Acute (subacute) subdural hematoma
Alternative names:
acute/subacute subdural hematoma; acute/subacute subdural
hemorrhage; epidural hematoma
Definition:
A brain disorder involving a collection of blood in the
space between the inner and the outer membranes covering the
brain, where symptoms usually develop within a short time
after a head injury.
Causes, incidence, and risk factors:
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.
Update Date: 10/08/99
Updated by: adam.com editorial
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