- eyes retract into the socket (enophthalmos)
- eyelid drooping on one side only (unilateral)
- decreased sensation or numbness
- lower extremities (right leg or left leg)
- upper extremities (right arm or left arm)
- face (right side of face or left side of face)
- individual is aware of reduced ability to feel (sensory deficit)
- inattention to environment on the same side as the reduced sensation
- loss of movement ( paralysis )
- on only one side of the body
- the individual is aware of movement difficulty (motor deficit)
- confusion , delirium
- changes in personality
- decreased memory
- slowed thought processes
- impaired speech or language
- loss of the ability to read but can still understand speech
- unable to repeat a phrase
- slurred speech ( dysarthria )
- unable to use muscles for speech but muscles are not paralyzed
- speech is missing, mute
- impaired ability to name objects (anomia)
- comprehension of spoken word is impaired
- withdrawal from social interaction
- absent sweating on one side of the forehead
Symptoms peculiar to infants less than 6 months old: - fontanelles - bulging
- increased head circumference
- sutures - separated
- irritability
- high-pitched cry
- setting-sun sign
- the eyes appear to look downward and there is a small amount of white sclera visible above the iris ; it may be easiest to see when the infant is changed from a sitting position to supine (lying face up).
- focal seizures
- generalized tonic-clonic seizure
Signs and Tests:
Consult the health care provider promptly for any head injury that results in even a brief loss of consciousness , or if other symptoms are present after head injury even without loss of consciousness. Acute /subacute subdural hematoma may be diagnosed after the health care provider has ruled out other possible causes of symptoms that occur after a head injury, such as intracerebral hemorrhage .
Examination may show focal neurologic deficits (localized, specific brain function changes such as decreased movement or sensation). Reflexes may be abnormal. There may be signs of increased intracranial pressure . The skull may be tender to when gently tapped on one or both sides. Examination may reveal a need for emergency surgery to relieve pressure within the head without further testing to pinpoint the location and type of injury.
In abused infants, there may be a history of poor feeding and/or failure to thrive . Retinal hemorrhages are peculiar to infants with subdural bleeding that results from shaking (shaken baby syndrome) or from blows to the head.
Tests: - A head CT scan confirms the diagnosis of subdural hematoma and will pinpoint the exact location of the hematoma.
- This disease may also alter the results of a cranial MRI .
Treatment:
Acute /subacute subdural hematoma is an emergency condition!
Treatment goals include lifesaving measures, control of symptoms, and minimizing or preventing permanent brain damage. Lifesaving measures may include support of breathing and/or circulation.
Medications prescribed vary according to the type and severity of symptoms and the extent of brain damage that occurs. Corticosteroid medications such as dexamethasone may be used to reduce inflammation and swelling of the brain (see corticosteroids - oral). Diuretics may also be used to reduce swelling. Anticonvulsant medications such as phenytoin may be used to control or prevent seizures .
Emergency or urgent surgery may be required to reduce pressure within the brain. This may involve drilling a small hole in the skull to relieve pressure and allow drainage of the hematoma. Large hematomas or solid blood clots may need to be removed through a larger opening in the skull ( craniotomy ).
Prognosis:
Acute subdural hematoma progresses rapidly. The condition has a high death rate, even with prompt treatment because of uncontrollable rapid increase in intracranial pressure.
Subacute subdural hematoma may result in death or in permanent brain damage if untreated or, in some cases, even if treated.
Symptoms such as seizures may persist for several months after treatment. Seizures may begin as late as 2 years after the injury.
In adults, most recovery occurs in the first 6 months, with some improvement over approximately 2 years. Children usually recover more quickly and completely than adults. Incomplete recovery is the result of permanent brain damage.
Complications:
Call Your Healthcare Provider:
Go to the emergency room or call the local emergency number (such as 911) if symptoms of subdural hematoma occur!
Emergency symptoms (that may indicate complications) include:
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