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Spinal epidural hematoma (SEH) is an accumulation of blood in the
potential space between the dura and the bone. Hemorrhage into the spinal
canal most commonly occurs in the epidural space because of the prominent
epidural venous plexus. SEH may be spontaneous or may follow minor trauma,
such as lumbar puncture or neuraxial anesthesia. It is more likely to occur
in anticoagulated or thrombocytopenic patients, or in those with liver
disease or alcoholism. Approximately one quarter to one third of all cases
are associated with anticoagulation therapy.1,2
Spontaneous bleeding is rare but may be seen with anticoagulation,
thrombolysis, blood dyscrasias, coagulopathies, thrombocytopenia, neoplasms,
vascular malformations, or vertebral hemagioma.3,4 The
peridural venous plexus is usually involved, though arterial sources of
hemorrhage also occur.5 SEHs are mostly venous in nature
because the venous plexus lacks valves, and the plexus has been shown to
permit a reversal in blood flow during pressure increase from physical
activity.6 Hematoma sites are usually found in the
cervical and thoracic spine.7 Most SEHs are located dorsal
to the dural sac because of the firm adherence of the dural sac to the
posterior longitudinal ligament in the ventral aspect of the spinal canal.
The dorsal aspect of the thoracic or lumbar region is involved commonly, and
expansion is limited to a few vertebral levels.
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SEH represents a rare spinal emergency, with a frequency of less than
1% of spinal space-occupying lesions.8 SEH affects 1
per 1,000,000 people annually.9,10 The actual incidence of
neurologic dysfunction resulting from hemorrhagic complications associated
with central neural blockade is unknown. In an extensive review of the
literature, the calculated incidence was approximated to be less than 1 in
150,000 epidural and less than 1 in 220,000 spinal
anesthesias.11 No racial predilection has been reported,
but SEH is more frequent in females. Increased age has been associated with
more frequent SEH.
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Anticoagulant therapy in association with neuraxial analgesia, as well
as the length and intensity of anticoagulation, has been identified as one
of the most important risk factors for epidural
hematoma.12 Decreased weight and concomitant hepatic or
renal disease, which may exaggerate the anticoagulant response, represent
theoretical concerns for bleeding tendency. Thrombolytic therapy represents
the greatest risk factor for bleeding complications.13
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History & Physical Examination
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The patient is usually in significant distress and usually presents
with ...