Microsurgical DREZotomy for pain due to spinal cord and/or cauda equina injuries: long-term results in a series of 44 patients

According to the literature estimations, 10-25% of patients with spinal cor d and cauda equina injuries eventually develop refractory pain. Due to the fact that most classical neurosurgical methods are considered of little or no efficacy in controlling this type of pain, the authors had recourse to m icrosurgery in the dorsal root entry zone (DREZ). This article reports on t he long-term results of the microsurgical approach to the dorsal root entry zone (DREZotomy) in a series of 44 patients suffering from unbearable neur opathic pain secondary to spine injury. The follow-up ranged from 1 to 20 y ears (6 years on average). The series includes 25 cases with conus medullar is, 12 with thoracic cord, four with cauda equina and three with cervical c ord injuries. Surgery was performed in 37 cases at the pathological spinal cord levels that corresponded to the territory of the so-called 'segmental pain'. and in seven cases, on the spinal cord levels below the lesion for ' infralesional pain' syndromes. The post-operative analgesic effect was cons idered to be 'good' when a patient's estimation of pain relief exceeded 75% , 'fair' if pain was reduced by 25-75%. and 'poor' when the residual pain w as more than 75% of preoperative estimations. immediate pain relief was obt ained in 70% of patients and was long-lasting in 60% of the total series. T he results varied essentially according to the distribution of pain. Good l ong-term results were obtained in 68% of the patients who had a segmental p ain distribution, compared with 0% in patients with predominant infralesion al pain. Regarding pain characteristics, a good result was obtained in 88% of the cases with predominantly paroxysmal pain, compared with 26% with con tinuous pain. There were no perioperative mortalities. Morbidity included c erebrospinal fluid leak (three patients), wound infection (two patients), s ubcutaneous hematoma (one patient) and bacteremia (in one patient). The abo ve data justify the inclusion of DREZ-lesioning surgery in the neurosurgica l armamentarium for treating 'segmental' pain due to spinal cord injuries. (C) 2001 International Association for the Study of Pain. Published by Else vier Science B.V. All rights reserved.