Dorsal root entry zone lesions for conus medullaris root avulsions.

We have found dorsal root entry zone (DREZ) lesions to be an effective treatment of chronic deafferentation pain in patients who have had avulsions of the dorsal rootlets from the spinal cord. Eight patients were operated in whom chronic pain of the lower extremity resulted from dorsal root avulsions from the conus medullaris. In 7 of the 8 patients, the mechanism of injury was a motor vehicle accident; all 7 sustained severe pelvic trauma. Seven of the 8 patients remained pain-free, off all narcotics, with an average follow-up of 33 months. All patients had DREZ lesions of the conus performed by radiofrequency techniques.