Thermoregulation during exercise in individuals with spinal cord injuries

The increased participation in wheelchair sports in conjunction with environmental challenges posed by the most recent Paralympic venues has stimulated interest into the study of thermoregulation of wheelchair users. This area is particularly pertinent for the spinal cord injured as there is a loss of vasomotor and sudomotor effectors below the level of spinal lesion. Studies within this area have examined a range of environmental conditions, exercise modes and subject populations. During exercise in cool conditions (15-25 degrees C), trained paraplegic individuals (thoracic or lumbar spinal lesions) appear to be at no greater risk of thermal injury than trained able-bodied individuals, although greater heat storage for a given metabolic rate is evident. In warm conditions (25-40 degrees C), trained subjects again demonstrate similar core temperature responses to the able-bodied for a given relative exercise load but elicit increased heat storage within the lower body and reduced whole-body sweat rates, increasing the risk of heat injury. The few studies examining a wide range of lesion levels have noted that, for paraplegic individuals where heat production is matched by available sweating capacity, excessive heat strain may be offset. Studies relating to tetraplegic subjects (cervical spinal lesions) are fewer in number but have consistently shown this population to elicit much faster rates of core and skin temperature increase and thermal imbalance in both cool and warm conditions than paraplegic individuals. These responses are due to the complete absence or severely reduced sweating capacity in tetraplegic subjects. During continuous exercise protocols, the main thermal stressor for tetraplegic subjects appears to be environmental heat gain, whereas during an intermittent-type exercise protocol it appears to be metabolic heat production. Fluid losses during exercise and heat retention during passive recovery from exercise are related to lesion level. Future research is recommended to focus on the specific role of absolute and relative metabolic rates, sweating responses, training status and more sport- and vocation-specific exercise protocols.     

Temperature responses to electrically induced cycling in spinal cord injured persons

PURPOSE: The purpose of the study was to investigate the core temperature responses to the induction of electrical exercise and to clarify whether an increase in temperature could be responsible for some of the observed reactions to acute and repeated exposure to electrical muscle stimulation. METHODS: The paralyzed thigh and gluteal muscles were stimulated electrically with surface electrodes in seven persons with transection of the spinal cord. By this means, they were able to pedal a lower extremity ergometer at 50 revolutions per minute for 30 min. Skin surface, esophageal (Tes), rectal (Tre), and muscle temperature in m. quadriceps were measured with thermocouples. RESULTS: The average rate of oxygen consumption was 0.91 +/- 0.16 L.min-1, and the heart rate after 20 min was 123 +/- 9 bpm during the electrically induced exercise. The involuntary, induced exercise led to increases in core temperature, whereas skin surface temperature was the same before and after exercise. Average Tes and Tre both rose 0.7 degrees C from, respectively, 36.6 +/- 0.2 and 36.9 +/- 0.1 degrees C, and muscle temperature increased even more: 2.9 degrees C from 33.9 +/- 0.3 degrees C. CONCLUSION: It is suggested that these increased temperatures may act as stimuli, directly or, through resulting release of humoral factors, and elicit the changes in heart rate, as well as the previously observed adaptive changes after electrically induced exercise, e.g., in muscle fiber size, and capillarization.     

组织工程脊髓修复脊髓损伤的研究进展

脊髓损伤可以导致损伤平面以下神经功能的破坏性丢失,严重地影响身体多个系统.脊髓损伤的效应随着损伤部位不同而不同,这是脊神经有序地按照脊髓排列的缘故.除了损伤平面以下运动功能受损,同时还伴有感觉异常.其造成的功能缺陷包括心血管系统功能、呼吸系统功能、胃肠道消化功能、排汗功能、性功能以及排尿功能,这些缺陷可继发泌尿系感染、褥疮、肌肉痉挛、慢性神经性疼痛和感觉异常等,更严重的可致命.因此,脊髓损伤成为人类急需解决的医学难题之一,至今仍困扰着无数医学工作者。     

Alternative foot placements for individuals with spinal cord injuries standing with the assistance of functional neuromuscular stimulation

This study investigated the effects of altering foot placement for two individuals with spinal cord injuries (SCI) that stood using functional neuromuscular stimulation (FNS) as compared to an able-bodied subject group. FNS-assisted standers used parallel bars as needed for support, while the able-bodied group stood hands-free. Three different foot placements were tested: side-by-side, wide, and modified tandem. For SCI subjects, the percentage of body weight loaded on the feet was not greatly affected by foot placement, which potentially could be altered to provide postural benefits during functional tasks. Anterior/posterior (A/P) center of pressure (COP) origins tended to be located more anterior in the base of support for SCI subjects as compared to able-bodied subjects. SCI subjects also tended to have medial/lateral (M/L) COP excursions that were larger than able-bodied subjects. The sacrum appeared to hold some promise as a sensor location for monitoring A/P postural sway, but movements in the M/L direction were inconsistent and will require additional study. General guidelines such as positioning the A/P COP more posterior in the base of support and feedback concerning excessive M/L COP displacements may be useful to improve standing performance for SCI subjects. In addition, the modified tandem placement was an effective alternative for making postural adjustments in one SCI subject who experienced excessive right knee flexion with other foot placements.     

Exercise recommendations for individuals with spinal cord injury

Persons with spinal cord injury (SCI) exhibit deficits in volitional motor control and sensation that limit not only the performance of daily tasks but also the overall activity level of these persons. This population has been characterised as extremely sedentary with an increased incidence of secondary complications including diabetes mellitus, hypertension and atherogenic lipid profiles. As the daily lifestyle of the average person with SCI is without adequate stress for conditioning purposes, structured exercise activities must be added to the regular schedule if the individual is to reduce the likelihood of secondary complications and/or to enhance their physical capacity. The acute exercise responses and the capacity for exercise conditioning are directly related to the level and completeness of the spinal lesion. Appropriate exercise testing and training of persons with SCI should be based on the individual's exercise capacity as determined by accurate assessment of the spinal lesion. The standard means of classification of SCI is by application of the International Standards for Classification of Spinal Cord Injury, written by the Neurological Standards Committee of the American Spinal Injury Association. Individuals with complete spinal injuries at or above the fourth thoracic level generally exhibit dramatically diminished cardiac acceleration with maximal heart rates less than 130 beats/min. The work capacity of these persons will be limited by reductions in cardiac output and circulation to the exercising musculature. Persons with complete spinal lesions below the T(10) level will generally display injuries to the lower motor neurons within the lower extremities and, therefore, will not retain the capacity for neuromuscular activation by means of electrical stimulation. Persons with paraplegia also exhibit reduced exercise capacity and increased heart rate responses (compared with the non-disabled), which have been associated with circulatory limitations within the paralysed tissues. The recommendations for endurance and strength training in persons with SCI do not vary dramatically from the advice offered to the general population. Systems of functional electrical stimulation activate muscular contractions within the paralysed muscles of some persons with SCI. Coordinated patterns of stimulation allows purposeful exercise movements including recumbent cycling, rowing and upright ambulation. Exercise activity in persons with SCI is not without risks, with increased risks related to systemic dysfunction following the spinal injury. These individuals may exhibit an autonomic dysreflexia, significantly reduced bone density below the spinal lesion, joint contractures and/or thermal dysregulation. Persons with SCI can benefit greatly by participation in exercise activities, but those benefits can be enhanced and the relative risks may be reduced with accurate classification of the spinal injury.     

Cervical spinal cord injuries in patients with cervical spondylosis

Eighty-eight patients over age 40 with traumatic cervical spinal cord injuries were clinically and radiographically evaluated, and comparison was made with 35 spinal cord injury patients under age 36. While most older patients sustained obvious bony and/or ligamentous damage commensurate with their neurologic findings, 25 (28%) of the 88 patients had no demonstrable bony abnormalities and 17 (20%) of the 88 patients had only minimal evidence of bony injury. Of particular interest are the patients with severe cord injuries, yet no bony abnormalities, who seem to form a distinct subgroup of the cervical spinal cord injury patient on the basis of radiographic and clinical features. Of these 25 patients, 24 (96%) had severe cervical spondylosis. Fourteen (56%) of the 25 patients were injured in falls, five (36%) of these 14 being of a seemingly trivial nature. Of the 42 patients with minimal or no demonstrable bony abnormalities, 33 (79%) were evaluated with plain tomography and no occult fractures or other significant pathology was demonstrated. Pantopaque myelography in 27 (64%) of the 42 cases revealed no extruded disk or other surgical lesion in any patient. In large measure, these injuries can be attributed to cervical spondylosis, which narrows the canal and makes the cord more susceptible to compression by the bulging ligamenta flava during hyperextension.     

多发伤中脊柱脊髓损伤的治疗对策

目的探讨多发伤中脊柱脊髓损伤早期治疗的意义. 方法回顾我院1998年6月-2003年6月间急诊收治的多发伤伴脊柱脊髓损伤患者116例,其中男97例,女19例;年龄15～69岁,平均38.5岁.损伤严重度评分(ISS)10～51分,平均18.5分.应用伤害控制骨科学观念和VIP 程序救治,对符合条件的脊柱脊髓损伤患者早期采用大剂量甲基强的松龙冲击治疗,病情相对稳定后早期行手术减压和内固定78例,其中前路手术30例,后路手术37例,前后联合入路11例. 结果116例中,生存113例;死亡3例,ISS均≥30分;随访3～48个月,平均24个月.随访时感觉和运动美国脊柱脊髓损伤学会(ASIA)评分较伤后明显改善,无神经功能恶化者.2例椎弓根螺钉断裂,4例伤口深部感染,其中2例换药愈合,2例再次手术清创后愈合. 结论应用伤害控制骨科学和VIP 程序救治合并脊柱脊髓损伤的多发伤的同时,对脊柱脊髓损伤采用临时固定、大剂量甲基强的松龙,病情相对稳定后早期手术治疗,有利于改善预后.多发伤的手术治疗原则为抢救生命--先脏器,后骨折;遵循原则--先开放,后闭合;手术顺序--先四肢,后盆脊;固定选择--优髓内,辅髓外;手术时间--早手术,少并发;治疗目的--利康复,便护理.     

Basic science of closed head injuries and spinal cord injuries

Traumatic CNS injury is one of the most important health issues in our society and is a risk to all athletes, both in competitive and recreational sports. Our understanding of the pathophysiology has improved tremendously in the last 20 years. This progress has led to the identification of several possible treatments for improving outcome following spinal cord injury and traumatic brain injury. As no panacea exists, improvements in experimental models have empowered researchers in their search for novel therapeutic strategies.     

Neurovascular injuries of the spinal cord

Neurovascular spinal cord injuries are very prevalent and in a busy trauma center radiology practice these injuries are commonly seen. Imaging neurovascular injuries has been greatly facilitated by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). The histopathological changes that occur with spinal cord trauma have been found to correlate well with what is seen on MRI examinations. The MRI findings in spinal cord trauma have also been found to be useful in determining patient prognosis. Spinal cord infarcts due to arterial injury from trauma are relatively rare, but it has been shown by imaging that vertebral artery injuries are not an unusual occurrence. The specific findings associated with neurovascular injuries will be described with an emphasis on the findings on MRI and MRA examinations. MRI and MRA techniques have become the procedure of choice for evaluating neurovascular injuries because of their proven accuracy and because they are non-invasive. Conventional angiography, although, does remain quite useful for evaluating arterial injuries.     

Traumatic spinal cord injuries from snowboarding

BACKGROUND: Little information has yet been made available on the types and mechanisms of snowboard-related spinal cord injuries or their neurologic involvement. PURPOSE: To review the cause and types of spinal cord injuries seen in snowboarders. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The subjects were 18 patients (mean age, 24.0 years) referred to the authors' institution for neurologic deficits associated with spinal injuries between November 1, 1995, and April 9, 2005. The clinical features of these patients were reviewed with respect to epidemiologic factors, mechanism of injury, fracture pattern, and neurologic status. RESULTS: The 18 snowboarders with spinal cord injuries constituted a very homogeneous group. First, almost all patients (94.4%) were young men. Second, most of the patients were intermediate or expert boarders. Third, the most common cause of injury was a failure of intentional jumping (83.3%). Fourth, the most commonly affected site was the thoracolumbar junction (66.7%), and the most common type of fracture was an anterior dislocation fracture (66.7%). Finally, in the thoracolumbar group, most patients (83.3%) were classed as Frankel grade A or B. CONCLUSION: It is fundamentally important that snowboarders, especially young men, be made aware of the spinal injury risk associated with jumping.     

Military gunshot wound-induced spinal cord injuries

Gunshot wounds are the second leading cause of spinal cord injuries in developed countries, whereas in undeveloped and developing countries, this likelihood is much more. However, the weapon and injury characteristics are very different between those two groups of countries. The aim of this study was to review our experience with gunshot wound-caused spinal cord injury during our struggle with terrorism, to examine surgical and medical complications, and to determine the difference between civilian and military gunshot wounds. One hundred five male patients (mean, 25 years of age) were examined according to completeness, spinal and nonspinal injuries, American Spinal Injury Association classification, motor and pinprick scores, surgical and nonsurgical interventions, surgical complications, and spinal cord injury-related medical complications. This study has shown that the likelihood of completeness was higher in gunshot wounds with high velocity weapons. Because of their higher wounding capacity, the difference between vertebral and neurological levels was not very different as it was on the other etiologies. Fortunately, spinal cord injury-related medical complications were less than expected.     

严重多发创伤合并脊柱脊髓损伤的早期诊治体会

探讨降低严重多发创伤合并脊柱脊髓损伤病例的伤残率、死亡率的有效措施。本组31例,临床治愈21例,好转5例,死亡5例。早期检查、诊断及早期治疗至关重要,对降低伤残率、死亡率有重要的临床意义。     

核磁共振成像在脊髓损伤中的应用

核磁共振成像（ＭＲＩ）在脊髓损伤的诊台中具有重要的意义：ＭＲＩ上表现为出血者较单纯水肿者的病情重,预后差,且均与病灶的大小有关;有脊髓压迫者的病情重,预后差;ＭＲＩ对指导创伤性脊髓空洞症的治疗也有重要的价值。     

胰岛素治疗脊髓损伤的研究进展

胰岛素样生长因子（insulin—like growth factor system，IGFS）包括胰岛素、胰岛素样生长因子-Ⅰ（IGF—Ⅰ）、胰岛素样生长因子-Ⅱ（IGF—Ⅱ）及3个相应的受体即胰岛素受体（insulin receptor，IR）、胰岛素样生长因子-Ⅰ受体（IGF—Ⅰ receptor，IGF—IR）、胰岛素样生长因子-Ⅱ受体（IGF—ⅡR），同时还有6个结合蛋白（IGF binding protein，IGFBP）。     

急性脊髓损伤临床研究进展

急性脊髓损伤可导致终身残疾和功能障碍，造成沉重的家庭和社会负担。在美国，其初次医疗费用约为28万美元，而残障引起的社会损失约为每人每年5．7万美元。因而，对急性脊髓损伤的研究始终是脊柱外科的热点。手术减压促进神经功恢复、重建脊柱正常序列和稳定性，已被广泛接受作为脊柱脊髓损伤的标准治疗方式。但急性脊髓损伤的治疗现状仍远不尽如人意。目前，研究重点集中在脊髓损伤的病理生理和神经修复再生，并取得了许多重要成就，手术治疗和康复重建也有了新的进展，但其中很多内容尚不成熟、存在争议。笔者就近期的临床研究进展进行综述。     

Physical performance during rehabilitation in persons with spinal cord injuries.

PURPOSE: The objective of the present study was to evaluate the effect of rehabilitation on physical capacity, mechanical efficiency of manual wheelchair propulsion, and performance of standardized activities of daily living (ADL). METHODS: Nineteen recently injured subjects with spinal cord injuries were tested on a wheelchair ergometer (maximal isometric strength, sprint and maximal power output, and peak oxygen uptake) and during standardized ADL (physical strain and performance time) at the beginning (t1) and at the end (t2) of the active rehabilitation period. RESULTS: Paired Student t-tests showed significant increases for maximal isometric strength (24%, P < 0.01), sprint power output (l7%, P < 0.001) and maximal power output (38%, P < 0.001). Peak oxygen uptake showed no statistically significant improvement (11%, P = 0.06). Mechanical efficiency of submaximal wheelchair exercise was significantly higher at t2 (9.0%) compared to t1 (7.9%, P < 0.01). No significant differences were found for physical strain during ADL, except for passing a door (P < 0.05). Performance time showed a significant decrease for most tasks. CONCLUSIONS: The results of this study show considerable improvements in physical capacity and mechanical efficiency of manual wheelchair propulsion during rehabilitation, and a concomitant lower performance time during standardized ADL. The higher mechanical efficiency and the decrease in performance time during standardized ADL suggest improvement in wheelchair propulsion technique.     

Rugby injuries of the spine and spinal cord

This article analyzes the type and circumstances of injury in 50 rugby players who sustained cervical spinal cord injury with paralysis. Specific mechanisms of injury occurring during certain phases of the game are identified as being responsible for the majority of injuries. Each phase of the game is discussed in detail, emphasizing the vulnerability of the cervical spine to certain maneuvers, the dangers of illegal play, and the importance of preventive measures to decrease the incidence of these catastrophic injuries.     

Oxygen myelography for cervical spinal cord injuries

Summary Oxygen myelographies were performed on 15 patients with cervical spinal cord injuries, in seven of whom narrowing of the spinal cord was caused by a fracture-dislocation. In eight the fracture was of bursting type, and the neurological involvement in these was more severe than in the former type. The main findings in seven early myelograms were swelling of the cord (3/7) and non-visualization of the spinal canal at the injury level (6/7). The main findings in eight late myelograms were narrowing of the cord (5/8) and anterior stretching of the cord over the obstructing bony ridge.