Hirayama's disease: the importance of flexion magnetic resonance imaging

Hirayama's disease is a form of juvenile muscular atrophy affecting young individulas in their second to third decade. The underlying pathogenetic mechanism is believed to be an imbalanced growth between the individuals' vertebral column and the spinal canal contents, which causes abutment of the anterior spinal cord against the vertebral column and detachment of the posterior dura, leading to microcirculatory disturbances and ischemic changes in the cord. This mechanism is exiquisitely demonstrated on magnetic resonance imaging (MRI), but requires additional imaging, with the neck in the flexed position. Neurphysiological imaging studies have provided supporting evidence by demonstrating changes in the N13 potential, with neck flexion. Nonetheless, few studies have also reported contradictory findings with MRI and somatosensory evoked potentials, in Hirayamas Disease. This condition is underdiagnosed because most clinicians are not familiar with this disorder and do not request a flexion MRI. Early recognition of this entity and differentiation from other causes of focal cord atrophy is important, because limitation of neck flexion by using a simple neck collar can prevent its further progression. We report the classical MRI findings in a young patient with Hirayama's disease with neutral and flexion MRI.     

青少年上肢远端肌萎缩症临床解剖及MRI特点

目的　探讨青少年上肢远端肌萎缩症的临床解剖及MRI特点,为该病的早期诊断和治疗提供依据。 方法 对13例确诊的青少年上肢远端肌萎缩症患者的临床表现、临床解剖、神经电生理特征及影像学资料进行回顾性分析。 结果 青少年上肢远端肌萎缩症平均发病年龄18.6岁,表现为局限于手和前臂的肌萎缩,前臂呈斜坡样;肌电图显示患者双侧上肢远端肌肉均呈神经源性损害,受损节段多在下颈髓前角细胞;屈颈MRI均见下段颈髓前移、变平,硬脊膜向前移位,硬脊膜外间隙增宽,硬脊膜外间隙内半月形信号影;与正常自愿者比较,在C6椎体上沿水平,MRI自然位和前屈位可显示出青少年上肢远端肌萎缩症患者脊髓前后径明显缩小（P＜0.05）。 结论 青少年上肢远端肌萎缩症可能为下颈段脊髓病变,神经电生理及影像学检查有助于其早期临床诊断与鉴别诊断,患者应早期佩带颈托和避免长时间屈颈位。     

脊髓型颈椎病高场强磁共振成像探讨

目的 研究脊髓型颈椎病(CSM)的MRI成像特点及其临床意义。方法 分析主诉有颈肩痛或／和肢体麻木、乏力就诊者134例，经诊断CSM者80例，并根据临床表现分组比较MRI表现。结果 非CSM者MRI表现出椎间盘变性或轻度突出、骨赘形成但不构成对脊髓压迫；CSM病例表现不同程度椎间盘突出、椎体后缘骨赘形成及硬膜囊和脊髓受压，其中69例(86．25％，)脊髓受压，11例(13．75％)脊髓受压变性。临床症状严重者，MRI表现出颈髓变性显著增多，术后脊髓变性信号仍存在。结论 高场强MRI可良好显示CSM中椎间盘退变突出、骨赘形成及脊髓受压变性，为临床诊断与外科治疗提供依据。     

磁共振扩散张量成像序列对脊髓型颈椎病的诊断价值

目的:分析3.0T磁共振（MR）扩散张量成像（DTI）序列对脊髓型颈椎病（CSM）的诊断价值。方法:选择福建中医药大学附属康复医院收治的30例CSM患者纳入观察组,另选择同期体检人群中年龄匹配的30例健康志愿者为对照组,均运用常规MRI序列及DTI技术进行扫描,运用DTI技术测量FA及ADC值,进行图像后处理及数据分析,观察组患者根据MR平扫结果分为A组（n=10,单纯硬膜囊受压）、B组（n=14,颈髓受压,信号正常）和C组（n=6,颈髓受压,T2WI高信号）,分析各组FA及DA值差异,评价DTI诊断脊髓型颈椎病的诊断价值。结果:对照组脊髓C2-3、C3-4、C4-5、C5-6、C6-7节段的ADC值与FA比较差异无统计学意义（P>0.05）;对照组与A、B、C组的ADC值、FA值存在显著性差异（P<0.05）,B组、C组的ADC值显著高于对照组（P<0.05）,FA值显著低于对照组（P<0.05）,A组ADC值、FA值与对照组比较差异无统计学意义（P>0.05）;从A组到C组,ADC值呈升高趋势,FA值呈降低趋势,差异显著（P<0.05）;MR T2WI、DTI序列扫描FA值、MR DTI序列扫描ADC值诊断扫描诊断CSM的敏感度与特异度为20.00%（6/30）与80.00%（24/30）,80.00%（24/30）与20.00%（6/30）,66.67%（20/30）与30.00%（9/30）。结论:DTI较常规MRI能更早期而准确地诊断CSM,是一种显示CSM病变和观察病变修复过程的有效手段。     

下颈椎前路内固定联合后路经关节金属螺钉置入固定的生物力学稳定性

背景：对退变性颈椎管狭窄单纯采用前路椎体次全切除或椎间盘切除或单纯后路单开门椎管扩大成行均不能彻底完成脊髓减压和脊柱三柱稳定。 目的：探讨下颈椎前路固定联合后路经关节螺钉固定的生物力学稳定性。  方法：正常成人尸体颈椎标本,每具分别制作以下两种模型：①经后路C3~C7单开门和下颈椎前路C5椎体次全切除钛网支撑植骨、ORION内固定模型(对照组)。②经后路C3~C7单开门和经关节螺钉内固定及下颈椎前路C5椎体次全切除钛网内植骨、ORION内固定模型(实验组)。 结果与结论：实验组在前屈、后伸、左、右侧屈及左、右旋转移位角度均小于对照组(P < 0.001)。提示：①在生物力学实验中,下颈椎前路固定联合后路经关突节螺钉固定的生物力学性能优良,对抗前屈、后伸、左、右旋转的作用力更强,颈椎可获得更可靠的稳定性。②下颈椎前路固定联合后路经关节螺钉固定在对抗颈椎前屈运动时力学稳定性更为强大。     

颈椎前路减压手术解剖标志定位测量及其临床意义

目的　为颈椎前路减压手术在有限显露术野中达到安全、有效减压提供更科学的减压标志。 方法　在15具成人尸体标本上,解剖观测C3~7节段相关解剖数据,以所测量的数据为基础,计算：(1)椎体钩前脚至颈长肌内侧缘的距离/颈长肌内侧缘至正中矢状面的距离(AULD/MLPD); (2)椎体钩前脚至横突孔内侧缘的距离/椎体钩前脚至颈长肌内侧缘的距离(AUTD/AULD); (3)椎体钩前脚至硬膜囊外侧缘的垂直距离/椎体钩后脚至硬膜囊外侧缘的距离(AUDD/PUDD)和(4)椎体钩与神经根最近点和椎体钩前脚的垂直距离/椎体钩前后脚的垂直距离(UNAD/APUD)。 结果　AULD/MLPD在C3的平均值为0.83,在C4的平均值为0.55,在C5的平均值为0.20,在C6的平均值为0.34,在C7的平均值为0.27;AUTD/AULD的平均值为2.71;AUDD/PUDD的平均值为0.28;UNAD/APUD的平均值为0.34。 结论　椎体钩前脚是颈椎体前部恒定的解剖标志,可作为颈椎前路手术的稳定、可靠的骨性减压标志,依据AUDD/PUDD、UNAD/APUD和AUTD/AULD的比值,有助于术中判断硬膜囊、颈神经根和椎动脉的位置。     

胸腰脊神经后根形态计量研究

在15具成人尸体上对胸腰脊神经后根进行了大体解剖和形态计量研究.结果表明:(1)上胸段脊神经后根的囊外段长度、硬膜点横径和脊髓点束数在逐节减少;后根的囊外段与囊长轴之下夹角>90°,囊内段及脊髓点分布长度在逐节增加,交通支最丰富.(2)中胸段脊神经后根的囊外段长度、硬膜点横径和脊髓点束数各节段波动范围较小,下夹角在90°左右,囊内段短,脊髓点分布长.(3)下胸段脊神经后根的脊髓点分布长度转而下降,下夹角<90°,其它指标均逐节增加.(4)腰段脊神经后根的脊髓点分布长度进一步减少,下夹角最小,其它指标达最大值,交通支丰富.根据研究结果进行后根受损危险排序,腰>下胸>上胸>中胸.     

Lateral cervical meningocele.

Lateral cervical meningocele is an extremely rare developmental anomaly. We could find only one such case protruding from an enlarged C2-3 intervertebral foramen. It may be confused with an extradural cyst or cystic hygroma. Direct needling may introduce infection and thereby pyogenic meningitis and so should be avoided. Similarly, incision and drainage may transform it into cerebrospinal fluid fistula. A computed tomography scan is the most fruitful form of investigation for confirmation and localization of the disease. A lumboperitoneal shunt or water tight closure of the dural sac at the neck is the recommended procedure of choice.     

下颈椎全脊椎切除术后两种内固定重建方法的有限元分析

研究下颈椎C5椎体全脊椎切除术(TS)之后,前后路不同联合内固定重建方法对颈椎稳定性的影响。基于CT图像建立下颈椎C3-C7节段完整无损模型,在无损模型基础上,建立C5全脊椎切除术后两种内固定重建模型：一为钛网重建+前路钢板+后路单节段椎弓根螺钉模型(TM+AP+SPS);二为钛网重建+前路钢板+后路双节段椎弓根螺钉模型(TM+AP+DPS)。对模型分别施加0.5、1.0、1.5、2.0 N·m的扭矩,分析两种模型在前屈、后伸、左右侧弯和左右扭转等工况下的关节活动度（ROM）以及钛网、钢板、椎弓根螺钉的应力分布情况。结果表明,重建节段ROM随着扭矩的增大而增加,呈现出非线性的趋势,TM+AP+SPS模型的增加幅度较大。1.0 N·m工况下,两种模型重建节段ROM均减少83%以上;TM+AP+SPS模型在后伸、侧弯和扭转时,邻近节段的ROM均增加11%以上,C6-C7节段的ROM在扭转时增加41.79%,TM+AP+DPS模型的邻近节段ROM则显著降低。TM+AP+SPS模型和TM+AP+DPS模型中钛网应力分别集中于受压侧和后方。TM+AP+SPS模型的邻近节段有较大的代偿活动,TM+AP+DPS模型各节段ROM均大幅度减小,TM+AP+DPS模型的稳定性更好。     

颈后路全内镜下颈椎间盘切除术与颈前路颈椎间盘切除植骨融合术治疗颈椎间盘突出症的疗效对比

目的比较颈后路全内镜下椎间盘切除术(PPECD)与颈前路颈椎间盘切除植骨融合术(ACDF)治疗单节段旁中央型颈椎间盘突出症的疗效和对邻近节段退变的影响。方法回顾性分析2016年1月至2018年1月期间在本院行手术治疗的88例单节段旁中央型颈椎间盘突出症患者病例资料。按照所行的手术方式分为PPECD组(n=42)及ACDF组(n=46)。比较两组患者的基线情况,手术前、后颈及上肢视觉疼痛评分(VAS),颈椎功能障碍指数(NDI),手术邻近节段左、右侧屈曲及前屈后伸测定值和颈椎相邻节段退变情况。结果两组患者术后随访时间均为12个月。末次随访时,两组患者颈及上肢VAS和NDI评分与术前相比均有改善(0.05),而两组间比较差异无统计学意义(0.05); PPECD组邻近节段左、右侧屈曲及前屈后伸测定值术前比差异无统计学意义(0.05),ACDF组较术前增大(0.05),并且大于PPECD组(0.05); PECD组颈椎邻近节段退变情况优于ACDF组(0.05)。结论 PPECD和ACDF均能显著改善单节段旁中央型颈椎间盘突出症患者的临床症状,但PPECD对维持患者术后颈椎活动度、减少术后邻近椎体节段退变有一定优势。     

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。     

颈后经硬膜囊手术入路的应用解剖学研究

目的分析颈椎硬膜囊内结构的解剖学资料,为颈后经硬膜囊手术入路提供参考依据。方法解剖15具成人尸体标本,观测颈椎硬膜囊内解剖形态结构与特征、颈神经根与相应椎间盘的关系。结果C3-C8后根所含根丝数目一般略少于相应节段前根根丝数目,但较前根粗大;各节段前、后根自脊髓相应节段的前、后外侧沟发出的角度由上往下逐渐减小;硬膜囊与脊髓横径分别在（17．03±0．51）mm-（18．17±0．59）mm和（11．37±0．30）mm-（12．64±0．43）mm之间;各平面蛛网膜下腔两侧间隙宽度为（5．52±0．33）mm-（5．78±0．48）mm;前、后根根丝间距分别在（1．93±0．49）mm-（4．70±0．35）mm和（1．38±0．38）mm-（3．90±0．31）mm之间;根间距在（10．54±0．75）mm-（12．55±0．58）mm;神经根与相应椎间盘后下缘的最短距离在（-1．82±0．40）mm-（4．70±0．39）mm之间。结论通过对颈椎硬膜囊内解剖形态结构的研究证实颈椎硬膜囊内存在显微镜下经硬膜囊入路的手术操作区。     

Measurement of the Vertebral Canal Dimensions of the Neck of the Rat with a Comparison to the Human

The aim of this study was to determine the dimensions of the vertebral canal in the neck of the rat, because little is known about the morphology of the rat's cervical spine. A comparison then was made to the vertebral canal in the neck of the human. In part 1 of this study, we determined the precision of three different methods to measure the vertebral canal. The error (coefficient of variation) in these methods was found to range from 1 to 8%. In part 2, we used a computer‐based system to measure digital images of the vertebra and determined the anterior to posterior and the transverse vertebral canal dimensions in the neck of 19 young adult Sprague‐Dawley rats. The anterior to posterior dimension of the vertebral canal was greatest at the upper cervical (C1–C2) level and progressively decreased in the more caudal segments (C3–T1). The transverse dimension was greatest at the atlas (C1) vertebra and smallest at the axis (C2) vertebra with a steady increase in the transverse dimension with more caudal segments and a maximum transverse dimension at the level of the C6 and C7 vertebra. This study has demonstrated that the vertebral canal in the neck of young adult rats is similar in some regards to that of human. However, there are clear differences between the rat and human. These may be associated with differences in the morphology of the spinal cord or postural differences such as the cervicothoracic lordosis in bipeds compared with that in quadrupeds. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.     

颈椎病的屈伸位MRI研究

目的初步描述颈椎病人椎管狭窄在屈伸位MRI上的动态改变。方法54例颈椎病病人,均接受中立、前屈及后伸位MRI,在不同体位下,观察颈椎病人颈椎曲度、稳定性及椎间盘突出位置,分析前屈及后伸位时椎管狭窄程度的变化。结果颈椎病病人后伸位上出现椎管狭窄的数量(29/54)较前屈位(11/54)明显多(P<0.01),8例在前屈或后伸位上椎管狭窄程度无明显变化,6例前屈及后伸位时,蛛网膜下腔变窄程度均较中立位时重。结论屈伸位MRI可在人体动态下为研究颈椎病病人颈椎及其周围关系提供更多的功能性信息。     

多间隙微创前路椎间孔减压术对颈椎稳定性的影响

背景临床上颈椎钩突关节增生经常是多节段存在,由于多间隙病变复杂,手术方案的制定需要考虑多种因素。临床医生发现,即使是采用微创前路椎间孔减压术治疗两节段的神经根型颈椎病,减压充分后也不一定都需要行椎间融合术。目的本文对两个节段的钩突进行部分切除后,研究对颈椎稳定性的影响。方法依据健康志愿者的影像学资料,采用Mimics13.1、Solid Works2012软件建立三维几何模型,ANSYS15.0软件进行网格划分和网格优化,赋值各类组织的材料属性,建立颈椎(C2-C7)三维有限元模型,通过有限元分析技术研究部分切除单侧两个钩突后对颈椎稳定性和邻近节段椎体应力的影响。结果采用文中所述切除方法进行左侧钩突部分切除后,当切除双节段(60+60模型)时,各个工况下的最大位移相对于前3种切除方式均有明显的增大,而且各个工况下的最大应力相对于前3种切除方式均有显著增大。结论随着切除节段的增多和切除范围的增大,节段之间的活动度增大,局部应力增大,给颈椎带来一定的影响,导致颈椎不稳,加速颈椎的退变。因此在制定手术方案时,要严格掌握手术适应证,除非有明确的神经根、脊髓受压的指征,否则不可盲目扩大切除范围。     

大鼠颈髓中央核向前庭神经外侧核的定位纤维投射

目的　探讨大鼠颈髓中央核向前庭神经外侧核的定位投射。方法　本实验通过向脊髓内单侧注射菜豆—白细胞凝集素 ,在不同节段上对由脊髓向前庭神经核的纤维投射做顺行示踪。结果　在颈髓颈 2和颈 3节段包括颈髓中央核单侧注射示踪剂后 ,应用免疫组织化学法在对侧前庭神经下核以及前庭神经内侧核的大型细胞、小型细胞部和尾部内可见大量标记终末。在对侧前庭神经外侧核由头部至尾部整个范围内 ,标记物数量最多 ;在颈膨大处单侧注射示踪剂后 ,在对侧前庭神经内侧核的大型细胞部见很多标记轴突和终末 ,但在前庭神经外侧核和前庭神经下核内 ,仅见少量标记轴突和终末。在颈膨大以下脊髓节段注射示踪剂后 ,在前庭神经内侧核的大型细胞部、前庭神经下核及前庭神经外侧核的尾部标记纤维和终末仅零星存在。结论　颈部初级传入纤维经过颈中央核中继后 ,可直接投射到对侧前庭神经外侧核 ,同时 ,研究结果亦提示颈髓中央核可能是颈部传入冲动的中继和整合之处     

Distinctive pattern of c-fos expression in the feline cervico-lumbar spinal cord after stimulation of vanilloid receptors in dorsal neck muscles

In the present study, c-fos expression in the spinal cord has been used as a marker of neuronal activation induced by capsaicin-sensitive sensory afferents from the dorsal neck muscles in cats (n = 6). The number of Fos-immunoreactive neurons, which were revealed using the avidin-biotin-peroxidase method, was significantly increased in the cervical and lumbar spinal cord. In contrast to the control group (n = 3), 2 h after intramuscular capsaicin injection, c-fos expression was more extensive ipsilaterally to the injected side in the C3-C6 segments, and bilaterally in the L4-L6 segments. Most labeled neurons in the cervical spinal cord were small and giant cells, predominantly located in the middle and lateral parts of lamina I and, additionally, at the neck of the dorsal horn (lamina V), i.e., within the zones of termination of high-threshold muscle afferents. The widespread distribution of labeled cells throughout the cervical cord within the intermediate zone (lamina VII) coincided with the sites of last-order premotor interneurons and cells of origin of long crossed and uncrossed descending propriospinal pathways to the lumbar spinal cord. These findings suggest possible mechanisms for spreading of nociceptive signals between cervical and lumbar regions.     

Cervical Klippel-Feil syndrome predisposing an elderly African man to central cord myelopathy following minor trauma

An otherwise-healthy, active 83-year-old Nigerian man developed reversible central cord myelopathy from a mild fall on a level surface. Cervical spine magnetic resonance imaging (MRI) revealed C5, 6, and 7 block vertebrae and marked disc extrusions only at the immediately adjoining upper and lower non-fused segments of the cervical spine. There was no spinal canal stenosis otherwise. We think that the unique presentation of this case of Klippel-Feil syndrome further supports the impression that following fusion (congenital or acquired) of one segment of the spinal column, hypermobility of the non-fused adjoining segments may strongly predispose to more disc extrusions.     

Cauda equina syndrome

Single or double-level compression of the lumbosacral nerve roots located in the dural sac results in a polyradicular symptomatology clinically diagnosed as cauda equina syndrome. The cauda equina nerve roots provide the sensory and motor innervation of most of the lower extremities, the pelvic floor and the sphincters. Therefore, in a fully developed cauda equina syndrome, multiple signs of sensory disorders may appear. These disorders include low-back pain, saddle anesthesia, bilateral sciatica, then motor weakness of the lower extremities or chronic paraplegia and, bladder dysfunction. Multiple etiologies can cause the cauda equina syndrome. Among them, non-neoplastic compressive etiologies such as herniated lumbosacral discs and spinal stenosis and spinal neoplasms play a significant role in the development of the cauda equina syndrome. Non-compressive etiologies of the cauda equina syndrome include ischemic insults, inflammatory conditions, spinal arachnoiditis and other infectious etiologies. The use of canine, porcine and rat models mimicking the cauda equina syndrome enabled discovery of the effects of the compression on nerve root neural and vascular anatomy, the impairment of impulse propagation and the changes of the neurotransmitters in the spinal cord after compression of cauda equina. The involvement of intrinsic spinal cord neurons in the compression-induced cauda equina syndrome includes anterograde, retrograde and transneuronal degeneration in the lumbosacral segments. Prominent changes of NADPH diaphorase exhibiting, Fos-like immunoreactive and heat shock protein HSP72 were detected in the lumbosacral segments in a short-and long-lasting compression of the cauda equina in the dog. Developments in the diagnosis and treatment of patients with back pain, sciatica and with a herniated lumbar disc are mentioned, including many treatment options available.     

L5 radiculopathy caused by ossification of the ligamentum flavum: a case report

We describe a case of ossification of the ligamentum flavum in the thoracolumbar junction presenting as an L5 radiculopathy. Magnetic resonance imaging revealed a hypodense lesion on T2-weighted image at the T10-T12 level causing the right dural sac compression, and electrodiagnostic findings were compatible with the right L5 radiculopathy. The location and cause of the compression were confirmed by a surgery. The clinical findings and electrodiagnostic features of such lesions located at the thoracolumbar spinal junction are discussed.