PNEUMATIC NERVE ROOT COMPRESSION - EPIDURAL GAS IN ASSOCIATION WITH LATERAL DISC HERNIATION - REPORT OF 2 CASES

Extreme lateral disc herniations are increasingly recognized as a caus e of lumbar nerve root compression syndromes. This disorder often pres ents major diagnostic and therapeutic challenges, especially in the pr esence of multiple degenerative changes and chronic back pain in elder ly patients. The authors describe two patients with presentations and findings that have not been previously described in the literature. Bo th patients had histories of upper lumbar back and leg pain. Degenerat ive spine disease, gaseous degeneration of the intervertebral discs, a nd epidural gas in the lateral recesses were noted on imaging studies. However, because both patients had undergone prior epidural diagnosti c and therapeutic procedures, the epidural gas in the lateral recesses could be attributed either to gaseous disc degeneration or to the pre vious intraspinal procedures. One patient was found to have a large, f ar lateral extruded disc fragment that contained air. The nerve root i n the second patient was impaled by an unusual combination of a small extruded disc fragment as well as an air-filled sac that was surrounde d by the walled-off fragment's capsule and which freely communicated w ith the gaseous degenerated disc space. The suspected mechanism of roo t compression is illustrated and discussed. The possibility of disc he rniation should be seriously considered in cases of nerve root compres sion in which epidural gas is present, especially those associated wit h gaseous degenerated discs.