DORSAL-ROOT ENTRY ZONE LESIONS FOR INTRACTABLE PAIN AFTER TRAUMA TO THE CONUS MEDULLARIS AND CAUDA-EQUINA

This review was undertaken to determine the efficacy of using dorsal r oot entry zone (DREZ) lesions to treat intractable pain caused by trau ma to the conus medullaris and cauda equina. Traumatic lesions of this area are unique in that both the spinal cord and the peripheral nerve roots are injured. Although DREZ lesions have been shown to relieve p ain of spinal cord origin in many patients, they have been shown not t o relieve pain of peripheral nerve origin. Therefore, 39 patients with trauma to the conus medullaris and cauda equina who underwent DREZ le sioning for intractable pain were reviewed retrospectively. The result s of this review demonstrate the efficacy of DREZ lesions in these pat ients. At a mean follow-up period of 3.0 years, 54% of patients were p ain-free without medications, and 20% required only nonnarcotic analge sic drugs for pain that no longer interfered with their daily activiti es. Better outcomes were noted in patients with an incomplete neurolog ical deficit, with pain having an ''electrical'' character, and with i njuries due to blunt trauma. Operative complications included weakness (four patients), bladder or sexual dysfunction (three), cerebrospinal fluid leak (two), and wound infection (two), but overall, 79.5% of pa tients (31 of 39) were without serious complications. Complications we re limited to patients with prior tissue damage at the surgical explor ation site and were most prevalent in patients who underwent bilateral DREZ lesions. In conclusion, this preliminary report suggests that DR EZ lesions may be useful in combating intractable pain from traumatic injuries to the conus medullaris and cauda equina, with some risk to n eurological function that may be acceptable in this group of patients.