Cervical spinal cord compression attributable to a calcified intervertebral disc in a patient with X-linked hypophosphatemic rickets: case report and review of the literature

OBJECTIVE AND IMPORTANCE: X-linked hypophosphatemic rickets is a common inherited phosphate-wasting disorder, but it is a rare cause of spinal cord compression. We present the first reported case of a calcified intervertebral disc causing spinal canal stenosis in X-linked hypophosphatemic rickets. CLINICAL PRESENTATION: A 44-year-old woman presented with paresthesia of her left arm and a loss of grip in both hands. Magnetic resonance imaging revealed a calcified intervertebral disc, as well as a posterior osteophytic bar causing marked cervical cord compression at C6/C7. INTERVENTION: An anterior cervical discectomy at C6/C7 and fusion with autologous bone graft were performed. The patient then exhibited significant improvement. CONCLUSION: A review of the 16 published cases demonstrates that thickening of the vertebral laminae, facet joint hypertrophy, and ossification of the intervertebral discs, posterior longitudinal ligament, and/or ligamentum flavum contribute to spinal canal stenosis in X-linked hypophosphatemic rickets. Those changes are caused by the disease itself and are unlikely to be related to long-term vitamin D treatment. Eleven of 16 patients were reported to have experienced favorable outcomes after surgery.     

Anterior approach for complex cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) is a slowly progressive disease resulting from age-related degenerative changes in the spine that can lead to spinal cord dysfunction and significant functional disability. The degenerative changes and abnormal motion lead to vertebral body subluxation, osteophyte formation, ligamentum flavum hypertrophy, and spinal canal narrowing. Repetitive movement during normal cervical motion may result in microtrauma to the spinal cord. Disease extent and location dictate the choice of surgical approach. Anterior spinal decompression and instrumented fusion is successful in preventing CSM progression and has been shown to result in functional improvement in most patients.     

颈腰椎间盘病

目的： 探讨颈腰椎间盘病的特点和诊断。方法： 对近４ 年中的颈腰椎间盘突出症、退变性椎管狭窄和颈椎病并施行手术的１９ 例进行了分析。结果： 发现颈腰椎间盘突出症是本病的重要原因。结论： 根据临床症状、体征和影像学检查, 颈椎 Ｍ Ｒ Ｉ和腰椎 Ｃ Ｔ 检查, 是防范混淆和误诊的必要条件。     

无骨折脱位型颈髓损伤的临床研究

目的：探讨颈椎在无骨折脱位情况下出现颈髓损伤的临床机制。方法：观察２４例无骨折脱位型颈髓损伤，重点分析其影像学检查特点。结果：２７％病例合并椎管狭窄，８３％的病例存在椎间盘突出，不同程度压迫脊髓。结论：无骨折脱位型颈脊髓损伤机制中，存在外伤致颈椎间盘损伤，突出的间盘向后压迫损伤颈髓。颈椎间盘损伤受力机制为屈曲→压缩→过伸。颈椎管狭窄、椎间盘退变等是此类脊髓损伤的病理解剖基础     

Theory of Bowstring Disease: Diagnosis and Treatment Bowstring Disease

Bowstring disease (BSD) is a new classification of spine disease caused by axial stretched lesion on nerve roots and the spinal cord, which is differentiated from disc herniation and canal stenosis in that it is caused by nerve compression lesions. BSD could be caused by mismatched growth rates between the spine and nerve roots (the juvenile type), or by imbalanced degenerative rates between the spine column and nerve roots (degenerative type). Here, we propose that there are several self‐adjust mechanisms to relieve axial nerve tension: (i) nerve growth; (ii) posture adjustment and low back pain; (iii) autogenous degeneration of intervertebral disc; and (iv) idiopathic and degenerative scoliosis. Iatrogenic lesions could also result in BSD, which could be presented as adjacent segment degeneration, leading to adding‐on effects and other neurological symptoms. The diagnosis criteria are proposed based on symptoms, physical examination, and radiological presentations. To remove axial tension on nerve roots, lumbar surgery should aim to restore the coordination of spine and cord units. Capsule surgery, shortening the spine column, could decompress cord and nerve roots 3‐dimensionally.     

脊髓型颈椎病患者椎间隙狭窄程度与颈椎不稳的关系

目的探讨脊髓型颈椎病(cervicalspondyloticmyelopathy,CSM)患者椎间隙狭窄程度与颈椎不稳和脊髓压迫部位的关系及其对术式选择的意义。方法回顾性分析35例伴有椎间隙明显狭窄的CSM患者的动态X线和MRI表现,观察颈椎不稳和脊髓压迫部位与狭窄椎间隙的关系,并与同期75例椎间隙接近正常的CSM患者比较。结果伴有椎间隙明显狭窄的CSM患者组中,25例狭窄椎间隙上方的邻近椎体出现不稳(71.4%),21例上方邻近椎间盘明显退变(60%)。椎间隙接近正常的CSM患者组,17例存在节段性颈椎不稳(22.7%)。结论CSM患者明显狭窄椎间隙的上方邻近椎体有失稳倾向,上方邻近椎间盘有加速退变的趋势。手术时应注意对邻近节段的处理。     

强直性脊柱炎合并颈椎无骨折脱位型脊髓损伤

目的 总结强直性脊柱炎合并颈椎无骨折脱位型脊髓损伤的临床特征、诊断和手术治疗。方法 1986～2004年，笔者手术治疗累及颈椎的强直性脊柱炎合并无骨折脱位型脊髓损伤27例。结果 本组27例中椎管内韧带骨化18例，脊髓损伤的原因依次为韧带骨化所致的椎管狭窄，椎间盘损伤和椎体后骨刺及椎间不稳定。术前均为不完全性损伤，非手术治疗不提高脊髓功能。术后脊髓ASIA分级平均改善1级。后路手术椎板切除率、出血量、手术时间、术后引流量明显高于不合并强直性脊柱炎的患者。前路手术可达到骨性融合。结论 强直性脊柱炎合并颈椎无骨折脱位型脊髓损伤一般为不完全性损伤，损伤的内因依次为椎管内韧带骨化所致的椎管狭窄、椎间盘损伤、椎间骨赘和椎间不稳定。适当的手术可改善脊髓功能。手术难度大，风险高。     

Spinal cord compression due to pagetic spinal stenosis with involvement of extradural soft tissues: a case report.

Although Paget's disease of the spine may cause neurological dysfunction by bone hypertrophy or collapse, it is very rare for the disease process to extend into the soft tissues of the spinal canal. We report a case of Paget's disease causing ossification of the ligamentum flavum and extradural fat, thus causing spinal cord compression. Decompressive laminectomy was carried out, resulting in neurological improvement. In such cases surgical decompression should be followed by therapy with calcitonin.     

Anterolisthesis and retrolisthesis of the cervical spine in cervical spondylotic myelopathy in the elderly

Background Degenerative spondylolisthesis of the cervical spine has received insufficient attention in contrast to that of the lumbar spine. The authors analyzed the functional significance of anterior and posterior degenerative spondylolisthesis (anterolisthesis and retrolisthesis) of the cervical spine to elucidate its role in the development of cervical spondylotic myelopathy (CSM) in the elderly. Methods A total of 79 patients aged 65 or older who eventually had surgical treatment for CSM were evaluated radiographically. Results Altogether, 24 patients (30%) had displacement of 3.5 mm or more (severe spondylolisthesis group), 31 had displacement of 2.0–3.4 mm (moderate spondylolisthesis group), and 24 had less than 2.0 mm displacement (mild spondylolisthesis group). The severe spondylolisthesis group consisted of 14 patients with anterolisthesis (anterolisthesis group) and 10 patients with retrolisthesis (retrolisthesis group). Patients with severe spondylolisthesis had a high incidence (93%) of degenerative spondylolisthesis at C3/4 or C4/5 and significantly greater cervical mobility than those with mild spondylolisthesis. The anterolisthesis group, but not the retrolisthesis group, had a significantly wider spinal canal than the mild spondylolisthesis group, although the degree of horizontal displacement and cervical mobility did not differ significantly between the anterolisthesis and retrolisthesis groups. Severe cord compression seen on T1-weighted magnetic resonance imaging (MRI) scans and high-intensity spinal cord signals seen on T2-weighted MRI scans corresponded significantly to the levels of the spondylolisthesis. Conclusions Degenerative spondylolisthesis is not a rare radiographic finding in elderly patients with CSM, which tends to cause intense cord compression that is seen on MRI scans. Greater mobility of the upper cervical segments may be a compensatory reaction for advanced disc degeneration of the lower cervical segments, leading to the development of degenerative spondylolisthesis. With a similar degree of displacement, anterolisthesis tends to have a greater impact on the development of CSM than retrolisthesis.     

Analysis of hypertrophy of the posterior longitudinal ligament of the cervical spine, on the basis of clinical and experimental studies

OBJECTIVE: The goal of this study was to elucidate the pathophysiological features and treatment of hypertrophy of the posterior longitudinal ligament (HPLL) of the cervical spine. HPLL is defined as a pathological thickening of the posterior longitudinal ligament (PLL), causing spinal cord compression. Incomplete decompression via removal of only coexisting herniated intervertebral discs or spondylotic spurs might be performed, resulting in unsatisfactory surgical outcomes, when the PLL becomes abnormally thickened and contributes to myelopathy. METHODS: Patients with HPLL who underwent cervical decompression surgery were selected. Medical records and radiographs were retrospectively reviewed, to obtain data on the pre- and postoperative clinical conditions of the patients. Autopsy cases with HPLL proven by low-energy x-ray examinations were chosen for assessment of the pathological characteristics. RESULTS: Seventeen men and three women with HPLL underwent treatment via an anterior approach, with direct removal of HPLL. Nineteen patients developed myelopathy, whereas one patient developed radiculopathy. Radiologically, all HPLL cases exhibited coexisting herniated intervertebral discs and 10 exhibited small segmental ossifications of the PLL. Magnetic resonance imaging or computed tomographic myelography revealed extensive cord compression across the vertebral endplate level. The average preoperative Benzel modified Japanese Orthopaedic Association score was 10.8, and the average postoperative score was 13.2. Histological examinations revealed thickening of the PLL with proliferation of chondrocytes, together with various degenerative changes. CONCLUSION: Patients with HPLL can benefit from an anterior approach with direct removal of the HPLL and associated herniated intervertebral discs or ossification of the PLL. Cervical polytomography, computed tomography, and magnetic resonance imaging are useful in establishing a diagnosis of HPLL.     

Cervical spine in diastrophic dysplasia: an MRI analysis

In this cross-sectional study, we evaluated the cervical spine in patients with diastrophic dysplasia (DD) by using magnetic resonance imaging (MRI). From 90 (57 female, 33 male) patients of different ages (0.3-56.0 years), T1- and T2-weighted images were obtained. The craniocervical junction and status of the medulla were examined, and the transverse areas of dural tube and medulla were measured. Alignment of the cervical spine, vertebral abnormalities, and disc changes also were evaluated. The cervical spinal canal was moderately narrowed, particularly in adults. The transverse areas of the medulla and especially of the dural tube were smaller compared with a normal population (p < 0.0001). There was no stenosis of the foramen magnum in patients with DD, but the spinal canal was narrowed. Degenerative changes were common. In all age groups, intervertebral discs were dark and disc heights were narrowed. Three (3%) patients (two children, one adult) had cervical kyphosis. Compression of the medulla was noted in association with severe cervical kyphosis in one child and one adult. Typical findings of the cervical spine in DD were exceptionally wide foramen magnum, narrowed spinal canal and early degenerative changes, and in older age groups, especially midcervically narrowed spinal canal. Severe cervical kyphosis caused medullar compression. The intervertebral discs developed abnormally. Abnormal disc structure may be one etiologic factor in the development of cervical kyphosis. Early and rapid progression of the degenerative changes is a normal finding in patients with DD, regardless of their age, and this also explains the stiffness of the cervical spine in clinical examination.     

Morphological changes of the cervical spinal canal and cord due to aging

Cervical spondylotic myelopathy is a condition in which degenerative changes of the cervical vertebral bodies and the intervertebral discs cause disturbances to the spinal cord either by direct mechanical compression or by disturbing the blood supply. There have been a number of studies on roentgenological measurements of the anteroposterior (AP) diameter of the cervical spinal canal relating to the disorder. However, there are only a few reports concerning the shape and the size of the spinal canal and the spinal cord. Murone reported that the cervical spinal canal of Japanese was significantly smaller than those of Europeans on roentgenograms. However, whether the size of the spinal cord of Japanese is proportionally smaller or not remains to be studied. The aim of the present study is to perform various measurements of the human cervical spine specimens to find any influence of the age on them and to see relative correlation of the spinal cord size to the corresponding spinal canal size. Methods: Seventy-seven human cervical spinal columns taken én bloc from C3 to C7 at post-mortem examination were used for the study. After taking AP and lateral roentgenograms, the specimen was horizontally transsected at the middle of each vertebral body and at the level of each intervertebral disc. The reason why the middle of the vertebral body was selected is to exclude modifications by osteophyte formation at the upper and the lower ends of the body and to see possible genuine appearance and change of the spinal canal. The measured items were AP diameter of the vertebral body (A), AP diameter of the spinal canal (B), area of the spinal canal (C), AP diameter of the spinal cord (beta) and area of the spinal cord (gamma). In five untreated specimens, CT-scan was performed prior to the horizontal section, and the CT-scan findings were compared to those by direct measurements. Lateral cervical roentgenograms of 249 patients of various ages were used as a comparison. Results: The AP diameter of the vertebral body (A) and the AP diameter of the spinal canal (B) showed some correlation with the age. The former became larger whereas the latter became smaller with the age. The area of the spinal canal (C) did not show correlation with the age. The AP diameter of the spinal cord (beta) showed correlation with the age, whereas the area of the spinal cord (gamma) failed to show the correlation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Postnatal maturation and radiology of the growing spine

Postnatal maturation of the spine is marked by the ossification process and by changes in the shape of the vertebrae, spinal curvature, spinal canal, discs, and bone marrow. Different aspects of the spine's maturation process are demonstrated on the three most common radiologic modalities used to evaluate the spine. Conventional plain spine imaging (plain spine radiography) provides a good initial evaluation of the bony spine. CT provides better bone detail and allows finer evaluation of subtle structures, the soft tissues of the spine (discs, ligaments), and the spinal cord. MRI provides excellent resolution of the bone marrow, ligaments, and discs of the spine, and can be used as an adjunct for evaluating the soft tissue of the spine and intraspinal contents.     

颈椎病致脊髓前动脉综合征

目的 报告一组因颈椎病引起的脊髓前动脉综合征,分析其临床表现,并探讨其机制和影像学表现特点和治疗.方法 共25例,男16例,女9例;平均年龄53.2岁.在典型的脊髓型颈椎病基础上无外伤等明显诱因,短期内症状急剧加重19例,逐渐加重6例.除脊髓型颈椎病的体征外,均出现浅感觉丧失或减退,而深感觉存在的"感觉分离"现象.下肢痉挛性瘫痪.其中12例伴有不同程度的肛门、膀胱功能失控.X线片和CT显示颈椎不同程度的退变.其中伴有颈椎管狭窄10例、颈椎不稳12例、颈椎后纵韧带骨化6例.MR检查发现均为椎间盘中央型突出,脊髓前中央受压迫.脊髓多有不同程度地萎缩.大部分病例在脊髓前2/3 T1WI信号稍低或无明显变化,T2WI高信号或稍高信号,但有6例T1WI和T2WI信号均无改变.在缓慢起病的患者中,有3例脊髓前2/3囊性变.前路减雎24例,后路减压1例,采用JOA评分评估疗效.结果 平均随访16个月,术后疗效优(脊髓功能恢复率≥75%)11例,良(50%～74%)7例,一般(25%～49%)6例,差(≤24%)1例.结论 在无明显诱因下颈椎病椎间盘中央型突出可引起脊髓前动脉综合征."感觉分离"是诊断此疾病的基础,同时结合病史、临床症状和其他体征以及影像学检查给予确诊.及时减压可取得较佳的疗效.     

Development of a chronic cervical cord compression model in rat: changes in the neurological behaviors and radiological and pathological findings

Cervical myelopathy is caused by chronic segmental compression of the spinal cord because of degenerative changes of the spine. However, the exact mechanisms of chronic cervical cord compression are not fully understood. The purpose of this study was to validate a new animal model of chronic cervical cord compression capable of reproducing the clinical course without laminectomy in rats. A polyethylene line attached to a plastic plate was fastened with three turns around the vertebral body of C4 in 1-month-old rats. After surgery, the polyethylene line grows deeper into the dorsal wall of the spinal canal along with the growth of the spinal canal and vertebral body, producing a gradual compression of the spinal cord. The results show that this cervical canal stenosis (CCS) model in rats caused motor deficits and sensory disturbances 9 months after initiating CCS; however, no clinical manifestations took place until 6 months. The intramedullary high-intensity area on T2-weighted images was observed in 70% of the CCS model rats at 12 months after initiating CCS. In histological sections, the spinal cord was compressed along the entire circumference at 12 months after initiating CCS. The number of ventral neurons was decreased, and the white matter showed wallerian degeneration. This model might reproduce characteristic features of clinical chronic cervical cord compression, including progressive motor and sensory disturbances after a latency period and insidious neuronal loss, and represents chronic compression of the cervical spinal cord in humans.     

Dynamic electrophysiological examination of cervical flexion myelopathy

Cervical flexion myelopathy is thought to arise following compression of the spinal cord by vertebrae or intervertebral discs and dura mater, or from overstretching of the spinal cord induced by cervical spinal flexion. However, the influence of spinal flexion on the spinal cord and the detailed origins of this disease are unknown. In this article the authors report a case of cervical flexion myelopathy in which dynamic electrophysiological examination was performed using an epidural electrode. This investigation showed the real-time influence of flexion of the cervical spine on spinal cord function. This technique was considered to be useful for diagnosis and in decision making for treatment. Anterior fusion was the optimal surgical method for treating this disease.     

Measurement of volume-occupying rate of cervical spinal canal and its role in cervical spondylotic myelopathy

Purpose

To compare volume-occupying rate of cervical spinal canal between patients with cervical spondylotic myelopathy (CSM) and normal subjects, and to investigate its significance in cervical spine disease.

Methods

Spiral computed tomography (CT) scan (C4–C6 cervical spine unit) was performed in 20 normal subjects and 36 cases of CSM at a neutral position, and data were transferred to the Advantage Workstation Version 4.2 for assessment. Bony canal area and fibrous canal area in each cross section, and sagittal diameters of cervical spinal canal and cervical spinal body were measured. Volume-occupying rate of cervical spinal canal was calculated using MATLAB. Cervical spinal canal ratio and effective cervical spinal canal ratio were calculated, and Japanese Orthopaedic Association score was used to assess cervical spinal cord function.

Results

Volume-occupying rate of cervical spinal canal at a neutral position was significantly higher in CSM patients as compared to normal subjects (P < 0.01). There was no correlation between cervical spinal canal ratio and JOA score in CSM patients, with a Pearson’s correlation coefficient of 0.171 (P > 0.05). However, sagittal diameter of secondary cervical spinal canal, effective cervical spinal canal ratio and volume-occupying rate of cervical spinal canal were significantly associated to JOA score, with Pearson’s coefficient correlations of 0.439 (P < 0.05), 0.491 (P < 0.05) and ?0.613 (P < 0.01), respectively.

Conclusions

Volume-occupying rate of cervical spinal canal is an objective reflection of compression on cervical spine and spinal cord, and it is associated with cervical spinal cord function. These suggest that it may play a significant role in predicting the development of CSM.     

Imaging modalities and tests for cervical myelopathy

Cervical spondylotic myelopathy (CSM) is a progressively degenerative disease of the spine that results from compression of the spinal cord. Diagnostic imaging, in addition to a history and physical examination, is essential to diagnose CSM, to guide surgical decision making, and to identify prognostic indicators to surgical success. We discuss the modalities of imaging in common practice and examine the use of radiographs, magnetic resonance imaging (MRI), CT/CT myelography, diffusion tensor imaging (DTI), and magnetization transfer imaging (MT) in the diagnostic evaluation of patients with CSM.     

认识颈腰椎间盘病

目的　探讨颈腰椎间盘病的特点和诊断。方法　对近 6年中的颈腰椎盘突出症伴退变性椎管狭窄症和颈椎病并施行手术的 5 6例进行分析。结果　发现颈腰椎间盘突出症是本病的重要原因。结论　根据临床症状、体征和影像学检查 ,颈椎MRI和腰椎CT检查 ,是防范混淆和误诊的必要条件     

臂丛神经根性撕脱伤前根椎管内植入手术入路探讨

目的通过对臂丛神经根部及椎管内结构的显微外科解剖学研究,寻找臂丛神经前根再植入脊髓的最佳手术入路。方法在成人19例38侧颈胸段尸体标本上,显露臂丛神经并追踪至椎间孔,切除椎弓,切开硬脊膜,暴露脊髓及臂丛神经根,对臂丛神经根走行、长度及周围相关骨性结构,各脊髓节段与对应椎间盘相对位置和椎动脉与臂丛神经的关系进行观测。结果脊髓节段与椎间盘的对应关系为：C_(5-7)脊髓节段对应C_(3-4)、C_(4-5)、C_(5-6)椎间盘,C_8、T_1脊髓节段对应C_6、C_7椎体,根据解剖学结果寻找出侧前方、椎间孔扩大侧方、侧后方、侧-后方联合四条可行的手术入路。结论侧前方及侧方入路是臂从神经前根再植入脊髓的最佳入路,侧后方及侧-后方联合入路再植入脊髓的位点差,但其难度和危险小。