Acute cauda equina syndrome caused by a gas-containing prolapsed intervertebral disk.

Gas production as a part of disk degeneration can occur, but it rarely causes clinical nerve compression syndromes. A rare case of gaseous degeneration in a prolapsed lumbar intervertebral disk causing acute cauda equina syndrome is described. Radiologic features and intraoperative findings are reported. A 78-year-old woman with severe lumbar canal stenosis had acute cauda equina syndrome. Magnetic resonance imaging revealed a large disk protrusion, and she underwent an urgent operation for this. Surgery confirmed the severe lumbar canal stenosis, but the disk prolapse contained gas that had caused the nerve compression.