Cervical degenerative disease at flexion-extension MR imaging: prediction criteria

PURPOSE: To determine if there are any neutral-position imaging criteria that can help predict functional cord impingement at flexion-extension cervical magnetic resonance (MR) imaging. MATERIALS AND METHODS: Sixty-two patients with cervical degenerative disease were evaluated with regard to the dynamic changes of canal stenosis at flexion-extension MR imaging. Functional cord impingement was considered if the cord was impinged or more impinged after neck flexion or extension. Selection criteria for neutral-position MR imaging, such as cervical curvature, canal space, degenerative stage, intramedullary high signal intensity on T2-weighted images, and resting instability, were evaluated for their ability to predict functional cord impingement at flexion-extension MR imaging (Fisher exact test, logistic regression analysis). RESULTS: MR images in 19 (31%) of 62 patients showed functional cord impingement at extension MR imaging compared with images in two (3%) patients at flexion MR imaging. Statistically significant differences were found for the criteria cervical degeneration stage (P <.001) and spinal canal space (P =.037) for predicting functional cord impingement at extension MR imaging. In contrast, no significant differences were found among selection criteria for flexion MR imaging. Probabilities of functional cord impingement at extension MR imaging were calculated with different combinations of degenerative stages and canal spaces. Probability could increase to 79% if the patient had both stabilization degeneration (disk protrusion or osteophytic formation with hypertrophy of the ligamentum flavum) and C7 canal space of 10 mm or less. CONCLUSION: None of the selection criteria evaluated in this study has the ability to predict functional cord impingement at flexion MR imaging; however, prediction of impingement at extension MR imaging can increase from 31% to 79% if proper criteria are selected.     

颈椎病动态MRI扫描揭示椎管狭窄及脊髓受压因素的价值

颈椎动态MRI扫描直观地显示屈伸状态下导致椎管狭窄及脊髓受压的动态因素,为临床提供了中立位扫描所不能揭示的致病机制,以后伸位为著。后伸位颈椎功能性受压与颈椎退变阶段及椎管矢径密切相关,当中立位MRI显示黄韧带肥厚,或椎关节僵硬伴发椎管矢径≤10.0mm时,建议行动态MRI扫描。前屈位虽然可以减轻脊髓受压,但持久前屈会促使或加重颈椎病的发生。     

Dynamics of the spinal cord: an analysis of functional myelography by CT scan

Summary The antero-posterior movement of the spinal cord with flexion and extension of the neck was analyzed in order to clarify the mechanism of spinal cord compression in cases with postoperative spinal deformity, and to contribute to the improvement of the surgical methods of conventional laminectomy. The control subjects were 47 cases without cervico-thoracic neurological symptoms, who underwent CT myelography in flexion and extension of the neck; the cervical spinal cord was examined in 27 of these cases and the thoracic cord in the other 20. CT myelography was also carried out in 16 patients with cervical myelopathy and in 5 patients after posterior decompression surgery (suspension laminotomy). CT sections in flexion and extension of the neck were analyzed for 1) change of configuration of the dura mater and the spinal cord, and 2) antero-posterior shift of the spinal cord in the subarachnoid space. In the control subjects, the configuration of the dura mater was slightly flattened at C5/6, C6 and C6/7 in extension of the neck. The cervical spinal cord shifted anteriorly in flexion and posteriorly in extension of the neck, and was flattened at the midcervical level in flexion in the control subjects. There was a statistically significant correlation between the location of the spinal cord and the adjacent intervertebral angles at the levels of C4, C5 and C6. These results were compared with the results from the 16 patients with cervical myelopathy and 5 patients after suspension laminotomy. The thoracic spinal cord shifted anteriorly in neck flexion and posteriorly in extension, especially at upper thoracic level. In order to avoid spinal cord compression due to anterior shift of the spinal cord caused by postoperative kyphosis, it is necessary to employ the surgical method which can prevent postoperative kyphotic deformity.Presented at the 17th World Congress of the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT 87), Munich, FRG, 16–21 August 1987     

Kinematic MR imaging in surgical management of cervical disc disease, spondylosis and spondylotic myelopathy

PURPOSE: To estimate the clinical value and influence of kinematic MR imaging in patients with degenerative diseases of the cervical spine. MATERIAL AND METHODS: Eighty-one patients were examined with a 1.5 T whole body magnet using a positioning device. Cervical disc disease was classified according to clinical and radiographic findings into 4 stages: stage I=cervical disc disease (n=13); stage II=spondylosis (n=42); stage III=spondylosis with restricted motion (n=11); and stage IV=cervical spondylotic myelopathy (n=15). Findings on kinematic MR images were compared to those on flexion and extension radiographs, myelography, CT-myelography and static MR imaging. Furthermore, the influence of kinematic MR imaging on surgical management and intra-operative patient positioning was determined. RESULTS: Additional information obtained by kinematic MR imaging changed the therapeutic management in 7 of 11 (64%) patients with stage III disease, and in 13 of 15 (87%) patients with stage IV disease. Instead of an anterior approach, a posterior surgical approach was chosen in 3 of 11 patients (27%) with stage III disease and in 6 of 15 patients (40%) with stage IV disease. Hyperextension of the neck was avoided intra-operatively in 4 patients (27%) with cervical spondylotic myelopathy, and in 1 patient with stage II (2%) and in 1 patient with stage III (9%) disease. Kinematic MR imaging provided additional information in all patients with stages III and IV disease except in 1 patient with stage III disease, when compared to flexion and extension radiographs, myelography, CT-myelography and static MR examination. CONCLUSION: Kinematic MR imaging adds additional information when compared to conventional imaging methods in patients with advanced stages of degenerative disease of the cervical spine.     

Hirayama disease: MR diagnosis.

We report the MR findings in two cases of Hirayama disease, a kind of cervical myelopathy related to flexion movements of the neck. In flexion MR studies, we can see the striking and pathognomonic picture of anterior shifting of posterior dura at the lower cervical spinal canal. In nonflexion studies, we find that asymmetric cord atrophy, especially at the lower cervical cord, though subtle, is highly suggestive of Hirayama disease. When it is seen, a flexion MR study is warranted to prove this diagnosis.     

Rheumatoid arthritis: epidural enhancement as an underestimated cause of subaxial cervical spinal stenosis

PURPOSE: To assess the frequency and site of subaxial spinal canal stenosis due to enhancing tissue in patients with rheumatoid arthritis. MATERIALS AND METHODS: Data from 33 consecutive patients with rheumatoid arthritis were evaluated; these patients had undergone 1.5-T magnetic resonance imaging following gadolinium chelate administration, in combination with a frequency selective fat-suppression technique. Stenosis and enhancement were scored for each of six cervical spinal levels and were compared with results in a control population consisting of 16 patients with degenerative disease. Enhancement was scored as superficial or deep on the anterior and posterior sides from the cervical spinal cord. Differences between patient groups were tested by using the chi(2) test for trend and the Fisher exact test. RESULTS: No significant difference was found in the frequency or severity of subaxial stenosis between rheumatoid arthritis and degenerative disease. Deep epidural enhancement was observed more often with rheumatoid arthritis than with degenerative disease both anterior (25 of 33 patients vs seven of 16 patients, respectively; P <.001) and posterior (24 of 33 patients vs two of 16 patients, respectively; P =.001) to the spinal cord. Enhancing stenosing tissue in rheumatoid arthritis frequently occurred anterior and posterior at the same time and at the same level, with segmental cufflike extension of enhancing tissue around the dural sac. Stenosing tissue enhanced more frequently with rheumatoid arthritis than with degenerative disease (22 of 33 vs four of 16 patients, respectively; P =.008). CONCLUSION: In patients with rheumatoid arthritis, subaxial stenosis is frequently caused by enhancing epidural tissue. This enhancing tissue presumably represents pannus.     

MRI运动扫描分析脊髓型颈椎病的脊髓致压因素

目的 探讨动态运动MR扫描揭示椎管内退变结构对脊髓的动力性致压作用，提高脊髓型颈椎病的早期诊断作用。方法 在开放式MR机上，通过颈椎的多角度分次扫描、关节运动扫描和MR透视扫描3种方法检查60例颈椎病患者，分别观察退变结构在常规自然位、前屈位和后伸位时对脊髓的致压作用。结果 (1)椎管内退变结构在颈椎伸屈活动时常形成较自然位更加严重的脊髓压迫征象，而且它们间还有“动态叠加作用”。(2)椎间盘突出(29例)、椎体骨赘增生、椎体错位滑脱(7例)、后纵韧带增厚(36例)等在前屈位时常较自然位形成更明显的混合性致压物。(3)34例患者的退变黄韧带在后伸位时皱折凸入椎管，凸入黄韧带又可与脊髓前方致压物形成“钳夹效应”而严重压迫脊髓(9例)。(4)14例患者在伸屈活动时加重椎体的错位滑脱。(5)硬膜囊前间隙在前屈位(41例)和后伸位(16例)时较自然位变小；囊后间隙后伸位变小见于43例，前屈位对其影响较小(4例)。结论 颈椎病患者动态MR扫描不仅从形态上而且能从致病作用上显示出早期的、潜在性的、动态性的脊髓致压因素，从而起到较静态扫描更早期地对脊髓型颈椎病的诊断作用。     

Thoracic disc disease and stenosis

Disc herniation and stenosis in the thoracic spine are relatively uncommon compared with their occurrence in the cervical or lumbar spine. They are usually degenerative, although trauma may be an aggravating or initiating factor. The clinical presentation includes local and/or radicular pain with or without signs and symptoms of cord dysfunction. Radicular pain may be secondary to mechanical compression or vascular impingement. MR imaging is the best way to define the specific abnormality as well as the effect on the adjacent spinal cord. CT after myelography may be useful as well, especially in those patients in whom there is involvement of the posterior ligamentous and osseous structures of the thoracic spinal canal. MR imaging may finally reveal the true incidence of thoracic disc herniation.     

Intensity of Intraoperative Spinal Cord Hyperechogenicity as a Novel Potential Predictive Indicator of Neurological Recovery for Degenerative Cervical Myelopathy

ObjectiveTo analyze the correlations between intraoperative ultrasound and MRI metrics of the spinal cord in degenerative cervical myelopathy and identify novel potential predictive ultrasonic indicators of neurological recovery for degenerative cervical myelopathy.Materials and MethodsTwenty-two patients who underwent French-door laminoplasty for multilevel degenerative cervical myelopathy were followed up for 12 months. The Japanese Orthopedic Association (JOA) scores were assessed preoperatively and 12 months postoperatively. Maximum spinal cord compression and compression rates were measured and calculated using both intraoperative ultrasound imaging and preoperative T2-weight (T2W) MRI. Signal change rates of the spinal cord on preoperative T2W MRI and gray value ratios of dorsal and ventral spinal cord hyperechogenicity on intraoperative ultrasound imaging were measured and calculated. Correlations between intraoperative ultrasound metrics, MRI metrics, and the recovery rate JOA scores were analyzed using Spearman correlation analysis.ResultsThe postoperative JOA scores improved significantly, with a mean recovery rate of 65.0 ± 20.3% (p < 0.001). No significant correlations were found between the operative ultrasound metrics and MRI metrics. The gray value ratios of the spinal cord hyperechogenicity was negatively correlated with the recovery rate of JOA scores (ρ = −0.638, p = 0.001), while the ventral and dorsal gray value ratios of spinal cord hyperechogenicity were negatively correlated with the recovery rate of JOA-motor scores (ρ = −0.582, p = 0.004) and JOA-sensory scores (ρ = −0.452, p = 0.035), respectively. The dorsal gray value ratio was significantly higher than the ventral gray value ratio (p < 0.001), while the recovery rate of JOA-motor scores was better than that of JOA-sensory scores at 12 months post-surgery (p = 0.028).ConclusionFor degenerative cervical myelopathy, the correlations between intraoperative ultrasound and preoperative T2W MRI metrics were not significant. Gray value ratios of the spinal cord hyperechogenicity and dorsal and ventral spinal cord hyperechogenicity were significantly correlated with neurological recovery at 12 months postoperatively.     

Focal Anterior Displacement of the Thoracic Spinal Cord without Evidence of Spinal Cord Herniation or an Intradural Mass

Objective

We report magnetic resonance imaging (MRI) findings on focal anterior displacement of the thoracic spinal cord in asymptomatic patients without a spinal cord herniation or intradural mass.

Materials and Methods

We identified 12 patients (male:female = 6:6; mean age, 51.7; range, 15-83 years) between 2007 and 2011, with focal anterior displacement of the spinal cord and without evidence of an intradural mass or spinal cord herniation. Two radiologists retrospectively reviewed the MRI findings in consensus.

Results

An asymmetric spinal cord deformity with a focal dented appearance was seen on the posterior surface of the spinal cord in all patients, and it involved a length of 1 or 2 vertebral segments in the upper thoracic spine (thoracic vertebrae 1-6). Moreover, a focal widening of the posterior subarachnoid space was also observed in all cases. None of the patients had myelopathy symptoms, and they showed no focal T2-hyperintensity in the spinal cord with the exception of one patient. In addition, cerebrospinal fluid (CSF) flow artifacts were seen in the posterior subarachnoid space of the affected spinal cord level. Computed tomography myelography revealed preserved CSF flow in the two available patients.

Conclusion

Focal anterior spinal cord indentation can be found in the upper thoracic level of asymptomatic patients without a spinal cord herniation or intradural mass.     

Intracranial dural arteriovenous fistulas with spinal venous drainage: relation between clinical presentation and angiographic findings.

PURPOSETo investigate why some patients with an intracranial dural arteriovenous fistula (DAVF) with spinal venous drainage have myelopathy and others do not.METHODSWe reviewed the clinical and radiologic data for 12 patients who had a DAVF with spinal venous drainage diagnosed at our institutions from 1982 to 1995.RESULTSSix patients had progressive spinal cord indications of disease (patients with myelopathy) and six others (patients without myelopathy) had cerebral indications (five had intracranial hemorrhage and one had a seizure). Cerebral angiography showed a posterior fossa DAVF with spinal venous drainage in all cases. The clinical presentation of DAVFs with spinal venous drainage was compared with the extent of the drainage. In patients without myelopathy, the spinal venous drainage exited the intradural canal via the cervical medullary-radicular veins and was therefore limited to the cervical perimedullary veins. In patients with myelopathy, no medullary-radicular vein was seen, and the venous drainage descended along the perimedullary veins of the entire spinal cord toward the conus medullaris.CONCLUSIONWe found an exact relation between clinical presentation and venous drainage of DAVFs with spinal venous drainage. Patients had no myelopathy when the venous drainage was limited to the cervical cord; myelopathy was present when the venous drainage descended toward the conus medullaris.     

The Restless Spinal Cord in Degenerative Cervical Myelopathy

BACKGROUND AND PURPOSE:The spinal cord is subject to a periodic, cardiac-related movement, which is increased at the level of a cervical stenosis. Increased oscillations may exert mechanical stress on spinal cord tissue causing intramedullary damage. Motion analysis thus holds promise as a biomarker related to disease progression in degenerative cervical myelopathy. Our aim was characterization of the cervical spinal cord motion in patients with degenerative cervical myelopathy.MATERIALS AND METHODS:Phase-contrast MR imaging data were analyzed in 55 patients (37 men; mean age, 56.2 [SD,12.0] years; 36 multisegmental stenoses) and 18 controls (9 men, P = .368; mean age, 62.2 [SD, 6.5] years; P = .024). Parameters of interest included the displacement and motion pattern. Motion data were pooled on the segmental level for comparison between groups.RESULTS:In patients, mean craniocaudal oscillations were increased manifold at any level of a cervical stenosis (eg, C5 displacement: controls [n = 18], 0.54 [SD, 0.16] mm; patients [n = 29], monosegmental stenosis [n = 10], 1.86 [SD, 0.92] mm; P < .001) and even in segments remote from the level of the stenosis (eg, C2 displacement: controls [n = 18], 0.36 [SD, 0.09] mm; patients [n = 52]; stenosis: C3, n = 21; C4, n = 11; C5, n = 18; C6, n = 2; 0.85 [SD, 0.46] mm; P < .001). Motion at C2 differed with the distance to the next stenotic segment and the number of stenotic segments. The motion pattern in most patients showed continuous spinal cord motion throughout the cardiac cycle.CONCLUSIONS:Patients with degenerative cervical myelopathy show altered spinal cord motion with increased and ongoing oscillations at and also beyond the focal level of stenosis. Phase-contrast MR imaging has promise as a biomarker to reveal mechanical stress to the cord and may be applicable to predict disease progression and the impact of surgical interventions.

Degenerative changes of the cervical spine lead to cervical spinal stenosis, with consecutive spinal cord compression and degenerative cervical myelopathy (DCM), a common health burden in the elderly population.¹ The pathophysiology of DCM is attributed to immediate (ie, direct or static) cord compression, spinal malalignment leading to altered cord tension, impaired vascular supply, and repeat dynamic injury.^2-5 Dynamic spinal cord injury is often narrowed to segmental hypermobility; however, cardiac-related periodic cord motion may play a by far underestimated role in this pathophysiologic consideration. The cervical spinal cord is subject to physiologic craniocaudal motion supposedly due to cardiac pulse wave dynamics, which can be readily assessed by phase-contrast MR imaging (PCMR).^6,7 In a person with 70 heartbeats per minute, the spinal cord oscillates >100,000 times per day. In patients with DCM, increased spinal cord motion at the level of the cervical stenosis has been independently reported.^8-11 However, due to differences in analysis techniques applied,^8,10,11 results are not sufficiently comparable. Most interesting, increased spinal cord motion was associated with sensory deficits,^8,10 impaired electrophysiologic readouts,¹⁰ and decreased functional scores in patients with DCM.¹¹ While measurements of CSF flow have been shown to be less reliable and rather complex (ie, not easy to implement and run for clinical application) at the level of stenosis,¹¹ spinal cord motion appears to be a more feasible alternative.In summary, altered spinal cord motion provides a potential surrogate of spinal cord tissue distress, contributing to intramedullary damage even before it becomes clinically evident; therefore, it warrants further research to reveal mechanisms of cord damage in cervical spinal cord stenosis.We hypothesiszed the following: 1) The cord motion pattern during the cardiac cycle is altered in patients with DCM, and 2) due to elastic properties of the spinal cord and its surroundings, increased cord motion will extend to segments remote from the spinal stenosis.In axial PCMR, craniocaudal spinal cord motion within the cardiac cycle was tracked with an evaluation method established in healthy controls.⁶ In summary, cord displacement was measured 20 times during the cardiac cycle using a predefined ROI and corrected for the phase drift.     

Computerized tomography in the study of myelopathy in cervical spondylosis

This study involved 107 patients selected according to symptoms and signs of myelopathy due to cervical spondylosis. All patients were examined by high resolution CT without intravenous or intrathecal contrast enhancement. Diagnostic accuracy of CT is discussed with regard to idiopathic and degenerative cervical spinal stenosis. Emphasis is placed on CT findings of ossification of posterior longitudinal ligament. The authors conclude that plain CT may be a reliable method for diagnosing cervical spondylothic myelopathy. Nevertheless the authors stress how intrathecal contrast enhanced CT is far superior to plain CT in the selection of a definitive anterior or lateral surgical approach without a delay.     

Cervical myelography: survey of modes of practice and major complications

A total of 68 major complications of cervical myelography were reported by 220 neuroradiologists in a mail survey. Two-thirds of the complications were attributed to cervical spine hyperextension and one-third to lateral C1-2 puncture. Narrow sagittal diameter of the spinal canal and severe cervical spondylosis were frequent contributing factors to hyperextension injury of the cervical spinal cord. Clinical and radiographic premyelography screening is suggested, with magnetic resonance imaging performed first in patients with spinal canal stenosis, severe spondylosis, and/or myelopathy of any cause. Neck extension should be minimal during myelography. All C1-2 punctures should be monitored with lateral fluoroscopy for accurate needle positioning and prevention of contrast medium injection into the spinal cord.     

+Gz associated stenosis of the cervical spinal canal in fighter pilots

Previous magnetic resonance imaging (MRI) studies have shown that repeated exposure to +Gz forces can cause premature degenerative changes of the cervical spine (i.e. a work-related disease). This paper reports on two clinical cases of +Gz-associated degenerative cervical spinal stenosis caused by dorsal osteophytes in fighter pilots. Conventional x-rays and MRI were used to demonstrate narrowing of the cervical spinal canal. The first case was complicated by a C6-7 intervertebral disk prolapse and a congenitally narrow spinal canal. The second case involved progressive degenerative spinal stenosis in the C5-6 disk space which required surgery. The findings in this case were confirmed by surgery which showed posterior osteophytes and thickened ligaments compressing the cervical medulla. These two cases suggest that +Gz forces can cause degenerative spinal stenosis of the cervical spine. Flight safety may be jeopardized if symptoms and signs of medullar compression occur during high +Gz stress. It is recommended that student fighter pilots undergo conventional x-rays and MRI studies in order to screen out and reject candidates with a congenitally narrow spinal canal. These examination methods might be useful in fighter pilots' periodic medical check-ups in order to reveal acquired degenerative spinal stenosis.     

A rare cause of cervical spinal stenosis: posterior arch hypoplasia in a bipartite atlas

We describe CT and MRI of a previously unreported combination of atlantoaxial anomalies consisting of posterior arch hypoplasia in a bipartite atlas with an os odontoideum, in a 30-year-old woman presenting with neck and left arm pain. MRI showed the os odontoideum, marked stenosis of the spinal canal at the level of the atlas, with cord compression and evidence of myelopathy. CT revealed a bipartite atlas with midline clefts in anterior and posterior arches, thickening in the anterior arch and hypoplasia of the posterior arch with incurving of both hemiarches. Flexion and extension radiographs demonstrated atlantoaxial instability.     

无骨折脱位型颈髓损伤的手术治疗

目的探讨无骨折脱位型颈髓损伤的病理基础、手术方法的选择和治疗效果。方法对20例采用手术治疗的无骨折脱位型颈髓损伤患者进行回顾分析，并根据不同的特点采用不同的手术方式，观察近期疗效。结果20例无骨折脱位型颈髓损伤患者中，退变性椎管狭窄13例(65％)，节段性不稳6例(30％)。以颈椎间盘脱出为主要表现7例(35％)；存在各种原因所致的椎管储备间隙明显减少或消失的病理基础7例(35％)；在椎管储备间隙明显减少或消失的病理基础上，伴有节段性椎间不稳或椎间盘脱出6例(30％)。20例术后随访9～84个月，平均36．5个月。前路手术固定节段均获骨性融合，内固定物无松动，断裂；后路手术无再关门现象。术后MRI检查显示椎管容积扩大，颈髓受压缓解。3例术后脊髓功能无改善，其余患者均有不同程度恢复。结论颈椎椎管狭窄是无骨折脱位型颈髓损伤的重要病理基础；合理选择术式，手术操作正确，前、后路手术均能获得较理想的脊髓功能恢复效果。     

脊髓型颈椎病前路术后脊髓损伤的原因及防治对策

目的 探讨脊髓型颈椎病前路手术引起脊髓损伤的原因和防治策略.方法 分析2001年-2009年共749例实施前路减压融合手术的脊髓型颈椎病患者病历资料.共有5例患者在术后即刻或术后早期出现了脊髓功能下降.其中男3例,女2例;年龄48-62岁,平均52岁.2例合并有后纵韧带骨化.术前日本骨科学会(JOA)评分9-16分,平均12.4分.手术方式采用前路经颈椎间盘或椎体次全切除减压、自体髂骨或Cage融合、钛合金板内固定术.术中出血50～200 ml.2例患者术后即刻发现脊髓功能障碍加重,1例术后6 h出现下肢感觉运动消失,1例术后24 h出现一侧肢体瘫痪,1例术后5 d出现四肢麻木加重.4例患者早期给予大剂量甲基强的松龙冲击治疗.5例患者均再次行颈椎前路探查术,其中1例患者同时又行后路单开门椎管扩大成形术.结果 随访时间1～2年,平均16个月.4例患者脊髓功能(JOA评分)术后3个月均恢复或优于术前水平,术后1年均优于术前水平;1例患者术后1年神经功能仍无改善.分析脊髓损伤原因:术中减压和止血伤及脊髓2例,减压不彻底1例,血肿和止血纱布压迫各1例.结论 颈前路减压手术引起脊髓损伤的主要原因是术后延迟损伤,如果发现和处理及时,脊髓功能大多数可以恢复至术前水平.应尽量避免术中操作伤及脊髓,从而导致脊髓功能永久性障碍.

Abstract：

Objective To investigate the causes and prevention strategies of postoperative spinal cord injury after anterior approach surgery for cervical spondylotic myelopathy. Methods The clinical data of 749 patients with cervical spondylotic myelopathy treated with anterior approach surgery from 2001 to 2009 were retrospectively studied.There were five patients with spinal cord dysfunction instantly or early after operation,including three males and two females at average age of 52 years (range,48-62 years).Two patients were combined with ossification of the posterior longitudinal ligament.The Japanese Orthopaedic Association (JOA) score was average 12.4(9-16)preoperatively.The surgeries included anterior cervical diskectomy(or corpectomy)and interbody fusion(iliac bone graft or cage or titanium mesh)and locking plates fixation.The blood loss was 50-200 ml.The symptoms included instant spinal cord injury in two patients,loss of the motor and feeling of both legs at 6 h after surgery in one,paralysis of one side limbs at 24 h after surgery in one and numbness of limbs at 5 days after surgery in one.Four patients were treated by large dose of methylprednisolone.Five patients underwent anterior exploration surgery,of which one patient received posterior cervical one-door expansive laminoplasty. Results The patients were followed up for average 16 months(12-24 months).The JOA score of four patients was recovered at three months and WaS better than preoperation after surgery.The function of spinal cord of one patient showed no improvement at one year after surgery.The causes for spinal cord injury included inappropriate surgical manipulation in decompression and haemostasis in two patients,insufficient decompression in one,epidural hematoma in one and absorbable hemostatic gauze in one. Conclusions The major causes of postoperative spinal cord injury in anterior approach surgery for cervical spondylofic myelopathy are the delayed postoperative injury.The spinal cord can recover to normal and has satisfactory prognosis if discovered promptly.We must avoid the spinal cord injury by surgical Manipulation that may result in permanent neurological deficits.     

HASTE sequence and cine-MRI evaluation of the cervical spinal canal: evaluation in 11 healthy subjects

PURPOSE: We studied 11 healthy subjects were evaluated using cine MR imaging comparing HASTE and gradient echo sequences. Materials and methods :HASTE is a high-speed turbo-spin echo T2-weighted sequence. All examinations were performed using dynamic MRI using a simple process allowing acquisition of images at different stages during flexion and extension. The cine MR evaluation was obtained by rebuilding a cine-loop sequence. RESULTS: HASTE sequence provides a myelographic effect of the cervical spine. The size, the pattern and the movements of the cervical spine, the spinal cord, as well as the functional reserve of cerebro-spinal fluid are analysable. CONCLUSION: Because of its very high speed, HASTE sequence is particularly useful for cine MR imaging.