无骨折脱位型急性颈脊髓损伤的MRI特点及意义

目的探讨无骨折脱位型急性颈脊髓损伤的MRI改变特点及其在脊髓损伤程度、预后及治疗中的作用。方法回顾性分析26例无骨折脱位型急性颈脊髓损伤的MRI和临床资料。结果无骨折脱位型急性颈脊髓损伤MRI绝大多数表现为脊髓水肿，急性期T1加权像等信号，T2加权像高信号。慢性期部分T1加权像局限性低信号，T2加权像局限性高信号。MRI T2加权像单节段脊髓水肿预后较双节段以上者好。结论无骨折脱位型急性颈脊髓损伤MRI信号改变及其范围能反映脊髓损伤程度，提示预后，指导治疗。     

MRI信号强度比值判断脊髓型颈椎病预后的意义

 目的 利用量化脊髓MRI信号强度的方法来探讨高信号对判断脊髓型颈椎病预后的意义。方法 2000年 2月至 2008年 2月行后路减压手术治疗且随访 2年以上的多节段脊髓型颈椎病患者 57例,所有患者术前均行高分辨率 1.5T MR扫描.如果患者 T₂加权像存在信号强度增加的区 II 则测量此区 II 信号强度值.同时于 T₁加权像测量与 T2加权像高信号区 II 处于相同节段的脊髓信号强度值.两者测量所取面积相近,操作均于 MR工作台进行。T₂加权像信号强度值与 T₁加权像信号强度值的比值作为研究的 T₂/T₁比值。无 T₂加权像高信号的患者归为无高信号组,T₂加权像高信号的患者以 T₂/T₁比值的中位数为分界点分为低 T₂/T₁比值组和高 T₂/T₁比值组。结果 无高信号组 20例;其他 37例均有T2加权像高信号(T₂/T₁比值范围为 1.28~2.80.中位数为 1.65),分为低 T₂/T₁比值组 19例(1.28≤T₂/T₁≤1.63)和高 T₂/T₁比值组 18例(1.67≤T₂/T₁≤2.80)。经方差分析三组在年龄、病程、术前 JOA评分、术后JOA评分及改善率等指标间差异均有统计学意义。 T₂/T₁比值与年龄、病程呈正相关.与术前、术后 JOA评分及改善率呈负相关。结论 有 T₂加权像高信号的患者其术前病情较重.手术治疗效果较差.并且随着信号强度的增加.这一趋势更加明显。 T₂加权像高信号可作为判断脊髓型颈椎病预后的一项指标。     

The Relationship between Spinal Stenosis and Neurological Outcome in Traumatic Cervical Spine Injury: An Analysis using Pavlov's Ratio, Spinal Cord Area, and Spinal Canal Area

Background

This study examined the relationship between four radiological parameters (Pavlov''s ratio, sagittal diameter, spinal cord area, and spinal canal area) in patients with a traumatic cervical spine injury, as well as the correlation between these parameters and the neurological outcome.

Methods

A total of 212 cervical spinal levels in 53 patients with a distractive-extension injury were examined. The following four parameters were measured: Pavlov''s ratio on the plain lateral radiographs, the sagittal diameter, the spinal cord area, and the spinal canal area on the MRI scans. The Pearson correlation coefficients between the parameters at each level and between the levels of each parameter were evaluated. The correlation between the radiological parameters and the spinal cord injury status classified into four categories, A (complete), B (incomplete), C (radiculopathy), and D (normal) was assessed.

Results

The mean Pavlov''s ratio, sagittal diameter, spinal cord area and spinal canal area was 0.84, 12.9 mm, 82.8 mm² and 236.8 mm², respectively. An examination of the correlation between the radiological spinal stenosis and clinical spinal cord injury revealed an increase in the values of the four radiological parameters from cohorts A to D. Pavlov''s ratio was the only parameter showing statistically significant correlation with the clinical status (p = 0.006).

Conclusions

There was a correlation between the underlying spinal stenosis and the development of neurological impairment after a traumatic cervical spine injury. In addition, it is believed that Pavlov''s ratio can be used to help determine and predict the neurological outcome.     

Effect of intramedullary signal changes on the surgical outcome of patients with cervical spondylotic myelopathy.

BACKGROUND CONTEXT: Intramedullary signal intensity changes on magnetic resonance imaging (MRI) in cervical spondylotic myelopathy are thought to be indicative of the prognosis. However, the prognostic significance of signal intensity changes remains controversial. PURPOSE: To determine the radiographic and clinical factors that correlate with the prognosis after surgery in patients with cervical spondylotic myelopathy and to investigate the factors affecting the outcome of intramedullary signal changes on MRI. STUDY DESIGN: A prospective study evaluating clinical parameters and MRI in consecutive patients operated on for cervical spondylotic myelopathy. PATIENT SAMPLE: A total of 146 consecutive patients with cervical spondylotic myelopathy operated on during a 2-year period (September 1999 to September 2001) formed the study group. OUTCOME MEASURES: Age, duration of symptoms, number of cervical prolapsed intervertebral discs, surgical approach, preoperative signal changes, residual compression and postoperative outcome of signal changes; clinical outcome (motor, sensory, autonomic and disability improvement). METHODS: The participants in this study underwent anterior cervical discectomy/corpectomy or laminectomy/laminoplasty for cervical spondylotic myelopathy. Clinical features and MRI findings were studied in detail and compared with postoperative clinical and radiological status. The spinal cord signal intensity changes were evaluated before and after surgery. The multifactorial effect of such variables as age, duration of symptoms, number of prolapsed intervertebral discs, surgical approach (anterior/posterior), preoperative cord changes on T1- and T2-weighted sequences and persistence/regression of cord changes on clinical outcome (motor/sensory/autonomic/disability improvement) was studied using stepwise logistic regression. The highlight of the study is the analysis of the factors affecting regression of cord changes and their effect on postoperative outcome. RESULTS: Preoperative intramedullary signal changes were present in 121 of 146 patients (82.9%); of these 121 patients, T1- and T2-weighted images were present in 81, and T2-weighted images were present in 40 (no patient had isolated T1 change). Postoperative MRI could be obtained in 44 of 121 patients (36.4%) with preoperative intramedullary signal changes; 14 had regression of cord changes. There was no significant difference in the clinical presentation of patients with and without cord changes. There was a significant correlation between the surgical outcome of patients and their age, duration of symptoms, number of cervical prolapsed intervertebral discs, surgical approach, preoperative signal changes, residual compression and postoperative outcome of signal changes. The patients with no intramedullary signal changes and signal changes only on T2-weighted images had a better outcome than patients with signal changes on both T1- and T2-weighted images. The patients with regression of intramedullary signal changes had significantly better outcome. There was no significant correlation between regression of signal changes and other factors. However, chronicity of disease, multiplicity of discs and postoperative residual compression relatively affect persistence of intramedullary signal changes. CONCLUSIONS: The presence of intramedullary signal changes on T1- as well as T2-weighted sequences on MRI in patients with cervical spondylotic myelopathy indicates a poor prognosis. However, the T2 signal intensity changes reflect a broad spectrum of spinal cord reparative potentials. Predictors of surgical outcomes are preoperative signal intensity change patterns of the spinal cord and their postoperative persistence/regression on radiological evaluations, age at the time of surgery, multiplicity of involvement and chronicity of the disease and surgical approach (anterior/posterior).     

中央脊髓综合征的手术治疗

背景：中央脊髓综合征是常见的不完全性颈脊髓损伤,目前关于其手术与非手术处理的利与弊仍是脊柱外科争论的焦点。目的：探讨中央脊髓综合征的手术治疗效果及预后。方法：回顾性分析2009年1月至2012年6月采用手术治疗的34例中央脊髓综合征患者的临床资料,男24例,女10例;年龄39~76岁,平均53.6岁;前路手术26例,后路手术8例。采用日本骨科协会（JOA）评分标准对患者神经功能进行评定,记录所有患者术前、术后6个月及末次随访的JOA评分,评估手术疗效并分析其预后情况。结果：34例患者全部获得随访,随访时间为6~23个月,平均（14.5±3.8）个月。术前JOA评分平均为（8.8±1.8）分,术后6个月提高至（13.9±2.1）分,末次随访为（14.6±1.5）分。术后6个月及末次随访时的评分改善率分别为（66.1±21.6）%和（73.6±15.2）%。术后1例发生脑脊液漏,1例发生硬膜外血肿,无一例发生椎动脉损伤、切口感染、内固定物失败等并发症。结论：手术解除椎管内的压迫是治疗中央脊髓综合征的有效方法。对于诊断明确的中央脊髓综合征,在全身情况允许的条件下,宜早期根据椎管内脊髓损伤的节段、压迫来源及程度等选择相应的手术方案,以改善脊髓内血供,减少脊髓继发性损害,促进神经功能的改善和恢复。     

颈椎后纵韧带骨化症的手术疗效分析

目的探讨不同术式治疗颈椎后纵韧带骨化症（ossification of posterior longitudinal ligament,OPLL）的疗效和MRIT2脊髓高信号（increased signal intensity．ISI）对预后的影响。方法分析132例因OPLL行手术治疗的病例．其中前路手术46例．后路手术59例,前后路联合手术27例。统计手术前后JOA评分及术后改善率,分析不同术式的疗效及MRIT2脊髓高信号对预后的影响。结果三组病例JOA评分均较术前明显提高,差异有统计学意义;前路组改善率为（74．95±9．83）％,后路组改善率为（69．90±9．56）％,前后路联合组改善率为（76．61±10．19）％,前路组和前后路联合组的改善率均优于后路组．差异有统计学意义;术前有ISI组改善率为（67．04±7．91）％,无ISI组改善率为（77．88±9．11）％,差异有统计学意义。结论a）三种术式均可获得较好的疗效,但前路手术和前后路联合手术的改善率优于后路手术;b）术前无MRIT2脊髓高信号者的预后相对较好。     

Prognostic relevance of the postoperative evolution of intramedullary spinal cord changes in signal intensity on magnetic resonance imaging after anterior decompression for cervical spondylotic myelopathy

OBJECT: Areas of intramedullary signal intensity changes (hypointensity on T1-weighted magnetic resonance [MR] images and hyperintensity on T2-weighted MR images) in patients with cervical spondylotic myelopathy (CSM) have been described by several investigators. The role of postoperative evolution of these alterations is still not well known. METHODS: A total of 47 patients underwent MR imaging before and at the end of the surgical procedure (intraoperative MR imaging [iMRI]) for cervical spine decompression and fusion using an anterior approach. Imaging was performed with a 1.5-tesla scanner integrated with the operative room (BrainSuite). Patients were followed clinically and evaluated using the Japanese Orthopaedic Association (JOA) and Nurick scales and also underwent MR imaging 3 and 6 months after surgery. RESULTS: Preoperative MR imaging showed an alteration (from the normal) of the intramedullary signal in 37 (78.7%) of 47 cases. In 23 cases, signal changes were altered on both T1- and T2-weighted images, and in 14 cases only on T2-weighted images. In 12 (52.2%) of the 23 cases, regression of hyperintensity on T2-weighted imaging was observed postoperatively. In 4 (17.4%) of these 23 cases, regression of hyperintensity was observed during the iMRI at the end of surgery. Residual compression on postoperative iMRI was not detected in any patients. A nonsignificant correlation was observed between postoperative expansion of the transverse diameter of the spinal cord at the level of maximal compression and the postoperative JOA score and Nurick grade. A statistically significant correlation was observed between the surgical result and the length of a patient's clinical history. A significant correlation was also observed according to the preoperative presence of intramedullary signal alteration. The best results were found in patients without spinal cord changes of signal, acceptable results were observed in the presence of changes on T2-weighted imaging only, and the worst results were observed in patients with spinal cord signal changes on both Tl- and T2-weighted imaging. Finally, a statistically significant correlation was observed between patients with postoperative spinal cord signal change regression and better outcomes. CONCLUSIONS: Intramedullary spinal cord changes in signal intensity in patients with CSM can be reversible (hyperintensity on T2-weighted imaging) or nonreversible (hypointensity on T1-weighted imaging). The regression of areas of hyperintensity on T2-weighted imaging is associated with a better prognosis, whereas the T1-weighted hypointensity is an expression of irreversible damage and, therefore, the worst prognosis. The preliminary experience with this patient series appears to exclude a relationship between the time of signal intensity recovery and outcome of CSM.     

Magnetic resonance imaging of diseased cervical and lumbar intervertebral discs

Magnetic resonance images (MRI) of diseased cervical and lumbar intervertebral discs involving both intrinsic and extrinsic cord lesions were examined using either a 0.15 T resistive or a 0.5 T superconductive magnetic imaging system. High resolution images were obtained by means of a surface coil in most cases. The vertebrae, intervertebral discs, and spinal cord were delineated in greatest detail on spin-echo (SE) images with a long repetition time (TR) and a short echo time (proton density-weighted image), on which the spinal cord was appreciated without overshadowing by the cerebrospinal fluid-filled subarachnoid space. Protrusion of degenerated intervertebral discs into the spinal canal was clearly demonstrated not only on sagittal but also on parasagittal and transverse views. The location of protruded discs and compression of the spinal cord, caudal sac, and nerve roots were well visualized three-dimensionally. Pathological features of intervertebral discs were better appreciated on T2-weighted images with long TR and SE pulse sequences. Degeneration of intervertebral discs resulted in decreased signal intensity in cases involving lumbar disc lesions but not those involving cervical disc lesions. In a case of suspected myelomalacia, the intrinsic cord lesion resulting from traumatic disc protrusion appeared as focal low signal intensity on T1-weighted images and as somewhat high intensity on T2-weighted images. The inversion recovery sequence with median inversion time displayed an inferior image of low contrast and was judged uninformative in comparison to SE images. The authors' observations demonstrate that MRI is an essential diagnostic technique for spinal cord disorders.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased signal intensity of the spinal cord on magnetic resonance images in cervical compressive myelopathy. Does it predict the outcome of conservative treatment?

STUDY DESIGN: Correlation between a lesion of the spinal cord that elicits increased signal intensity (ISI) on magnetic resonance images (MRIs) and the outcome of conservative treatment for cervical compressive myelopathy was retrospectively investigated. OBJECTIVE: To investigate whether ISI could predict the outcome of conservative treatment for cervical compressive myelopathy. SUMMARY OF BACKGROUND DATA: It is unknown whether ISI is related to the outcome of conservative treatment for cervical compressive myelopathy. METHODS: Fifty-two patients with mild cervical myelopathy underwent conservative treatment with a cervical brace. The compressive lesions were spondylosis in 29 patients, disc herniation in 12, and an ossification of the longitudinal ligament in 11. They also underwent MRI (1.5 T), and ISI was evaluated on T2-weighted sagittal and axial images. The ISI areas were classified as focal or multisegmental. Thirty-nine patients underwent follow-up MRI after a mean interval of 2 years, 4 months. The transverse area of the spinal cord was also measured on T2-weighted axial images. The outcome of conservative treatment was assessed using the Japanese Orthopedic Association Score (JOA score). Patients showing either an improvement in the JOA score or with a JOA score of 15 or more were considered to have a satisfactory outcome. RESULTS: The average JOA score was 14.0 +/- 1.4 (range, 10-16) before conservative treatment and 14.4 +/- 1.9 (range, 10-17) at follow-up. The average gain in the JOA score was 0.4 points +/- 1.9 (range, -5 to +6). The outcome was satisfactory in 36 patients (69%). An area of ISI was observed in 34 patients (65%) before treatment (24 focal and 10 multisegmental). A satisfactory outcome was obtained in 78% of the patients without ISI, in 63% of those with focal ISI, and in 70% of those with multisegmental ISI. No statistically significant difference was seen among these three groups in the percentages of patients with satisfactory outcome, JOA scores before and after treatment or transverse spinal cord area. Of the 39 patients who were re-examined by MRI, 28 showed an area of ISI. The ISI regressed in five patients (18%). Satisfactory outcome was obtained in all 5 patients with regression of ISI, in 16 (70%) of the 23 patients without regression of ISI, and in 10 (91%) of the 11 patients without ISI apparent on the the first images (difference, not significant). CONCLUSIONS: Increased signal intensity was not related to a poor outcome of conservative treatment or severity of myelopathy in the patients with mild cervical myelopathy.     

Prognostic value of changes in spinal cord signal intensity on magnetic resonance imaging in patients with cervical compressive myelopathy

Background contextSignal intensity on preoperative cervical magnetic resonance imaging (MRI) of the spinal cord has been shown to be a potential predictor of outcome of surgery for cervical compressive myelopathy. However, the prognostic value of such signal remains controversial. One reason for the controversy is the lack of proper quantitative methods to assess MRI signal intensity.PurposeTo quantify signal intensity and to correlate intramedullary signal changes on MRI T1- and T2-weighted images (WIs) with clinical outcome and prognosis.Study designRetrospective case study.Patient samplePatients (n=148; cervical spondylotic myelopathy, n=102 and ossified posterior longitudinal ligament, n=46) who underwent surgery for cervical compressive myelopathy and had high signal intensity change on sagittal T2-WI MRI before surgery between 2006 and 2010.Outcome measureNeurologic assessment was conducted with the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy. The rate of neurologic improvement was calculated with the use of preoperative and postoperative JOA scores.MethodsQuantitative analysis of MRI signal on both T1- and T2-WIs via use of the signal intensity ratio (SIR; signal intensity of lesion relative to that at C7-T1 disc level) was performed. Correlations between SIR on T1- and T2-WIs and preoperative JOA score, JOA improvement rate, disease duration, and MRI morphologic classification (cystic or diffuse type) were analyzed. Multivariate regression analysis for JOA improvement rate was also analyzed. In a substudy, 25 patients underwent follow-up MRI starting from 6 months after surgery to analyze the relationship between changes in SIR on follow-up MRI and clinical outcome.ResultsSIR on T1-WIs, but not SIR on T2-WIs, correlated with postoperative neurologic improvement. The disease duration correlated negatively with SIR on T1-WIs and JOA improvement rate but not with SIR on T2-WIs. SIR on T2-WIs of “cystic type” was significantly greater than of “diffuse type,” but SIR on T1-WI and JOA improvement rate were not different in the two types. Stepwise multivariate regression analysis indicated that SIR on T1-WIs and long disease duration were significant predictors of postoperative neurologic outcome. SIR on follow-up T1-WI and changes in SIR on T1-WI after surgery correlated positively with postoperative improvement rate. SIR on follow-up T2-WI and changes on T2-WI correlated negatively with postoperative neurologic improvement.ConclusionsOur results suggest that low intensity signal on preoperative T1-WIs but not T2-WIs correlated with poor postoperative neurologic outcome. Furthermore, decreased signal intensity on postoperative T1-WIs and increased signal intensity on postoperative T2-WIs are predictors of poor neurologic outcome.     

Ultra-early MRI showing no abnormality in a fall victim presenting with tetraparesis

STUDY DESIGN: Case report. SETTING: Department of Neurosurgery, Sapporo Azabu Neurosurgical Hospital and Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. CASE REPORT: A patient presented to us with complete C4 tetraplegia after a 3-m fall. MRI performed 120 min after his fall showed spinal canal stenosis due to disk protrusion at the C3/4 level without spinal cord signal changes on T1- and T2-weighted images. He underwent laminoplasty between C2 and C6. Intraoperative ultrasound, performed 6 h after his fall, disclosed a hyperechoic lesion at the C3/4 level of the cervical cord; postoperative T2-weighted MRI, obtained at 8 h after his fall, showed high intensity at the same level. CONCLUSION: In patients with cerebral infarction, approximately 6 h between the insult and the acquisition of T2-weighted MRI are required to detect signal changes. We postulate that the time course on MRI scans obtained immediately after spinal cord injury is similar in patients with spinal cord injury and cerebral infarction and suggest that the absence of spinal cord abnormalities in the ultra-early post-injury stage is not always predictive of a good prognosis.     

脊髓型颈椎病MRI信号改变与术后恢复的相关性分析

目的：探讨颈髓MRI高信号的存在能否作为脊髓型颈椎病（CSM）手术预后的预测指标。方法-53例CSM患者，男35例，女18例；病程6个月～7年，平均28．2个月。根据日本矫形外科学会（JOA）制定的脊髓功能评分标准对其手术前后疗效和MRI进行对比，观察脊髓内高信号与临床预后之间的关系。结果：所有患者均随访1～4年，平均2．5年。术前配加权存在高信号患者较正常信号患者往往病情重，术后恢复也不满意（P〈0．05）；少数单节段高信号患者可恢复良好，但多节段的高信号患者手术效果较差。结论：颈髓MRI高信号对CSM预后判断有重要意义。     

磁共振对脊髓型颈椎病前路减压及融合术后评价

目的：研究脊髓型颈椎病前路减压及融合术后的MRI表现与临床意义,评价术后MRI表现及其与术后疗效的关系。方法：回顾性分析58例脊髓型颈椎病患者对照术前与术后MRI图像与临床资料,观察颈椎磁共振影像表现与临床疗效间的关系。结果：前路减压术中植骨MRI信号强度根据手术时间由低逐渐向等信号转变,而纯钛钢板均为无信号影,术前仅表现出骨赘和椎间盘突出者其术后功能改善好,而术后功能不佳者术前MRI特征表现为脊髓T2WI高信号,融合平面与融合相邻椎间层面出现不同程度的脊髓受压。结论：MRI可根据信号变化反映前路植骨融合状况,并通过术后MRI不同表现为评价脊髓型颈椎病前路术后的功能变化提供了影像学基础。     

Factors associated with early onset post-traumatic syringomyelia

Study design:Retrospective study.Objectives:To identify factors associated with the development of early onset post-traumatic syringomyelia within 5 years of spinal cord injury.Setting:Department of Rehabilitation Medicine, Pusan National University School of Medicine, Korea.Methods:We retrospectively examined the records of 502 patients with traumatic cervical or thoracic spinal cord injury who underwent follow-up magnetic resonance imaging (MRI) examinations more than once a year for at least 5 years. Patients were assessed in terms of the neurological level of injury, the severity of initial spinal cord injury, the use of surgery and the extent of spinal canal involvement. The latter was evaluated by calculating the shortest antero-posterior diameter of the injured vertebral canal and the spinal reserve capacity as shown on MRI at the time of trauma onset and at the time of diagnosis of syringomyelia.Results:Syringomyelia developed within 5 years in 37 (7.3%) of the 502 patients. The mean age of these 37 patients was 44.6 years (range, 17-67 years) and the mean interval from spinal cord injury to onset of syringomyelia was 38.8 months (range, 2-54 months). The development of post-traumatic syringomyelia within 5 years was not significantly related to the severity or level of injury, the use of spinal surgery or the extent of spinal canal encroachment (P≥0.05 for each comparison).Conclusion:Early onset syringomyelia occurring within 5 years after spinal cord injury was not associated with neurological injury level, severity of injury, the use of spinal surgery or canal encroachment.     

Diffusion tensor imaging of the spinal cord and its clinical applications

The identification of the extent of neural damage in patients with acute or chronic spinal cord injury is imperative for the accurate prediction of neurological recovery. The changes in signal intensity shown on routine MRI sequences are of limited value for predicting functional outcome. Diffusion tensor imaging (DTI) is a novel radiological imaging technique which has the potential to identify intact nerve fibre tracts, and has been used to image the brain for a variety of conditions. DTI imaging of the spinal cord is currently only a research tool, but preliminary studies have shown that it holds considerable promise in predicting the severity of spinal cord injury. This paper briefly reviews our current knowledge of this technique.     

Surgical results and prognostic factors for thoracic myelopathy caused by ossification of ligamentum flavum: posterior surgery by laminectomy

Background

Thoracic ossification of ligamentum flavum (TOLF) of the spine is characterized by a heterotopic bone formation in the thoracic ligamentum flavum, which causes slowly progressing spinal cord injury. Surgical decompression is the most common treatment of choice for patients with compressive myelopathy due to TOLF. However, the surgical outcome is not always satisfactory.

Methods

To identify the predictors of surgical outcome, we retrospectively studied the associations between various clinical and radiological parameters and postoperative recovery in 78 patients who underwent decompressive laminectomy for thoracic myelopathy due to TOLF between October 1998 and June 2011. Surgical outcomes were assessed using modified Japanese Orthopedic Association (mJOA) recovery rate (RR)/outcome scores.

Results

At a minimum of 1 year after surgery for TOLF treatment, the postoperative clinical scores showed statistically significant changes with improvement in the JOA scores. The results indicated that a longer duration of preoperative symptoms, fused-type TOLF, and the degree of compression of the anteroposterior diameter and ossified region (middle thoracic OLF) was related to poor prognosis.

Conclusion

Early diagnosis and sufficient surgical decompression improved the functional outcomes of TOLF patients. The surgical risk is relatively higher due to the tenuous blood supply of the spinal cord and the limited spinal canal volume of the middle thoracic spine extending from T4 to T9.     

Do intramedullary spinal cord changes in signal intensity on MRI affect surgical opportunity and approach for cervical myelopathy due to ossification of the posterior longitudinal ligament?

Some controversy still exists over the optimal treatment time and the surgical approach for cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL). The aim of the current study was first to analyze the effect of intramedullary spinal cord changes in signal intensity (hyperintensity on T2-weighted imaging and hypointensity on T1-weighted imaging) on magnetic resonance imaging (MRI) on surgical opportunity and approach for cervical myelopathy due to OPLL. This was a prospective randomized controlled study. Fifty-six patients with cervical myelopathy due to OPLL were enrolled and assigned to either group A (receiving anterior decompression and fusion, n = 27) or group P (receiving posterior laminectomy, n = 29). All the patients were followed up for an average 20.3 months (12–34 months). The clinical outcomes were assessed by the average operative time, blood loss, Japanese Orthopedic Association (JOA) score, improvement rate (IR) and complication. To determine the relevant statistics, we made two factorial designs and regrouped the data of all patients to group H (with hyperintensity on MRI, n = 31), group L (with hypointensity on MRI, n = 19) and group N (no signal on MRI, n = 25), and then to further six subgroups as well: AH (with hyperintensity on MRI from group A, n = 15), PH (with hyperintensity on MRI from group P, n = 16), AL (with hypointensity on MRI from group A, n = 10), PL (with hypointensity on MRI from group P, n = 9), AN (no signal intensity on MRI from group A, n = 12) and PN (no signal intensity on MRI from group P, n = 13). Both hyperintensity on T2-weighted imaging and hypointensity on T1-weighted imaging had a close relationship with the JOA score and IR. The pre- and postoperative JOA score and postoperative IR of either group H or group L was significantly lower than that of group N (P < 0.05), regardless of whether the patients had received anterior or posterior surgery. On the other hand, both the JOA score and IR of subgroup AH were higher than those of subgroup PH at 1 week, 6 and 12 months postoperatively (P < 0.05), as well as between subgroup AL and PL; but in group N, there was no difference between the subgroup AN and PN (P > 0.05). In conclusion, regardless of hyperintensity on T2-weighted imaging or hypointensity on T1-weighted imaging in patients with OPLL, severe damage to the spinal cord is indicated. Surgical treatment should be provided before the advent of intramedullary spinal cord changes in signal intensity on MRI. The anterior approach is more effective than posterior approach for treating cervical myelopathy due to OPLL characterized by intramedullary spinal cord changes in signal intensity on MRI.     

后前路联合早期手术治疗合并颈椎管狭窄的颈髓损伤临床疗效分析

目的探讨早期后前路联合手术治疗合并颈椎管狭窄的颈髓损伤临床疗效。方法回顾性分析2003-05-2010-05收治的96例合并颈椎管狭窄的颈髓损伤病例,均早期行Ⅰ期后前路联合手术治疗。采用JOA评分进行术前和术后2周、3个月、12个月脊髓功能改善疗效评定,评价神经功能恢复情况。结果术后2周3、12个月神经功能改善率分别为(31.75±11.26)%、(60.67±14.20)%和(68.47±16.35)%,与术前相比,差异均有统计学意义(均P<0.05);但术后12个月与术后3个月相比,差异均无统计学意义(均P>0.05)。结论Ⅰ期后前路联合早期手术治疗合并颈椎管狭窄的颈髓损伤,能及时彻底的解除脊髓压迫,恢复颈椎稳定性,为脊髓功能的恢复提供有效保证,是安全有效的手术方式。     

前路根治性减压治疗严重颈椎后纵韧带骨化症

目的 报告前路后纵韧带根治性切除治疗椎管占位率＞50%的严重颈椎后纵韧带骨化症(OPLL)的手术疗效.方法 2002年7月至2006年2月,采用前路切除骨化韧带减压术治疗椎管占位率＞50%的严重OPLL患者26例.男性18例,女性8例;年龄43～73岁,平均59岁;骨化物形态均为基底开放型.术前骨化率50%～85%,平均(65±20)%;脊髓矢状径相对值(25±7)%;JOA评分(8.7±2.8)分.采用前路减压直接切除骨化物,行钛网或自体髂骨植骨,带锁钢板固定.26例患者中,行一个椎体次全切除+单节段椎间隙减压10例,2个椎体次全切除术3例,单节段椎体次全切除13例.所有患者均行脑诱发电位(ECP)监护,CT横断面测量骨化率,MRI T2 加权测量脊髓矢状径相对值;记录患者并发症、JOA评分,计算改善率.结果 26例患者均顺利实施前路手术,随访6个月至4年(平均2年8个月).术后骨化率平均(10±5)%,脊髓矢状径相对值(75±15)%,JOA评分(14.2±2.5)分,改善率(61±24)%.3例合并糖尿病患者出现短暂神经症状恶化,其中1例行二次血肿清除术,患者神经症状均在8周内恢复;2例出现脑脊液漏(包括1例合并糖尿病者),经保守治疗2周后痊愈;无内固定失败.结论 前路手术直接减压治疗严重OPLL,神经功能恢复更彻底,但对技术要求较高.     

Acute spinal cord injury. A study using physical examination and magnetic resonance imaging

Magnetic resonance imaging (MRI) was performed on 37 patients with acute spinal injury using T1- and T2-weighted images. Three different types of MRI signal patterns were detected in association with these spinal cord injuries. A classification was developed using these three patterns. Type I, seen in ten (27.0%) of the patients, demonstrated a decreased signal intensity consistent with acute intraspinal hemorrhage. Type II, seen in 16 (43.2%) of the patients, demonstrated a bright signal intensity consistent with acute cord edema. Type III, seen in three (8.1%) of the patients, demonstrated a mixed signal of hypointensity centrally and hyperintensity peripherally consistent with contusion. The remaining eight patients had normal cords by MRI. All 37 patients had an admitting neurologic assessment and classification of their spinal injury according to the Frankel classification and the Trauma Motor Index (TMI). At an average of 12.1 months postinjury, their neurologic function was reassessed. Patients with Type I patterns showed no improvement in their Frankel classification and minimal improvement in their TMI, 32.1 to 42.4. In comparison, all of the Type II and III patterns improved at least one Frankel classification. The Type II TMI increased from 70.8 to 91.9 and Type III from 37.3 to 75.7. This preliminary report indicates a distinct correlation between the pattern of spinal cord injury as identified by MRI and neurologic recovery. It appears that the ability of MRI to aid in examination of the condition of the spinal cord will offer a means of predicting neurologic recovery following acute spinal cord injury.