AN EXPERIMENTAL STUDY OF LUMBAR RADICULOPATHY PRODUCED BY CHRONIC COMPRESSION TO THE NERVE ROOTS

本研究试图建立一种慢性压迫神经根的腰神经根病动物模型，并分析神经根功能观察与组织学改变的关系。结果表明：1）自体髓核慢性压迫神经根建立的大鼠腰神经根病模型中，可观察到机械性痛觉过敏，但随访期间未观察到神经功能缺损。在该模型中，随着时间的推移，髓核引起的神经周围瘢痕对神经根产生机械压迫，对神经根的最大压迫约为直径的30%。术后6周Kluver-Barerra染色神经根纤维染色较弱，提示神经根纤维脱髓鞘。2）在另一种自体髂骨联合b-FGF和铬肠慢性压迫神经根的大鼠模型中，术后3 ~ 6周观察到中央狭窄或侧部狭窄。神经根隧道的最大骨压缩范围为30 ~ 50%，然而，大部分大鼠未见对神经根纤维的直接压迫。术后12周，骨压缩有减轻或缩小的趋势。在该模型中，在随访期间没有任何典型的功能变化，如运动无力或感觉障碍。

In a present research project, we have tried to develop an animal model of lumbar radiculopathy produced by the chronic compression to the nerve roots and analyze the relationship between functional observation and histological changes of nerve roots. And, we have obtained several conclusions as follows.1)In a rat lumbar radiculopathy model by chronic compression to the nerve roots with autologous nucleus pulposus, mechanical hyperalgesia was observed, however, neurological deficit was not seen during follow-up period. In this model, mechanical compression to the nerve roots was produced by perineural scarring induced by the nucleus pulposus with time.The maximum compression to the nerve roots was approximately 30% in diameter. Hiotologically, staining of nerve root fibers by Kluver-Barerra's stain tended to be low at 6 weeks post-operatively, which suggested the demyelination of nerve root fibers.2)In approximately 1/3 of another rat model of chronic compression to the nerve roots produced by autologous iliac bone combined with b-FGF and chromic gut, central stenosis or lateral stenosis was observed at 3 to 6 weeks post-operatively.Maximum bony compression to the nerve root tunnel ranged from 30 to 50%, however, direct compression to the nerve root fibers was not seen in most of rats. Furthermore, this osseous compression showed tendency of reduction or diminution at 12 weeks post-operatively. In this model, there are not any typical functional changes such as motor weakness or sensory disturbance during follow-up period.