Application of the collision technique and development of fast-recovery preamplifier for detecting conduction delicits in lumbar spinal stenosis.

碰撞技术的应用和快速恢复前置放大器的开发用于检测腰椎管狭窄症的传导缺陷。

基本信息

批准号：
11671442
负责人：
TANI Toshikazu
金额：
$ 2.18万
依托单位：
Kochi Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Clinically recorded lumbosacral evoked potentials after peripheral nerve stimulation are less sensitive than might be expected for a single radicular lesion. Direct nerve root stimulation, despite its potential advantage, is not practical because of an overloading stimulus artifact. A collision technique should circumvent these problems. For a single L-5 radicular lesion produced in rats by constant, localized compression, sequential changes of epidurally recorded potentials after sciatic nerve stimulation (Group 1) or direct L-5 root stimulation (Group 2) were compared to those after a combination of L-6 root and sciatic nerve stimulation (Group 3). At every step of recording, the N1 peak amplitude was significantly smaller in group 2 and 3 than in group 1, whereas there was no significant difference between group 2 and 3. Thus, the collision technique in gourp 3 achieved nearly the same diagnostic yield as the direct L5 root stimulation in group 2 by blocking the unwanted impulses transmitted via the L6 root.In clinical practice, unlike animal experiments, it is difficult to control the stimulus artifact by shielding the stimulator from the surrounding tissues and thereby reducing spread of stimulus current. To circumvent this problem, we developed a fast-recovery preamplifier. This preamplifier interposed between the recording electrodes and the amplifier allows opening the conduction path at the moment of large stimulus input and closing the path with the wane of its magnitude. The printed circuit plate of the preamplifier was made of glass epoxy because of an excellent high frequency specificity of the material. It was shielded from the outside electric noise by being doubly encased in two aluminum boxes. In addition, the electric noise occurring when the switch closes and opens was minimized by using the MCD-5221 switch.

周围神经刺激后临床记录的腰椎诱发电位比单个辐射病变所预期的要敏感。直接的神经根刺激尽管具有潜在的优势，但由于刺激伪影的过载，但不实用。碰撞技术应规避这些问题。对于通过恒定局部压缩在大鼠中产生的单个L-5辐射病变，将坐骨神经刺激（第1组）或直接L-5根刺激（第2组）在L-6根和Sciatic神经刺激（第3组）组合后的坐骨神经刺激（第1组）或直接L-5根刺激（第2组）进行比较（第2组）。在记录的每个步骤中，第2组和第3组的N1峰值幅度明显小于第1组，而第2组和第3组之间没有显着差异。因此，Gourp 3中的碰撞技术几乎达到了与直接L5根刺激在第2组中的直接L5根刺激相同的诊断产量，从而阻止了不知力的施加动物的实验，而不是在L6根部进行的刺激，这是不存在的刺激性。屏蔽刺激器免受周围组织的影响，从而减少刺激电流的扩散。为了解决这个问题，我们开发了快速恢复前置放大器。在记录电极和放大器之间插入的这个前置放大器允许在大型刺激输入时打开传导路径，并以其大小的衰减关闭路径。前置放大器的印刷电路板是由玻璃环氧树脂制成的，因为材料的高频特异性很高。通过双重包裹在两个铝制盒中，它被屏蔽了外部电噪声。此外，使用MCD-5221开关将开关关闭并打开时发生电噪声。