坐骨神经痛的病因

As I see it, there are three possible "causes" of acute sciatica--excluding the more exotic forms: (1) disc herniation induced sciatica; that is, the posterior of the disc herniates into the adjacent sciatica nerve root, which in turn physically compresses and irritates that nerve root into a painful state; (2) grade V annular tear induced sciatica; that is, the disc rips open and allows biochemical (cytokines) to leak out and soak the adjacent sciatica nerve root(s), which in turn inflammes the sciatica nerve root into a painful state; and (3) discogenic sciatica; that is, the patient may experience a "referred" pain (that often is dermatomal) down the lower limb from severe irritation of the tiny sensory nerve fibers (sinuvertebral nerve) that live within the outer 1/3 of the annulus of the disc. This is NOT an irritation of the actual sciatica nerve but simply the patient"s preception of sciatic nerve irritation--like the left arm pain felt by someone suffering a heart attack. 上海仁济医院疼痛科王祥瑞

一般而言，急性坐骨神经痛可能有三种原因：（1）椎间盘突出症引起的坐骨神经痛：椎间盘向后突出至邻近的坐骨神经根引起物理性压迫和刺激其引起疼痛；（2）V级变量纤维环形撕裂引起的坐骨神经痛：即椎间盘撕开使得生化因子（细胞因子）渗出浸润相邻的坐骨神经根，通过炎症刺激坐骨神经根引起坐骨神经痛；（3）椎间盘源性坐骨神经痛：也就是说，处于椎间盘环外三分之一的细小感觉神经纤维（窦椎神经）的严重刺激时，病人可能会出现特定区域的疼痛（常常呈皮节分布）。这不是一个实际的坐骨神经的刺激，只是病人有坐骨神经痛的感觉??就像有些人心脏病发作时表现为左上臂的疼痛。

In a general sense, disc herniation and/or stenosis are by far the most frequent causes of compressive sciatica, there are, however, other more exotic causes of sciatica; such as, Spondylolisthesis, Piriformis Syndrome, Obturator Syndrome, Far-Out Syndrome, Synovial Cysts, Hypertrophied Epidural Vessels, Gas-containing Ganglion cysts, and Tumors.椎间盘突出症和/或狭窄是迄今为止压迫坐骨神经最常见的原因，然而，也有其他引起坐骨神经痛的原因：如腰椎滑脱症，梨状肌综合征，闭孔综合症，far-out症候群，滑膜囊肿，硬膜外导管过长，含气腱鞘囊肿和肿瘤。

And before we dig deeping into the phenomenon of sciatica, here is another important fact that need be remembered: the mechanism of lower limb pain (sciatica) is most likely VERY complex and is not nearly as simple as the disc herniates, pinches the nerve, and you get pain. There are many other factors (some of which that are still unknown) that contribute to the pain of sciatica. In fact, recently we have learned from the work of Karppinen et al. that neither the amount of nerve root compression nor the size of the disc displacement (posterior outpouching of the disc) relates to the amount of pain (VAS) or disability (Oswestry) the patient suffers (70). Those "other factors" are still being debated within the research community, but proinflammatory cytokines (especially TNF-alpha) are certainly involved (96-99). Pain "referred" directly from the disc may also have a role in the sensation of sciatica (11,12).

我们深入探索坐骨神经痛时需要记住：下肢疼痛的机制（坐骨神经痛）是非常复杂并不是简单的椎间盘突出，压迫神经后引起的痛苦。还有许多其它因素（其中一些尚未知）引起坐骨神经痛。事实上，神经根受压的数量及椎间盘移位的大小与病人所疼痛（VAS）程度和行动（Oswestry）能力无关。其他因素在研究界内仍存在争议，但促炎因子（尤其是TNF -α）肯定参与其中，盘源性疼痛在坐骨神经痛的感觉方面起重要的作用。