Sensorimotor cortical activity in patients with complete spinal cord injury: a functional magnetic resonance imaging study

Residual activation of the cortex was investigated in nine patients with complete spinal cord injury between T6 and L1 by functional magnetic resonance imaging (fMRI). Brain activations were recorded under four conditions: (1) a patient attempting to move his toes with flexion-extension, (2) a patient imagining the same movement, (3) passive proprio-somesthesic stimulation of the big toes without visual control, and (4) passive proprio-somesthesic stimulation of the big toes with visual control by the patient. Passive proprio-somesthesic stimulation of the toes generated activation posterior to the central sulcus in the three patients who also showed a somesthesic evoked potential response to somesthesic stimulation. When performed under visual control, activations were observed in two more patients. In all patients, activations were found in the cortical areas involved in motor control (i.e., primary sensorimotor cortex, premotor regions and supplementary motor area [SMA]) during attempts to move or mental imagery of these tasks. It is concluded that even several years after injury with some local cortical reorganization, activation of lower limb cortical networks can be generated either by the attempt to move, the mental evocation of the action, or the visual feedback of a passive proprio-somesthesic stimulation.     

Influence of motor complete spinal cord injury on visceral and subcutaneous adipose tissue measured by multi-axial magnetic resonance imaging

Objective

Abdominal obesity conveys substantial health risks, in association with high levels of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and an increased proportion of VAT to SAT. The purposes were to determine the influence of spinal cord injury (SCI) on the associations between single axial cross-sectional area (CSA) slices and the average CSA or volumes of VAT and SAT across multi-axial slices of magnetic resonance imaging (MRI); and the relationships relative to the whole body composition and anthropometrics.

Methods

Thirteen healthy male participants with traumatic motor complete SCI underwent fast spin-echo MRI to measure VAT and SAT across multi-axial slices, followed by dual-energy X-ray absorptiometry to measure whole body fat-free mass (FFM) and fat mass (FM). Waist circumference (WC) was also measured in the seated position.

Results

The trunk CSAs of VAT and SAT were 99 ± 51 and 164 ± 69 cm², respectively, and the ratio of VAT to SAT was 0.68 ± 0.33. The CSAs of VAT and SAT at a single slice strongly predicted the average CSA and modestly predicted the volumes across multi-axial slices. VAT and SAT represented 5.7 ± 1.8% and 9.7 ± 3.2% of the total body FM, respectively. Percent body FFM was negatively related to VAT and SAT volumes, but not to a single axial CSA.

Conclusion

A single slice CSA can modestly predict the volume of multi-axial slices in individuals with SCI, yet it is not related to any of the body composition variables. Increased percent FFM is associated with a reduction in VAT and SAT volumes measured across multi-axial slices. The ratio of VAT to SAT is greater than 0.4, suggesting that individuals with SCI are at high risk of developing metabolic sequelae.     

完全性颈脊髓损伤患者的手术时机选择

<正>创伤性脊髓损伤(traumatic spinal cord injury,t SCI)是一种严重的致残性疾病。通过手术对损伤节段进行减压和固定是治疗颈脊髓损伤的重要方式之一。早在一个世纪以前,Burrell就认为损伤程度和手术时机是影响脊髓损伤预后的两个关键点[1]。然而到目前为止,包括系统分析在内的诸多文献依然对包括完全性颈脊髓损伤在内的脊髓损伤手术时机选择存在争议[2、3]。     

Relationship between magnetic resonance imaging findings and spinal cord injury in extension injury of the cervical spine

Objective

The purpose of this study was to determine the relationship between magnetic resonance imaging (MRI) findings and neurologic symptoms in cervical spine extension injury and to analyze the MRI parameters associated with neurologic outcome.

Materials and methods

This study included 102 patients with cervical spine extension injury, whose medical records and MRI scans at the time of injury were available. Quantitative MRI parameters such as maximum spinal canal compression (MSCC), maximum cord compromise (MCC), and lesion length showing intramedullary signal changes were measured. Furthermore, intramedullary hemorrhage, spinal cord edema, and soft tissue damage were evaluated. Fisher’s exact test was used for a cross-analysis between the MRI findings and the three American Spinal Injury Association category groups depending on the severity level of neurologic injury: complete (category A), incomplete (categories B–D), and normal (category E).

Results

MSCC accounted for 23.05, 19.5, and 9.94 % for the complete, incomplete, and normal AIS categories, respectively, without showing statistically significant differences (P = 0.085). MCC was noted in 22.05, 15.32, and 9.2 %, respectively, with the complete-injury group (AIS category A) showing significantly higher. In particular, cases of complete injury had >15 % compression, accounting for 87.5 % (P < 0.001). The mean intramedullary lesion length was significantly higher in complete-injury patients than in incomplete-injury patients (24.22 vs. 8.24 mm). Intramedullary hemorrhage and spinal cord edema were significantly more frequently observed in complete-injury cases (P < 0.001). The incidence of complete injury was proportional to the severity of soft tissue damage.

Conclusion

MCC, intramedullary lesion length, intramedullary hemorrhage, and spinal cord edema were MRI parameters associated with poor neurologic outcomes in patients with cervical spine extension injury.

     

Shoulder magnetic resonance imaging findings in manual wheelchair users with spinal cord injury

Objective: To investigate the prevalence of rotator cuff and long head of the biceps pathologies in manual wheelchair (MWC) users with spinal cord injury (SCI).Design: Cross-sectional study.Setting: Outpatient clinic at a tertiary medical center.Participants: Forty-four adult MWC users with SCI (36 men and 8 women) with an average age (SD) of 42 (13) years. SCI levels ranged from C6 to L1; complete and incomplete SCI.Outcome Measures: Participants’ demographic and anthropometric information, presence of shoulder pain, Wheelchair User’s Pain Index (WUSPI) scores, and magnetic resonance imaging findings of shoulder pathologies including tendinopathy, tendon tears, and muscle atrophy.Results: Fifty-nine percent of the participants reported some shoulder pain. The prevalence of any tendinopathy across the rotator cuff and the long head of biceps tendon was 98%. The prevalence of tendinopathy in the supraspinatus was 86%, infraspinatus was 91%, subscapularis was 75%, and biceps was 57%. The majority of tendinopathies had mild or moderate severity. The prevalence of any tears was 68%. The prevalence of tendon tears in the supraspinatus was 48%, infraspinatus was 36%, subscapularis was 43%, and biceps was 12%. The majority of the tears were partial-thickness tears. Participants without tendon tears were significantly younger (P < 0.001) and had been wheelchair user for a significantly shorter time (P = 0.005) than those with tendon tears.Conclusion: Mild and moderate shoulder tendinopathy and partial-thickness tendon tears were highly prevalent in MWC users with SCI. Additionally, the findings of this study suggest that strategies for monitoring shoulder pathologies in this population should not be overly reliant on patient-reported pain, but perhaps more concerned with years of wheelchair use and age.     

Perfusion-weighted magnetic resonance imaging of the spinal cord in cervical spondylotic myelopathy

Principles of echo shifting with a train of observations was used to perform magnetic susceptibility-weighted magnetic resonance imaging with bolus-tracking in 14 patients with spondylotic myelopathy to assess changes in perfusion parameters of the spinal cord before and after decompression surgery for cervical spondylotic myelopathy. The mean transit time (MTT), bolus arrival time (T0), and time to peak (TTP) were obtained from regions of interest (ROIs) and assessed as the ratio between the spinal cord and the pons (MTT index = MTT(ROI)/MTT(pons), T0 index = T0(ROI)/T0(pons), TTP index = TTP(ROI)/TTP(pons)). The patients were divided into two groups according to percentage improvement on the Neurosurgical Cervical Spine Scale. The MTT index in patients with good recovery (> or =50%) was significantly reduced. The T0 index and TTP index showed no significant change in both groups. Reduction of MTT index may indicate improved perfusion of the spinal cord following surgery for cervical spondylotic 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.     

Longitudinal comparison of two severities of unilateral cervical spinal cord injury using magnetic resonance imaging in rats

Magnetic resonance imaging (MRI) should be a powerful tool for characterization of spinal cord pathology in animal models. We evaluated the utility of medium-field MRI for the longitudinal assessment of progression of spinal cord injury (SCI) in a rat model. Thirteen adult rats were subjected to a 6.25 or 25 g-cm unilateral cervical SCI, and underwent MRI and behavioral tests during a 3-week study period. MRI was also performed post-mortem. Quantification of cord swelling, hypointense and hyperintense signal, and lesion length were the most valuable parameters to determine and were highly correlated to behavioral and histopathological measures. Immediately after injury, MRI showed loss of gray matter-white matter differentiation, presence of scattered hyperintense signal and local hypointense signal, and cord swelling in both groups. At 7 days after injury, the spinal cord in the 25 g-cm group was significantly larger than that of the 6.25 g-cm group (p = 0.02). Contrast enhancement of the lesion was seen at 24 h in the 6.25 g-cm group, and at 24 h and 7 days in the 25 g-cm group. The volume of hypointense signal, representing hemorrhage, throughout the lesion region was significantly larger in the 25 g-cm compared to the 6.25 g-cm group at both 14 and 21 days after SCI (p, 相似文献   

脊髓型颈椎病患者颈脊髓磁共振扩散张量成像的特点及临床意义

目的 :观察脊髓型颈椎病(cervical spondylotic myelopathy,CSM)患者磁共振扩散张量成像(diffusion tensor imaging,DTI)的特点,探讨DTI在评价颈脊髓慢性损伤的价值。方法:纳入2011年2月~2015年2月间收治的20例CSM患者(CSM组),并选择年龄匹配的42例健康志愿者作为对照组,均行颈椎磁共振DTI,测量CSM组病变节段以及对照组C2/3~C6/7节段颈脊髓的表观弥散系数(apparent diffusion coefficient,ADC)、各向异性分数(fractional aniostropy,FA)。比较对照组不同节段颈脊髓的ADC值和FA值,将CSM组和对照组颈脊髓的ADC值和FA值分别进行比较,并对CSM患者颈脊髓ADC、FA评分和颈椎改良JOA(m JOA)评分分别进行相关性分析。结果:对照组颈脊髓的ADC值自C2/3~C6/7节段呈上升趋势,而FA值呈下降趋势,C2/3节段颈脊髓的ADC值较C5/6和C6/7节段明显低,而FA值明显高(ADC:F=3.546,P=0.008;FA:F=13.82,P0.001)。CSM组颈脊髓的FA值与对照组比较显著性减小(P0.001),而ADC值则显著性增加(P0.001)。CSM组颈脊髓的ADC值与m JOA评分无显著相关性(r=-0.287,P=0.220),而颈脊髓的FA值与m JOA评分存在显著性正相关(r=0.359,P=0.005)。结论:CSM患者颈脊髓DTI与正常人群存在差异,其ADC值较正常人群升高,而FA值则明显降低;m JOA评分与FA值呈正相关。     

Central spinal cord injury: magnetic resonance imaging confirmation and operative considerations

A case of central cervical spinal cord injury, confirmed by magnetic resonance imaging (MRI) and treated by myelotomy, is presented. After recovering well from his central cord syndrome and walking with assistance, the patient developed a rapidly progressive myelopathy beginning 2 months after injury. His main injury localized clinically to the C8, T1 level; but central cord abnormalities were identified 3 months after injury at the C6 level by MRI: a high signal intensity on the proton density sequence and a low-signal intensity on the T1-weighted sequence. At operation 41/2 months after his injury and 1 month after complete paraplegia, a myelotomy at C6 failed to reveal any cavity (syrinx) but instead disclosed only intense gliosis inside a slightly atrophic spinal cord. Rapid clinical improvement ensued. Secondary syringomyelia may be an endstage condition after spinal cord insults that trigger a progressive, pathophysiological reaction leading to central cord necrosis. In selected cases, myelotomy may interrupt this MRI-identified, nosogenic process before cavitation has occurred.     

High-resolution magnetic resonance imaging of experimental spinal cord injury in the rat.

The ability of magnetic resonance imaging (MRI) to display the anatomic changes after spinal cord injury in the rat were examined in postmortem specimens. With the clip compression technique, acute spinal cord injuries of three grades of severity were produced in adult male rats. One hour after injury, during which time physiological parameters were measured and maintained within the normal range, the rats were killed by transcardiac perfusion of formalin. The vertebral column containing the cervical and upper thoracic segments was excised and, after further formalin fixation, 20 contiguous MRI scans centered on the injury site were obtained using a spin-echo imaging sequence. The volume of signal acquisition for each image was 15 x 15 x 1.0 mm thick. The spinal cords were then removed from the vertebral column, sectioned, and stained for histological examination. Ten-micrometer serial sections of each cord were examined microscopically. MRI scans and microscopic sections at comparable levels were examined to determine the quality of anatomical detail and spatial resolution of the MRI scans. MRI scans with resolution of about 75 microns per pixel edge were obtained. At the site of injury, there was disruption of the normally well demarcated gray-white interface and variable areas of low signal intensity. Because of the resolution achieved, it was possible to determine that these low signal intensity areas were post-traumatic hemorrhages. Indeed, hemorrhages with dimensions of the order of 100 microns were detected on the MRI scans. Furthermore, by examining the serial sections of the cord, the extent of the injury along the cord could be determined.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tendon transfers in patients with cervical spinal cord injury

Between 1983 and 1988, 32 patients with cervical spinal cord injuries underwent 124 upper limb tendon transfers during 85 procedures. Of the numerous surgical procedures that have been recommended for treatment of this condition, my experience indicates that the most successful are posterior deltoid-to-triceps transfer, restoration of finger flexion, and restoration of thumb opposition. Longitudinal incisions prove to be quite cosmetic.     

Dysphagia in patients with acute cervical spinal cord injury

STUDY DESIGN: Longitudinal observational. OBJECTIVES: (a) To establish a reliable and feasible method to indicate the presence and severity of dysphagia and (b) to establish a course of treatment in individuals presenting with cervical spinal cord injury (CSCI). SETTING: Spinal Cord Injury Center, Werner Wicker Klinik, Bad Wildungen, Germany. PATIENTS AND METHODS: This is a cross-sectional study of 51 patients consecutively admitted to the Intensive Care Unit of the SCI in-patient service. They were subjected to neurological and fiberoptic endoscopic examination of swallowing (FEES). Data concerning artificial respiration, presence of tracheostomy, oral or non-oral feeding were obtained from the medical charts. Statistics were carried out by a calculation of a nonparametric correlation (Spearman). RESULTS: Five levels of dysphagia could be distinguished. At levels 1 and 2, patients presented with a severe impairment of swallowing, in level 3 aspiration was met by a powerful coughing reflex, level 4 comprised a laryngeal edema and/or a mild aspiration of fluids only and at level 5 laryngeal function was not compromised. On admission, 20 patients with CSCI presented with mild (level 4), eight with moderate (level 3) and 13 with severe dysphagia (levels 1 and 2). In 10 no signs of dysphagia could be detected. After treatment, level 1 was no longer detected, one patient showed level 2, two patients showed level 3, all other patients showed only mild or no signs of dysphagia any longer. CONCLUSIONS: Dysphagia of various severities was present in the majority of these patients with CSCI together with respiratory insufficiency. FEES allows for the detection and classification of dysphagia as well as for an evaluation of the therapeutic management. Under interdisciplinary treatment the prognosis of dysphagia is good.     

脊髓型颈椎病患者脊髓MRI T2WI高信号的危险因素

目的:探讨脊髓型颈椎病(CSM)患者脊髓MRI T2WI高信号的危险因素。方法 :2014年1月~2014年4月因CSM于我院骨科行手术治疗的185例患者被纳入研究。将脊髓MRI T2WI高信号分为3级:0级,无高信号;1级,T2WI有模糊而边界不清的高信号,且高信号范围局限于一个节段;2级,T2WI有明亮而边界清晰的高信号或高信号范围超过一个节段。在MRI T2WI横断位上测量脊髓压迫程度,在过伸、过屈位X线片上测量颈椎节段和整体活动度。对可能影响高信号的因素(性别、年龄、病程、术前mJOA评分、脊髓压迫程度、颈椎活动度、椎间盘退变程度)行单因素分析,挑选出有意义指标(P0.1)行有序Logistic回归分析。结果:脊髓MRI T2WI高信号的发生率为72.4%。按照分级标准,0级51例(27.6%),1级86例(46.5%),2级48例(25.9%)。性别和脊髓压迫程度对高信号的影响有统计学意义(女性相对于男性的OR=0.366,脊髓压迫比值的OR=0.904,P0.05),而年龄、病程、术前mJOA评分、椎间盘退变程度、颈椎活动度与高信号均无明显相关性(P0.05)。结论:男性、脊髓压迫程度重为CSM患者脊髓MRI T2WI高信号的独立危险因素。