Analysis of cauda equina compression in lumobar spinal stenosis

硬膜外压力测量的研究清楚地表明，椎管狭窄患者狭窄节段的局部硬膜外压力随运动而改变。卧位和坐位的压力较小，站立时的压力较大。尤其是腰椎后伸时压力增加，而前屈时压力降低。硬膜外压力的变化与神经根受压的临床症状的发生有关。这些压力变化可能解释了椎管狭窄症状的体位依赖性。神经源性间歇性跛行患者行走时硬膜外压力也发生了变化。硬膜外压力变化呈先增后减的规律，步行过程中反复出现这种规律。单纯步行时硬膜外压力高，屈腰时硬膜外压力低。行走过程中对神经根的间歇性压迫可能在神经源性间歇性跛行的发病机制中起重要作用。躯干肌肉锻炼如背部肌肉力量训练可显著增加神经源性间歇性跛行的压力。这一结果暗示背部肌肉锻炼对腰椎管狭窄症患者可能是危险的。腰椎动态加压对腰椎管狭窄症的病理生理有重要意义。

The study of epidural pressure measurements clearly demonstrated that the local extradural pressure at the stenotic level was changed by motion in patients with spinal stenosis. The pressure was low in lying and sitting, and high in standing. Especially, the pressure was increased by lumbar extension, but decreased by forward flexion. Changes of the epidural pressure correlated with the occurence of clinical symptoms of nerve roots compression. These pressure changes may explain the postural dependency of symptoms in spinal stenosisThe epidural pressure was also changed at walking in patients with neurogenic intermittent claudication. The epidural pressure change had a pattern of increase and decrease, and this pattern was repeated during walking. The epidural pressure was high at simple walking and low at walking with lumbar flexion. Intermittent compression to the nerve roots during walking might have a important role in the pathogenesis of neurogenic intermittent claudicationThe pressure was extremely increased by trunk muscle exercises e. g. back muscle strength exercise. This result imply that back muscle exercise might be dangerous for patients with lumbar spinal stenosisIn conclusion, static compression in lumbar spinal stenosis is low compared to lumbar disc herniation. Dynamic compression by lumbar motion would be important for the pathophysiology of lumbar spinal stenosis