Nerve root compression by a gas-containing cyst associated with stenotic lateral recess. Case report and review of the literature.

The authors describe a case in which a gas-containing cyst was associated with a stenotic lateral recess at the same level in the absence of any disc material. A young man presented a one-month history of sciatica caused by compression of the left L5 nerve root. The neuroradiological investigations performed (CT, MRI) showed the presence of a gas-containing cyst associated with a stenotic lateral recess. The clinical, etiopathological characteristics and treatment of this condition are discussed and the pertinent literature is reviewed. Decompression of the nerve root was obtained by surgery. The herniated gas collected within a capsule (gas-containing cyst) can act as a mass and produce symptoms, much like a herniated nucleus pulposus. The antalgic stance adopted by the patient with marked flexion of the spine helps to distribute the pressure exerted by the cyst over a wider area (Pascal's law I). The appropriate procedure to relieve the radicular compression caused by gas-containing cyst seemed to be the surgical treatment.