Problems related to dorsal root entry zone lesions.

Several clinical problems related to the dorsal root entry zone lesions (DREZLs) in 15 patients with chronic pain are presented and discussed in terms of ratings of pain relief following surgery, development of sensory or motor weakness and postmortem histologies. Subjective pain relief exceeding 70% was achieved at around 2 weeks after the operations in most patients (13/15), and then decreased in some to 30 from 70% in the follow-up observations. Our new "objective" pain relief score was tested in these patients. A significant positive correlation between subjective pain relief and our objective pain relief scale was found, but some discrepancies between them were also found during the follow-up. Sensory loss, motor weakness, paraesthesia and a new pain were found as complications in 12, 7, 4 and 6 patients, respectively. Postmortem histological findings of the spinal cord in two patients with systemic lupus erythematosus and uterine cancer, who received bilateral DREZLs twice and bilateral DREZLs plus commissural myelotomy, respectively, indicate that care should be taken to avoid extension of the coagulation beyond the dorsal horn.