Image Quiz
A Rare Cause of Acute Cauda Equina Syndrome1
A thirty-year-old man who is a native of India presented with a one-month history of pain in the lumbar region, difficulty walking for one week, and urinary hesitancy for two days. There was weakness of the ankle plantar flexors (grade-2 of 5 strength) and dorsiflexors (grade-2 of 5 strength), and both ankle reflexes were absent. Hypoesthesia in the fourth lumbar to fifth sacral dermatomes (the right side was greater than the left) was noted. There was no deformity, but tenderness was elicited over the spinous processes of the third and fourth lumbar vertebrae. Radiographs of the lumbosacral spine revealed a loss of sharpness of the margins of the laminae of the fourth lumbar vertebra (Fig. 1).
Fig. 1 |
Fig. 1 Anteroposterior and lateral radiographs of the lumbosacral spine, showing no apparent abnormality except for a loss of sharpness of the margins of the laminae of the fourth lumbar vertebra.
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Magnetic resonance imaging of the lumbosacral spine (Figs. 2 and 3) showed altered signal intensity (a hyperintense signal in the T2-weighted image and a hypointense signal in the T1-weighted image) in the posterior elements of the third lumbar to the first sacral vertebra and in the posterior portions of the fourth and fifth lumbar vertebral bodies, with a large multiloculated fluid collection in the right paraspinal region. This epidural fluid collection caused marked extradural compression of the thecal sac and the cauda equina from the third lumbar to the first sacral vertebra.
Fig. 2 |
Fig. 2 Sagittal T2-weighted magnetic resonance images showing compression of the cauda equina by an epidural fluid collection lying posterior to the third, fourth, and fifth lumbar vertebrae.
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Fig. 3 |
Fig. 3 Transverse T2-weighted magnetic resonance images showing hyperintensity of the posterior elements of the fourth lumbar vertebra and an epidural fluid collection compressing the thecal sac and cauda equina.
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