Acute Cord Injury Research Articles

Pathogen distribution and risk factors of pulmonary infection after acute cervical spinal cord injury

Objective To investigate the pathogen distribution and risk factors of pulmonary infection after acute cervical spinal cord injury(ACSCI)in an attempt to offer reference for early anti-infection therapy. Methods The study comprised 223 cases who were admitted from October 2011 to October 2014. There were 149 males and 74 females, at(43.3±13.5)years of age. Species of pathogens identified were gram-positive, gram-negative and mixed. Effects of age, gender, injury types and tracheotomy on pathogen distribution were analyzed. Results Gram-negative infection was found in 114 cases(51.1%), with tracheotomy accounting for 7.0% of the cases and death accounting for 1.8% of the cases, and the main causative pathogens were Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii. Gram-positive infection was found in 41 cases(18.4%), with tracheotomy accounting for 12.2% of the cases and death accounting for 7.3% of the cases, and the main causative pathogens were Staphylococcus aureus and Streptococcus pneumonia. Mixed infection was found in 68 cases(30.5%), with tracheotomy accounting for 22.1% of the cases and death accounting for 13.2% of the cases. Gender had no significant correlation with pathogen distribution. For the cases of complete spinal cord injury and tracheotomy, the ratio of mixed infection increased significantly(P<0.05). For the cases younger than 30 years, the pathogens were mainly gram-positive bacteria(P<0.05). Conclusions Main pathogens of pulmonary infection after ACSCI are gram-negative bacteria. The cases younger than 30 years are associated with higher risk of gram-positive infection, while the cases with complete injury or tracheotomy are associated with higher risk of mixed infection. Key words: Spinal cord injuries; Lung diseases; Pathogen

Value of susceptibility - weighted imaging in detecting in intramedullary hemorrhage in traumatic acute spinal cord injury

Objective To evaluate the clinical value of susceptibility- weighted imaging(SWI) in detecting intramedullary hemorrhage of traumatic acute spinal cord injury. Methods From October 2012 to December 2014, 37 TSCI (traumatic spinal cord injuries) patients undergone the MRI scans including routine MRI and SWI were enrolled. Further according to ASIA classification standard, all patients were evaluated as ASIA A (n=4), ASIA B (n=4), ASIA C (n=19) and ASIA D (n=10). Referring to axial T2WI images at the same slice, the manifestations of hemorrhage in amplitude image, phase image and SWI were evaluated. At the slice with maximal size of hemorrhage area and its neighboring slices, the hemorrhage regions were manually drawn; and the total area was automatically calculated. The number of hemorrhage lesions was defined as the number of hemorrhage lesions at single slice × slice number. One-way ANOVA was used to compare the differences among different grading ASIA in terms of hemorrhage area and number. Meanwhile, the relations between hemorrhage area and ASIA grade; hemorrhage number and ASIA grade were evaluated by Spearman rank correlation. Results The hemorrhage was detected by SWI in 15 patients, including 4 ASIA A, 4 ASIA B, 7 ASIA C. Hemorrhage represents as isointense in T1WI and a slightly low signal intensity or isointense in the center companied by high intensity at circus in T2WI. In magnitude image and SWI hemorrhage appears as low signal intensity and low signal intensity in the center companied by high intensity at circus in phase image. In detecting the hemorrhage, SWI (98 lesions were detected) was 5.4 times of T2WI (19 lesion were detected). As for the number of hemorrhage, significant differences were found among ASIA grading A, B and C (grading A: 22.5±1.3, grading B: 19.5±1.3, grading C: 4.0±1.1; F= 38.720, P<0.01); Further the pairwise comparison showed statistical significance (P<0.05); besides, the number of hemorrhage lesions closely related with the ASIA grade (r=0.864, P<0.01). For the hemorrhage area, the calculated results of grading ASIA A, B and C were (23.5 ± 0.6), (21.8 ± 1.9), (3.9 ± 0.7) mm2, respectively; there were significant differences among the different ASIA grades (F=29.987, P<0.001); furthermore the hemorrhage area also showed closely relation with the ASIA grade (r=0.778, P<0.01). Conclusions SWI is more sensitive in detecting the hemorrhage in traumatic acute spinal cord injury. The more number and area of bleeding area suggest the more severe of the damage level. Key words: Spinal cord injuries; Magnetic resonance imaging; Hemorrhage

Timing of Decompression in Patients with Acute Spinal Cord Injury: A Systematic Review

Introduction To perform an evidence synthesis of the literature assessing the comparative effectiveness, safety and cost effectiveness of early decompression (≤ 24 hours) versus later decompression (&gt;24 hours) in adults with acute traumatic spinal cord injury. Material and Methods A systematic search was conducted for literature published through November 6th, 2014. Included studies were critically appraised and GRADE methods were used to determine the overall strength of evidence. Based on clinical expert opinion, an improvement of two or more grades for Frankel or ASIA grades or 5 point improvement in ASIA Motor Score was considered a priori to represent clinically meaningful improvement. Results Six studies met inclusion criteria. All but one was considered to be a moderately high risk of bias. Single studies in cervical SCI, thoracolumbar SCI, cervical and thoracolumbar SCI, acute central cord injury without instability were identified, and two studies report across SCI levels. Due to the heterogeneity across studies (injury level, measures used, and clinical characteristics), pooling of data was not done. No studies of conservative management met inclusion criteria. No full economic studies or studies of patient preferences or values were identified. Across studies and injury levels, early surgical decompression, defined as surgery ≤ 24 hours of injury, was not consistently associated statistically with clinically important improvement in neurological status. (low to very low strength of evidence) Isolated studies reported statistically significant and clinically important improvement at 6 months for cervical injury and following discharge from inpatient rehabilitation but not at other time points in a population comprised of injury at any level; another study reported a statistically significant 6 point improvement in ASIA Improvement Score only among patients with AIS B, C, or D, but not for those with AIS A. (very low strength of evidence). In one study of acute traumatic cord injury without instability, a clinically and statistically meaningful improvement in total motor scores was seen at six months but not 12 months and there were no statistical differences in ASIA Impairment Scale up to 12 months. (very low strength of evidence) Only one of three studies found a shorter length of hospital stay associated with early surgical decompression. Safety and harms were reported in only three studies; although no statistical differences between early and late decompression were seen, including for mortality, neurologic deterioration, pneumonia or pressure ulcers, studies were underpowered to detect differences particularly for rare outcomes. Conclusion The overall strength (quality) of evidence across studies was low to very low that early decompression may lead to clinically important improvement in neurologic status in some instances. For studies considering cervical SCI alone and thoracolumbar SCI alone, the overall quality (strength) of evidence was low. For studies involving a combination of cervical, thoracic and lumbar SCI the strength of the same conclusion was very low. Although no statistical or clinically significant differences were noted between early and late groups, firm conclusions regarding the safety of early versus delayed surgical decompression are difficult given small sample sizes and rare events.

Acute traumatic cord injury associated with ossified ligamentum flavum

Ossification of the ligamentum flavum (OLF) is an uncommon condition, which usually occurs amongst people of Asian descent, and most commonly in the thoracic spine region. Whilst often asymptomatic, OLF can cause spinal canal stenosis, with patients presenting with back pain, posterior cord syndrome or myelopathy. We present a rare case of acute spinal cord injury associated with OLF after a kite surfing accident, with the resulting paraplegia partially improved after decompression was performed. The prevalence, presentation and management of OLF are also discussed.

Application of individualized nutritional support in patients with acute complete cervical spinal cord injury

Objective To explore the clinical effects of individualized nutritional support on patients with acute complete cervical spinal cord injury. Methods The patients with acute complete cervical spinal cord injury in the Trauma Emergency Center of a hospital between January 2011 and December 2012 were randomly divided into experimental group (n=49) and control group (n=54). The diets of patients in the control group were provided by family members guided by nurses in hospital, and the patients in the experimental group were given individualized nutritional supports which were formulated by nutrition consultation according to patients′ specific conditions. The incidence of complications (constipation, lung infection, hyponatremia and hypoproteinemia) within 14d and the average stay in hospital in two groups were compared. Results In the experimental group, the incidence of constipation, lung infection, hyponatremia and hypoproteinemia were significantly lower and the average stay in hospital was shorter than those in the control group. The differences between the two groups were statistically significant (P<0.05). Conclusions Providing individualized nutritional support for patients with acute complete cervical spinal cord injury can reduce the incidence of complications and the average stay in hospital. Key words: Cervical spinal cord injury; Nutritional support; Complication

Risk factors of deep vein thrombosis in patients with acute traumatic spinal cord injury

Objective To investigate the incidence and risk factors of deep vein thrombosis (DVT) in a cohort of Chinese patients with traumatic spinal cord injury (TSCI) , and in addition, to evaluate the effect of injury types and concomitant injuries of other parts of body. Method Records of 143 casualties admitted to our institute for TSCI were analyzed retrospectively. Both lower extremities of all casualties were examined routinely with color Doppler ultrasonography (CDUS) before major surgical treatment. None of these casualties received any thromboprophylaxis before CDUS. Logistic regression was used to analyze risk factors of DVT. Results Of the 143 patients, 32.2% (n=46) suffered from DVT (proximal n=15, distal n=31). All casualties were diagnosed within one week after injury (mean 3.35±1.65 days). Risk factors associated with DVT induced complete motor paralysis (odds ratio [OR]5.05, 95% CI 1.70-14.90) , concomitant fracture of lower extremities (OR 4.30, 95% CI 1.34-17.64) , and lumbar vertebra injury (OR 4.29. 95% CI 1.50-10.83). Conclusions Clinically detectable DVT in TSCI are not uncommon in the Chinese population. Casualties with multiple risk factors may be benefited from early administration of thromboprophylaxis. Key words: Trauma; Spinal cord injury; Deep vein thrombosis; Risk factors

Prognostic factors for surgical outcome in spinal cord injury associated with ossification of the posterior longitudinal ligament (OPLL).

BackgroundOssification of the posterior longitudinal ligament (OPLL) may increase the risk of spinal cord injury (SCI) with various neurological deficits after minor trauma. However, few studies have investigated the influence of OPLL on neurological outcome after acute cord injury. We examined whether severe spinal canal stenosis caused by OPLL affects neurological outcome after SCI based on intramedullary signal intensity (SI) changes on magnetic resonance imaging (MRI).MethodsFrom June 2006 to July 2013, we treated 246 patients with cervical cord injury. Fifty-one (20.7 %) patients had ventral cord compression due to OPLL without any bony fractures. Among them, 38 patients (34 men, mean age 62.7 years) underwent cervical laminoplasty (8) and cervical decompression and fixation (30). The neurologic assessments were performed in patients who had 1-year follow-up, and the mean follow-up period was 42.2 months. OPLL type, cause of injury, cervical sagittal angle, cervical spine stenosis, cord compression ratio (space available for the spinal cord (SAC)), and grade of intramedullary SI (grade 0, none; grade 1, light; grade 2, intense T2WI) were assessed.ResultsMean American Spinal Injury Association (ASIA) motor score at admission was 38.4 ± 21.9 (range, 2–70) and improved to 67.7 ± 19.1 (range, 8–94) at last follow-up (p < 0.05). Mean recovery rate of the motor score was 55.8 ± 19.9 %. Five patients had SI grade 0, 20 patients had SI grade 1, and 13 patients had SI grade 2. Among the variables tested, age, initial ASIA motor grade, intramedullary SI grade, and SAC were significantly related to neurological outcome. However, initial cervical alignment, canal diameter, length of SI, time interval between injury and operation, and OPLL type had no significant effect on neurological outcome.ConclusionsPreoperative neurological status, cord compression ratio, and SI grade are related to neurological outcome in patients with SCI associated with OPLL. The better the preoperative neurological status, the more favorable the neurological outcome after surgery. A higher SI grade on preoperative T2WI was negatively related to neurological outcome. Therefore, the severity of SI change, cord compression ratio, and preoperative neurological status can be regarded as significant prognostic factors in patients with SCI associated with OPLL.

Neuron regeneration after spinal cord injury in rats

Objective To observe the neuronal regeneration after spinal cord injury in adult rats. Methods Thirty-six adult Wistar rats were randomly divided into normal control group (n=6) and spinal cord injury group (n=30). Allen's weight-drop method (25 g/cm) was adopted to produce acute spinal cord injury at T10 segment. Rats were sacrificed at 3 days and 1, 2, 3, and 4 weeks postinjury. BrdU was administered intraperitoneally to the rats 72 hours before operation, once per 12 hours. Double immunofluorescence staining of NF-200 and BrdU was performed at spinal sites within 10 mm away from the injury to detect the positive cells in both groups. Results A few BrdU-positive cells were founded in the normal control group, with no BrdU/NF-200 positive cells. In spinal cord injury group, BrdU-positive cells were abundant at day 3 and peaked at week 1 along with few Brdu/NF-200 positive cells; Brdu/NF-200 positive cells showed a peak increase at week 2 with majority accumulated at area 3-5 mm away from the injury, were rare at week 3 and none at week 4. Conclusion Neuronal regeneration is detected in the vicinity of the injury, which provides new ideas for induction of endogenous stem cells to treat spinal cord injury. Key words: Spinal cord injuries; Neurons; Stem cells; Rats

Effect of the shenxiong glucose injection on the recovery of neural function and the expression of AQP-4 in rats after spinal cord injury

Objective To explore the action mechanism of shenxiong glucose injection in treatment of acute spinal cord injury(SCI) through observing its effects on the recovery of motor function and the expression of aquaporin-4(AQP-4) in SCI rats.Methods Totally 90 healthy,aduh,Sprague-Dawley rats were randomly divided into a sham operation group (n=30),aSCI group (n=30) and a drug group (n=30).The SCI rat models in both the SCI group and the drup group were established aecording to the modified Allen's method,while the sham operation group was only given laminectomy.After the operation,the drug group was given intraperitoneal shenxiong glucose injection of 30 rnl/kg a day,while the other two groups were injected in the same way with normal saline.The neural function recovery,the pathological changes after SCI and the expressions of AQP-4 were observed 1,3,7,14 and 21 d after the operation using the Tarlov score,the hematoxylin and eosin staining,as well as immunofluorescence techniques and Western blotting.And the correlation of Tarlov scores with AQP-4 expressions was analyzed.Results No significant changes in Tarlov scores were observed in the sham operation group (P ＞ 0.05),while in the SCI group and the drug group,postoperative Tarlov scores decreased significantly.The hindlimb nerve function recovered to some degree with time in the SCI group and drug group.At 3,7,14 and 21 days after the operation,the Tarlov scores in the drug group were significantly higher than the SCI group (P ＜ 0.05).The drug group showed less severe pathological changes,with more residual neurons still visible of nucleoli than the SCI group 21 days after the operation.Compared with the sham operation group,the expression levels of AQP-4 were significantly higher in the SCI group and drug group at all the time points (P ＜ 0.05).However,the expression levels of AQP-4 in the drug group were significantly lower than the SCI group accordingly (P ＜ 0.05).The Tarlov scores were found to be significantly and negatively related to the AQP-4 protein expression levels 3 days(r =-0.523,P =0.003),7 days(r =-0.437,P=0.016),14 days(r=-0.417,P=0.022) and 21 days(r=-0.377,P=0.040)after the operation.Conclusion Injecting shenxiong with glucose can effectively promote the recovery of motor function after SCI,at least in rats.And its mechanism may be that the development of spinal cord edema is prevented and the secondary spinal cord injury alleviated by restraining the expressions of AQ P-4 in the injured areas. Key words: Shenxiong glucose injection; Spinal cord injury; AQP-4; Tarlov score

Establishment of minimally acute spinal cord injury in mice model by the self-made device

Objective Try to construct the self-made spinal impactor and the simple interspinous process distraction stabilizing device.Discussion on the feasibility,stability and reliability of method establishing the acute spinal cord injury in mice model retaining the lamina.Methods Using a electric push fool,a pressure sensor and so on,to manufacture the spinal inpactor and the interspinous process distraction stabilizing device.32 adult female rats were randomly divided into four groups,using the self-made spinal impactor device to make varying degrees on the spinal cord of the mice model retaining the lamina,non-combat (0 g),mild (5 g),medium (10 g),and severe (20 g).Taking two mice from every group randomly and making pathological section of damage zone spinal cord after 12 h,testing the behavior BBB grade post operation 1,3 d,7,14 w,in order to evaluate its correlation with the strike force.Results The spinal impactor device and the interspinous process distraction stabilizing device was producted successfully,and the minimally invasive spinal cord injury model retaining the lamina was built.Pathological examination and behavioral score was related with the strike force closely and the grade differences was obvious (P ＜ 0.05).Conclusion A a stable and reliable spinal cord injury model retaining the lamina can be made by the self-made device,and this conducive to the further research on spinal cord injury. Key words: Self-made device; Minimally invasive; Spinal cord injury; Mice model

The micro-vascular morphological changes of the rat spinal cord after injury by Absorb-contrast imaging of synchrotron radiation

Objective Using the synchrotron radiation-based micro-computed tomography (SRμCT) to observe the changes of three-dimensional micro-vascular morphology structure after acute spinal cord injury in rat.Methods Eight male Sprague-Dawley rats were randomly divided into control group and injury group (n =4).Injury group were deal with improved Allen' s weight dropping to establish the acute spinal cord injury model.All rats were deal with ascending aorta angiography in the next day.Freezing the specimens for 24 hours and then scanned them in Shanghai Institute of Applied Physics,Chinese Academy of Sciences.Processed and reconstructed the Data to three-dimensional images.Results The SRμCT can show the micro-vascular structure of spinal cord in rat completely and clearly.Combining with control group,we can see the lack and fracture of the micro-vessels of spinal cord in injury group significantly.The number and diameter of the micro-vessels were decreased obviously.The average number of vascular in injury group was 77.25 ± 16.80,and the control group was 168.30 ± 12.79 ; The average diameter of vascular in injury group was (16.270 ± 1.201) μm,but the control group was (20.210 ± 1.094) μm.Significant differences were existed between control group and injury group (P ＜ 0.05).Conclusion The SRμCT can get the three-dimensional and high resolution imaging of micro-vessels in small animal' s spinal cord.The micro-circulation network structure of spinal cord was prominently destroyed after acute spinal cord injury.The blood circulation of spinal cord in injury areas and its vicinity was serious damaged. Key words: Synchrotron radiation; Spinal cord injury ; Micro-vessels ; Morphology

Intramedullary Signal Intensity and Other Prognostic Factors for Surgical Outcome in Spinal Cord Injury Associated With Ossification of the Posterior Longitudinal Ligament (OPLL)

Ossification of the posterior longitudinal ligament (OPLL) might cause stenotic changes in the spinal canal and lead to cervical myelopathy. Also, it may increase the risk of spinal cord injury (SCI) with various neurological deficits after minor trauma. However, there are only a few reports that discuss the influence of OPLL on the neurological outcome after acute cord injury. We have tried to find out whether severe spinal canal stenosis caused by OPLL affects neurological outcome after SCI without any bony fractures or intramedullary signal intensity (SI) changes on MRI to evaluate critical prognostic factors for SCI associated with OPLL.

Effect of ginkgo biloba extract on neuron apoptosis after acute spinal cord injury in a rat model

Objective To observe the effect of ginkgo biloba extract (EGb761) on neuron apoptosis and motor functional recovery after spinal cord injury(SCI) and the possible underlying mechanisms.Methods Sixty SD female rats were randomly divided into 3 equal groups (n =20):sham-operation,Allen impact SCI and EGb761-treatmrnt.Egb761-treated group received intraperitoneal injection of 100 mg/kg EGb761 per day; the other 2 groups were given normal saline of the same amount at the same time.After Basso Beattie Bresnahan (BBB) assessment and footprint analysis of the hind limb were performed on days 1,3,7 and 14 post-injury in each group,the animals were sacrificed to extract the spinal cord for HE staining.Apoptosis of nerve cells was observed by immunohistochemistry using TdT-mediated dUTP nick end labeling (TUNEL) and 3,3 '-diaminobenzidine tetrahydrochloride(DAB).Results In the sham-operation group,no influence on the BBB scores or footprint analysis of the hind limb was observed.There was no significant difference in ethology assessments on days l,3 and 7 between the SCI and EGb761 groups,but on the 14th day after surgery,the BBB score was significantly higher,the step length was significantly longer,and the step width was significantly smaller in the EGb761 group than in the SCI group (P ＜ 0.05).On days 1,3,7 and 14,there were significantly more TUNEL-positive and Caspase-3 protein-positive cells in the SCI and EGb761 groups than in the sham-operation group (P ＜ 0.05) ; on days 3 and 7 after surgery,the TUNEL-positive and Caspase-3 protein-positive cells in the EGb761 group were significantly fewer than in the SCI group (P ＜0.05).Conclusions EGb761 has a positive protective effect on nervous injury after SCI.This protective effect may be realized by down-regulating the expression of Caspase-3 protein,inhibiting cellula nervosa (especially glial cells) apoptosis at injured and surrounding portions in the myeloid tissue. Key words: Spinal cord injury; Apoptosis; Ginkgo biloba extract

Role of new K(+) channel blocker 4-AP-3-MeOH in acute spinal cord compression injury in rats

To evaluate the effects of 4-aminopyridine-3-methyl hydroxide (4-AP-3-MeOH) in rat's acute spinal cord injury. A total of 12 adult male SD rats (250-300 g) were randomly divided into treatment (n = 6) and control (n = 6) groups. After compressing segment T11 of spinal cord for 30 min, the injured segment received 1 ml 4-AP-3-MeOH (100 µmol/ml) by topically application in treatment group while the control group received 1 ml saline.Somatosensory evoked potential (SSEP) was detected in both groups at pre-injury, 30 min post-injury and post-dosing. Then Luxol fast blue (LFB) staining of target spinal segment was performed. In treatment group, the values of SSEP at pre-injury, 30 min post-injury and post-dosing were 1.26 ± 0.35, 0.03 ± 0.05 and 0.45 ± 0.19 µv respectively. Comparing SSEP of 30 min post-injury with post-dosing, the difference was statistically significant (P < 0.01).While in control group, the values of SSEP at pre-injury, 30 min post-injury and post-dosing were 1.05 ± 0.39, 0.01 ± 0.02 and 0.02 ± 0.02 µv respectively. Comparing SSEP of 30 min post-injury with post-dosing, there was no statistical difference (P > 0.05). After 30 min injury, there were swelling and bleeding of spinal cord.LFB staining showed that both gray and white matter had swelling and bleeding and central canal was destroyed with varying degrees of demyelination. After 30 min of acute spinal cord injury, there are bleeding of gray and white matter with varying degrees of demyelination. Topical usage of K(+) blocker 4-AP-3-MeOH can effectively improve the conduction of SSEP after acute spinal cord injury in rats.

Effect of asiatic acid on oxidative stress after acute spinal cord injury in rats

Objective To observe the effect of asiatic aicd treatment on acute spinal cord injury in rats.Methods Forty-five SD rats were randomly divided into a sham-operation group,model control group and asiatic acid treatment group.Functional outcome measurements were evaluated by the Basso,Beattie and Bresnahan (BBB) score at 24,48 and 72 h.The sections were stained with hematoxylin and eosin for morphological and histopathological analyses.The reactive oxidative species and inflammatory factor were detected.Results The BBB score was significantly higher in the asiatic acid treatment group (6.70 ± 1.09 and 9.58 ±2.81) than in the model control group (3.05 ±0.98 and 4.55 ±0.65) at 48 h and 72 h (P ＜ 0.05).Compared to the model control,HE staining showed the histopathological performance was improved greatly in rat spinal cord in asiatic acid treatment group.At the three time points,tissue malondialdehyde (MDA) content in asiatic acid treatment group [(6.42 ± 0.15),(6.17 ± 0.25) and (5.48 ± 0.33) nmol/ml] was statistically significantly lower than in the model group [(7.55 ±0.37),(7.61 ± 0.24) and (6.59 ±0.22) nmol/ml].The superoxide dismutase (SOD) activity in the asiatic acid treatment group [(220.55 ±3.76),(231.44 ±4.88) and (235.98 ±5.26) U/mg] was higher than in the model group [(180.31 ±4.68,175.32 ±3.45 and 170.51 ±3.44) U/mg] at the three time points.After injury,tissue myeloperoxidase (MPO) and IL contents were increased,and showed a significant difference between the model control group and asiatic acid treatment group at the three time points.Conclusion The present study suggests that asiatic acid exerts neuroprotection by reducing oxidative stress. Key words: Asiatic acid; Spinal cord injury; Oxidative stress

A modified goat model of acute spinal cord compression injury from a percutaneous balloon catheter: method feasibility and preliminary observation

To establish a goat model of acute spinal cord compression injury through a modified percutaneous technique with a Foley double-lumen urine catheter and explore the method feasibility and preliminary observation. Twelve adult male Chongming goats were randomly divided into 3 groups:control (A, n = 4), 0.5 ml compression (B, n = 4) and 1 ml compression (C, n = 4). After local anesthesia, all animals received epidural balloon catheter (5Fr) insertion via a percutaneous trans-lumbosacral interlaminar space technique that mimicked the method used in vascular access for angiography. The balloon catheter was advanced under fluoroscopic guidance until its distal tip reached the middle of T6 level.One week later, for groups B and C, the balloon was inflated by half-strength contrast material, 0.5 ml and 1 ml, respectively. The balloon was left inflated for 30 min and then deflated. The images of computed tomography (CT) and magnetic resonance (MR) were taken before and after surgical procedures.Quantitative assessment of spine canal occupying rate was accomplished by an off-line software program based on CT results. Motor function was assessed by the modified Tarlov scale. Two animals of each group were sacrificed after a total observation period of 48 h and 72 h respectively.Spinal cords from the injured level were then obtained for pathologic examinations. All animals underwent successful catheterization occupying 6.8%±0.7% (Group A), 6.7%±0.7% (Group B) and 6.6%±0.6% (Group C) of spine canal respectively. After inflation, the occupying rate of groups B and C achieved 43.4%±2.5% and 88.1%±2.3% respectively.Ventral compression of spinal cord was noted on MR images.Hindlimb movement remained normal after catheter insertion in all groups. All animals in group B and C became paraplegic after inflation. And a positive correlation existed between injection volume and Tarlov score. Pathological findings confirmed neuron atrophy, increased gap around neurons, mild demyelination and vacuolar degeneration both in groups B and C at 48 h after injury. Pathological changes deteriorated at 72 h after injury. The results of behavioral evaluation, radiographic images and pathological examination reveal an evidence of acute spinal cord injury. Percutaneous epidural balloon catheter insertion differs from previous techniques by avoiding surgical exposure and associated artifacts, yet it offers injury mechanisms similar to those of human spinal cord injury. As a new means of modeling spinal cord injury in animals, this technique has many potential applications.

Effect of L-serine on apoptosis of nerve cells and proliferation of endogenous neural stem cells in rats after spinal cord injury

Objective To observe the role of L-serine (L-Ser) in neuronal apoptosis and proliferation of endogenous neural stem cells in rats after spinal cord injury (SCI).Methods A total of 100normal adult SD rats were randomly divided into 5 even groups (n =20) to receive different operations and treatments:sham operation group (only the vertebral lamina was excided without SCI),only SCI group (intraperitoneal injection of only physiological saline was performed after SCI modeling),L-serine treatment group (intraperitoneal injection of L-Ser after SCI modeling),D-cycloserine (DCS) treatment group (intraperitoneal injection of DCS after SCI modeling),and DCS antagonism group (intraperitoneal injection of DCS plus L-Ser after SCI modeling).In the tihboard tests,the angle of slope and the Basso,Beattie,Bresnahan (BBB) locomotor rating score were observed and recorded for each rat in the 3 groups on days 1,3,5and 7.The sample of spinal cord 5 mm from the center of damaged region received Nissle staining; in situ end labeling (TUNEL) was used to detect apoptosis and immunofluorescence to measure the expressions of double-labeled positive cells of Brdu/Nestin in each group.Results Three days postoperation,the angle of slope and BBB score in the L-serine treatment group were significantly higher than those in the only SCI group,DCS treatment group and DCS antagonism group (P ＜ 0.05).The angle of slope tended to increase with days of treatment.The Brdu positive cells,Nestin positive cells and Brdu/Nestin double labeled cells were significantly more in the L-serine treatment group than in the only SCI group,DCS treatment group and DCS antagonism group while TUNEL-positive cells in the injured spinal cord parenchyma decreased significantly as compared to the other 3 groups (P ＜0.05).There were no significant differences between the only SCI group,DCS treatment group and DCS antagonism group regarding the angle of slope,BBB score,Brdu positive cells,Nestin positive cells or Brdu/Nestin double labeled cells (P ＞ 0.05).Conclusion L-serine can inhibit neuronal apoptosis and promote the proliferation of endogenous neural stem cells after acute spinal cord injury in rats. Key words: Apoptosis; Cell proliferation; Spinal cord injuries; Serine; Endogenous neural stem cells

Effect of brain-derived neurotrophic factor-genetically modified adipose derived mesenchymal stem cells on acute spinal cord injury in rats

Objective To investigate the applied value of brain-derived neurotrophic factor (BDNF)-transfected adipose-derived stem cells (ADSCs) hy lentivirus in spinal transplantation.Methods Rat ADSCs were isolated and cultured in vitro under sterile conditions.Then they were transfected with GDNF by high titer lentivirus.Thirty-six SD rats were randomly divided into 3 groups,respectively treated with ADSCs transfected with GDNF by lentivirus (A),ADSCs (B),normal saline (C).Basso-Beattie-Bresnahan (BBB) score,immunofluorescence stain,and the expression levels of BDNF,nerve growth factor (NGF) and glial fibrillary acidic protein (GFAP) were observed.Results On the postoperative week (POW) 3 and 4,the BBB scores in group A were (15.02 ± 1.25) and (17.43 ± 1.05) points,obviously higher than in group B (10.35 ±2.25) and (13.44 ± 1.83) points and group C (5.88 ±2.46) and (6.94 ± 3.22) points.The immunofluorescence stain revealed that the transplanted ADSCs migrated to the injury site.On POW 3,the BDNF,NGF and GFAP expression levels in group A were (38.70 ± 2.75),(35.62 ± 2.74) and (13.17 ± 3.09) cells/HP,significantly different from those in group B (28.80 ±2.05),(24.99 ± 3.58) and (21.83 ± 5.99) cells/HP and group C (24.60 ± 2.44),(20.33 ± 2.25)and (27.10 ±6.47) cells/HP.Conclusion After transplantation of ADSCs in rats with spinal cord injury,the expression of BDNF and NGF was increased,and that of GFAP was suppressed,which was promoted by the modification of BDNF.Maybe it is one of the mechanisms of promoting restoration of injured spinal cord and improving motor function. Key words: Brain derived neural growth factor; Adipose derived mesenchymal stem cell; Acute spinal cord injury

Can diffusion tensor imaging predict outcome in acute traumatic deterioration of degenerative cervical spine disease

IntroductionPatients with degenerative diseases of cervical spine are likely to develop acute cord injury following trivial trauma. However many of them can have a poor functional outcome. Routine MRI may not be helpful in accurately predicting the recovery in these cases. DTI of spinal cord is a promising tool in prognostication of various neurological diseases. Materials and methodA prospective study was done to know the use of DTI in predicting outcome in acute deterioration of degenerative cervical spine disease. Cases presenting within 48 h of acute traumatic deterioration were included in the study. A screening MRI was done to know the extent of disease and cord damage. Using DTI, apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated at the level of injury. 3D tractography was done using Label map seeding technique. Clinical correlation was done with ASIA and FIM scores. ResultsFive cases of cervical cord injury with a mean age of 46 ± 11 years were studied. The diffusion parameters were compared with three age matched controls. The cases were followed up prospectively. All the cases had a decrease in ADC values and increase in FA at the level of injury compared to other levels (p = 0.02) and to normal controls (p = 0.001). It was extending beyond the level of cord contusion identified by routine MRI. DiscussionDTI is well suited for evaluating effects of spinal cord injury like cellular swelling and myelin membrane disruption which is not diagnosed using conventional MRI. ADC helps us to define the type and extent of spinal cord injury. 3D tractography delineates the fiber disruption. ConclusionADC is a sensitive marker of acute cervical cord injury, in degenerative spine disease.3D tractography can help us to select the cases for early surgical intervention and to predict clinical outcome.

Effect of early hyperbaric oxygen therapy on the expression of inducible nitric oxide synthase in acute spinal cord injury and it＇s therapeutic implications

Objective To explore inducible nitric oxide synthase (iNOS) activity expression in the early stages of hyperbaric oxygen (HBO) therapy for acute spinal cord injury (SCI) and its therapeutic potential.Methods Seventy rats were randomly divided into a treatment group (including four sub-groups) and a control group (including three sub-groups).Acute SCI was induced at Ts-T9 in both groups using the modified Allen method.The four subgroups of the treatment group were treated with HBO at 2,4,6 and 8 hours after the injury,respectively.After 7 HBO therapy sessions,combined behavioral scores (CBSs) and evoked potentials were used to assessthe rats＇ limb function.Diazo colorimetric determination was used to detect iNOS expression and the nitrate reductase method was used to determine the content of nitric oxide.Results Compared with the control group and the other treatment subgroups,the 8 hour group recovered motor function the best.iNOS expression and NO production were reduced,and the differences were statistically significant.Conclusion HBO administered 8 hours after acute spinal cord injury had the best effect in reducing synthesis of iNOS and promoting motor function recovery. Key words: Hyperbaric oxygen; Spinal cord injury; Inducible nitric oxide synthase; Nitric oxide