Omarker Kjell, Myers Robert R
Peripheral Nerve Research Laboratory, Departments of Anesthesiology and Pathology (Neuropathology), VA Medical Center, San Diego, and the University of California San Diego, La Jolla, CA, USA Department of Orthopaedics Sahlgrenska University Hospital Göteborg University S - 413 45 Gothenburg, Sweden.
Pain. 1998 Nov;78(2):99-105. doi: 10.1016/S0304-3959(98)00119-5.
The basic pathophysiologic mechanisms related to disc herniation and sciatica are poorly understood. Recently it was demonstrated that nucleus pulposus from an intervertebral disc could induce structural and functional changes in adjacent nerve roots when applied epidurally, however, it is not known if such changes are painful. In a model for inducing disc herniation in the rat, we found that puncture of a lumbar disc with subsequent herniation of nucleus pulposus without nerve root compression, or chronic displacement of the 4th lumbar nerve root and ganglion, did not individually induce significant changes in thresholds for mechanical or thermal stimulation compared to sham-operated animals. However, the combination of disc puncture and displacement induced a reduction of the threshold for thermal stimulation, indicating hyperalgesia, that was present 2 days after surgery and gradually recovered during a 14-day period. These data and the associated description of this new model for experimental disc herniation may increase our understanding of the pathophysiologic events leading to sciatica and help in evaluating new modalities for diagnosis and treatment of disc herniation and sciatica.
与椎间盘突出症和坐骨神经痛相关的基本病理生理机制目前仍知之甚少。最近有研究表明，将椎间盘的髓核硬膜外应用时，可诱导相邻神经根发生结构和功能变化，然而，尚不清楚这些变化是否会引起疼痛。在一个诱导大鼠椎间盘突出的模型中，我们发现，穿刺腰椎间盘导致髓核突出但无神经根受压，或第四腰神经根和神经节的慢性移位，与假手术动物相比，单独并不会引起机械性或热刺激阈值的显著变化。然而，椎间盘穿刺和移位相结合会导致热刺激阈值降低，表明存在痛觉过敏，这种情况在手术后2天出现，并在14天内逐渐恢复。这些数据以及对这种新的实验性椎间盘突出模型的相关描述，可能会增进我们对导致坐骨神经痛的病理生理事件的理解，并有助于评估诊断和治疗椎间盘突出症和坐骨神经痛的新方法。
