A Symptomatic Spinal Extradural Arachnoid Cyst with Lumbar Disc Herniation

Figure 1

Magnetic resonance (MR) images immediately after injury show a dorsally located cystic lesion extending from L3 to L5 and disc herniation at the L4-L5 level (a). Preoperative magnetic resonance images show progression of herniation and compression of the dural sac (b). Computerized tomography (CT) myelogram shows the communication site at the L4 level ((c), arrowhead). Compression of the cauda equina and blockage of CSF at the L4-L5 level are also shown. CT myelogram obtained 2 h later demonstrates the L5 root sandwiched between the cyst and herniation ((d), arrow).

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(b)

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