Rossitch E, Abdulhak M, Ovelmen-Levitt J, Levitt M, Nashold B S
Division of Neurosurgery, Duke University Medical Center, Durham, North Carolina.
J Neurosurg. 1993 Apr;78(4):598-602. doi: 10.3171/jns.1993.78.4.0598.
Extensive longitudinal lesions of the dorsal root entry zone (DREZ) are effective in relieving some chronic deafferentation pain in humans. A deafferentation syndrome follows C5-T2 dorsal root ganglionectomies in rats. The syndrome consists of biting and scratching the completely and partially denervated limb areas, respectively. This study examines the effect of DREZ lesions on the deafferentation syndrome in the rat. Of 37 rats, 24 underwent C5-T2 ganglionectomies only, five received C4-T3 micromechanical DREZ lesions only, and eight underwent ganglionectomies plus simultaneous DREZ lesions. The animals were observed for 45 days post-operatively. Histological analysis of the spinal cord lesions was performed. All rats with ganglionectomies alone exhibited the deafferentation syndrome; however, no rats with DREZ lesions alone showed this feature. Only 25% of rats with combined ganglionectomies and DREZ lesions exhibited the deafferentation syndrome in the first 30 days, whereas 80% of the animals with ganglionectomies only did so. Although 75% of the animals with combined lesions eventually bit the insensitive forepaw, this behavior was significantly attenuated: the day of onset was delayed and the extent of self-mutilation was reduced. Postmortem histological examination of the DREZ lesions indicated a close association between the completeness of the dorsal horn destruction and the reduction or prevention of self-mutilation. These data support the validity of the animal model and also the hypothesis stating that the deafferentation syndrome results from abnormal spontaneous neural activity in the dorsal horn. Moreover, the variability of the histological findings in these experiments stresses the importance of making contiguous and complete dorsal horn lesions in human DREZ surgery.
背根入髓区（DREZ）广泛的纵向损伤对缓解人类某些慢性去传入性疼痛有效。大鼠C5 - T2背根神经节切除术后会出现去传入综合征。该综合征分别表现为啃咬和抓挠完全和部分去神经支配的肢体区域。本研究考察了DREZ损伤对大鼠去传入综合征的影响。37只大鼠中，24只仅接受C5 - T2神经节切除术，5只仅接受C4 - T3微机械DREZ损伤，8只接受神经节切除术并同时进行DREZ损伤。术后对动物观察45天。对脊髓损伤进行了组织学分析。所有仅接受神经节切除术的大鼠均表现出去传入综合征；然而，仅接受DREZ损伤的大鼠未表现出该特征。在最初30天内，仅接受神经节切除术和DREZ联合损伤的大鼠中只有25%表现出去传入综合征，而仅接受神经节切除术的动物中有80%表现出该综合征。尽管75%的联合损伤动物最终会啃咬无感觉的前爪，但这种行为明显减轻：发作时间延迟且自残程度降低。DREZ损伤的死后组织学检查表明，背角破坏的完整性与自残行为的减少或预防之间存在密切关联。这些数据支持了该动物模型的有效性，也支持了去传入综合征是由背角异常自发神经活动引起这一假说。此外，这些实验中组织学结果的变异性强调了在人类DREZ手术中进行连续且完整的背角损伤的重要性。
