髓核对大鼠脊神经节非压迫性损伤的组织形态学研究

目的 观察硬膜外移植自体髓核后，大鼠脊神经节组织形态学的变化。方法 20只Sprague—Dawley(SD)雄性大鼠随机分成对照组和实验组，分别将自体肌肉混悬液和尾椎髓核混悬液注射到腰椎硬膜外腔，对脊神经节组织形态学进行观察。结果 在无机械压迫情况下，大鼠硬膜外移植自体髓核能使脊神经节组织形态产生明显改变。结论 髓核所致的炎性反应是引起脊神经节损伤和坐骨神经痛的重要原因之一。     

大鼠非压迫性髓核突出模型的建立

目的:设计一种新的非压迫性腰椎间盘髓核突出动物模型。方法:16只SD雄性大鼠随机分对照组和实验组,分别将生理盐水和大鼠自身尾椎髓核混悬液注射到腰椎硬膜外腔,对其马尾神经传导速度和神经根组织形态学进行观察。结果:无明显机械压迫情况下,大鼠硬膜外移植自体髓核能使马尾神经根传导速度和组织形态产生明显改变。结论:本动物模型简单、可靠、费用低廉,为进一步研究腰椎间盘突出症提供了一种动物模型。     

大鼠非压迫性髓核突出模型的建立

目的:设计一种新的非压迫性腰椎间盘髓核突出动物模型.方法:16只SD雄性大鼠随机分对照组和实验组,分别将生理盐水和大鼠自身尾椎髓核混悬液注射到腰椎硬膜外腔,对其马尾神经传导速度和神经根组织形态学进行观察.结果:无明显机械压迫情况下,大鼠硬膜外移植自体髓核能使马尾神经根传导速度和组织形态产生明显改变.结论:本动物模型简单、可靠、费用低廉,为进一步研究腰椎间盘突出症提供了一种动物模型.     

大鼠非压迫性髓核突出模型的建立

目的：设计一种新的非压迫性腰椎间盘髓核突出动物模型。方法：16只SD雄性大鼠随机分对照组和实验组，分别将生理盐水和大鼠自身尾椎髓核混悬液注射到腰椎硬膜外腔，对其马尾神经传导速度和神经根组织形态学进行观察。结果：无明显机械压迫情况下，大鼠硬膜外移植自体髓核能使马尾神经根传导速度和组织形态产生明显改变。结论：本动物模型简单、可靠、费用低廉，为进一步研究腰椎间盘突出症提供了一种动物模型。     

硬膜外移植自体髓核对大鼠神经根功能和组织学的影响

目的:探讨无机械压迫时,腰椎间盘髓核突出引起腰腿痛的发病机制.方法:用硬膜外穿刺的方法给大鼠注射生理盐水及自体髓核混悬液,并对机械刺激缩爪阈值、马尾神经传导速度,神经根组织形态、疼痛行为进行了测定和观察.结果:大鼠硬膜外移植自体髓核能产生明显的痛觉过敏反应,马尾神经传导速度和神经根组织形态产生明显改变.结论:髓核所致的炎症反应是引起坐骨神经痛的重要原因之一.     

硬膜外移植自体髓核对大鼠神经根功能和组织学的影响

目的：探讨无机械压迫时，腰椎间盘髓核突出引起腰腿痛的发病机制。方法：用硬膜外穿刺的方法给大鼠注射生理盐水及自体髓核混悬液，并对机械刺激缩爪阈值、马尾神经传导速度，神经根组织形态、疼痛行为进行了测定和观察。结果：大鼠硬膜外移植自体髓核能产生明显的痛觉过敏反应，马尾神经传导速度和神经根组织形态产生明显改变。结论：髓核所致的炎症反应是引起坐骨神经痛的重要原因之一。     

实验性髓核突出诱致神经根性疼痛机理的探讨

目的 探索单纯自体髓核组织放置于神经根邻近,并与神经根接触后对大鼠后爪机械刺激痛觉敏感性的影响。方法 取大鼠自体尾椎髓核组织无压迫下置于腰4和腰5神经根旁并与神经根相接触,术后不同的时间点观察大鼠双侧后爪机械刺激敏感性的变化;同时采用HE染色方法观察髓核组织和神经根的变化。结果 无明显机械压迫情况下,自体髓核组织与神经根接触后可诱导大鼠术侧后爪出现明显的机械性痛觉敏感性的升高;HE染色显示髓核组织发生了明显的炎性改变,邻近神经根出现空泡变性。结论 髓核组织自身介导的炎症反应可能参与机械性痛觉敏感性的发生。除机械因素外,突出髓核组织发生的炎症反应也可能是腰椎间盘突出所致坐骨神经痛的原因。     

周围神经旁移植自体髓核对大鼠疼痛行为的影响

目的　探讨髓核在坐骨神经痛发病机制中的作用。方法　选择 16只SD雄性大鼠随机分为两组 ,分别将自体尾椎髓核混悬液注射到腰椎硬膜外腔或坐骨神经周围。测定其后肢机械刺激缩爪阈值。结果　在没有明显机械压迫下 ,腰椎硬膜外腔的髓核使大鼠后肢产生明显的痛觉过敏反应 ,坐骨神经旁的髓核不能使大鼠产生上述变化。结论　与髓核相关的炎症的介质是引起坐骨神经痛的原因之一 ,神经根缺乏神经外膜保护是引起疼痛的解剖学基础。     

一氧化氮在神经根性疼痛中的作用

目的：探索一氧化氮(NO)在髓核突出所致的神经根性疼痛中的作用。方法：取大鼠自体尾椎髓核无压迫下放置在L4和L5神经根表面，分别在术后3d及1、2、3、4周时观察大鼠后足机械刺激和热刺激敏感性的变化，并用免疫组化方法对移植髓核中的一氧化氮合酶(NOS)进行检测．探索NO在疼痛中的作用：结果：在无明显机械压迫情况下，大鼠腰神经根上放置自体髓核可产生痛觉过敏，移植髓核组织中NOS染色阳性一结论：髓核自身是引起腰腿痛的重要原因，NO可能参与疼痛的产生.     

白细胞介素-1α在髓核源性神经根性疼痛中的作用

目的:探讨白细胞介素-1琢(IL-1琢)是否参与髓核突出所致的坐骨神经疼痛的产生。方法:将大鼠自体尾椎的髓核无压迫下放置在L4和L5神经根表面,在术后不同时间测量大鼠后足对机械刺激敏感性的变化,同时用免疫组化方法对移植髓核中的IL-1琢进行检测。结果:在无明显机械压迫的情况下,大鼠腰神经根上放置自体髓核后,术侧后足可产生明显机械刺激痛觉过敏;实验组大鼠移植髓核组织中IL-1琢免疫组织化学染色阳性。结论:髓核组织的生物学作用是引起腰腿痛的重要因素,炎性介质IL-1琢可能参与疼痛的发生。     

米帕林对硬膜外移植自体髓核大鼠疼痛相关行为的影响

目的：探讨与椎间盘突出相关的腰腿痛的发病机制。方法：通过硬膜外置管的方法给硬膜外移植自体髓核的大鼠注射生理盐水及阿的平,并对其疼痛相关行为进行了观察。结果：大鼠硬膜外移植自体髓核后能产生明显的疼痛相关行为,注射生理盐水后疼痛相关行为无明显改善,在注射阿的平后,大鼠的疼痛相关行为明显改善,与髓核移植组比较,在术后3－9d有显著性区别。结论：磷脂酶A2在腰椎间盘相关性腰腿痛的发病机制中起重要的作用,研制有效的磷脂酶A2抑制剂能进一步提高腰腿痛的治疗。     

Chronic effects of the nucleus pulposus applied to nerve roots on ectopic firing and conduction velocity.

STUDY DESIGN: This study analyzed the effects of the autologous nucleus pulposus (NP) on nerve root function using electrophysiologic methods. OBJECTIVES: To investigate the chronic effects of the NP applied to nerve roots and dorsal root ganglions (DRGs) on ectopic firing and nerve conduction velocity. SUMMARY OF BACKGROUND DATA: It was reported that ectopic firing in DRGs is involved in abnormal sensation such as sciatica and that ectopic firing was increased shortly after application of the NP to nerve roots. It was also reported that various inflammatory reactions occur around herniated NP clinically, which may affect nerve roots. However, the chronic action of NP on ectopic firing in the stage of inflammatory reaction is unknown. METHODS: Forty-six rats were divided into three groups: nucleus pulposus (NP) group, sham group, and control group. In the NP group the autologous NP was applied to L4 and L5 nerve roots. At 1, 2, 4, and 8 weeks after treatment, antidromically propagated ectopic firing from nerve roots was recorded from the sural nerve, and the nerve conduction velocity between the cauda equina and sciatic nerve was analyzed. The frequencies of ectopic firing in the three groups were compared. The ratios of the nerve conduction velocities on the treatment side and opposite side were compared between the NP and sham groups. RESULTS: The frequency was significantly higher in the NP group than in the sham group at 4 weeks. There were no significant differences among the three groups at 8 weeks. There was no significant difference in the treatment side/opposite side ratio of nerve conduction velocity between the NP and sham groups at any time point. CONCLUSIONS: Increased ectopic firing in the stage of inflammatory reaction to NP may be related to abnormal sensation.     

破裂型腰椎间盘突出症的诊断与治疗：（附32例报告）

介绍３２例因腰椎间盘纤维环破裂而引起的髓核直接突入椎管内压迫马尾神经和神经根所出现的临床症状、脊髓造影及术中所见、按术中所见，髓核突破纤维环时对硬膜囊及神经根压迫类型，结合术前脊髓造影及临床表现将其分为四种类型：大块型、碎块型、部分破裂型及硬膜囊内型。对破裂型椎间盘突出症的诊断、预防、治疗及预后提出了讨论。     

Early effects of nucleus pulposus application on spinal nerve root morphology and function

It is known that 24 h or more after epidural application of autologous nucleus pulposus, functional and structural changes are established in adjacent nerve roots. It is, however, not known how soon after the application these changes appear. The aim of this study was to reduce the exposure duration to 3 h and to evaluate nerve function and histological changes in the nerve tissue during this time period. A total of 12 pigs was used. In ten pigs, autologous nucleus pulposus (NP) was applied epidurally on the cauda equina. Nerve function was then monitored for 3 h by measurements of muscle action potentials (MAP) in the tail muscles, following nerve root stimulation cranial to the exposed zone. In five of the ten pigs with NP application, nerve root compression to 50 mm Hg was added by means of an inflatable balloon. In two control animals, neither NP nor compression was applied. At the end point, nerve root specimens were harvested for histological assessment. No reduction of MAP amplitude was detected in any of the series. However, there was an epidural accumulation of leucocytes and mast cells, as well as minor axonal and Schwann cell changes in both the NP and NP+ compression series, as compared to the control series. Morphological changes in terms of an epidural inflammatory reaction and minor axonal and Schwann cell damage may thus be demonstrated within 3 h of NP application, with or without compression. However, there is no functional deterioration of the nerve roots detectable within this time period. Received: 19 February 1998 Revised: 26 June 1998 Accepted: 8 July 1998     

Selective inhibition of tumor necrosis factor-alpha prevents nucleus pulposus-induced thrombus formation, intraneural edema, and reduction of nerve conduction velocity: possible implications for future pharmacologic treatment strategies of sciatica

STUDY DESIGN: The possibility to prevent nucleus pulposus-induced functional and structural nerve root injury by selective tumor necrosis factor-alpha inhibition was assessed in an experimental model in the pig spine. OBJECTIVE: The objective of the study was to evaluate the role of tumor necrosis factor-alpha in the mediation of nucleus pulposus-induced nerve injury by using selective inhibition. SUMMARY OF BACKGROUND DATA: The cytokine tumor necrosis factor-alpha has been suggested to play a key role in the nerve root injury induced by local application of nucleus pulposus. However, previous studies have not been able to distinguish the effects between tumor necrosis factor-alpha and other disc-related cytokines because of the use of nonspecific cytokine inhibition. METHODS: Autologous nucleus pulposus was harvested from a lumbar disc and applied to the porcine sacrococcygeal cauda equina. The pigs were simultaneously treated with two selective tumor necrosis factor-alpha inhibitors (etanercept n = 8 and infliximab n = 5), a heparin analogue (enoxaparin n = 5) or saline for control (n = 5). After 7 days the nerve conduction velocity over the application zone was determined and samples of the exposed nerve roots were collected for light microscopic evaluation. RESULTS: The two tumor necrosis factor-alpha inhibitors prevented the reduction of nerve conduction velocity and also seemed to limit the nerve fiber injury, the intracapillary thrombus formation, and the intraneural edema formation. However, treatment with enoxaparin did not seem to be different from control regarding reduction of nerve conduction velocity or histologic changes. CONCLUSIONS: The data clearly indicate that tumor necrosis factor-alpha is involved in the basic pathophysiologic events leading to nerve root structural and functional changes after local application of nucleus pulposus. The study therefore provides a basic scientific platform with potential clinical implications regarding the use of anti-tumor necrosis factor-alpha medication as treatment in patients with disc herniation and sciatica.     

Transdural cauda equina incarceration after microsurgical lumbar discectomy: case report

OBJECTIVE AND IMPORTANCE: Complications usually occur when they are least expected. We present an unusual case of nerve entrapment after microsurgical discectomy. CLINICAL PRESENTATION: A patient undergoing uneventful first lumbar microsurgical discectomy developed severe back and leg pain and a progressive neurological deficit during the first postoperative night. Herniation of cauda equina nerve roots had occurred through an unnoticed minimal defect in the dura, which had not caused cerebrospinal fluid leakage. The roots were incarcerated and swollen, and they filled the space of the resected nucleus pulposus. It was presumed that elevation of intra-abdominal pressure and consequent increased intraspinal pressure during extubation led to the herniation of arachnoid and cauda equina roots. The nerve roots were then trapped and incarcerated in the manner of bowel loops in an abdominal wall hernia. INTERVENTION: During reoperation, the nerve roots were repositioned into the dural sac. The patient recovered without further complications and without long-term sequelae. CONCLUSION: All dural tears that occur during intraspinal surgery, even if they are small and the arachnoid is intact, should be closed with stitches or at a minimum with a patch of muscle or gelatin sponge with fibrin glue. Care should be taken to avoid increased intra-abdominal pressure during extubation. Excessive pain and progressive neurological dysfunction occurring shortly after microsurgical lumbar discectomy or any intraspinal procedure is indicative of possible hemorrhage with subsequent compression of nerve roots. The case reported here provides anecdotal evidence that this situation can also be caused by a herniation of cauda equina nerve roots through a small dural defect that was not evident during the initial operation.