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

在本研究项目中，我们试图建立慢性压迫神经根引起的腰椎神经根病动物模型，并分析功能观察与神经根组织学改变的关系。并得到了以下几点结论。1)自体髓核慢性压迫神经根的大鼠腰椎神经根病模型，出现机械性痛觉过敏，但随访期间未见神经功能缺损。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直径约为30%。术后6周，神经根纤维Kluver-Barerra染色呈低染色趋势，提示神经根纤维脱髓鞘。2)约1/3的自体髂骨联合b-FGF和慢性肠形成的神经根慢性压迫大鼠模型在术后3 ~ 6周出现中枢性狭窄或外侧狭窄。对神经根隧道的最大骨压迫在30 - 50%之间，但对神经根纤维的直接压迫在大多数大鼠中未见。此外，在术后12周，这种骨压迫表现出减少或缩小的趋势。本模型随访期间未见运动无力、感觉障碍等典型功能改变。

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.