Pathophysiology of lumbai radiculopathy -A study of ectopic finng-

坐骨神经痛是腰椎管狭窄症和椎间盘突出症的典型神经病理性疼痛。然而，坐骨神经痛的发病机制知之甚少。最近，神经根的异位放电被发现作为坐骨神经痛的起源起着重要的作用。本研究建立了一个分析异位放电的模型。然后观察静脉淤血、缺氧、神经元活动增加、交感神经作用、手术减压和各种药物的作用。在实验中，从大鼠腓肠神经逆向记录异位放电。在慢性腰椎管狭窄症大鼠中，自发频率增加和静脉瘀血和缺氧引起的放电增加是其特征性的病理变化。激活后肢神经或交感神经也能增加锉削频率。研究中获得的结果被认为与间歇性跛行等临床症状相关。多普勒血流仪也证实了静脉瘀血引起的神经根血流变化。腰椎管狭窄症的治疗方法，如手术减压，药物和块被认为是有效的。本研究结果为了解腰椎管狭窄症的病理生理机制提供了重要信息。

Sciatica is a representative neuropathic pain seen in lumbar spinal canal stenosis and disk herniation. However the pathogensis of sciatica is poorly understood. Recently, ectopic firings in the nerve root has been found to play an important role as an origin of sciatica. In the present study', a model to analyze the ectopic firing was established. Then the effects of venous stasis, anoxia, increased neuronal activity, sympathetic action, surgical decompression and various drugs were investigated. In the experiments, ectopic firing was antidromically recorded from sural nerve of rats. In the rats with chronic lumbar spinal canal stenosis, increased spontaneous frequency and an increase of firing by venous stasis and anoxia were characterized as pathological changes. Activation of hindlimb nerve or sympathetic nerve increased filing frequency as well. The findings obtained in the study were thought to be related to the clinical symptoms such as intermittent claudication. The changes of nerve root blood flow due to venous stasis was also confirmed by a lazor-doppler flowmeter. The therapeutic treatments for lumbar stenosis such as surgical decompression, medications and blocks were found to be effective. The results obtained in the present study provided improtant information to understand the pathophysiology of lumbar spinal canal stenosis.