DNA methylation and behavioral changes induced by neonatal spinal transection

Although the importance of epigenetic mechanisms in behavioral development has been gaining attention in recent years, research has largely focused on the brain. To our knowledge, no studies to date have investigated epigenetic changes in the developing spinal cord to determine the dynamic manner in which the spinal epigenome may respond to environmental input during behavioral development. Animal studies demonstrate that spinal cord plasticity is heightened during early development, is somewhat preserved following neonatal transection, and that spinal injured animals are responsive to sensory feedback. Because epigenetic alterations have been implicated in brain plasticity and are highly responsive to experience, these alterations are promising candidates for molecular substrates of spinal plasticity as well. Thus, the current study investigated behavioral changes in the development of weight-bearing locomotion and epigenetic modifications in the spinal cord of infant rats following a neonatal low-thoracic spinal transection or sham surgery on postnatal day (P)1. Specifically, global levels of methylation and methylation status of the brain-derived neurotrophic factor (Bdnf) gene, a neurotrophin heavily involved in both CNS and behavioral plasticity, particularly in development, were examined in lumbar tissue harvested on P10 from sham and spinal-transected subjects. Behavioral results demonstrate that compared to shams, spinal-transected subjects exhibit significantly reduced partial-weight bearing hindlimb activity. Molecular data demonstrate group differences in global lumbar methylation levels as well as exon-specific group differences in Bdnf methylation. This study represents an initial step toward understanding the relationship between epigenetic mechanisms and plasticity associated with spinal cord and locomotor development.     

Plasticity: implications for opioid and other pharmacological interventions in specific pain states

The spinal mechanisms of action of opioids under normal conditions are reasonably well understood. The spinal effects of opioids can be enhanced or reduced depending on pathology and activity in other segmental and nonsegmental pathways. This plasticity will be considered in relation to the control of different pain states using opioids. The complex and contradictory findings on the supraspinal actions of opioids are explicable in terms of heterogeneous descending pathways to different spinal targets using multiple transmitters and receptors--therefore opioids can both increase and decrease activity in descending pathways. These pathways could exhibit considerable plasticity. There is increasing evidence that delta opioid receptor agonists have the potential to replace morphine as major analgesics with reduced side-effect profiles. The concept of preemptive analgesia, based on preventing the induction of some of the negative plastic influences on opioid controls and the detrimental effects of pain, is sound, but experimental verification in the clinical setting is difficult. For example, a delayed compensatory upregulation of inhibitory systems, particularly in inflammation, may counter persistent painful inputs. Combination therapy with opioids may be beneficial in many pain states where either negative influences are blocked or inhibitory controls are enhanced. Finally, developmental aspects of these systems are discussed in connection with the treatment of pain in young children, where inhibitory systems in the spinal cord are immature.     

Ethical considerations surrounding first time procedures: a study and analysis of patient attitudes toward spinal taps by students

A patient is not always told when a student is performing a procedure for the first time. Withholding this information is a form of deception. It is justified on paternalistic grounds (it is in the patient's interest not to know), or on public policy grounds (given the choice, patients would refuse, thus compromising the training of future physicians). Using the spinal tap procedure (lumbar puncture) as a paradigm, 173 patients were surveyed to determine how they felt about first time procedures by medical students, interns, and residents. The patients indicated that they would be willing to be the subject for a student's (52%), intern's (62%), or resident's (66%) first spinal tap. This paper reassesses the ethics of consent for first time procedures based on responses to this survey.     

Ablation of cerebellar nuclei prevents H-reflex down-conditioning in rats

While studies of cerebellar involvement in learning and memory have described plasticity within the cerebellum, its role in acquisition of plasticity elsewhere in the CNS is largely unexplored. This study set out to determine whether the cerebellum is needed for acquisition of the spinal cord plasticity that underlies operantly conditioned decrease in the H-reflex, the electrical analog of the spinal stretch reflex. Rats in which the cerebellar output nuclei dentate and interpositus (DIN) had been ablated were exposed for 50 d to the H-reflex down-conditioning protocol. DIN ablation, which in itself had no significant long-term effect on H-reflex size, entirely prevented acquisition of a smaller H-reflex. Since previous studies show that corticospinal tract (CST) transection also prevents down-conditioning while transection of the rubrospinal tract and other major descending tracts does not, this result implies that DIN output that affects cortex is essential for generation of the CST activity that induces the spinal cord plasticity, which is, in turn, directly responsible for the smaller H-reflex. The result extends the role of the cerebellum in learning and memory to include participation in induction of plasticity elsewhere in the CNS, specifically in the spinal cord. The cerebellum might simply support processes in sensorimotor cortex or elsewhere that change the spinal cord, or the cerebellum itself might undergo plasticity similar to that occurring with vestibulo-ocular reflex (VOR) or eyeblink conditioning.     

Do Older Adults and Those Recovered from Low Back Injury Share Common Muscle Activation Adaptations?

Theoretical models suggest trunk muscle activation compensates for spinal systems impairments. The purpose of this study was to determine if two populations (older adults and those recovered from a lower back injury (rLBI)) with spinal system impairments have similar muscle activation patterns to each other, but differ from controls. Trunk electromyograms collected from 12 older adults, 16 rLBI, and 19 controls during two dynamic tasks showed that older adults and rLBI had higher activation amplitudes, sustained temporal and more synergistic activation relative to controls. However, differences found between older adults and rLBI suggest that spinal system impairments differed between groups or that recent pain (rLBI) uniquely influenced muscle activation. This sheds light on our understanding of the relationship between spinal system impairments and muscle activation.     

特殊类型的无骨折脱位型颈髓损伤治疗分析

为了探讨多节段后纵韧带骨化伴颈椎间盘突出的无骨折脱位型颈髓损伤的治疗,回顾了本院收治的4例多节段后纵韧带骨化伴颈椎间盘突出的无骨折脱位型颈髓损伤患者的临床资料,并结合相关文献报道进行分析。结果显示,4例患者均早期行前后路联合手术椎管减压,3例患者行预防性气管切开,4例患者术后随访时间6个月～48个月,平均随访24个月。固定节段均获骨性融合,内固定物无松动、断裂;后路手术无再关门现象。术后神经功能评价按Frankel分级,均有1个～2个级别恢复,术前A级2例,B级2例;术后B级2例,C级1例,D级1例。提示对于多节段后纵韧带骨化伴颈椎间盘突出的无骨折脱位型颈髓损伤早期行前后路联合手术减压;预防性气管切开可获得良好的治疗结果。     

Spinal manifestations of sarcoidosis

This is a report on the spinal manifestation of sarcoidosis, which has heretofore been infrequently dealt with in the specialized literature. In addition to diffuse manifestation, there has become known circumscribed and solitary manifestation with tumorous symptomatology as a result of spinal compression. Transverse syndromes, pareses, manifestations of sensibility, and disorders of the bladder and rectum are of major clinical importance in this connection. Pathomorphologically, it is possible to distinguish granulomatous leptomeningitis, myelitis, and (poly-) radiculitis, combined simultaneous involvement being frequently observed. So far as differential diagnosis is concerned, considerable difficulties are encountered especially in the case of isolated spinal monosymptomatology. Prognosis, because of special topographic conditions, is less favorable than for other organic manifestations. Secondary phenomena and complications are often responsible for the consequences of spinal sarcoidosis. In addition to spontaneous healing, treatment with corticosteroids (of acute disease processes which, however, are a relatively rare occurrence) and surgical operation (in the case of solitary spinal sarcoid granulomata with compression syndromes) have proven to be most successful.     

Spinal and locus coeruleus noradrenergic lesions abolish the analgesic effects of 5-methoxy-N,N-dimethyltryptamine

Two experiments were performed on Sprague-Dawley rats to study the effects of noradrenaline and 5-hydroxytryptamine depletion upon the antinociceptive effects of acute 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) administration. 6-Hydroxydopamine-induced lesions following microinjections to either the locus coeruleus or the spinal cord (lumbar) abolished completely 5-MeODMT-induced analgesia in the tail-flick, hot-plate, and shock titration tests whereas 5,7-dihydroxytryptamine-induced lesions of the nucleus raphe magnus and the lumbar spinal cord attenuated 5-MeODMT analgesia in the tail-flick and shock titration tests. Thus, the experiments serve to demonstrate an important interaction between descending noradrenergic and serotonergic pathways, possibly at a spinal locus.     

Effects of postural anxiety on the soleus H-reflex

Previous research has proposed that spinal reflex modulation may mediate anxiety-related changes in postural control. This study investigated how soleus H-reflex amplitude was influenced by standing at heights that induced different levels of anxiety. H-reflexes were elicited in 15 participants standing at the center and edge of a platform raised from a low to a high height (with and without vision). Increased skin conductance confirmed the anxiety effect of elevated surface heights. When standing at the edge of the platform with vision, H-reflex amplitude was attenuated in the high compared to low height condition. Changes in background muscle activity could not explain observed H-reflex changes, suggesting the potential involvement of pre-synaptic inhibition or fusimotor drive on anxiety-related changes in reflex modulation. This study reveals that healthy participants reduce spinal reflex excitability in the presence of increased postural anxiety and a postural threat imposed by standing at the edge of a raised platform. These findings have implications for understanding control of standing balance in individuals with postural instability and/or fear of falling, such as the elderly or stroke.     

胸椎管狭窄症的临床分型与术式选择

为探讨胸椎管狭窄症的临床分型与术式选择,对35例患者行后路椎管减压术,所有患者术后12个月时ASIA分级均有1级或1级以上的恢复;按Epstein标准：优良率：85．7％;影像学检查示脊髓减压充分,植骨患者术后6个月均达骨性融合。据不同的临床类型选择不同的术式,可取得满意的临床疗效。     

Sparing and recovery of function in spinal larval frogs (Rana catesbeiana): effect of level of transection.

Bullfrog tadpoles with cervical or midthoracic transection of the spinal cord were allowed to recover for 5 weeks, at which time axonal growth across the transection site was assessed by transport of horseradish peroxidase. Weekly behavioral tests included those for posture, spontaneous locomotion, cutaneously elicited swimming, and intersegmental coordination. Behavioral and electrophysiological assessments suggest that behavioral recovery depends, at least in part, on the growth of fibers across the transection site. Anatomical and behavioral recovery does not appear to differ with the level of spinal transection, but there was greater sparing of posture, spontaneous locomotion, and stimulus-induced locomotion in tadpoles with thoracic transection of the spinal cords.     

Synergistic influences of sensory and central stimuli on non-voluntary rhythmic arm movements

In recent years, neuromodulation of the cervical spinal circuitry has become an area of interest for investigating rhythmogenesis of the human spinal cord and interaction between cervical and lumbosacral circuitries, given the involvement of rhythmic arm muscle activity in many locomotor tasks. We have previously shown that arm muscle vibrostimulation can elicit non-voluntary upper limb oscillations in unloading body conditions. Here we investigated the excitability of the cervical spinal circuitry by applying different peripheral and central stimuli in healthy humans. The rationale for applying combined stimuli is that the efficiency of only one stimulus is generally limited. We found that low-intensity electrical stimulation of the superficial arm median nerve can evoke rhythmic arm movements. Furthermore, the movements were enhanced by additional peripheral stimuli (e.g., arm muscle vibration, head turns or passive rhythmic leg movements). Finally, low-frequency transcranial magnetic stimulation of the motor cortex significantly facilitated rhythmogenesis. The findings are discussed in the general framework of a brain-spinal interface for developing adaptive central pattern generator-modulating therapies.     

对脊柱结核诊疗策略的思考

脊柱结核是临床常见病,其诊疗策略主要包括正确的诊断思路、合适的治疗选择。尤其重视非典型性脊柱结核的诊断,治疗方面要重视药物治疗、营养支持、休息制动等手段。对于需要手术治疗的患者,需个体化选择最适合的术式,且应完整理解并客观评估新技术的应用。     

Toward a Metric for Mental Functions

The purpose of this study was to investigate the correlation between the incidence of decubitus ulcers and the level of spinal cord injury, sex, race, level of intellectual functioning, and level of academic achievement. A total of 114 subjects with spinal cord injuries were surveyed and tested at the Woodrow Wilson Rehabilitation Center, Fishersville, Virginia. The results of this study indicated no relationship between the incidence of decubitus ulcers and the demographic or personality factors studied.     

Normal cerebrospinal fluid findings in spinal tumors--an analysis of 503 cases

Till now almost nothing has been published about normal liquor findings in spinal cord tumours. Out of 503 cases there were normal findings of total proteins and cells in 30 cases (6 per cent). A connection with the severity of the compression-syndrome was not evident. Nevertheless liquor examinations are important in diseases of the medulla spinalis. This is especially useful in the differential diagnostical demarcation of inflammable spinal cord diseases, accompanying reactions or bleedings into the spinal channel.     

Changes in spinal excitability during dual task performance

ABSTRACT The authors investigated how the nervous system responds to dual task performance. Because dual tasking is associated with greater postural challenges, it was hypothesized that spinal excitability would be reduced when simultaneously performing 2 tasks. For this experiment, participants maintained a lying or standing posture with or without performing a concurrent cognitive task (i.e., reacting to an auditory tone). Spinal excitability was assessed by eliciting the soleus Hoffmann reflex (H-reflex). Results indicated that the H-reflex was 6.4 ± 2.3% smaller (p = .011) when dual compared to single tasking. The reduced H-reflex amplitude, indicating a depressed spinal excitability, when dual tasking is suggested to reflect a neural strategy that individuals adopt to maintain postural stability when cognitive resources are divided between 2 concurrent tasks.     

Corporeal illusions in chronic spinal cord injuries

While several studies have investigated corporeal illusions in patients who have suffered from a stroke or undergone an amputation, only anecdotal or single case reports have explored this phenomenon after spinal cord injury. Here we examine various different types of bodily misperceptions in a comparatively large group of 49 people with spinal cord injury in the post-acute and chronic phases after the traumatic lesion onset. An extensive battery of questionnaires concerning a variety of body related feelings was administered and the results were correlated to the main clinical variables. Six different typologies of Corporeal Illusion emerged: Sensations of Body Loss; Body-Part Misperceptions; Somatoparaphrenia-like sensations; Disownership-like sensations; Illusory motion and Misoplegia. All of these (with the exception of Misoplegia) are modulated by clinical variables such as pain (visceral, neuropathic and musculoskeletal), completeness of the lesion, level of the lesion and the length of time since lesion onset. In contrast, no significant correlations between bodily illusions and personality variables were found. These results support data indicating that at least some cognitive functions (in particular the body, action and space representations) are embodied and that somatosensory input and motor output may be necessary to build and maintain a typical self-body representation.     

Local dynamic stability of trunk movements during the repetitive lifting of loads

The local dynamic stability of trunk movements was assessed during repetitive lifting using nonlinear Lyapunov analyses. The goal was to assess how varying the load-in-hands affects the neuromuscular control of lumbar spinal stability. Thirty healthy participants (15M, 15F) performed repetitive lifting at 10 cycles per minute for three minutes under two load conditions: zero load and 10% of each participant's maximum back strength. Short- and long-term maximum finite-time Lyapunov exponents (λ(max-s) and λ(max-l)), describing responses to infinitesimally small perturbations, were calculated from the measured trunk kinematics to estimate the local dynamic stability of the system. Kinematic variability was also assessed using mean standard deviations (MeanSD) across cycles. The results of a mixed-design repeated-measures ANOVA showed that increasing the load lifted significantly reduced λ(max-s) (μ(0%-LOAD)=0.379, μ(10%-LOAD)=0.335, p<.001), but not λ(max-l) (μ(0%-LOAD)=0.46E-03, μ(10%-LOAD)=2.41E-03, p=.055) or MeanSD (μ(0%-LOAD)=2.57, μ(10%-LOAD)=2.89, p=.164). There were no between-subject effects of sex, or significant interactions (α<.05). The present findings indicated improved dynamic spinal stability when lifting the heavier load; meaning that as muscular and moment demands increased, so too did participants' abilities to respond to local perturbations. These results support the notion of greater spinal instability during movement with low loads due to decreased muscular demand and trunk stiffness, and should aid in understanding how lifting various loads contributes to occupational low back pain.     

The prevalence of symptoms of Post-Traumatic Stress Disorder among soldiers with amputation of a limb or spinal injury: a report from a rehabilitation centre in Sri Lanka

Post-Traumatic Stress Disorder has been identified as one of the most commonly occurring mental illnesses in combatants. This study was conducted to determine the prevalence of Post-Traumatic Stress Disorder among soldiers who had undergone amputation of a lower or an upper limb or sustained a spinal cord injury in the battlefield, and to compare the prevalence among these categories. The research presented seeks to increase the awareness of this condition among those treating war casualties so that appropriate treatment choices could be made to address them. The study was carried out in 2009 at a rehabilitation centre for combatants of war. Data were collected from 96 male army veterans between the ages of 18-49 years using a pre-tested self-administered questionnaire based on the Diagnostic and Statistical Manual of Mental Disorders, the Impact of Event Scale and the PTSD symptom scale. Soldiers with injuries sustained at least four weeks prior to the study were selected by a convenience sampling technique. Soldiers with multiple injuries, head injuries or those diagnosed with psychiatric disorders were excluded. The results revealed that 41.7% of the study population was compatible with the diagnosis of Post-Traumatic Stress Disorder. Within the three groups, 42.5% of the lower limb amputees, 33.3% of the upper limb amputees and 45.7% of the participants with spinal cord injury had symptoms compatible with Post-Traumatic Stress Disorder. There was no difference between the prevalence among the different injury categories considered. This study highlights the need to pay more attention in providing psychological care as a part of the overall health management of injured combatants. Early preparation of soldiers for stressors of war and screening for and proper management of Post-Traumatic Stress Disorder will improve the overall outcome of rehabilitation.     

一期前后联合入路治疗上颈椎畸形

回顾9例因颅底凹陷症合并其它畸形在我科接受一期经口咽齿状突切除、后路枕骨大孔减压、寰枢椎或枕颈融合术治疗的,临床资料,观察该术式对脊髓功能、枕颈部稳定性的影响及其临床疗效。本组术前诊断均为颅底凹陷症合并邻近结构畸形。所有患者均接受前后联合入路手术。末次随访JOA评分15±1分。影像学检查示齿状突残留基底部均位于钱氏线以下,脊髓减压充分,寰枢间、枕颈间植骨均获坚强融合,融合时间平均3．9±1.1个月。因此一期前后路联合手术治疗颅底凹陷症,脊髓减压充分,重建稳定性后骨融合好,治疗效果满意。