常压及控制性降压下脊髓急性牵拉损伤比较研究

目的 评价控制性降压是否增加脊髓对牵拉损伤的易感性。材料与方法健康成年杂种犬6只，随机分为常压和控制性降压脊髓牵拉损伤组。观察常压及控制性降压水平下相同程度牵拉损伤后脊髓血流(SCBF)、体感诱发电位(SEP)、神经源性运动诱发电位(NMEP)改变的差异。结果 外周血有创动脉压(MABP)平均下降幅度为40．5％。经SSPS统计软件独立样本t检验，不同牵拉水平下，常压组及低压组的SCBF(％)、SEP波幅(Asep)(％)及NMEP波幅(％)无显著差异。结论 尼卡地平控制性降压不增加脊髓对牵拉损伤的易感性。     

肋间神经转位脊髓神经根桥接联合应用GDNF促进大鼠脊髓损伤后功能恢复

目的：肋间神经转位脊髓神经根桥接联合应用胶质源性神经营养因子(GDNF)恢复大鼠脊髓损伤的功能。方法：将成年大鼠分为脊髓半切洞损伤组(A组)、脊髓半切洞损伤 肋间神经转位脊髓神经根桥接组(B组)、脊髓半切洞 肋间神经转位脊髓神经根桥接 胶质源性神经营养因子(C组)。手术后应用联合行为评分(CBS)。感觉诱发电位(SEP)和运动诱发电位(MEP)检查，测定脊髓功能恢复情况。结果：3组CBS得分A组＞B组＞C组，SEP和MEP潜峰时，均A组＞B组＞C组，统计分析均有显著差异性(P＜0.05)。结论：肋间神经转位脊髓神经根桥接联合应用胶质源性神经营养因子能促进损伤脊髓功能的恢复。     

脊髓及神经根监测技术在脊柱外科手术中的应用

[目的]应用体感诱发电位（somatosensory evoked potential，SEP）行颈、胸椎手术脊髓监护及应用自发肌电图行腰椎手术神经根监护，对2种电生理检查的方法学、准确性及影响因素进行分析。[方法]颈、胸椎手术采用SEP监测，根据不同阶段SEP的变化与术后功能相结合，判断SEP的准确性。腰椎手术采用自发肌电图监测神经根功能，以判断神经根在术中是否受到牵拉、激惹及刺激。并观察手术中SEP及自发肌电图的影响因素，减少监测假阳性及假阴性的发生。[结果]颈、胸椎手术128例病人中，监护未达到预警标准116例，术后无神经症状加重表现。术中SEP变化达到预警标准8例，及时提醒手术医生，暂停手术操作，7例患者SEP波幅渐恢复，术后无神经症状加重。1例患者因SEP波幅降低时间超过10min未恢复，术后神经症状加重。非手术原因如麻醉、低血压及局部低温对SEP的影响均未达到预警标准。假阴性3例，假阳性1例。腰椎手术40例，12例术中出现肌电反应，及时提醒手术医生，避免过多的刺激及牵拉，术后均未出现神经根损伤症状。[结论]颈、胸椎手术，采用SEP监测，排除各种干扰因素，体感诱发电位可较准确地反应脊髓的生理或病理状况。腰椎手术采用自发性肌电图，在严格控制肌松剂使用下，可准确及时地反应神经根的功能，避免神经根的损伤。     

SPR治疗成人脊髓损伤后肢体痉挛的临床及电生理观测

目的 :对选择性脊神经后根切断术 (SPR)治疗成人脊髓损伤后肢体痉挛的疗效进行观察 ,并探讨手术前后诱发电位的变化对SPR的意义。方法 :对胸椎压缩性骨折致脊髓损伤 (30例 )及脊柱结核后期 (1 1例 )出现肢体痉挛的患者行L2～S1双侧节段开窗式椎板切除 ,将L2～S1的脊神经后根进行分束 ,电刺激仪测阈值 ,将阈值较低的神经束切断 ,神经根切断比例结合肌张力、肌力、体重及肌群功能进行量化 ,均 <30 %。术前 3d及术后 2 1d行诱发电位测定。结果 :经平均 5年随访 ,41例病人痉挛解除率 90 % ,功能改善率 75 %。术后皮层SEP波幅降低 ,感觉神经传导速度减慢 ,手术前后有显著差异 (P <0 0 1 )。结论 :选择性脊神经后根切断术能较有效地治疗成人脊髓损伤后肢体痉挛。手术前后诱发电位测定支持肌张力调节“大、小环路”理论 ,支持脊髓损伤后出现肢体痉挛的机制     

腰椎后路椎体间融合术中神经根牵拉损伤的研究

[目的]探讨腰椎后路椎体问融合术中神经根牵拉损伤的发生率和神经根耐受牵拉的阈值.[方法]应用神经根安全拉钩完成腰椎后路椎体间融合手术共116例,术中应用节段性皮神经刺激体感诱发电位技术进行监测,记录SEP潜伏期和SEP波幅、神经根拉力和牵拉时间.术后10 d、1个月、3个月、1年进行随访,记录JOA评分.[结果]术中共有19例患者出现潜伏期延长、波幅下降,此时神经根拉力为(4.1±0.45)N,累积拉力为(42.89±2.96)N*min,明显高于潜伏期和波幅平稳组和好转组,术后FBSS的发牛率也明显高于后两组.[结论]术中神经根的牵拉损伤是腰椎后路椎体问融合术后早期引起腰椎手术失败综合证(fail back surgery syndrome,FBSS)的主要原因,单次神经根拉力小于(4.1±0.45)N或累积拉力小于(42.89±2.96)N*min,发生神经根牵拉损伤的几率较小.     

大剂量维生素C联合小剂量甲基强的松龙对脊髓损伤后脊髓病理生理变化的影响

[目的]探讨脊髓受压及减压后,大剂量维生素C(vitaminC)联合小剂量甲基强的松龙(MP)对脊髓灰质血流量,体感诱发电位(SEP),组织学变化,运动功能的影响.[方法]36只犬随机分为3组,每组12只.A组于SEP消失后5min静脉注射MP 30 mg/kg,以5.4 mg (kg·h)输液泵静脉注射;B组于SEP消失后5min以同样方式注射vitaminC 200 mg/kg+ MP 10 mg/kg,减压后12 h,24h各注射vitaminC 200 mg/kg;C组于SEP消失后5min静脉注射0.9％氯化钠,同样以5.4 mg(kg·h)输液泵静脉注射.均持续90 min后减压,期间检测SEP及脊髓灰质血流量,减压后3h重复检测,并进行改良Tarlov评分.减压后28 d通过病理组织学分析确定损伤的范围.[结果]在持续压迫期间A组4只犬出现了SEP,B组5只犬出现了SEP,C组无一出现.减压后A组有2只犬出现SEP,B组有2只犬出现SEP,C组有1只犬出现SEP.三组犬中出现SEP的脊髓灰质血流量明显高于没有出现SEP的犬(P＜0.05).A、B组脊髓灰质血流量明显高于C组(P＜0.05).A、B组动物后肢的运动功能可以较快恢复,C组不能恢复.A、B组脊髓损伤范围与C组具有显著性差异,病理改变与SEP及脊髓血流量具有相关性,与运动功能的恢复具有相关性.[结论]大剂量维生素C与小剂量甲基强的松龙联合应用在神经功能保护及恢复方面提供了显著持续的作用,可能增加了脊髓局部的血流量.维生素C可以部分替代甲基强的松龙对于脊髓损伤的作用.     

建立人工膀胱反射弧治疗脊髓损伤后弛缓性膀胱的实验研究

目的探讨利用脊髓损伤平面以上健存的体反射重建人工膀胱反射弧,恢复脊髓损伤(spinalcordinjury,SCI)后膀胱排尿功能。方法1岁龄雄性Beegle犬8只,体重9.5±2.0kg。取后正中切口暴露L4～S3的棘突和椎板,全椎板切除后暴露硬膜和脊神经根,在硬膜外初步分离和确认L6和S2前根。确定犬左侧为实验侧,将左侧L6与S2前根分别在穿神经根管处切断,切开硬膜囊,从硬膜外L6和S2前根追溯硬膜内神经根,在显微镜下将L6和S2前根在硬膜内吻合。经一段时间轴突再生后,建立“膝腱-脊髓中枢-膀胱”人工反射弧。神经缝合术后8个月,在破坏S1～S4脊髓节段前后,分别进行神经电生理、膀胱肌电图及尿流动力学等远期功能观察。结果术后8个月,3只犬死亡,3只犬未能分离出吻合的神经,无实验结果。余2只犬均获得满意结果,定为1号和2号犬,进行观察。刺激(连续刺激强度200μV,刺激间隔为5ms)截瘫前和截瘫后2只犬左侧L6后根、神经吻合口,均可在吻合口远端记录到运动诱发电位,其波形和波幅相似;尿流动力学检查可见,当刺激开始时膀胱内压迅速上升,而腹内压增加幅度较小,刺激中止后膀胱内压迅速下降,证实膀胱内压升高主要是由逼尿肌收缩产生,电刺激左侧L6后根和吻合口膀胱内压升高值均可达到正常的60%左右。结论利用脊髓损伤平面以上健存的体反射重建膀胱反射通路是成功和有效的,体神经的运动支通过轴突再生能够长入自主神经的副交感神经纤维,并具有良好的传导运动兴奋的功能。     

腰骶神经根牵拉损伤动物模型的建立

目的以拉力为参数建立不同程度的腰骶神经根牵拉损伤动物模型。方法将40只中国大白兔随机分为对照组、轻度牵拉组、中度牵拉组和重度牵拉组。全椎板切除显露双侧S1神经根,用测力神经根拉钩分别以不同的拉力造成神经根的牵拉性损伤。行体感诱发电位(somatosensory evoked potential,SEP)监测和神经功能评分,神经根和骶髓做组织病理学研究。结果轻度牵拉组SEP潜伏期比对照组稍延长(P>0.05),神经根和骶髓结构正常,Hashi-zume行为学测试正常;中度牵拉组SEP潜伏期明显延长(P<0.05),去除牵拉后潜伏期接近正常(P>0.05),神经根结构轻度异常,骶髓结构正常,Hashizume行为学测试轻度异常;重度牵拉组SEP潜伏期明显延长(P<0.01),去除牵拉后潜伏期稍缩短,和对照组的差异有统计学意义(P<0.05),神经根结构明显异常,骶髓轻度异常,Hashizume行为学测试异常。所有实验动物改良Tarlov运动功能评分均正常。结论以拉力为参数可以稳定地建立不同程度的腰骶神经根牵拉性损伤动物模型。     

胚胎脊髓组织移植促进成年宿主损伤脊髓功能恢复的研究

目的 探讨胚胎脊髓组织移植促进成年宿主损伤脊髓功能恢复的作用。方法 采用成年大鼠脊髓半切洞损伤模型，移植胚胎大鼠脊髓组织，术后进行联合行为计分（CBS)、体感诱发电位(SEP）、运动诱发电位(MEP）和性行为及生育机能检查。结果 移植组CBS与对照组比较相差显著（P＜0.05)，移植术后4周以内两者相差非常显著(P＜0.01）；移植组SEP、MEP早期反应的峰潜伏时恢复优于对照组(P＜0.05)；术后4～12周75%的雌鼠阴道涂片检出精子并能正常生育。结论 胚胎脊髓移植能促进成年宿主损伤脊髓的功能恢复。     

脊髓髓外冲击负荷后脊髓血流与诱发电位变化的相关研究

[目的] 研究脊髓髓外冲击负荷对脊髓血流及诱发电位的影响,探讨脊髓损伤后脊髓血流与诱发电位变化的规律,以及它们之间的相关性.[方法] 选用雄性SD大鼠120只,随机分为4组,每组30只,A组为假手术组,B、C、D为实验组,在大鼠T10椎板处分别给予10、15、20 N的椎板外冲击负荷.术后0 min,1、6 h,1、6、12、24 d时间点测量冲击负荷位置的脊髓白质、灰质血流以及SEP、MEP测量,进行相关性分析.[结果] 脊髓内灰质白质的血流表现出随冲击负荷的增加而减小的趋势.A组脊髓血流及SEP、MEP无明显变化,B组脊髓血流及SEP、MEP出现一过性降低然后恢复正常,两组之间无明显差异.C、D组脊髓血流及SEP、MEP均表现为持续下降后再缓慢的回升的规律性变化,其中C组在24 d恢复正常,D组在24 d时仍然低于正常,经统计学分析脊髓血流与诱发电位具有明显的相关性.[结论] 椎板外冲击负荷通过改变脊髓血流来影响脊髓的功能,并且脊髓血流和诱发电位有明显的相关性.     

体感诱发电位评价家兔脊髓冲击伤模型的神经机能变化

目的 探讨脊髓冲击伤前后的体感诱发电位的变化,评价家兔神经机能的改变程度.方法 应用改良霍普金森杠杆设备根据冲击波的压力不同(0.40 MPa,0.60 MPa,0.80 MPa)建立不同损伤程度的胸T9-T10脊髓冲击伤模型,12 h后用体感诱发电位仪分别计测家兔脊髓冲击伤前后的体感诱发电位,利用分析软件对诱发电位P...     

脊髓纵向压缩过程中脊髓诱发电位,血流量和微循环变化

根据临床上脊往后凸畸形矫正过程中，脊柱截骨缩短后的脊髓受力情况，采用脊柱立体定位仪来调节脊髓的压缩量，设计了大鼠脊髓纵向压缩动物模型，模拟脊往后凸畸形矫正的病理变化．使用末梢循环血流仪（氢清除法）、奥林巴氏生物显微镜及显示系统、 ＳＥＮ３２０１刺激器、 ＡＰＰＬＥⅡ机诱发电位检测系统（硬膜外记录），分别观测了脊髓压缩部位及邻近节段不同压缩量脊髓灰白质血流量、动态微循环、运动诱发电位（ＭＥＰ）、感觉诱发电位（ＳＥＰ），并常规光镜检查．结果表明；大鼠脊髓不可逆性压缩的临界值为６．０ｍｍ，脊髓回缩率为１／２６— ｌ／２３；脊髓监护时ＭＥＰ较ＳＥＰ更敏感地反映脊髓功能，是较理想的监护手段；脊髓压缩过程中主要为瘀血性缺血改变，与目前脊髓牵拉压迫过程中报道的变化有所不同。     

Subpial spinal evoked potentials in patients undergoing junctional dorsal root entry zone coagulation for pain relief

Summary Seven patients with complete avulsion of the brachial plexus underwent junctional coagulation lesions of the dorsal root entry zone (DREZ) for relief of intractable pain in the paralyzed arm. Intra-operative monitoring by recording spinal cord somatosensory evoked potentials (SEP) resulting from tibial nerve stimulation was done using subpial recording electrodes situated dorsal to the posterior median sulcus at the C4 and T2 segment. SEP on the normal side showed an initial positive wave and two negative waves followed by a group of high frequency waves of relatively high amplitude which continued into high frequency, low amplitude potentials. The conduction velocity of the fastest spinal evoked potential components were, on average, 86 m/s. Recordings from the side of avulsion revealed a steep positive potential of high amplitude which appeared in five patients prior to the creation of the DREZ lesion. This effect was assumed to be secondary to spinal cord damage caused by avulsion. During the DREZ coagulation the SEP from the unaffected side did not change. On the side of DREZ coagulation the velocity of the fastest fibres decreased. Four patients reported sensory deficits after the operation, which were transient in three. In one of these patients, the first two negative potentials disappeared. In the fourth patient, who had permanent sensory deficits, the positive steep potential appeared after generation of the lesion. Our results point to the usefulness of the subpial SEPs monitoring during microneurosurgical procedures on the spinal cord to provide further insight into evoked electrical activity of the normal and injured spinal cord, and to minimize post-operative neurological morbidity.     

Direct spinal versus peripheral nerve stimulation as monitoring techniques in epidurally recorded spinal cord potentials

Summary We recorded spinal cord evoked potentials (SCEPs) and spinal somatosensory evoked potentials (spinal SEPs) in 30 operations following stimulation of the epidural spinal cord and the peripheral nerve, respectively, to compare their feasibility as an intraoperative technique for spinal cord monitoring. SCEPs produced quicker responses and had larger amplitudes with simpler waveforms. SCEPs could reflect residual function of the pathological spinal cord and predict the postoperative clinical outcome, findings which are not observed with spinal SEPs. Moreover, SCEPs had a much higher sensitivity to spinal cord insult. Therefore, we conclude that the SCEPs were more appropriate indicator than the spinal SEPs as an intra-operative monitoring method for spinal cord function.     

Motor versus somatosensory evoked potential changes after acute experimental spinal cord injury in rats

Summary In this study, averaged cortical somatosensory evoked potentials (SEP) after sciatic nerve stimulation, and lower extremity muscle responses after motor cortex stimulation (MEP) were compared in rats. 10 animals served as light (25g-cm) and 10 animals as severe (80g-cm) acute spinal cord injury group after weight dropping trauma. After the initial loss of components, both SEP and MEP recovered in most cases in the light injury group. In the severe injury group, however, no recovery was observed in cortical SEPs, while the muscle MEP recovered in some animals. Light spinal cord injury had little effect on muscle MEPs and caused a paradoxical amplitude increase in some MEP recordings. Latency values of muscle MEPs did not show great changes after either kind of injury, while cortical SEP latency was considerably delayed.In this model cortical SEPs were more sensitive to light spinal cord injury than muscle MEPs after single electrical cortical stimuli. Severe spinal cord injury caused amplitude changes or loss of waves from both SEP and MEP.This work was partly presented in the poster sections at 39. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie, Köln (F. R. G., May 8-1, 1988 and Congress of the International Medical Society of Motor Disturbances, Rome, Italy, June 2–4, 1988.     

The Effects of Hypertonic Saline on Spinal Cord Blood Flow Following Compression Injury

Summary  7.5% hypertonic saline was administered following spinal cord injury to test its effect on spinal cord blood flow. Four different groups of rats underwent 10 minutes of spinal cord compression (45g) at the C3 to C5 levels. A fifth group was not injured, but received hypertonic saline (5 ml/kg) at 5, 15 and 60 minutes following injury. Somatosensory evoked potentials and spinal cord blood flow were measured prior to and for 4 hours following the injury. The administration of hypertonic saline caused a significant increase in flow when administered 5 minutes following injury. Topical nitroprusside administration did not cause any increase in spinal cord blood flow during this time period. Hypertonic saline administration at the later time periods did not increase spinal cord blood flow. The group of animals which were not injured, but received hypertonic saline also showed no significant change in flow. The somatosensory evoked response of the treated animals was maintained for 4 hours after the injury where as the untreated animals began to lose their evoked responses 3 hours after injury.     

兔颈髓牵张性损伤早期脊髓血流变化的特点及意义

目的 观察兔颈髓不同程度牵张性损伤早期脊髓血流的动态变化，探讨其特点和意义。方法 构建颈髓牵张性损伤模型，应用激光多普勒血流仪按不同时相点检测颈5、6段脊髓血流变化，同时取相同节段颈髓行组织病理检查。结果 对照组A脊髓血流量平均基线值和B组、C组、D组牵张前无统计学差异。随着牵张距离的不断增加，颈髓血流量呈进行性下降。当颈髓牵张损伤程度超过脊髓微血管自我调节能力时，则脊髓血流不能恢复。各组颈髓组织病理学检查结果与相应的颈髓血流量变化趋势一致。结论 脊髓血流量的降低是颈髓牵张性损伤继发神经功能障碍的基础，与颈髓的牵张程度呈正相关。     

早期手术减压对损伤脊髓caspase-3表达的影响

目的探讨大鼠脊髓损伤后不同减压时间对大鼠脊髓细胞caspase-3表达的影响。方法将动物分为:大鼠脊髓挫伤即刻手术减压组(A组),大鼠脊髓挫伤2小时手术减压组(B组),大鼠脊髓挫伤8小时手术减压组(C组),大鼠脊髓挫伤24小时手术减压组(D组)。手术后1、3、7、14、28天对脊髓损伤区进行细胞凋亡caspase-3蛋白表达的测定(免疫组化法),采用计算机图像分析技术,进行定量分析。并用行为学和电生理检查观察大鼠功能恢复情况。结果A、B、C、D四组中均发现凋亡caspase-3蛋白阳性表达细胞,图象分析发现,各组凋亡细胞caspase-3免疫反应阳性细胞表达顺序为D>C>B>A,与大鼠后肢功能恢复有平行的变化趋势。结论大鼠脊髓损伤早期手术减压能抑制脊髓损伤后的细胞凋亡,促进大鼠后肢功能恢复。