Results of DREZ coagulations for pain related to plexus lesions, spinal cord injuries and postherpetic neuralgia.

The results of 58 dorsal root entry zone (DREZ) thermocoagulation procedures in 51 patients are reported. The postoperative analgesic effect was judged by the patients as being good (more than 75% pain reduction), fair (25-75% pain reduction) or poor (less than 25% pain reduction). Of the 14 patients who underwent surgery for pain due to cervical root avulsion, 10 (77%) had permanently good (8) or fair (2) pain relief after a mean follow up period of 76 months, another 2 (15%) experienced recurrence to the preoperative level (initially 1 good, 1 fair) after more than 2 and 4 years, respectively. Twenty two paraplegics were operated upon, 3 of whom twice, for intractable pain. After a mean observation time of 54 months, continuing pain relief was reported by 12 (55%) patients (11 good, 1 fair), and one (initially fair) had recurrent pain after 8 months. All 3 (early) re-operations remain successful for an average period of 75 months. Poor results were seen especially in cases of associated spinal cord cysts (5 out of 7), despite combined drainage, and in patients with diffuse pain distribution (5 out of 6). Continuous marked improvement for longer periods (mean follow up: 52 months) after DREZ lesions was reported only by 2 out of 10 patients with postherpetic neuralgia (12 procedures) and by 1 out of 5 with painful states due to radiation-induced brachial plexopathy (2), previous surgery (2) and malignant tumour infiltration of the brachial plexus (1). Three patients died postoperatively due to acute cardiac failure (2) and pulmonary embolism (1). Major complications, especially permanent gait disturbances were observed in 6 patients (12%) following primary procedures and in 2 out of 7 patients after re-operations, most of them suffering from postherpetic neuralgia. Minor neurological deficits were noted in 9 cases (18%). DREZ lesions revealed to be an effective procedure in patients with pain related to root avulsion and paraplegia. In contrast, it seems to be less successful for painful states due to other plexus lesions or postherpetic neuralgia.