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

本研究试图建立慢性压迫神经根所致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。1)采用自体髓核慢性压迫神经根的方法建立大鼠腰神经根病模型，可观察到机械性痛觉过敏，但在随访期内未见神经功能障碍。在该模型中，对神经根的机械压迫是由髓核随时间形成的神经周瘢痕形成的，对神经根的最大压迫直径约为30%。光镜下可见术后6周Kluver-Barera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和铬肠制作的慢性压迫神经根模型中，约1/3的大鼠在术后3~6周出现中央型或侧型狭窄，对神经根隧道的最大骨压为30%~50%，但大多数大鼠未见神经根纤维直接受压。此外，在术后12周，这种骨性压缩有减少或减少的趋势。该模型在随访期内未出现运动无力或感觉障碍等典型的功能改变。

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.