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) thermocoagnlation proc edures in 51 patients are reported. The postoperative analgesic effect was judged by the patients as bring good (more than 75% pain reductio n), fair (25-75% pain reduction) or poor (less than 25% pain reduction ). Of the 14 patients who underwent surgery for pain due to cervical r oot avulsion, 10 (77%) had permanently good (8) or fair (2) pain relie f after a mean follow up period of 76 months, another 2 (15%) experien ced recurrence to the preoperative level (initially 1 good, 1 fair) af ter more than 2 and 4 years, respectively. Twenty two paraplegics were operated upon, 3 of whom twice, for intractable pain. After a mean ob servation time of 54 months, continuing pain relief was reported by 12 (55%) patients (11 good, 1 fair), and one (initially fair) had recurr ent 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 combin ed 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 patient s with postherpetic neuralgia (12 procedures) and by 1 out of 5 with p ainful states due to radiation-induced brachial plexopathy (2), previo us surgery (2) and malignant tumour infiltration of the brachial plexu s (1). Three patients died postoperatively due to acute cardiac failur e (2) and pulmonary embolism (1). Major complications, especially perm anent gait disturbances were observed in 6 patients (12%) following pr imary procedures and in 2 out of 7 patients after re-operations, most of them suffering from postherpetic neuralgia. Minor neurological defi cits were noted in 9 cases (18%). DREZ lesions revealed to be an effec tive procedure in patients with pain related to root avulsion and para plegia. In contrast, it seems to be less successful for painful states due to other plexus lesions or postherpetic neuralgia.