Is magnesium sulfate by the intrathecal route efficient and safe?

The polypharmacological approach to the treatment of postoperative pain has become routine in an attempt to minimize the adverse side effects of opioids. Magnesium sulphate is a noncompetitive antagonist of the N-methyl-d-aspartate (NMDA) receptor and thus can modify nociceptive modulation. Intravenous administration of magnesium sulphate can improve postoperative analgesia and decrease the requirement for postoperative opiates, but the effects are inconsistent and have not been reliably accompanied by a reduction in the incidence of morphine-related adverse events. Several studies have shown that the administration of magnesium by the intrathecal route is safe and, in combination with opiates, extends the effect of spinal anaesthesia in both animal and human studies. The analysis of these studies justifies further investigation of the use of magnesium sulphate by the intrathecal route.     

Does high-dose opioid anesthesia exacerbate ischemic spinal cord injury in rabbits?

Purpose  Intrathecal morphine given during a post-ischemic period has been reported to have the potential to exacerbate ischemic spinal cord injury. However, it remains unknown whether synthetic opioids administered systemically exacerbate ischemic injury. We sought to compare the damage of the spinal cord after transient spinal cord ischemia in rabbits anesthetized with three different regimens; isoflurane, fentanyl with isoflurane, and remifentanil with isoflurane. Methods  We assigned rabbits to three groups (n = 9 in each); an isoflurane group (isoflurane 1 minimum alveolar concentration [MAC]), a fentanyl group (isoflurane 0.5 MAC + 100 μg·kg⁻¹ IV fentanyl given over 30 min before aortic occlusion), and a remifentanil group (isoflurane 0.5 MAC + 1 μg·kg⁻¹·min⁻¹ IV remifentanil started 30 min before aortic occlusion and maintained until 1 h after reperfusion). Spinal cord ischemia was produced by occluding the abdominal aorta for 13 min. Hindlimb motor function (score range: 4, normal to 0, paraplegia) was assessed daily for 7 days, and then the number of normal neurons in the anterior spinal cord was counted. Results  Severe motor dysfunction (score ≤ 1) was observed in seven, four, and five animals in the isoflurane, fentanyl, and remifentanil groups, respectively. There were no significant intergroup differences in neurological scores. There were no differences in the numbers of normal neurons among the three groups (22 ± 22, 42 ± 30, 33 ± 28, respectively). Conclusion  Our results suggest that neither IV fentanyl nor IV remifentanil added to 0.5 MAC isoflurane exacerbated ischemic spinal cord injury in rabbits when compared to 1 MAC isoflurane.     

Is remote preconditioning as effective as direct ischemic preconditioning in preventing spinal cord ischemic injury?

BACKGROUND: Spinal cord injury remains a devastating complication of thoracic and thoracoabdominal aortic operations. The aim of this study was to assess the affectivity of direct ischemic preconditioning (PC) and remote PC in preventing spinal cord ischemic injury in an experimental model. MATERIALS AND METHODS: Thirty-eight New Zealand white rabbits were divided into five groups: One group served as Sham group (n = 7). Rabbits in other groups had their abdominal aorta cross-clamped for 40 min. Before aortic occlusion, aorta was clamped twice at the same site of aortic occlusion for 5 min followed by 15 min of reperfusion after each ischemic episode in one group (Direct PC, n = 8), left renal artery was clamped twice for 5 min followed by 15 min of reperfusion after each renal ischemic episode in one group (Remote PC, n = 8), left renal artery was first clamped for 5 min followed by 15 min of reperfusion and then aorta was clamped for 5 min followed by 15 min of reperfusion in one group (Remote + Direct PC, n = 8), and no PC method was used in Control group (n = 7). RESULTS: In all PC groups, neurological status of rabbits (Tarlov score) at post-ischemia 24th and 48th hours was better than the control group (P < 0.05), but worse than Sham group (P < 0.05). Mean viability index values in PC groups were higher than control group (P < 0.01). Post-ischemia serum NSE and MDA levels obtained in all three PC groups were significantly lower than control group (P < 0.05 and P < 0.01). CONCLUSIONS: The use of direct ischemic PC and/or remote PC is an effective way of reducing spinal cord ischemic injury because of aortic occlusion, while direct PC is more effective. The combined use of direct PC and remote PC did not provide better protection.     

Is early enteral feeding safe in patients who have suffered spinal cord injury?

OBJECTIVE: To examine whether enteral feeding is a safe technique to use in the acute stage of spinal cord injury. METHODS: We searched the departmental computerised patient database and clinical records for all patients with spinal cord injuries admitted to the Auckland Hospital Intensive Care Unit (ICU), known as the Department of Critical Care Medicine (DCCM), between January 1988 and December 2000. Patients were included in the study if they had suffered complete spinal cord transection resulting in either paraplegia or quadriplegia. Data was collected for the following variables: length of time to commence enteral feeding, type of enteral feeding, duration of enteral feeding and reasons for interrupting the feed. RESULTS: Thirty-three patients were found and were included in the study. Twenty-seven (82%) of the patients commenced enteral feeding in the DCCM, 25 by nasogastric (NG) and 2 by nasojejunal (NJ) tube. Feeding was commenced a median of 2 days after admission and the median length of enteral feeding was 7.7 days. The main feeding complications that resulted in interrupting the feed were high gastric aspirates. One patient commenced on enteral feeding developed medical complications that prevented continuation. Two patients on NG feeding converted to NJ feeding. CONCLUSION: No major complications associated with enteral feeding were seen in this study. This would indicate that enteral feeding can be safely administered in the acute stage of spinal cord injury provided complications are monitored for daily.     

Antioxidation of quercetin against spinal cord injury in rats

Objective : To observe the effect of quercetin on experimental spinal cord injury (SCI) in rats. Methods: Sixty Sprague-Dawley rats were randomly divided into four groups : Group A only for laminectomy, Group B for laminectomy with SCI, Group C for SCI and intraperitoneal injection with a bolus of 200 mg/kg quercetin and Group D for SCI and intraperitoneal injection of saline. SCI model was made by using modified Aliens method on T12. Six rats of each group were killed at 4 h after injury and the levels of free iron and malondialdehyde ( MDA) of the involved spinal cord segments were measured by bleomycin and thiobarbituric acid (TBA) assays separately. The recovery of hind limb function was assessed by Modified Tarlov 's scale and inclined plane method at 7 d,14 d and 21 d after SCI. The histological changes of the damaged spinal cord were also examined at 7 d after SCI. Results: After SCI, the levels of free iron and MDA were significantly increased in Groups B and D, while not in Group C. The Modified Tarlov 's score and the inclined plane angles were significantly decreased in Groups B, C and D. The histological findings were not improved. Conclusions: After SCI, quercetin can reduce the level of lipid peroxidation, but not improve recovery of function.     

Is carpal tunnel release under-utilized in veterans with spinal cord injury?

Objective

Carpal tunnel syndrome (CTS) is a common disorder among individuals with spinal cord injury (SCI). Although carpal tunnel release is highly effective, the procedure may be under-utilized in this population. This study attempts to identify if CTS is under-treated in Veterans with SCI.

Design

The Veterans Affairs (VA) National Patient Care Database was used for data compilation within fiscal years 2007 and 2008. Using ICD-9-CM diagnoses codes, individuals with SCIs were identified, including those diagnosed with CTS. Current procedural terminology (CPT) codes further showed those who had undergone surgical intervention including open and endoscopic release of the transverse carpal ligament. The VA SCI cohort was compared to the general VA population with regard to demographics, diagnosis, surgical intervention, and treatment location.

Results

A total of 19 296 veterans with SCI were identified within the 2-year period. The prevalence of CTS within this cohort was 3.5%, compared to 2.1% in the general VA population. The rate of transverse carpal ligament release was similar between the VA SCI cohort and general population (0.24 and 0.17%, respectively). The majority of surgical treatment (89%) occurred within the VA ‘hub-and-spoke’ system of SCI care.

Conclusion

CTS appears to be under-diagnosed and under-treated in veterans with SCI.     

Is carpal tunnel release under-utilized in veterans with spinal cord injury?

Abstract

Objective

Carpal tunnel syndrome (CTS) is a common disorder among individuals with spinal cord injury (SCI). Although carpal tunnel release is highly effective, the procedure may be under-utilized in this population. This study attempts to identify if CTS is under-treated in Veterans with SCI.

Design

The Veterans Affairs (VA) National Patient Care Database was used for data compilation within fiscal years 2007 and 2008. Using ICD-9-CM diagnoses codes, individuals with SCIs were identified, including those diagnosed with CTS. Current procedural terminology (CPT) codes further showed those who had undergone surgical intervention including open and endoscopic release of the transverse carpal ligament. The VA SCI cohort was compared to the general VA population with regard to demographics, diagnosis, surgical intervention, and treatment location.

Results

A total of 19 296 veterans with SCI were identified within the 2-year period. The prevalence of CTS within this cohort was 3.5%, compared to 2.1% in the general VA population. The rate of transverse carpal ligament release was similar between the VA SCI cohort and general population (0.24 and 0.17%, respectively). The majority of surgical treatment (89%) occurred within the VA ‘hub-and-spoke’ system of SCI care.

Conclusion

CTS appears to be under-diagnosed and under-treated in veterans with SCI.     

Sacral examination in spinal cord injury: Is it really needed?

Objective: To determine if a self-report measure of S4-5 motor and sensory function in patients with chronic SCI accurately predicts sacral examination results.

Design: Prospective, single-blinded self-report survey compared with sacral exam.

Setting: Outpatient SCI clinic.

Participants: 116 patients aged 18+ with chronic SCI > 6 months who have undergone sacral exam.

Interventions: The survey included demographic/clinical and sacral function information such as light tough (LT), pinprick sensation (PP), deep anal pressure (DAP) and voluntary anal contraction (VAC). Survey results and sacral exam were compared and stratified by the patient’s American Spinal Cord Injury Association Impairment Scale (AIS) category.

Outcome Measures: Sacral self-report survey, AIS examination.

Results: Mean age was 41.3?±?14.4 years with majority male (69%) and Caucasian (71.6%). Overall, Positive Predictive Value (PPV) ranged between 48% (VAC) to 73% (DAP) and Negative Predictive Value (NPV) between 92% (VAC) to 100% (LT). AIS-A had NPV of 100% across all categories, and AIS-D had PPV of 100% across all categories.

Conclusion: Patient report of sacral sparing can predict negative sensation in patients with AIS-A and predict positive sensation in persons with AIS-D. Overall, the self-report of sacral sparing of motor and sensory function is not predictive enough to rely on for accurate classification.     

Interferon-γ decreases chondroitin sulfate proteoglycan expression and enhances hindlimb function after spinal cord injury in mice

Glial cells, including astrocytes and macrophages/microglia, are thought to modulate pathological states following spinal cord injury (SCI). In the present study, we evaluated the therapeutic effects of interferon-γ (IFN-γ), which is one of the cytokines regulating glial function, in a mouse contusive SCI model. We found that intraperitoneal injection of IFN-γ significantly facilitated locomotor improvement following SCI. Immunohistochemistry demonstrated that IFN-γ decreased the accumulation of chondroitin sulfate proteoglycans (CSPGs), which are critical axon outgrowth inhibitors produced by reactive astrocytes in the injured central nervous system (CNS). Quantitative real-time polymerase chain reaction (RT-PCR) and Western blotting demonstrated that neurocan, one of several CSPGs, was reduced in the spinal cords of IFN-γ-treated mice compared to vehicle-treated mice. Consistently, IFN-γ inhibited the production of neurocan from activated astrocytes in vitro. In addition, IFN-γ treatment enhanced the number of serotonin-positive nerve fibers and myelinated nerve fibers around the lesion epicenter. We also found that glial cell line-derived neurotrophic factor (GDNF) and insulin-like growth factor-1 (IGF-1) were upregulated post-SCI following IFN-γ treatment. Our results indicate that IFN-γ exhibits therapeutic effects in mouse contusive SCI, presumably by reducing CSPG expression from reactive astrocytes and increasing the expression of neurotrophic factors.     

Does ischemic preconditioning reduce spinal cord injury because of descending thoracic aortic occlusion?

OBJECTIVE: Ischemic preconditioning has been found to protect various organs from a subsequent longer ischemic insult. We investigated whether the late phase of ischemic preconditioning reduces spinal cord injury from occlusion of the descending thoracic aorta. METHODS: Twenty-four pigs (27 to 30 kg) were randomly divided in four groups: group I (n = 4) underwent a sham operation, group II (n = 4) underwent aortic occlusion for 20 minutes, group III (n = 8) underwent aortic occlusion for 35 minutes, and group IV (n = 8) underwent aortic occlusion for 20 minutes and, 48 hours later, aortic occlusion for 35 minutes. Aortic occlusion was accomplished with two balloon occlusion catheters placed fluoroscopically at T(6) to T(8) above the diaphragm and at the aortic bifurcation. Neurologic evaluation was performed by an independent observer according to Tarlov's scale (0 to 4, with 4 as normal). The lower thoracic and lumbar spinal cords were harvested at 120 hours and examined histologically with hematoxylin and eosin stain. Histologic results (number of neurons and grade of inflammation) were scored 0 to 4 (4, intact spinal cord; 0, no neurons and high inflammation) and were similarly analyzed. Results were expressed as the mean +/- the standard error of the mean, and statistical analysis used the Kruskal-Wallis test. RESULTS: Group IV had a better neurologic outcome at 24, 48, and 120 hours in comparison with group III (P <.001), although 120 hours after the end of the experiment, the neurologic outcome in group IV was worse than at 24 hours (P =.014). The histologic changes were proportional to the neurologic test scores, with the more severe and extensive gray matter damage in the animals of group III (number of neurons, P <.001; and grade of inflammation, P <.001). CONCLUSION: Ischemic preconditioning (late phase, 48 hours after the first occlusion) reduces spinal cord injury after aortic occlusion, as estimated with Tarlov's score and histopathology.     

Renal scarring in spinal cord injury: a progressive process?

STUDY DESIGN: A retrospective analysis. OBJECTIVES: To examine the natural history of renal scarring in the spinal cord injured population.Setting:United Kingdom. METHODS: All spinal cord injured patients with renal scars at our establishment were considered eligible. A total of 27 patients with renal scars were identified. No patient had renal scarring at presentation on radiological imaging. All patients had annual renal imaging with a mean follow up period of 19.1 years. The presence of new scars was considered as evidence of progression. RESULTS: In all, 59% of kidneys developed renal scars with a mean time interval between spinal injury and renal scar development of 13 years. Of these kidneys with scars, only 15.6% demonstrated progression of the scarring process. There were no deaths due to renal causes. CONCLUSION: The aetiology of renal scarring is multifactorial. The findings of this study suggest that renal scarring in the spinal cord injured population is predominantly a nonprogressive process once a scar has developed. This is in concordance with the belief that renal scarring in the paediatric population with vesicoureteric reflux is also a stable, nonprogressive process.     

Prevalence of pre-existing factors causing spinal cord compression: Is there a difference between patients suffering from cervical spinal cord injury with and without bone injury?

BackgroundRecently, the prevalence of elderly patients suffering from cervical spinal cord injury (CSCI) without bone injury has been increasing in various countries. Pre-existing factors causing spinal cord compression, such as ossification of the posterior longitudinal ligament (OPLL), can increase the risk of CSCI without bone injury. However, no study has compared the prevalence of pre-existing factors between CSCI with and without bone injury. This study aimed to compare the prevalence of pre-existing factors between CSCI with and without bone injury.MethodsIn 168 consecutive patients with CSCI, pre-existing factors including OPLL, posterior spur of the vertebral body, developmental stenosis, disc bulge and calcification of yellow ligament (CYL) were evaluated on imaging studies. The prevalence of each type of pre-existing factors was compared between patients with and without bone injury.ResultsThe prevalence of pre-existing factors in patients without bone injury (86%) was significantly higher than in those with bone injury (20%) (P < 0.001; odds ratio, 23.9). The most common pre-existing factor was OPLL followed by developmental stenosis, posterior spur, disc bulge and CYL in both groups. OPLL, development stenosis and posterior spur were significantly more common in patients without bone injury compared to those with bone injury (P < 0.01).ConclusionsPrevalence of pre-existing factors, such as OPLL, development stenosis and posterior spur was significantly higher in patients without bone injury than in those with bone injury. Thus, these pre-existing factors might be a potential risk of CSCI without bone injury.     

Anorectal functions in patients with lumbosacral spinal cord injury

Objective: To investigate the anorectal status in patients with lumbosacral spinal cord injury (SCI). Methods: Twenty six patients (23 males, 3 females) with lumbosacral SCI and 13 normal volunteers were enrolled into this study as controls. The median age was 43.7 years (ranging 17-68 years) and the median time of patients since injury was 59.1 months (ranging 8 months-15 years). They were diagnosed as complete lumbosacral SCI (n=2, American Spinal Injury Association (ASIA) score A), or incomplete lumbosacral SCI (n =24, ASIA score B-D) with mixed symptoms of constipation and/or fecal incontinence, and were studied by anorectal manometry. None of the patients had any medical treatments for neurogenic bowel prior to this study. Results: The maximum anal resting pressure in lumbosacral SCI patients group was slightly lower than that in control group (One-way ANOVA: P =0.939). During defecatory maneuvers, 23 of 26 (88. 5%) patients with lumbosacral SCI and 1 of 13 (7.7%) in the control group showed pelvic floor dysfunction ( PFD) ( Fisher' s exact test: P<0.0001). Rectoanal inhibitory reflex (RAIR) was identified in both patients with lumbosacral SCI and the controls. The rectal volume for sustained relaxation of the anal sphincter tone in lumbosacral SCI patients group was significantly higher than that in the control group (Independent-Samples t test: P <0.0001). The mean rectal volume to generate the first sensation was 92.7 ml±57.1 ml in SCI patients, 41. 5 ml±13. 4 ml in the control group (Independent-Samples t test: P < 0.0001). Conclusions: Most of the patients with lumbosacral SCI show PFD during defecatory maneuvers and their rectal sensation functions are severely damaged. Some patients exhibit abnormal cough reflex. Anorectal manometry may be helpful to find the unidentified supraconal lesions. RAIR may be modulated by central nervous system (CNS).     

Semen parameters in men with spinal cord injury： changes and aetiology

Aim： To assess the changes in semen parameters in men with spinal cord injury （SCI） and the possible causes of these changes. Methods： The study included 45 subjects with SCI. Semen retrieval was done by masturbation （2）, vigorous prostatic massage （n = 13）, penile vibratory stimulation （n = 13） or electroejaculation （n = 17）. Results： The semen of men with SCI showed normal volume （2.3 ± 1.9 mL） and sperm count （85.0 × 10^6 ± 83.8 × 10^6/mE） with decreased motility （11.6% ± 10.1%）, vitality （18.5 % ± 15.2%） and normal forms （17.5 ± 13.4%）, and pus cells has been increased （6.0 × 10^6 ± 8.2 × 10^6/mL）. Total （13.4 ± 9.9 vs. 7.1 ± 6.8） and progressive （4.4 ± 3.9 vs. 2.2 ± 2.1） motility were significantly higher in subjects with lower scrotal temperatures. There was no statistical significant difference between electroejaculation and penile vibratory stimulation groups as regards any of the semen parameters. Subjects＇ age, infrequent ejaculation, injury duration and hormonal profile showed no significant effect on semen parameters. Conclusion： The defining characteristics of the seminogram in men with SCI are normal volume and count with decreased sperm motility, vitality and normal forms, and the increased number of pus cells. The most acceptable cause of the deterioration of semen is elevated scrotal temperature.