A twenty-six-year-old woman presented to our unit with back and leg pain
thirty-six hours after she had slipped on snow and landed on her buttocks.
Twenty-four hours after the fall, increasingly severe low-back pain and
bilateral leg pain had developed. The patient reported subjective paresthesias
in the S1 and S2 dermatomes bilaterally. The straight-leg-raising test was
positive at 80°. The neurological examination revealed unremarkable
findings except for absent ankle jerks bilaterally. Radiographs of the lumbar
spine revealed normal findings. Routine laboratory analyses, including a
determination of the complete blood count and a coagulation screening,
revealed normal findings as well. A magnetic resonance imaging scan that was
acquired thirty-six hours after the injury revealed the presence of an
intrathecal hematoma that extended from the level of the L4 vertebral body to
the L5-S1 disc space. An isointense signal was seen on T1-weighted scans
(Fig. 1), whereas a hypointense
to isointense signal was seen on T2-weighted scans. Axial images demonstrated
a subdural hematoma lying anterior to the cauda equina
(Fig. 2). The patient was
admitted to the hospital for strict bed rest and observation.
The result of the straight-leg-raising test deteriorated in the twelve
hours following admission, becoming positive at only 40°. A repeat
magnetic resonance imaging scan with gadolinium enhancement confirmed the
diagnosis of an intrathecal hematoma but failed to demonstrate any increase in
the size of the hematoma. Furthermore, the hematoma demonstrated isointense
signal intensity surrounding a marked hypointense delta-shaped area, similar
in appearance to the emblem of a well-known automobile manufacturer
(Fig. 3).
Over the course of the following week, the patient's neurological status
remained stable. The straight-leg-raising test remained positive at 40°.
There was no additional sensory or motor deterioration, and the patient
remained continent. A repeat magnetic resonance imaging scan acquired seven
days after admission showed a minor reduction in the size of the hematoma. The
characteristic hypointense delta-shaped hematoma was again noted on the axial
images.
The patient was discharged ten days after admission. Six weeks after
discharge, a magnetic resonance imaging scan showed complete resorption of the
hematoma, with the neural elements clearly demonstrated in an otherwise empty
dural sac (Fig. 4).