Study on Blood-flow in Spinal Cord and Nerve Root

采用扫描电子显微镜、透射电子显微镜、马达、驱动高速摄像机、微量血流计(电化学氢气冲洗法)、氧分压计和肌电图仪(Dantec-N2000)，对成年犬脊髓和神经根损伤的超微结构、循环动力学和脑脊液在其中的作用进行了研究，以阐明脊髓和神经根损伤的病理生理机制。结论：1.滋养神经根的红动、静脉与脑脊液中的神经根鞘、底有疏松的联系。神经内间隙通过神经根鞘与蛛网膜下腔相通，神经根鞘非常薄，对脑脊液具有通透性。脑脊液被截留或排出，神经根血流量减少20%。小腿内毛细血管均为连续型，血神经屏障较强，但…当神经根受压超过30Grs时，由于屏障的破坏，会出现更多的血管源性水肿。静脉注射适量的盐酸依托里松(4-乙基-2-甲基-3-哌啶丙酮)可增加神经根的血流量。由于胸主动脉被截断，腰骶段脊髓的血流量严重减少。诱发脊髓动作电位也明显降低，潜伏期延长。阻断胸主动脉30min后松开钳夹，诱发的脊髓动作电位迅速恢复，但腰骶段脊髓特别是灰质的血流维持在较长时间的下降水平。脊髓也浸泡在脑脊液中，因为软脑膜对脑脊液是可渗透的，而Virchow-Robin血管周围间隙可以到达整个脊髓的终动脉和终静脉。由于脑脊液的截留或排斥，脊髓中的血流量减少了约15%。正常脑脊液的氧分压远高于脊髓内的氧分压，脊髓内的氧分压因脑脊液的截留或排出而降低约15%。这些结果表明，脊髓和神经根与脑脊液密切相关，脑脊液流动状态的改变对脊髓和神经根有严重影响。较少

The fine structure, circulatory dynamics and the role of cerebrospinal fluid in the spinal cord and nerve roots of adult dogs have been studied to clarify the pathophysiology of the spinal cord and nerve roots disturbance, using scanning electron micro-scope, transmission electron microscope, motor, driven high speed camera, micro-blood flow meter (electro chemically generated hydrogen washout method), partial oxygen pressure meter and electromygraphy (DANTEC-N2000).Results1. Redicular arteriesand veins nourishing nerve roots are loosely connected with the nerve root sheath and flooring in the cerebrospinal fluid.2. The endoneurial space is communicating with the subarachnoid space through the nerve root sheath which is very thin and permeable for the cerebrospinal fluid.3. The blood flow in the nerve root decreases by 20 percent due to interception or exclusion of the cerebrospinal fluid.4. Intraradicular capillaries are all continuous type and so the bloodnerve barrier is strong, but … More vasogenic edema occurs due to breakage of the barrier when the nerve root is compressed by more than 30 Grs.5. Intravenous injection of proper amount of Eperisone hydrochloride (4-Ethy-2-methy-3-piperidinopropiopheone) increases the blood flow in the nerve root.6. The blood flow in the lumbosacral spinal cord is reduced severely by interception of thoracic aorta. Evoked spinal cord action potentials are also decreased severely and the latency is prolonged.7. When the clamp is released 30 minutes after interception of thoracic aorta, evoked spinal cord action potentials recover quickly, but the blood flow in the lumbosacral spinal cord specially in the gray matter stays in the reduced level for longer time.8. The spinal cord is also soaked in the cerebrospinal fluid, because the pia mater is permeable for the cerebrospinal fluid and Virchow-Robin perivascular space reaches endarteries and endveins in all over the spinal cord.9. The blood flow in the spinal cord decreases by about 15 percent due to interception or exclusion of the cerebrospinal fluid.10. The partial oxygen pressure of the normal cerebrospinal fluid is considerably higher than the pressure in the spinal cord and the latter decreases by about 15 percent due to interception or exclusion of the cerebrospinal fluid.11. These results indicate that the spinal cord and nerve roots are closely concerned with the cerebrospinal fluid, and changes in the condition of the cerebrospinal fluid flow exert serious influence upon the spinal cord and nerve roots. Less