Lunsford L D, Bennett M H
Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pa.
Stereotact Funct Neurosurg. 1989;53(4):233-46. doi: 10.1159/000099539.
Somatosensory evoked potentials (SEP) were monitored intraoperatively in 15 patients who underwent spinal cord radiofrequency thermal dorsal root entry zone (DREZ) lesion procedures to treat chronic deafferentation pain. We found a significant correlation between transient latency shifts (recovery to prelesion values in the postlesioning period) of the first positive peak of the SEP (P1) during lesion production and the patients' subsequent postoperative neurological status (p less than 0.01). Transient increases in P1 latency above 2 ms were associated with detectable but transient postoperative sensorimotor deficits that resolved weeks to months after surgery. In 1 patient, the intraoperative P1 latency failed to return to baseline values; this patient had irreversible postoperative sensorimotor dysfunction. In 9 patients, we confirmed the value of recording bilateral SEP, using the contralateral side of the spinal cord (with no lesions) as a control. This experience has resulted in an improved SEP monitoring strategy: we now reconsider the risk-benefit ratio of additional DREZ lesions if early lesion production results in increased P1 latency. Rapid normalization of the P1 latency indicates that any postoperative deficits likely will resolve. Failure of P1 latency to return to control levels during the surgical wound closure period (approximately 1 h) indicates the high probability of permanent neurological deficits.
对15例行脊髓背根入髓区（DREZ）射频热凝术治疗慢性传入阻滞性疼痛的患者术中监测体感诱发电位（SEP）。我们发现，在损伤产生过程中SEP第一个正峰（P1）的瞬态潜伏期变化（在损伤后恢复到损伤前值）与患者术后随后的神经状态之间存在显著相关性（P<0.01）。P1潜伏期瞬态增加超过2毫秒与术后可检测到但短暂的感觉运动功能障碍相关，这些功能障碍在术后数周数月内可恢复。1例患者术中P1潜伏期未能恢复到基线值；该患者术后出现不可逆的感觉运动功能障碍。在9例患者中，我们证实了记录双侧SEP的价值，以脊髓对侧（无病变）作为对照。这一经验带来了改进的SEP监测策略：如果早期损伤产生导致P1潜伏期增加，我们现在会重新考虑额外DREZ损伤的风险效益比。P1潜伏期迅速恢复正常表明任何术后功能障碍可能会恢复。在手术伤口闭合期（约1小时）P1潜伏期未能恢复到对照水平表明存在永久性神经功能缺损的高可能性。
