Entropy-based analysis for diffusion anisotropy mapping of healthy and myelopathic spinal cord

The present study utilized diffusion MR imaging and fractional anisotropy (FA) mapping to delineate the microstructure of spinal cord. The concept of Shannon entropy was introduced to analyze the complex microstructure of healthy and injured spinal cords based on FA map. A total of 30 volunteers were recruited in this study with informed consent, including 13 healthy adult subjects (group A, 25±3 years), 12 healthy elderly subjects (group B, 53±7 years) and 5 cervical spondylotic myelopathy (CSM) patients (group C, 53±15 years). Diffusion MRI images of cervical spinal cord were taken using pulsed gradient spin-echo-echo-planar imaging (SE-EPI) sequence with a 3T MR system. The region of interest was defined to cover the spinal cord in FA maps. The Shannon entropy of FA values of voxels in the cord was calculated as well as the average FA values. The significant differences were determined among three groups using one-way ANOVA and post-hoc test. As compared with adult and elderly healthy subjects, the entropy of whole spinal cord was significantly lower in CSM patients (group A: 6.07±0.18; B: 6.01±0.23; C: 5.32±0.44; p<0.05). Whereas there were no significant difference in FA values among groups (group A: 0.62±0.08; B: 0.64±0.09; C: 0.64±0.12). In CSM patients, there was a loss of architectural structural complexity in the cervical spinal cord tissue as noted by the lower Shannon entropy value. It indicated the potential application of entropy-based analysis for the diagnosis of the severity of chronic compressive spinal cord injuries, i.e. CSM.     

Collateral nerve fibers in human spinal cord: visualization with magnetic resonance diffusion tensor imaging

Diffusion tensor magnetic resonance imaging provides structural information about nerve fiber tissue. The first eigenvector of the diffusion tensor is aligned with the nerve fibers, i.e., longitudinally in the spinal cord. The underlying hypothesis of this study is that the presence of collateral nerve fibers running orthogonal to the longitudinal fibers results in an orderly arrangement of the second eigenvectors. Magnetic resonance diffusion tensor scans were performed with line scan diffusion imaging on a clinical MR scanner. Axial sections were scanned in a human cervical spinal cord specimen at 625 microm resolution and the cervical spinal cord of four normal volunteers at 1250 microm resolution. The spinal cord specimen was fixed and stained for later light microscopy of the collateral fiber architecture at 0.53 microm resolution. Diffusion measured by MR was found to be anisotropic for both white and gray matter areas of the spinal cord specimen; the average fractional anisotropy (FA) was 0.63 +/- 0.09 (diffusion eigenvalues lambda1 0.38 +/- 0.05 micros/mm2, lambda2 0.14 +/- 0.03 micros/mm2, lambda3 0.10 +/- 0.03 micros/mm2) in white matter and 0.27 +/- 0.04 (lambda1 0.36 +/- 0.04 micros/mm2, lambda2 0.28 +/- 0.03 micros/mm2, lambda3 0.21 +/- 0.04 micros/mm2 in gray matter. The normal-volunteer FA values were similar, i.e., 0.66 +/- 0.04 (lambda1 1.66 +/- 0.14 micros/mm2, lambda2 0.55 +/- 0.02 micros/mm2, lambda3 0.40 +/- 0.01 micros/mm2) in white matter and 0.35 +/- 0.03 (lambda1 1.14 +/- 0.07 micros/mm2, lambda2 0.70 +/- 0.03 micros/mm2, lambda3 0.58 +/- 0.02 micros/mm2) in gray matter. The first eigenvector pointed, as expected, in the longitudinal direction. The second eigenvector directions exhibited a striking arrangement, consistent with the distribution of interconnecting collateral nerve fibers discerned on the histology section. This finding was confirmed for the specimen by quantitative pixel-wise comparison of second eigenvector directions and collateral fiber directions assessed on light microscopy image data. Diffusion tensor MRI can reveal non-invasively and in great detail the intricate fiber architecture of the human spinal cord.     

A comprehensive finite element model of surgical treatment for cervical myelopathy

BackgroundCervical myelopathy is a common and debilitating chronic spinal cord dysfunction. Treatment includes anterior and/or posterior surgical intervention to decompress the spinal cord and stabilize the spine, but no consensus has been made as to the preferable surgical intervention. The objective of this study was to develop an finite element model of the healthy and myelopathic C2-T1 cervical spine and common anterior and posterior decompression techniques to determine how spinal cord stress and strain is altered in healthy and diseased states.MethodsA finite element model of the C2-T1 cervical spine, spinal cord, pia, dura, cerebral spinal fluid, and neural ligaments was developed and validated against in vivo human displacement data. To model cervical myelopathy, disc herniation and osteophytes were created at the C4-C6 levels. Three common surgical interventions were then incorporated at these levels.FindingsThe finite element model accurately predicted healthy and myelopathic spinal cord displacement compared to motions observed in vivo. Spinal cord strain increased during extension in the cervical myelopathy finite element model. All surgical techniques affected spinal cord stress and strain. Specifically, adjacent levels had increased stress and strain, especially in the anterior cervical discectomy and fusion case.InterpretationsThis model is the first biomechanically validated, finite element model of the healthy and myelopathic C2-T1 cervical spine and spinal cord which predicts spinal cord displacement, stress, and strain during physiologic motion. Our findings show surgical intervention can cause increased strain in the adjacent levels of the spinal cord which is particularly worse following anterior cervical discectomy and fusion.     

Feasibility of grey matter and white matter segmentation of the upper cervical cord in vivo: A pilot study with application to magnetisation transfer measurements

Spinal cord pathology can be functionally very important in neurological disease. Pathological studies have demonstrated the involvement of spinal cord grey matter (GM) and white matter (WM) in several diseases, although the clinical relevance of abnormalities detected histopathologically is difficult to assess without a reliable way to assess cord GM and WM in vivo. In this study, the feasibility of GM and WM segmentation was investigated in the upper cervical spinal cord of 10 healthy subjects, using high-resolution images acquired with a commercially available 3D gradient-echo pulse sequence at 3T. For each healthy subject, tissue-specific (i.e. WM and GM) cross-sectional areas were segmented and total volumes calculated from a 15mm section acquired at the level of C2-3 intervertebral disc and magnetisation transfer ratio (MTR) values within the extracted volumes were also determined, as an example of GM and WM quantitative measurements in the cervical cord. Mean (±SD) total cord cross-sectional area (TCA) and total cord volume (TCV) of the section studied across 10 healthy subjects were 86.9 (±7.7) mm(2) and 1302.8 (±115) mm(3), respectively; mean (±SD) total GM cross-sectional area (TGMA) and total GM volume (TGMV) were 14.6 (±1.1) mm(2) and 218.3 (±16.8) mm(3), respectively; mean (±SD) GM volume fraction (GMVF) was 0.17 (±0.01); mean (±SD) MTR of the total WM volume (WM-MTR) was 51.4 (±1.5) and mean (±SD) MTR of the total GM volume (GM-MTR) was 49.7 (±1.6). The mean scan-rescan, intra- and inter-observer % coefficient of variation for measuring the TCA were 0.7%, 0.5% and 0.5% and for measuring the TGMA were 6.5%, 5.4% and 12.7%. The difference between WM-MTR and GM-MTR was found to be statistically significant (p=0.00006). This study has shown that GM and WM segmentation in the cervical cord is possible and the MR imaging protocol and analysis method presented here in healthy controls can be potentially extended to study the cervical cord in disease states, with the option to explore further quantitative measurements alongside MTR.     

急性脊髓损伤患者血清中单核趋化蛋白-1表达的意义

背景近年来国内外学者发现趋化性细胞因子可能参与了外周血细胞向损伤脊髓组织的募集.单核细胞趋化蛋白-1(MCP-1)属CC型趋化因子亚家族,对单核/巨噬细胞有较特异性的趋化作用.目的观察急性不完全脊髓损伤患者血清中MCP-1的表达,探讨继发性脊髓损伤的可能机制.设计以患者和健康者为研究对象,非随机化同期对照,探索性研究.单位一所大学医院的骨科.对象来源于武汉大学人民医院骨科2001-01/2002-12收治的急性不完全脊髓损伤患者8例和单纯椎体压缩骨折患者8例,另选健康者8例做对照.方法患者入院次日清晨空腹抽取外周静脉血8～10 mL,静置,离心取血清.ELISA方法检测其中MCP-1的水平.健康者于检查日晨空腹抽血,程序同患者组.主要观察指标各组血清中MCP-1的浓度.结果健康对照、单纯椎体压缩骨折及急性不完全脊髓损伤组患者血清中MCP-1的浓度分别为(124±15),(184±21),(428±11)ng/L,组间比较差异有非常显著性意义(P＜0.01).结论MCP-1可能通过向脊髓损伤部位募集炎症细胞而参与脊髓损伤部位的继发性炎症反应.     

磁共振扩散张量成像对脊髓型颈椎病脊髓慢性损伤的评价

目的 评价磁共振扩散张量成像（DTI）对脊髓型颈椎病脊髓慢性损伤早期诊断的可行性。方法 采用单次激发平面回波成像（SE-EPI）序列对31例临床确诊的脊髓型颈椎病患者行颈髓常规MRI和DTI检查。测量病变处ADC值和FA值并按病变常规T2WI高信号阳性与阴性分组进行数据分析,计算常规MRI和DTI对颈髓病变检出的敏感度、特异度、阳性预测值（PPV）、阴性预测值（NPV）。结果所有脊髓型颈椎病患者均能完成DTI检查,后处理图像颈髓显示清晰,无明显图像变形及伪影。9例（29%）表现为颈髓病变T2WI高信号的患者均出现颈髓受压平面ADC值升高,FA值下降,平均ADC值为（1183.44±121.96）×10-6mm2/s,相应FA值为（432.56±59.97）×10-3,与正常值相比有统计学意义;22例（71%）颈髓病变T2WI高信号阴性患者中,7例（32%）病变处平均ADC值及FA较正常值无明显变化;15例（68%）颈髓受压平面ADC值升高,FA值下降,平均ADC值（1055.07±80.61）×10-6mm2/s,FA值为（501.87±41.09）×10-3,有统计学意义。检查方法的敏感度常规T2WI为29.0%,DTI为67.7%;特异度常规T2WI为71.0%,DTI为22.6%;PPV常规T2WI为27.3%,DTI为72.7%;NPV常规T2WI为75.9%,DTI为24.1%。结论 DTI较常规MRI更早期而准确地诊断脊髓型颈椎病颈髓慢性损伤,是一种显示脊髓型颈椎病颈髓病变和观察病变修复过程的有效手段。     

大鼠腰、颈段脊髓神经元间联系的c-fos基因研究

目的：应用c-fos基因研究腰段和颈段脊髓神经元之间的联系。方法：成年雄性SD大鼠20只，钳夹左侧坐骨经神，灌注取材后行c-fos免疫组化染色。结果：在腰段L4-6脊髓中，钳夹诱发的c-fos基因表达均在钳夹同侧脊髓灰质内，脊髓灰质前角神经元和后角神经元中的c-fos基因表达明显增多，对照侧右侧脊髓中的神经元c-fos基因未见明显表达。在颈段C5-8脊髓中．双侧脊髓灰质前角中可见c-fos基因表达明显增多．双侧脊髓灰质后角中未见明显c-fos基因表达。结论：颈段脊髓和腰段脊髓神经元之间存在着神经纤维联系。     

颈椎前路减压并发脊髓损伤的高危因素回顾分析

目的探讨颈椎前路减压加重脊髓损伤的危险因素.方法对颈椎前路减压并发脊髓损伤加重11例回顾分析.结果所有病例颈椎椎管、椎体矢径比值均＜0.7,椎管横断面狭窄率在C4～5、C5～6间隙＞40%.结论一旦脊髓损伤加重,早期后路扩大半椎板减压是一种可选择的治疗方法.     

适合MRI研究的羊颈髓压迫损伤模型的制作

目的 探讨建立一种新的适合MRI研究的羊颈髓压迫损伤模型.方法 健康山羊10只,体重20～25 kg,随机分为实验组和对照组.手术显露左侧颈2-3椎间孔,将自制的导管球囊通过椎间孔插入硬膜外腔,达颈2-3椎间盘水平.实验组术后第10天经导管缓慢注射生理盐水0.2 ml使球囊膨胀.持续压迫40天.对照组不注水.利用MR、运动功能评分和病理学检查对模型进行评价.结果 置入的球囊位于脊髓的左前方.球囊未注水时,球囊所在部位蛛网膜下腔变窄,脊髓没有明显受压.注水0.2 ml后,球囊呈椭圆形,脊髓受压变扁.所有MR图像显示清楚,没有明显伪影.实验组运动功能评分下降,病理学检查示神经细胞和神经纤维肿胀、变性、坏死.结论 采用经颈椎椎间孔置入导管球囊制作羊颈髓压迫损伤模型,压迫程度、压迫速度和持续时间可控,保留了椎管的完整性,能获得较满意的MR图像.     

后路减压侧块螺钉置入内固定治疗颈椎多节段后纵韧带钙化：5年36例资料回顾

背景：后路减压侧块螺钉固定能够解除骨化灶对脊髓、神经根的压迫,扩大椎管矢状径,同时重建该区域的稳定。目的：验证应用后路减压、侧块螺钉置入内固定治疗颈椎多节段后纵韧带骨化症5年36例资料的临床疗效。方法：36例患者为3个节段9例,4个节段20例,5个节段7例。结果与结论：随访6～26个月,JOA评分由内固定前平均5.2分提高到10.2分。颈椎生理曲度由内固定前平均（3.6±0.5）mm提高到内固定后（9.1±0.7）mm,内固定物无松动。提示此方法治疗既能后方直接减压又能前方间接置入减压,既能恢复颈椎生理曲度,又能提供坚强的内固定效应。     

颈椎颈髓损伤后外科干预时间对神经功能恢复的影响

背景:脊髓损伤后决定预后的两个主要因素为损伤当时外力的大小和脊髓受压的时间。前者不能改变,而对于后者却可以通过尽早解除脊髓压迫来促进神经功能的恢复。目的:比较颈椎颈髓损伤后72h内与10～14d内进行外科干预后神经功能恢复的情况。设计:随机对照及前后对照观察。单位:哈尔滨医科大学附属第二医院脊柱外科。对象:选择1998-04/2001-08哈尔滨医科大学附属第二医院脊柱外科入院的颈椎脊髓外伤患者32例。严格按随机交替原则被分为早期手术组(损伤后72h内)16例,男10例,女6例;择期手术组(损伤后10～14d内)16例,男12例,女4例。方法:早期手术组于入院后72h内手术;择期手术组于入院后10～14d内手术。分别记录患者术前和术后24个月的Frankel分级和感觉、运动评分(依据美国脊髓损伤学会的标准)。主要观察指标:①两组患者术前、术后感觉评分及运动评分情况。②两组术前、术后Frankel分级结果。结果:①早期手术组感觉评分的改善程度(手术前后评分差值)明显高于择期手术组(42.6±20.2,19.2±19.1,P<0.01)。②早期手术组运动评分的改善程度(手术前后评分差值)明显高于择期手术组(39.7±17.8,17.3±18.6,P<0.01)。③早期手术组Frankel分级的改善程度明显优于择期手术组(P<0.01)。结论:急性颈椎颈髓损伤患者在72h内进行手术治疗,其神经功能恢复的结果优于10～14d内行手术者。因此,颈椎颈髓损伤后为了最大限度地促进神经功能的恢复,应早期进行外科干预。     

DTI在脊髓型颈椎病中的应用价值

目的探讨弥散张量成像(DTI)在脊髓型颈椎病(CSM)中的应用价值。方法40例临床及影像学证实为CSM且髓内无明显T2高信号患者,行颈髓MRI和扩散张量成像检查,并分析影像表现和测量其表观弥散系数(ADC)值及各向异性分数(FA)值。结果所有研究对象的DTI均可得到颈髓的ADC图及FA图。其中约90%(36/40)患者脊髓受压部位ADC值较正常部位升高(P=0.015),约70%(28/40)患者脊髓受压部位FA值较正常部位降低(P=0.037)。结论DTI对CSM患者早期脊髓损伤具有较高的敏感性。     

脊髓损伤患者自主神经功能障碍的临床分析

目的探讨脊髓损伤患者心脏节律变异性（HRV）和血浆D-二聚体水平改变的意义。方法采用回顾性分析的方法,分析本院2005年7月至2007年8月收治的60脊髓损伤患者临床资料,根据脊髓损伤部位的不同,分为颈髓损伤组（31例）、胸髓损伤组（20例）、腰髓损伤组（9例）,同时选取35例健康体检者为对照组。结果颈髓、胸髓组代表交感和迷走神经张力的低频检测结果为（299．28±310．25）ms^2、（254．16±221．71）ms^2,明显低于对照组的（560．32±320．14）ms^2,差异有统计学意义（P〈0．01）;脊髓各段（颈髓、胸髓、腰髓）损伤患者血浆D-二聚体水平均较对照组显著增高（P〈0．05）,同时各组脊髓损伤患者血浆D-二聚体水平随着治疗时间的延长,逐渐降低（P〈0．05）。结论HRV和血浆D-二聚体水平的联合检测可以作为脊髓损伤部位诊断及损伤程度的参考指标。     

颈椎病脊髓变性期的MRI诊断(附41例报告)

目的：了解脊髓变性期颈椎病的ＭＲＩ表现。方法：研究分析４１例脊髓变性期颈椎病患者的ＭＲＩ图像及临床资料。结果：４１例患者的ＭＲＩ主要表现为椎间盘变性、膨出、脱出、黄韧带肥厚、椎体后缘骨刺形成、后纵韧带钙化、椎体滑脱及脊髓受压、水肿、软化、囊变、出血。结论：ＭＲＩ扫描可为脊髓变性期颈椎病提供可靠的影像学根据，对该期颈椎病的诊断和治疗有重要意义     

C9和CD59在大鼠脊髓损伤组织中的表达

背景已有研究表明补体系统在继发性脑挫裂伤中发挥重要作用,但补体系统在脊髓损伤中是否存在表达并参与继发性损伤目前却鲜有报道.目的探讨补体系统固有成分C9及补体调节因子CD59在脊髓损伤组织中的表达.设计随机分组、实验对照研究.地点和对象实验在中国医科大学实验动物部完成,对象为55只体质量250～300 g健康SD大鼠,由中国医科大学实验动物部提供.干预55只SD大鼠随机分损伤组、假手术组及正常对照组,采用改良Allen重物打击法制成SD大鼠急性脊髓损伤模型,于伤后12 h,1,3,5,7 d对脊髓损伤组织取材制成冷冻切片,进行苏木精-伊红(HE)染色、C9和CD59免疫组化染色,半定量法图像分析.主要观察指标观察各实验组伤后各时间点脊髓损伤组织的变性坏死、中性粒细胞浸润及C9,CD59阳性反应物的表达部位及时程.结果伤后12 h损伤组织中开始有C9[灰度阈值面积(threshold ara,TA)(1.02±0.19),平均灰度值(average gray value,AG)(82.18±4.19)],CD59[TA(0.35±0.08),AG(95.12±4.89)]阳性表达,在伤后3 d达到高峰(C9TA 4.06±0.21,AG 61.75±2.39;CD59TA 1.21±0.14;AG 69.08±2.18)之后表达逐渐减少,伤后1周趋于稳定(C9TA1.34±0.21,AG 85.82±5.36;CD59TA 0.42±0.07,AG 96.21±2.97),随时间延长存在动态变化过程,且与脊髓损伤组织的变性坏死、中性粒细胞浸润程度相一致.正常对照组及假手术组各时间点均未见C9及CD59阳性表达.结论在脊髓损伤组织中有补体固有成分C9及补体调节因子CD59的表达,补体系统参与了继发性脊髓损伤.     

颈椎椎弓根钉置入治疗颈椎骨折脱位:操作技术、并发症及生物相容性

背景:熟悉颈椎解剖及椎弓根螺钉的特性,术中规范操作以及个体化置钉等是置入治疗成功的关键.目的:了解颈椎椎弓根钉材料置入治疗颈椎骨折脱位术中和随访期内材料及宿主反应及置入后脊髓神经功能的恢复情况.设计:病例分析.单位:解放军沈阳军区总医院骨科.对象:选择2002-02/2006-02解放军沈阳军区总医院骨科具有完整随访病例资料的颈椎骨折脱位患者41例.18例合并脊髓损伤,按Frankel分级:A级6例,8级1例,C级4例,D级7例.方法:①采用经椎弓根内固定置入治疗颈椎骨折脱位41例.病例于术前行X射线片、CT及MRI检查,根据测量结果对每一椎弓根钉实施个体化置入.②所有手术均由同一术者完成,施术者为第一作者,主任医师,术者资格符合岗位技术职责要求.主要观察指标:①螺钉置入过程中材料及宿主反应.②术后及随访过程中材料及宿主反应.③置入后脊髓神经功能恢复情况.结果:41例全部获得6～12个月随访,切口均Ⅰ期愈合.①螺钉置入过程中材料和宿主反应:共置入218枚螺钉.12枚在初次置钉后有松动感,其中11枚经调整进钉点和进钉方向或,和增加螺钉直径或长度后松动感消失,另外1枚经上述处理无效后通过增加固定节段维持了稳定性.10枚钻孔后钉道出血较多,经处理后出血停止:3例在显露时造成C1.2问静脉从出血,经压迫止血后出血停止,其中1例因术野不清改用Apofix内固定.②术后及随访过程中材料反应及宿主反应:共置入螺钉218枚.196枚位置正确,22枚存在不同程度偏差,其中1枚造成神经根损伤,1枚疑有血管损伤.38例获满意复位并骨性愈合,3例因系陈旧骨折脱位术中复位不完全并出现神经根刺激症状,其中1例术后因退钉而改行前路手术;其余未发现椎动脉、脊髓、神经根损伤及内固定破坏.③置入后脊髓神经功能恢复情况:18例合并脊髓损伤者神经功能除A级6例无变化外,余12例均有1～2级改善.结论:①颈椎椎弓根钉材料置入后发生生物相容性反应的几率低.②置钉后脊髓神经功能恢复较好,是治疗颈椎骨折脱位有效且相对安全的方法之一.     

脊髓慢性压迫损伤的磁共振扩散张量成像研究

目的研究脊髓慢性压迫损伤的扩散张量成像(DTI)表现及临床应用价值。方法对32例脊髓慢性压迫损伤患者和25例健康志愿者行常规MRI和横轴面DTI,测量其表观扩散系数(ADC)值、部分各向异性(FA)值。结果32例脊髓压迫损伤患者中13例可见T2WI高信号。压迫部位ADC值增高28例,不变4例,平均ADC值明显高于正常脊髓组织。ADC值和压迫程度、临床症状严重程度呈正相关。压迫部位FA值下降15例,不变11例,增高5例,平均FA值低于正常脊髓组织。FA值和压迫程度、临床症状严重程度呈负相关。结论DTI对判断脊髓慢性压迫损伤有一定价值,ADC值敏感度最高。     

大鼠臂丛神经根回植脊髓后神经再生对肱二头肌功能恢复的影响

背景臂丛根性撕脱伤是临床上一个极为棘手的课题,神经根回植术有望攻克这一难题.目的研究大鼠臂丛神经根回植至脊髓后,神经纤维能否再生并有效恢复对靶器官的支配.设计单因素随机对照设计.地点和对象在第一军医大学南方医院创伤骨科完成,清洁级健康雌性SD大鼠24只,体质量230～250 g,由第一军医大学实验动物中心提供.随机均分为3个月组和6个月组.干预在手术显微镜下,将C6神经根从脊髓上撕脱,然后切取尺神经桥接肌皮神经与脊髓间的缺损,制作臂丛根性撕脱伤后神经根再植术的动物模型.主要观察指标分别于3个月和6个月后测量肱二头肌肌肉动作电位、强直收缩力及湿质量,进行神经元的逆形标记,并对神经和肌肉组织进行组织学检测.结果术后3个月和6个月时,在相应的C6脊髓前角均出现逆行标记的神经元,回植神经内有再生的神经纤维.肱二头肌的肌肉动作电位、强直收缩力、湿质量恢复率6个月时分别为(56.01±11.62)%,(46.91±8.35)%,77.59±5.79)%,均明显高于3个月时的(30.15±7.52)%,23.14±5.72)%,59.31±3.43)%(t=6.597,t=8.138,=9.421,=0.000).结论臂丛根性撕脱伤后行神经根回植术,神经纤维可以再生,并在一定程度上恢复靶器官的功能.     

慢性颈脊髓压迫模型大鼠构建及评价

背景：在脊髓型颈椎病脊髓损伤发生机制的研究过程中,建立稳定且同人类体内疾病演变过程相似的疾病模型对于研究脊髓型颈椎病发病机制至关重要。目的：构建慢性颈脊髓压迫模型,观察该模型病理生理变化特点,进一步明确脊髓型颈椎病受压脊髓组织的病理改变。方法：30只SD大鼠随机均分为对照组、轻度压迫组、重度压迫组。将不同大小吸水性压迫材料聚乙烯醇丙烯酰胺互穿网络水凝胶植入C5-C7椎板下,制作慢性颈脊髓压迫动物模型,对照组不植入压迫材料。结果与结论：MRI检查显示两压迫组大鼠出现不同程度的椎管狭窄和脊髓压迫,而对照组椎管宽度正常无脊髓压迫。电生理检测显示两压迫组大鼠运动诱发电位潜伏期较对照组明显延长且振幅明显降低（P〈0．05）。神经元免疫荧光染色显示对照组大鼠脊髓有大量形态规则的神经元,而两压迫组大鼠神经元计数明显减少且神经元胞体形态明显皱缩,脱髓鞘现象明显,3组间比较差异有显著性意义（P〈0．05）。压迫组大鼠脊髓压迫节段发现较多凋亡细胞,而对照组未发现。说明构建的大鼠慢性颈脊髓压迫模型符合脊髓型颈椎病的病理改变,且手术操作简便,不易感染死亡率低;神经元损伤、脱髓鞘改变和凋亡机制参与了大鼠慢性颈脊髓压迫损伤的发生发展过程。     

颈神经在颈椎间孔及脊神经沟处受嵌压的解剖学因素

背景神经根型颈椎病中神经根能否受累,不仅与所在骨管是否狭窄、周围软组织是否存在炎性病变和肿胀有关,还与神经根外径的相对大小有关.目的通过颈神经在颈椎间孔及脊神经沟处受累的出现率,探讨神经根型颈椎病发生的解剖学因素.设计单一样本观察.单位承德医学院解剖研究室.对象甲醛固定成尸60具(男28,女32)120侧.方法在60具成尸上,用精确度0.02 mm的游标卡尺和直角规测量①脊神经沟外口宽度及其沟内段脊神经前支横径.②颈椎间孔及其脊神经根的前后径、上下径.计算颈神经前支横径与相应颈椎脊神经沟外口宽度的比值和脊神经根前后径、上下径与相应椎间孔前后径、上下径的比值.得出颈神经前支横径大于或等于脊神经沟外口宽度的出现率和脊神经根各径线大于或等于相应椎间孔各径线的出现率.主要观察指标①C3～6颈神经前支横径大于或等于相应脊神经沟外口宽度的出现率.②C3～6颈神经根上下径、前后径分别大于或等于相应颈椎间孔上下径、前后径的出现率.结果共测量成尸60具120侧(男56侧,女64侧).①颈神经根在椎间孔处可造成嵌压男女合计总出现率为24.6%其中女性明显高于男性(35.2%,10.9%,x2=6.72,P＜0.01).②颈神经前支在颈椎脊神经沟处可造成嵌压男女总出现率为6.3%,其中男性明显高于女性(8.9%,3.9%,x2=6.65,P＜0.01).结论颈神经受累不仅与骨管狭窄有关,而且与周围软组织损伤有关,通过神经根外径与椎间孔的比值和颈神经前支与脊神经沟外口宽度比值,选其≥1的出现率可直接获得神经受压的出现率.