Upper thoracic myelopathy caused by delayed neck extensor weakness in myotonic dystrophy

Myotonic dystrophy is the most common autosomal dominant myopathy in adults. Our patient, a 41 year-old female suffering from myotonic muscular dystrophy, developed upper thoracic myelopathy due to hypertrophy of the ligamentum flavum and the posterior longitudinal ligament. She had a typical hatchet face and ptosis with "head hanging forward" appearance caused by neck weakness. Motor weakness, sensory changes and severe pain below T4 level, along with urinary incontinence began 3 months ago. Genetic and electrodiagnostic studies revealed myotonic dystrophy type 1. Magnetic resonance imaging of the spine showed loss of cervical lordosis and spinal cord compression due to hypertrophied ligamentum flavum and posterior longitudinal ligament at T1 to T3 level. We concluded that her upper thoracic myelopathy was likely related to the thickness of the ligamentum flavum and posterior longitudinal ligament due to repetitive mechanical stress on her neck caused by neck muscle weakness with myotonic dystrophy.     

Biomechanical comparison of spinal cord compression types occurring in Degenerative Cervical Myelopathy

BackgroundDegenerative Cervical Myelopathy results from spine degenerations narrowing the spinal canal and inducing cord compressions. Prognosis is challenging. This study aimed at simulating typical spinal cord compressions observed in patients with a realistic model to better understand pathogenesis for later prediction of patients' evolution.MethodsA 30% reduction in cord cross-sectional area at C5-C6 was defined as myelopathy threshold based on Degenerative Cervical Myelopathy features from literature and MRI measurements in 20 patients. Four main compression types were extracted from MRIs and simulated with a comprehensive three-dimensional finite element spine model. Median diffuse, median focal and lateral types were modelled as disk herniation while circumferential type additionally involved ligamentum flavum hypertrophy. All stresses were quantified along inferior-superior axis, compression development and across atlas-defined spinal cord regions.FindingsAnterior gray and white matter globally received the highest stress while lateral pathways were the least affected. Median diffuse compression induced the highest stresses. Circumferential type focused stresses in posterior gray matter. Along inferior-superior axis, those two types showed a peak of constraints at compression site while median focal and lateral types showed lower values but extending further.InterpretationMedian diffuse type would be the most detrimental based on stress amplitude. Anterior regions would be the most at risk, except for circumferential type where posterior regions would be equally affected. In addition to applying constraints, ischemia could be a significant component explaining the early demyelination reported in lateral pathways. Moving towards patient-specific simulations, biomechanical models could become strong predictors for degenerative changes.     

肥厚腰椎黄韧带中成纤维细胞生长因子、转化生长因子及结缔组织生长因子的表达

背景：腰椎黄韧带肥厚是临床上引起腰椎管狭窄的主要因素之一,但其分子机制仍不是非常清楚。目的：分析纤维化相关细胞因子碱性成纤维细胞生长因子、转化生长因子β1和结缔组织生长因子在腰椎黄韧带肥厚过程中的作用。方法：取临床手术所取黄韧带,对照组6例（椎管内占位且无腰椎不稳患者黄韧带）、突出组（单纯腰椎间盘突出症患者黄韧带）6例、腰椎管狭窄症组6例。采用实时定量RT-PCR的方法检测各组黄韧带中碱性成纤维细胞生长因子、转化生长因子β1、结缔组织生长因子及Ⅰ、Ⅲ、Ⅴ型胶原蛋白的mRNA含量,分析3个细胞因子在黄韧带肥厚过程中的作用。结果与结论：腰椎管狭窄症组碱性成纤维细胞生长因子mRNA表达均明显高于突出组和对照组（均P 〈0.05）;腰椎管狭窄症组转化生长因子β1mRNA在3组中的表达明显高于对照组和突出组（均P 〈0.01）;结缔组织生长因子 mRNA 3组间差异无显著性意义（P 〉0.05）。腰椎管狭窄症组Ⅰ型胶原蛋白mRNA表达明显高于突出组和对照组（均P 〈0.05）;Ⅲ型胶原蛋白、Ⅴ型胶原蛋白mRNA表达3组之间差异无显著性意义（P 〉0.05）。结果说明碱性成纤维细胞生长因子、转化生长因子β1在腰椎黄韧带肥厚形成过程中有重要作用,引起黄韧带肥厚的主要胶原产物为Ⅰ型胶原蛋白。     

胸椎黄韧带骨化症的手术治疗

目的 :探讨胸椎黄韧带骨化症的手术治疗方法与技巧 ,以提高胸椎黄韧带骨化症的诊疗水平。方法 :胸椎黄韧带骨化症 2 1例 ,均行胸椎后路节段全椎板切除椎管扩大脊髓减压术。结果 :本组术后平均随访 1 5a ,优 16例 ( 76 2 %) ,良 5例 ( 2 3 8%)。疗效满意。结论 :早期诊断并尽早手术是治疗胸椎黄韧带骨化症的关键。     

颈椎过伸性脊髓损伤节段的相关性因素研究

目的 探讨颈椎过伸性损伤的退变性因素、损伤节段的分布及其原因.方法 温州医学院附属东阳医院89例颈椎过伸性损伤患者进行回顾性分析,统计颈椎退行性病变、T2WI相脊髓高信号的位置及颜面部外伤的位置.结果 间盘突出58例,居首位;其后依次为后纵韧带骨化(8例)、发育性椎管狭窄(7例)及椎间盘突出+黄韧带肥厚(6例).单节段T2WI相脊髓高信号在椎间盘水平:C2～3者4例,额部外伤1例;C3～4者12例,额部外伤10例,颧部外伤1例;CA～5者12例,额部外伤5例,额部+颧部外伤1例,额部+下颌部外伤1例;C5～6者11例,额部外伤3例,颧部外伤3例,下颌部外伤2例.单节段脊髓高信号位置不在椎间盘水平4例,脊髓高信号在两个不连续节段10例,脊髓高信号超过2个节段2例,脊髓高信号超过3个节段6例.结论 椎间盘突出是颈椎过伸性损伤患者最多见的退变性因素,T2WI相脊髓高信号的水平与额面部撞击的部位相关,拐点的剪切力(inflection point shear force)合并(或)颈椎过伸的前后挤压力是颈椎过伸性损伤的机制.     

MSCT在腰椎小关节综合征诊断中的临床应用研究

目的：探讨多层螺旋CT（MSCT）合并三维后处理对腰椎小关节综合征诊断中的价值。方法对180例经临床或相关提示腰椎小关节综合征患者的MSCT进行回顾性分析,三维后处理采用曲面重建（CPR）、容积再现（VTR）和多平面重建（MPR）等技术进行重建,分析椎间小关节病变情况。结果180例病人中发现椎间关节病变161例,发现椎间关节病变左侧共353个,右侧391个,双侧255个,其中椎间关节增生、硬化、肥大104例,椎间关节狭窄87例,椎间关节变性31例,椎间关节半脱位33例,合并其他病变如椎间盘病变91例,黄韧带肥厚45例,椎体侧弯36例,椎管狭窄19例,椎体滑移21例。结论 MSCT合并三维后处理可充分显示椎间小关节的解剖结构及病理变化,对诊断腰椎小关节综合征具有一定的影像学价值。     

Analysis of the mechanical response of damaged human cervical spine ligaments

BackgroundCervical spine ligaments that protect the spinal cord and stabilize the spine are frequently injured in motor vehicle collisions and other traumatic situations. These injuries are usually incomplete, and often difficult to notice. The focus of the presented study is placed on analysis of the effect of subfailure load on the mechanical response of the three main cervical spine ligaments: the anterior and the posterior longitudinal ligament and the ligamentum flavum.MethodsA total of 115 samples of human cadaveric ligaments removed within 24–48 h after death have been tested. Uniaxial tension tests along the fiber direction were performed in physiological conditions on a custom designed test equipment. The ligaments were loaded into an expected damage zone at two different subfailure values (based on previously reported reference group of 46 samples), and then reloaded to failure.FindingsThe main effect of a high subfailure load has proven to be the toe elongation change. The toe elongation increase is affected by the subfailure load value. While anterior and posterior longitudinal ligament showed similar changes, the smallest subfailure effect was found in ligamentum flavum.InterpretationsThe normal physiological region of the cervical spine ligaments mechanical response is modified by a high subfailure load. The observed ligament injury significantly compromises ligament ability to give tensile support within physiological spinal motion.     

腰椎小关节综合征CT诊断分析(附22例报告)

目的:介绍腰椎小关节综合征的CT诊断征象及其临床价值。材料与方法:分析22例腰椎小关节征的CT表现及其常见伴随征象。结果:CT直接一次性显示小关节面骨质改变,关节间隙改变,关节囊改变以及伴随的椎间盘膨出、突出,椎间孔、侧隐窝和椎管狭窄,黄韧带肥厚、钙化等征象。结论:CT可以为腰椎小关节综合征的诊断提供直观、充分的影像学根据,可作为本征的首选检查。     

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     

Incidental Diagnosis of Intradural Lumbar Disc Herniation During Discography: A Case Report

▪ Abstract:   We describe an incidental finding of intradural lumbar disc herniation diagnosed radiographically during discography. A patient was referred to our center for discography with symptoms of worsening, intractable low back pain radiating to both hips and the left leg which was exacerbated when standing and walking. Magnetic resonance imaging of the lumbar spine revealed multiple disc bulges and lumbar facet arthroses with ligamentum flavum hypertrophy producing moderate central canal and lateral recess stenosis. Discography was performed at three levels (L3-4, L4-5, L5-S1). During fluoroscopically guided injection into L4-5 it was noted that contrast was not contained within the disc and spread intrathecally with a myelographic appearance. Computerized tomography confirmed accurate needle placement and a spread of contrast into the intrathecal space. To the best of our knowledge, this is the first report describing a finding of intradural disc herniation while performing discography. Physicians should be aware of this potential finding while performing this technique. ▪     

Syringomyelia associated with cervical spondylosis: A rare condition

Spinal spondylosis is an extremely common condition that has only rarely been described as a cause of syringomyelia. We describe a case of syringomyelia associated with cervical spondylosis admitted at our division and treated by our institute. It is the case of a 66-year-old woman. At our observation she was affected by moderate-severe spastic tetraparesis. T2-weighted magnetic resonance imaging (MRI) showed an hyperintense signal within spinal cord from C3 to T1 with a more sharply defined process in the inferior cervical spinal cord. At the same level bulging discs, facets and ligamenta flava hypertrophy determined a compression towards subarachnoid space and spinal cord. Spinal cord compression was more evident in hyperextension rather than flexion. A 4-level laminectomy and subsequent posterior stabilization with intra-articular screws was executed. At 3-mo follow up there was a regression of tetraparesis but motor deficits of the lower limbs residuated. At the same follow up postoperative MRI was executed. It suggested enlargement of the syrinx. Perhaps hyperintensity within spinal cord appeared “bounded” from C3 to C7 with clearer margins. At the level of surgical decompression, subarachnoid space and spinal cord enlargement were also evident. A review of the literature was executed using PubMed database. The objective of the research was to find an etiopathological theory able to relate syringomyelia with cervical spondylosis. Only 6 articles have been found. At the origin of syringomyelia the mechanisms of compression and instability are proposed. Perhaps other studies assert the importance of subarachnoid space regard cerebrospinal fluid (CSF) dynamic. We postulate that cervical spine instability may be the cause of multiple microtrauma towards spinal cord and consequently may damage spinal cord parenchyma generating myelomalacia and consequently syrinx. Otherwise the hemorrhage within spinal cord central canal can cause an obstruction of CSF outflow, finally generating the syrinx. On the other hand in cervical spondylosis the stenotic elements can affect subarachnoid space. These elements rubbing towards spinal cord during movements of the neck can generate arachnoiditis, subarachnoid hemorrhages and arachnoid adhesions. Analyzing the literature these “complications” of cervical spondylosis are described at the origin of syringomyelia. So surgical decompression, enlarging medullary canal prevents rubbings and contacts between the bone-ligament structures of the spine towards spinal cord and subarachnoid space therefore syringomyelia. Perhaps stabilization is also necessary to prevent instability of the cervical spine at the base of central cord syndrome or syringomyelia. Finally although patients affected by central cord syndrome are usually managed conservatively we advocate, also for them, surgical treatment in cases affected by advanced state of the symptoms and MRI.     

Mechanisms of neurovascular compression within the spinal and intervertebral canals

OBJECTIVE: To describe some possible causes of encroachment on human spinal and intervertebral canal (foramen) neurovascular II structures. DATA SELECTION AND SYNTHESIS: A review of some imaging films of patients aged 38 to 52 years and some human autopsy histopathologic sections from 40- to 60-year-old cadavers to determine what structures may be responsible for neurovascular compression in individuals in this relatively young-to-middle-age group and to illustrate some examples. RESULTS: Stenosis of the spinal and intervertebral canal neurovascular structures can be caused by various bony and soft-tissue structures. Stenosis can be related to osteophytosis of the vertebral body, uncoverte-intervertebral disc protrusion, ossification of the posterior longitudinal ligament, and ligamentum flavum hypertrophy or buckling. DISCUSSION: Various forms of spinal and intervertebral canal stenosis can cause compression of neurovascular structures that may, in turn, be responsible for symptomatology. Of course, autopsy findings cannot be equated with painful syndromes in patients.     

经皮椎间孔镜髓核摘除术后椎间盘生物力学改变的有限元分析

目的 探讨经皮椎间孔镜髓核摘除术后椎间盘生物力学的变化,以及摘除不同位置和大小的椎间盘对术后椎间盘应力的影响。方法 基于CT扫描数据,建立L₄-L₅椎间盘部分摘除术后腰椎及椎间盘的三维有限元模型,施加载荷后模拟人体7个运动方向（直立、前屈、后伸、左右侧弯、左右旋转）,记录并分析椎间盘的应力变化。结果 髓核去除的6组与正常组比较,不同体位下椎间盘的应力均升高。除旋转体位下,椎间盘应力的改变为A2组 > A1组 > B2组 > B1组,A1组均大于去除面积是其两倍的B2组。左旋转体位下,椎间盘应力增加明显,B2组 > B1组 > A2组 > A1组 > 正常组。在除了侧弯的5种体位下,C2组椎间盘应力为所有组中最高,且C1组应力大于A1组和B1组。结论 腰椎前屈时应力最大。在相同位置,去除椎间盘的大小和其术后应力改变成正相关。椎间盘切除过宽会使其应力增加较大。MSU分型为C型（外侧或极外侧椎间盘突出）,术后椎间盘应力增加最多,是椎间盘去除术后退变的高风险型,B型（旁中央型椎间盘突出）术后椎间盘应力增加最小,是术后的相对稳定型。     

Intra-spinal new bone formation and spinal cord compression in familial hypophosphataemic vitamin D resistant osteomalacia

Four patients with familial hypophosphataemic vitamin D resistant osteomalacia and spinal cord compression are reported. Three of these patients were treated by decompressive laminectomy and each made a good recovery. At surgery new bone formation in the ligamentum flavum and thickening of laminae were found to be responsible for the canal stenosis and cord compression. Two of these four patients, and 10 others were examined by computed tomography to determine the incidence, site and extent of any intra-spinal new bone formation. Facet joint hypertrophy and thickened laminae were observed at some level in all the patients, but much the most important cause of spinal canal stenosis was new bone formation in the ligamentum flavum, in the mid and lower thoracic spine, occurring at several, but mainly contiguous vertebral levels. Severe spinal canal stenosis was found in eight of the 12 patients scanned. No obvious relation was found between the presence of intra-spinal new bone formation and the clinical severity of the disease or the presence of extra-skeletal ossification in para-spinal and other sites. Computed tomography offers a simple, non-invasive technique for identifying those patients at risk of cord compression from new bone formation.     

Cervical spondylotic myelopathy: a common cause of spinal cord dysfunction in older persons

Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction in older persons. The aging process results in degenerative changes in the cervical spine that, in advanced stages, can cause compression of the spinal cord. Symptoms often develop insidiously and are characterized by neck stiffness, arm pain, numbness in the hands, and weakness of the hands and legs. The differential diagnosis includes any condition that can result in myelopathy, such as multiple sclerosis, amyotrophic lateral sclerosis and masses (such as metastatic tumors) that press on the spinal cord. The diagnosis is confirmed by magnetic resonance imaging that shows narrowing of the spinal canal caused by osteophytes, herniated discs and ligamentum flavum hypertrophy. Choice of treatment remains controversial, surgical procedures designed to decompress the spinal cord and, in some cases, stabilize the spine are successful in many patients.     

X线检查在黄韧带骨化症诊断中的价值

目的:探讨X线检查在诊断黄韧带骨化症中的作用.方法:对56例黄韧带骨化症的X线表现进行回顾性分析.结果:黄韧带骨化症X线特征为多节段受累,胸腰段多见,多为边疆性,多合并后纵韧带骨化,结论:X线检查对于防止漏,误诊和定位在诊断黄韧带骨化症中有其特殊的地位.     

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.     

多体位颈椎MRI诊断颈椎病

目的 探讨多体位颈椎MRI对颈椎病的诊断价值。方法 对30例临床诊断为颈椎病的患者进行颈椎中立位、过屈位、过伸位MR检查,比较三种体位下颈椎椎间盘突出矢状径指数(SI)的差异。结果 30例中共发现颈椎椎间盘突出92个,两两组间比较,三种体位下SI差异均有统计学意义(P<0.05);过屈位椎间盘突出程度最轻,过伸位椎间盘突出程度最重。结论 不同体位下颈椎MR检查显示椎间盘突出程度有所差异。多体位颈椎MRI对于临床选择颈椎病治疗方案有着重要意义,也为研究颈椎病发病机制提供了新的方法。     

A biomechanical study of proximal junctional kyphosis after posterior long segment fusion with vertebral body augmentation

BackgroundProximal junction kyphosis is a common clinical complication of posterior long-segment spinal fusion and vertebral body augmentation method is one of the effective approaches to prevent it. The purpose of this study was to explore the biomechanical effect of proximal junction kyphosis after posterior long-segment thoracolumbar fusion with different vertebral augmentation schemes using finite element analysis.Methods3D nonlinear finite element models of T1-L5 spine posterior long-segment T8-L5 thoracolumbar fusion combined with T7, T8 and T7&T8 vertebral bone cement augmentation were constructed from human spine CT data and clinical surgical operation scheme to analyze the von Mises stress in the vertebrae, intervertebral discs pressure and pedicle screws system loads under the flexion, extension, lateral bending and axial rotation motion.FindingsCompared with thoracolumbar posterior long-segment fusion model, T7 maximum stress in T7, T8 and T7&T8 vertebrae augmentation models were reduced by 8.64%, 7.17%, 8.51%;0.79%, −3.88%,1.67%;4.02%, 5.30%, 4.27% and 3.18%, 3.06%, −6.38% under the flexion, extension, lateral bending and axial rotation motion. T7/T8 intervertebral disc pressure in T7, T8, T7&T8 vertebral augmentation models were 36.71Mpa,29.78Mpa,36.47Mpa;22.25Mpa,18.35Mpa,22.06Mpa;84.27Mpa,68.17Mpa, 83.89Mpa and 52.23Mpa, 38.78Mpa,52.10Mpa under the same condition. The maximum stress 178.2Mpa of pedicle screws is mainly distributed at the root of screw.InterpretationThoracolumbar posterior long-segment fusion with proximal double-segment vertebral augmentation should be recommended to prevent proximal junction kyphosis than single-segment augmentation. Simulation results can provide theoretical foundations and assist surgeons in selecting the appropriate operation scheme.     

Long‐Term Results of Percutaneous Lumbar Decompression mild® for Spinal Stenosis

Background: Lumbar spinal stenosis (LSS) generally occurs from a combination of degenerative changes occurring in the lumbar spine. These include hypertrophy of ligamentum flavum, facet joint arthritic changes and bulging of the intervertebral disk. Spinal stenosis leads to compression of the lumbar neural elements (cauda equina), which manifests as low back and leg pain especially on standing and walking known as “neurogenic claudication.” Current treatment options for LSS are varied. Conservative management, including physical therapy with/without epidural steroid injections, may be adequate for mild stenosis. Surgical decompression is reserved for severe cases and results in variable degrees of success. Patients with moderate‐to‐severe LSS having ligamentum flavum hypertrophy as a key contributor are generally inappropriately treated or undertreated. This is due to ineffectiveness of conservative therapy and possibility that major surgical compression might be too aggressive. Percutaneous decompression offers a possible solution for this patient population. Methods: One‐year follow‐up study was conducted at 11 U.S. sites. Study cohort included 58 mild^® percutaneous decompression patients who underwent 170 procedures, the majority treated bilaterally at one or two lumbar levels. Outcome measures included the visual analog scale (VAS), Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and SF‐12v2^® Health Survey. Results: No major mild^® device or procedure‐related complications were reported. One‐year data showed significant reduction of pain as measured by VAS. Improvement in physical functionality, mobility, and disability was significant as measured by ZCQ, SF‐12v2, and ODI. Conclusions: At 1 year this 58‐patient cohort demonstrated continued excellent safety profile of the mild^® procedure and equally important, showed long‐term pain relief and improved functionality.