Extracellular Vesicles: Therapeutic Potential in Central Nervous System Trauma by Regulating Cell Death

CNS (central nervous system) trauma, which is classified as SCI (spinal cord injury) and TBI (traumatic brain injury), is gradually becoming a major cause of accidental death and disability worldwide. Many previous studies have verified that the pathophysiological mechanism underlying cell death and the subsequent neuroinflammation caused by cell death are pivotal factors in the progression of CNS trauma. Simultaneously, EVs (extracellular vesicles), membrane-enclosed particles produced by almost all cell types, have been proven to mediate cell-to-cell communication, and cell death involves complex interactions among molecules. EVs have also been proven to be effective carriers of loaded bioactive components to areas of CNS trauma. Therefore, EVs are promising therapeutic targets to cure CNS trauma. However, the link between EVs and various types of cell death in the context of CNS trauma remains unknown. Therefore, in this review, we summarize the mechanism underlying EV effects, the relationship between EVs and cell death and the pathophysiology underlying EV effects on the CNS trauma based on information in published papers. In addition, we discuss the prospects of applying EVs to the CNS as feasible therapeutic strategies for CNS trauma in the future.

Nerve recovery from treatment with a vascularized nerve graft compared to an autologous non-vascularized nerve graft in animal models: A systematic review and meta-analysis

Background

Treatment of nerve injuries proves to be a worldwide clinical challenge. Vascularized nerve grafts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous non-vascularized nerve graft. However, there is no adequate clinical evidence for the beneficial effect of vascularized nerve grafts and they are still disputed in clinical practice.

Objective

To systematically review whether vascularized nerve grafts give a superior nerve recovery compared to non-vascularized nerve autografts regarding histological and electrophysiological outcomes in animal models.

Material and methods

PubMed and Embase were systematically searched. The inclusion criteria were as follows: 1) the study was an original full paper which presented unique data; 2) a clear comparison between a vascularized and a non-vascularized autologous nerve transfer was made; 3) the population study were animals of all genders and ages. A standardized mean difference and 95% confidence intervals for each comparison was calculated to estimate the overall effect. Subgroup analyses were conducted on graft length, species and time frames.

Results

Fourteen articles were included in this review and all were included in the meta-analyses. A vascularized nerve graft resulted in a significantly larger diameter, higher nerve conduction velocity and axonal count compared to an autologous non-vascularized nerve graft. However, during sensitivity analysis the effect on axonal count disappeared. No significant difference was observed in muscle weight.

Conclusion

Treating a nerve gap with a vascularized graft results in superior nerve recovery compared to non-vascularized nerve autografts in terms of axon count, diameter and nerve conduction velocity. No difference in muscle weight was seen. However, this conclusion needs to be taken with some caution due to the inherent limitations of this meta-analysis. We recommend future studies to be performed under conditions more closely resembling human circumstances and to use long nerve defects.

Magnetically guided targeted delivery of erythropoietin using magnetic nanoparticles: Proof of concept

The objective of this proof-of-concept study was to demonstrate the targeted delivery of erythropoietin (EPO) using magnetically guided magnetic nanoparticles (MNPs).MNPs consisting of a ferric-ferrous mixture (FeCl3·6H2O and FeCl2·4H2O) were prepared using a co-precipitation method. The drug delivery system (DDS) was manufactured via the spray-drying technique using a nanospray-dryer. The DDS comprised 7.5 mg sodium alginate, 150 mg MNPs, and 1000 IU EPO.Scanning electron microscopy revealed DDS particles no more than 500 nm in size. Tiny particles on the rough surfaces of the DDS particles were composed of MNPs and/or EPO, unlike the smooth surfaces of the only alginate particles. Transmission electron microscopy showed the tiny particles from 5 to 20 nm in diameter. Fourier-transform infrared spectroscopy revealed DDS peaks characteristic of MNPs as well as of alginate. Thermal gravimetric analysis presented that 50% of DDS weight was lost in a single step around 500°C. The mode size of the DDS particles was approximately 850 nm under in vivo conditions. Standard soft lithography was applied to DDS particles prepared with fluorescent beads using a microchannel fabricated to have one inlet and two outlets in a Y-shape. The fluorescent DDS particles reached only one outlet reservoir in the presence of a neodymium magnet. The neurotoxicity was evaluated by treating SH-SY5Y cells in 48-well plates (1 × 10 cells/well) with 2 μL of a solution containing sodium alginate (0.075 mg/mL), MNPs (1.5 mg/mL), or sodium alginate + MNPs. A cell viability assay kit was used to identify a 93% cell viability after MNP treatment and a 94% viability after sodium alginate + MNP treatment, compared with the control. As for the DDS particle neurotoxicity, a 95% cell viability was noticed after alginate-encapsulated MNPs treatment and a 93% cell viability after DDS treatment, compared with the control.The DDS-EPO construct developed here can be small under in vivo conditions enough to pass through the lung capillaries with showing the high coating efficiency. It can be guided using magnetic control without displaying significant neurotoxicity in the form of solution or particles.

Do Neural Stem Cells Have a Choice? Heterogenic Outcome of Cell Fate Acquisition in Different Injury Models

The adult mammalian central nervous system (CNS) is generally considered as repair restricted organ with limited capacities to regenerate lost cells and to successfully integrate them into damaged nerve tracts. Despite the presence of endogenous immature cell types that can be activated upon injury or in disease cell replacement generally remains insufficient, undirected, or lost cell types are not properly generated. This limitation also accounts for the myelin repair capacity that still constitutes the default regenerative activity at least in inflammatory demyelinating conditions. Ever since the discovery of endogenous neural stem cells (NSCs) residing within specific niches of the adult brain, as well as the description of procedures to either isolate and propagate or artificially induce NSCs from various origins ex vivo, the field has been rejuvenated. Various sources of NSCs have been investigated and applied in current neuropathological paradigms aiming at the replacement of lost cells and the restoration of functionality based on successful integration. Whereas directing and supporting stem cells residing in brain niches constitutes one possible approach many investigations addressed their potential upon transplantation. Given the heterogeneity of these studies related to the nature of grafted cells, the local CNS environment, and applied implantation procedures we here set out to review and compare their applied protocols in order to evaluate rate-limiting parameters. Based on our compilation, we conclude that in healthy CNS tissue region specific cues dominate cell fate decisions. However, although increasing evidence points to the capacity of transplanted NSCs to reflect the regenerative need of an injury environment, a still heterogenic picture emerges when analyzing transplantation outcomes in injury or disease models. These are likely due to methodological differences despite preserved injury environments. Based on this meta-analysis, we suggest future NSC transplantation experiments to be conducted in a more comparable way to previous studies and that subsequent analyses must emphasize regional heterogeneity such as accounting for differences in gray versus white matter.

Predictive value of a diagnostic block in focal nerve injury with neuropathic pain when surgery is considered

OBJECT

In patients with focal nerve injury and neuropathic pain cutting the nerve to obtain permanent pain reduction can be considered. Surgery is indicated only if a diagnostic nerve block provides temporary pain relief. We evaluated the predictive value of a block on the outcome of surgery.

METHODS

In total, three blocks were performed at two week intervals. Patients were blinded to injections containing lidocaine 1% and a placebo was included. Surgery was offered regardless of the effect of the blocks. Twenty-four patients received 72 blocks. Sixteen patients opted for surgery, 5 patients refrained from surgery, and in 3 the blocks provided permanent pain relief. The predictive ability of the block on the outcome of surgery was assessed by calculating the area under a Receiver Operating Characteristic curve (AUC).

RESULTS

The AUC of the first lidocaine block was 0.35 with a 95% confidence interval from 0.077 to 0.62. At 95% confidence (two-sided), the AUC is less than 0.62, and hence the predictive ability of the block was poor. The outcome of the second lidocaine block and saline block did not change the conclusion of the first block.

CONCLUSIONS

We conclude that the use of blocks to select patients for surgery should be critically appraised.

PERSPECTIVE

A pain relieving response to one open block is currently considered mandatory before patients with focal nerve injury and neuropathic pain are offered surgery. Blinded blocks including a placebo show that responses for selection should be carefully interpreted because they may not be as predictive as generally presumed.

Environmental Neurologic Injuries

PURPOSE OF REVIEW

This article discusses neurologic complications resulting from environmental injuries and the treatment modalities for these conditions.

RECENT FINDINGS

Recent advances include improved management of altitude sickness. Relatively uncommon conditions, such as keraunoparalysis (lightning-induced paralysis) and high-pressure neurologic syndrome, are areas of ongoing study.

SUMMARY

Environmental injuries may be associated with serious neurologic sequelae. This article reviews thermal and electrical injuries as well as injuries related to aviation, altitude, and diving. Recognition of signs and symptoms of such complex injuries and exposures will permit accurate diagnoses and improved outcomes.

Transcutaneous Electrical Nerve Stimulation for Neuropathic Pain

This study examined the clinical effectiveness of high-frequency transcutaneous electrical nerve stimulation for reducing hypersensitivity of the hand. Nineteen patients suffering from hand hypersensitivity were randomly assigned into either a treatment or a placebo group. A visual analogue scale and the Downey Hand Centre Hand Sensitivity Test were used to measure the tactile tolerance of the hand. Grip strength was assessed by a grip dynamometer. Daily applications of electrical stimulation were provided for 2 weeks. Significantly lower pain scores were found in the treatment group than in the placebo group by Day 7 and Day 11. The ranking of ten dowel textures of the Downey Hand Centre Hand Sensitivity Test in the treatment group was significantly higher than in the placebo group by Day 7 and Day 11. However, no significant intergroup difference was found in grip strength.

Enhancing Rehabilitative Therapies with Vagus Nerve Stimulation

Pathological neural activity could be treated by directing specific plasticity to renormalize circuits and restore function. Rehabilitative therapies aim to promote adaptive circuit changes after neurological disease or injury, but insufficient or maladaptive plasticity often prevents a full recovery. The development of adjunctive strategies that broadly support plasticity to facilitate the benefits of rehabilitative interventions has the potential to improve treatment of a wide range of neurological disorders. Recently, stimulation of the vagus nerve in conjunction with rehabilitation has emerged as one such potential targeted plasticity therapy. Vagus nerve stimulation (VNS) drives activation of neuromodulatory nuclei that are associated with plasticity, including the cholinergic basal forebrain and the noradrenergic locus coeruleus. Repeatedly pairing brief bursts of VNS sensory or motor events drives robust, event-specific plasticity in neural circuits. Animal models of chronic tinnitus, ischemic stroke, intracerebral hemorrhage, traumatic brain injury, and post-traumatic stress disorder benefit from delivery of VNS paired with successful trials during rehabilitative training. Moreover, mounting evidence from pilot clinical trials provides an initial indication that VNS-based targeted plasticity therapies may be effective in patients with neurological diseases and injuries. Here, I provide a discussion of the current uses and potential future applications of VNS-based targeted plasticity therapies in animal models and patients, and outline challenges for clinical implementation.

Pilot study of the cortical correlates and clinical effects of passive ankle mobilisation in children with upper motorneuron lesions

Upper motoreuron lesions (UML) affects people of all ages and conditions and is a major cause of disability in the young. Whereas active exercise is recognised as paramount to restore the lost motor functions, passive mobilisation of the affected limbs is regarded as a means to safeguard muscular tissue properties during a period of disuse and lack of voluntary control, which often characterises the acute and sub-acute phases. The purpose of the present work is to study the cortical reactivity in UML patients who are treated for two weeks with a robotic passive ankle mobiliser, and the clinical effects of this treatment. The rationale is that, if passive mobilisation can affect positively the functional reorganisation at a cortical level, it could be proposed as a suitable tool to maintain afferentation and guide central nervous remapping, thus bridging the period of time when active exercise is impossible due to acute paresis. Preliminary results on 7 patients (aged 15.35±4.36) showed that this therapy is very well tolerated and suggest that its application could specifically improve ankle PROM and plantarflexor muscle length. EEG data showed improved desynchronisation in at least one frequency band in 3 patients of the study, thus confirming the effects of passive mobilisation on the cortical re-organisation of some patients having UML.

Neurologic emergencies in sports

PURPOSE OF REVIEW

Sports neurology is an emerging area of subspecialty. Neurologists and non-neurologists evaluating and managing individuals participating in sports will encounter emergencies that directly or indirectly involve the nervous system. Since the primary specialty of sports medicine physicians and other practitioners involved in the delivery of medical care to athletes in emergency situations varies significantly, experience in recognition and management of neurologic emergencies in sports will vary as well. This article provides a review of information and elements essential to neurologic emergencies in sports for the practicing neurologist, although content may be of benefit to readers of varying background and expertise.

RECENT FINDINGS

Both common neurologic emergencies and less common but noteworthy neurologic emergencies are reviewed in this article. Issues that are fairly unique to sports participation are highlighted in this review. General concepts and principles related to treatment of neurologic emergencies that are often encountered unrelated to sports (eg, recognition and treatment of status epilepticus, increased intracranial pressure) are discussed but are not the focus of this article. Neurologic emergencies can involve any region of the nervous system (eg, brain, spine/spinal cord, peripheral nerves, muscles). In addition to neurologic emergencies that represent direct sports-related neurologic complications, indirect (systemic and generalized) sports-related emergencies with significant neurologic consequences can occur and are also discussed in this article.

SUMMARY

Neurologists and others involved in the care of athletes should consider neurologic emergencies in sports when planning and providing medical care.

[Nutritional support in the neurocritical patient]

Neurocritical patients have a metabolic condition that makes them particularly sensitive to protein-caloric malnutrition in a short period of time. Due to this, it is essential nutritional support treatment. But the neurocritical patient has physiological connotations that makes it difficult to be able to establish an early nutrition: persistent gastroparesis for days and exacerbated metabolic response with hyperglycemia is a challenge to the therapist.This review intends to respond to nutritional difficulties in neurocritical patients and also review pharmaco-nutritients that may be helpful for the subsequent clinical course.

[Advances and new ideas of neurobiology scaffold in repair of nerve injury]

Nerve injury including peripheral nerve injury and central nerve injury has been a global problem. With the development of technology, many innovative approaches for nerve repair have been tested and some of the results are meaningful. It becomes a hot point that repair nerve injured by biological scaffold (nerve conduit). This article reviewed and analyzed several kinds of biological scaffold materials and microenvironment with better effect in recent years. Some new ideas were raised from the three aspects: appropriate materials, microstructure, and bionic microenvironment. It is better to combine multiple measures and achieve the best effect. In addition, nerve scaffold have a bright future in repair of central nervous system.

Roles of autoantibodies in central nervous system injury

Stroke, traumatic brain injury (TBI), and spinal cord injury (SCI) cause irreversible damage to the nervous system. Although these are neurological disorders, pathology and loss of function also occur outside the nervous system and are often not easily explained by paralysis or impaired neural function. Emerging data indicate that much of the pathological sequelae that accompanies CNS trauma has characteristics of a self-directed immunological disease. Here, we outline those data, describing basic mechanisms of B cell activation and autoantibody synthesis after CNS injury. A summary of the anti-CNS autoantibodies that have been identified in humans and animals is provided along with a discussion of how autoantibodies may affect survival of neuronal and non-neuronal tissues and whether autoimmune reactions are feasible therapeutic targets after CNS trauma.

[Integrin and repair following nervous system injury]

OBJECTIVE

To review the role of integrin in nervous system injury and its repair, and to analyze the possible mechanisms.

METHODS

Recent literature concerning integrin and its role in nervous system injury was reviewed and analyzed.

RESULTS

Integrin and its related signalling pathway were involved in nervous system injury, especially hypoxic-ischemic nervous injury, and their repair processes.

CONCLUSION

Intervention of integrin signalling pathway would be a potential strategy to treat nervous system injury, especially hypoxic-ischemic nervous injury.

Umbilical cord blood stem cells - potential therapeutic tool for neural injuries and disorders

Brain limited self-renewal capability is the main element behind the seriousness of neurodegenerative diseases and neural injuries. Any possible attempts to use cell replacement-therapy approaches rely on: first, the ability of such cells to generate neural cells and tissues with developmental and functional similarities to human brain cells and second, development of safe and effective protocols for cells transplantations. Many recent studies showed that human umbilical cord blood stem cells have the potential to generate cells with neuronal characteristics. It has also been shown that these stem cells have a positive impact on animal models of neural injuries and diseases. Umbilical cord blood stem cells are a potential candidate for clinical therapies for neural injuries and neural degenerative diseases for which current mode of therapy is inadequate. In addition, they might provide an in-vitro model of parenchymal neural cells for toxicology and drugs testing research.

EGFP Expression Controlled by GFAP Promoter in Mesenchymal Cells: An Efficient Tool for Glial Lineage Selection and Transplantation

In order to demonstrate a new method to label and select enough glial cells from induced MSCs to provide cells for cell therapy, MSCs were induced with Beta-mercaptoethanol followed by retinoic acid, forskolin, basic-FGF, PDGF and heregulin. Induced MSCs were transfected with reconstructed vector pGFAP-EGFP by inserting GFAP promotor into pEGFP-N3 to substitute CMV promotor. Living cells against G418 were enriched and checked by flowcytometry. EGFP expressing cells were sorted and used for transplantation in vivo. Immunoelectronmicroscopy was accomplished using anti-EGFP to relocalize the transplanted cells. Almost all MSCs took on phenotypes of glial cells after induction, expressing S100 and GFAP. The EGFP expression rate of survived MSCs against G418 was 82.74%. Glial cells expressing EGFP accumulated mainly around the damaged nerve fibers. MSCs were relocalized by immunoelectronmicroscopy and remyelination was observed. EGFP expression controlled by GFAP promoter in mesenchymal cells was an efficient tool for glial lineage selection and transplantation. Induced MSCs can promote nerve regeneration by participating remyelination.

Study on Small Gap Sleeve Bridging Peripheral Nerve Injury

Epineurium or perineurium neurorrhaphy to recover the nerve continuity was the choice of peripheral nerve mutilation. The nerve selective regeneration theory was put forth by Cajal et al. As this theory was gradually accepted, many researchers had focused on it and its possible application. Our labs had centered on the small gap sleeve bridging fields for about 30 years, using autogeneic vein, artery and biogradable chitin conduits. Our goal was to improve the nerve regeneration effect by means of nerve selective regeneration theory and degradable biomaterials. This serial experiment was to confirm the possibilities of using conduit small gap sleeve bridging to substitute the traditional epineurium neurorrhaphy.

Gradual stretching of the proximal nerve stump induces the growth of regenerating sprouts in rats

We investigated the effect of direct gradual stretching on the proximal nerve stump morphologically. A 10-mm-long nerve segment was resected from the sciatic nerve of a rat. The end of the proximal nerve stump was fixed to a small ring and the marking suture was placed at a point 1 mm proximal to the ring. Then, the nerve stump was lengthened at a rate of 1 mm/day via a stretching of the ring using an original external device. After a stretching of 20 days, the distance from the ring to the marking suture became 12 mm. Whereas large mature myelinated axons were observed in the proximal part of the marking, only small axons with thin myelin sheath were observed in the distal part, and the mean axonal diameter showed a significant difference between the two parts. Moreover, the mean internodal length was 172.4 +/- 13.4 microm in the distal part of the marking and 1019.0 +/- 56.2 microm in the proximal part. The internodal length also showed a significant difference between the two parts. Thus, the axonal diameter and internodal length were consistent with the characteristics of regenerating axons in the distal part. Furthermore, ultrastructural analysis also showed the histological characteristics of axonal regeneration. Thus, a transected proximal nerve stump may be lengthened by axonal regeneration during gradual stretching, and the stimulus of mechanical stretching may induce the growth of regenerating axons.

[Neurological and abdominal lesional associations in polytrauma]

Polytraumatisms have always been a concern in human history, their number increasing especially during wars. Their forecast depends on many factors, starting from means of transportation, first aid's promptitude, technical endowment which evolved a lot within the years. Amongst the thoracal-abdominal, the cranial-cerebral and vertebral-medullary injuries, the cranial-cerebral and the abdominal injuries are the most severe ones. We hereby present the evaluation scales according to various criteria (seriousness, prognosis, clinical valutation). In the case of abdominal and neurosurgical injuries the symptomatology can be modified by addition or defalcation, which may cause diagnostic errors with consequences upon morbidity and mortality.

MATERIAL AND METHOD

We hereby present a study accomplished within three departments: Piatra Neamţ Emergency Hospital, Piatra Neamţ Coronary Office and Iaşi Neurosurgery Clinic, and we find the injury associations in polytrauma cases.

RESULTS

We notice a prevalence of the male sex, of the country people, of traffic accidents, of the active age 20-60 years old. The association within abdominal trauma and neurological injuries is of 16.97% in Iaşi Neurosurgery Clinic. After being solved, the neurological injuries are sent to surgery departments, for solution or surveillance.

CONCLUSION

In order to optimize the medical assistance for traumatized persons we hereby recommend a polytrauma centre establishment.

Pediatric major trauma: an approach to evaluation and management

Trauma is the leading cause of death in children nationwide. Proper management of the pediatric trauma patient involves many of the components contained within standard trauma protocols. By paying strict attention to the anatomical and physiological differences in the pediatric population, clinicians will be assured the best possible outcomes. This article outlines the fundamentals of proper management of pediatric trauma patients.

The pivotal role of RhoA GTPase in the molecular signaling of axon growth inhibition after CNS injury and targeted therapeutic strategies

The dogma that the adult central nervous system (CNS) is nonpermissive to axonal regeneration is beginning to fall in the face of increased understanding of the molecular and cellular biology of axon outgrowth. It is now appreciated that axon growth is regulated by a combination of extracellular factors related to the milieu of the developing or adult CNS and the presence of injury, and intracellular factors related to the "growth state" of the developing or regenerating neuron. Several critical points of convergence within the developing or regenerating neuron for mediating intracellular cell signaling effects on the growth cone cytoskeleton have been identified, and their modulation has produced marked increases in axon outgrowth within the "nonpermissive" milieu of the adult injured CNS. One such critical convergence point is the small GTPase RhoA, which integrates signaling events produced by both myelin-associated inhibitors (e.g., NogoA) and astroglial-derived inhibitors (chondroitin sulfate proteoglycans) and regulates the activity of downstream effectors that modulate cytoskeletal dynamics within the growth cone mediating axon outgrowth or retraction. Inhibition of RhoA has been associated with increased outgrowth on nonpermissive substrates in vitro and increased axon regeneration in vivo. We are developing lentiviral vectors that modulate RhoA activity, allowing more long-term expression than is possible with current approaches. These vectors may be useful in regenerative strategies for spinal cord injury, brain injury, and neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and Huntington's disease.

Plasticity of the central nervous system and formation of "auxiliary niches" after stem cell grafting: an essay

It is hoped that stem cell biology will play a major role in the treatment of a number of so far incurable diseases via transplantation therapy. Today, we know that neural stem cell grafts not only represent a valuable source of missing cells and molecules for the host nervous system, but they also bring with them biological principles and processes assuring tissue plasticity and homeostasis found in early development and in postnatal neurogenic areas. In this review, we discuss the potential of grafted neural stem/progenitor cells to induce plasticity in the adult diseased brain by mimicking the cellular and molecular processes governing the biology of endogenous stem cell niches. If confirmed, such anlagen of "auxiliary niches" could help us to optimize intercellular communication in donor cell-initiated networks of graft-host interactions and to "rejuvenate" the adult nervous system in its response to disease and injury.

[What is intensive therapy? Neurointensive therapy]

The neurointensive care unit provides observation and treatment of acute, life-threatening disorders of and injuries to the central and peripheral nervous system. The primary aim of care is the prevention of secondary neuronal damage; this requires a highly multidisciplinary approach, involving neuromonitoring as well as management of systemic comorbidity and complications. This article presents major pathophysiological issues specific to neurointensive care, as well as recent advances in the management of the critically-ill neurosurgical and neurological patient.

Specificity in retraining craniocervical flexor muscle performance

STUDY DESIGN

A multivariate repeated-measures independent-group study design.

OBJECTIVES

To compare the effect of a craniocervical flexion exercise (CCFEx) program to that of a conventional cervical flexion exercise (CFEx) program in training isometric craniocervical flexor muscle performance.

BACKGROUND

The craniocervical flexor muscles are important muscles of the cervical spine, as they have been shown to be impaired in persons with chronic neck pain. While both CCFEx and CFEx protocols have been advocated to train craniocervical flexor muscle performance, at present there is no consensus as to the most effective method.

METHODS AND MEASURES

Fiftyfemales with chronic mild neck pain and disability status were randomly allocated into a 6-week program of either CCFEx (n = 27) or CFEx (n = 23). Isometric dynamometry measurements of craniocervical flexor muscle performance (maximal voluntary contraction, endurance at 50%'of maximal voluntary contraction) were recorded before and following the exercise program. Changes in craniocervical flexor muscle performance (pretraining-posttraining) within and between exercise groups were analyzed with analysis of variance models.

RESULTS

Both exercise interventions significantly improved isometric craniocervical flexor muscle performance (P<.02). No significant differences in improvement of muscle performance were observed between the2 exercise interventions.

CONCLUSION

It appearsthat isometric craniocervical flexor muscle performance can be Strained with either a CCFEx protocol or a conventional CFEx protocol in patients with mild neck pain and disability.

[Effects of immunosuppressants on cytokine expressions after repair for nerve injury in a rat model]

OBJECTIVE

To explore effects of several immunosuppressants on cytokine expressions after repair for a sciatic nerve injury in a rat model.

METHODS

The sciatic nerves of 42 rats were cut and sutured end-to-end. After operation, the rats were divided into 6 groups. Group A (n = 9) was served as a control with no medicines given. Group B (n= 9) was given methylprednisolone 20 mg/(kg x d) for 2 days. Groups C(n= 9) and D(n = 3) were given FK506 1 mg/(kg - d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. Groups E and F were given CsA 2 mg/(kg - d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. The sciatic nerves were sampled at 1, 2 and 4 weeks postoperatively. And immunohistochemistry stainings of interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), interferon gamma(IFN-gamma) and macrophage migration inhibitory factor(MIF) were performed. The staining results were compared and analyzed.

RESULTS

The expression peaks of IL-1beta and IFN-gamma were found at the 1st week postoperatively in Group A. Then, the expression decreased rapidly at the 2nd week and disappeared at the 4th week. As for TNF-a and MIF, they were only found to have a low expression until the 1st week in Group A. In groups C-F, the expression peaks of IL-1beta, TNF-alpha and IFN-gamma were found at the 2nd week, while the expression peak of MIF was still at the 1st week, and the expression of all the cytokines extended to the 4th week. The expressions of these cytokines in Group B were just between the expression levels of Group A and Groups C-F.

CONCLUSION

Immunosuppressants can delay the expression peaks and significantly extend the expression time of IL-1beta, TNF-alpha, IFN-gamma and MIF after repair for a sciatic nerve injury in a rat model.

Effects of hyperbaric oxygen on peripheral nerves

BACKGROUND

Injuries of peripheral nerves are common and usually are part of acute traumatic injuries to the limbs. Damage to peripheral nerves may be extensive. Microsurgery has improved the rate of recovery of these injuries, but some problems remain to be solved. The purpose of this investigation was to study the long-lasting effects of hyperbaric oxygenation on peripheral nerves after transection and repair with microsurgery in the rat sciatic nerve model.

METHODS

Forty male Wistar rats were divided randomly into four groups: (1) no hyperbaric oxygen, sectioned and repaired (n = 10), euthanized at 7 weeks; (2) hyperbaric oxygen, sectioned and repaired (n = 10), euthanized at 7 weeks; (3) no hyperbaric oxygen, sectioned and repaired (n = 10), euthanized at 14 weeks; and (4) hyperbaric oxygen, sectioned and repaired (n = 10), euthanized at 14 weeks. Nerve recovery was assessed by neurophysiologic studies at 7 or 14 weeks. Foot-ankle angle response (dorsiflexion) and histopathology with automated morphometry were performed after 7 or 14 weeks. Statistical analysis was performed with the Friedman test and the Mann-Whitney U test.

RESULTS

At 7 weeks, motor latency showed statistical significance in both groups, treated and not treated, whereas amplitude, axons, and blood vessel number was higher in the hyperbaric oxygen-treated group. After 14 weeks, electromyography showed no denervation and a better foot-ankle angle response in the hyperbaric oxygen groups.

CONCLUSION

These results suggest that functional recovery in transected peripheral nerves may be improved and accelerated by hyperbaric oxygenation following microsurgical repair.

Neuroregenerative Effects of Preinjury FK-506 Administration

BACKGROUND

FK-506 is used in organ transplantation because it promotes neurite outgrowth in vitro and enhances neuroregeneration in peripheral nerve injury transection models. Immunosuppressive mechanisms of FK-506 are well defined, with demonstration of decreased neuroregenerative effects with delayed administration. The purpose of this study was to describe the effects of preinjury administration of FK-506 in rats with tibial nerve transection injury.

METHODS

Eight inbred male Lewis rats per group in three separate groups underwent tibial nerve transection with primary repair. Group I received placebo, group II received FK-506 treatment at 1 day before surgery, and group III received FK-506 preloading 3 days before surgery.

RESULTS

Histologic and histomorphometric results demonstrated the preload FK-506 group had superior results compared with the immediate FK-506 group. Both FK-506 groups were superior to the placebo group. The preload FK-506 demonstrated superior regeneration in mean total nerve fiber counts (p < 0.05), greater percentage neural tissue (p < 0.05), greater mean nerve fiber density (p < 0.05), and lower percentage of debris (p > 0.05). Mean nerve fiber widths were similar in the preload and immediate FK-506 groups but superior to the placebo group.

CONCLUSION

These data suggest that enhancement of FK-506's neuroregenerative effect is enhanced when administered before nerve injury such as when performing elective surgery.

Pediatric neurotrauma in Kathmandu, Nepal: implications for injury management and control

OBJECTS

There is a scarcity of data regarding childhood neurological injuries in developing countries such as Nepal. The epidemiology of acute pediatric neurotrauma in Kathmandu was studied to assess the implications of these data for injury prevention programs.

METHODS

The clinical records of patients <or=18 years who presented to Tribhuvan University Teaching Hospital between April 1, 2001 and April 1, 2004 with acute neurological trauma and were subsequently admitted to hospital were retrospectively reviewed. A standard proforma was used to collect information on patient demographics, the nature and etiology of the injuries, their acute management, and outcomes.

CONCLUSIONS

Four hundred sixteen injured children were admitted to hospital, and the charts for 352 (85%) were available for review. Spinal injuries were relatively rare (4%) compared to head injuries (96%). Falls were the most common cause of injuries (61%). It took significantly longer (p<0.001) for children injured in rural Nepal (62%) to obtain neurosurgical care (30.1 h) than those injured within Kathmandu (7.1 h). A Glasgow Outcome Score of 5 was obtained for 96%, 76%, and 22% of patients with mild, moderate, or severe head injuries, respectively. Besides efforts to improve prehospital transport and acute management of these injuries, preventive measures that are applicable to the Nepalese scenario are urgently needed. Interventions should focus on health education programs directed at parents and children and upgrading of road safety measures. Neurological injuries must also be viewed in the context of the broader social issues in Nepal that contribute to injury.

Closed fractures complicated by peripheral nerve injury

Closed fractures may be complicated by associated peripheral nerve injury. However, because clinical information is limited, determining the best course of treatment is difficult. Most patients with closed fractures have a local nerve injury without nerve division; their prognosis for recovery is favorable. In the acute setting, immediate surgery is usually unwarranted because of the difficulty in accurately defining the severity and extent of nerve injury. When débridement of an open fracture or repair is not required, peripheral nerve injuries are best observed and the extremity treated with splinting and exercise to prevent loss of joint motion. Patients who fail to demonstrate signs of recovery at 6 months, either clinically or with electrodiagnostic testing, should undergo exploration to maximize the likelihood for return of function. When, during exploration, the nerve is in continuity, intraoperative measurement of nerve action potentials should be done. Measuring nerve action potentials will determine whether nerve grafting, local neurolysis, or excision of the injured segment, accompanied by primary repair, is the most appropriate treatment.

Severe posttraumatic craniocervical instability in the very young patient. Report of three cases

Children younger than 3 years of age represent a distinct subpopulation of patients at particular risk for high cervical and craniovertebral injuries. There are few descriptions of survivors of severe craniocervical trauma among the very young, and scarce data exist regarding management after initial emergency stabilization. The authors describe three children, age 1 to 32 months, who presented with craniocervical junction injuries. Variable neurological findings were observed at presentation (cranial nerve deficits, obtundation, and moderate-to-severe quadriparesis). All three were treated with prolonged immobilization and have recovered with minimal to no neurological deficit.

Scapulothoracic dissociation: evaluation and management

Scapulothoracic dissociation is an infrequent injury with potentially devastating outcomes. Knowledge of this injury is based on small patient series and case reports. The aim of this article is to review the evaluation, management and functional outcomes following scapulothoracic dissociation. Often caused by high traction forces applied to the shoulder girdle, there is a complete loss of the scapulothoracic articulation with lateral scapular displacement and intact skin. This is frequently associated with muscular, ligamentous and osseous injuries to the shoulder girdle, vascular injuries to the subclavian, or axillary, vessels and brachial plexus lesions. In the acute setting, the timely diagnosis of the associated neurovascular injuries is crucial. Severe neurovascular and soft tissue compromise often requires an early above-elbow amputation. Further, complete brachial plexus avulsions are associated with a limited potential for functional recovery.

Endogenous stem cell proliferation after central nervous system injury: alternative therapeutic options

The continuous regeneration of glial cells arising from endogenous stem cell populations in the central nervous system (CNS) occurs throughout life in mammals. In the ongoing research to apply stem cell therapy to neurological diseases, the capacity to harness the multipotential ability of endogenous stem cell populations has become apparent. Such cell populations proliferate in response to a variety of injury states in the CNS, but in the absence of a supportive microenvironment they contribute little to any significant behavioral recovery. In the authors' laboratory and elsewhere, recent research on the regenerative potential of these stem cells in disease states such as spinal cord injury has demonstrated that the cells' proliferative potential may be greatly upregulated in response to appropriate growth signals and exogenously applied trophic factors. Further understanding of the potential of such multipotent cells and the mechanisms responsible for creating a favorable microenvironment for them may lead to additional therapeutic alternatives in the setting of neurological diseases. These therapies would require no exogenous stem cell sources and thus would avoid the ethical and moral considerations regarding their use. In this review the authors provide a brief overview of the enhancement of endogenous stem cell proliferation following neurological insult.

[Advances of functional electrical stimulation in treatment of peripheral nerve injuries]

OBJECTIVE

To review the advances of functional electrical stimulation (FES) in treatment of peripheral nerve injuries.

METHODS

By index of recent literature, the measures of stimulation, the mechanisms of FES and unsolved problems were evaluated and analyzed.

RESULTS

Great advances have been made in the treatment of peripheral nerve injuries. It can not only enhance the regeneration of injured peripheral nerve, but also prevent muscular atrophy.

CONCLUSION

FES is an effective treatment for peripheral nerve injuries.

Injuries to the lumbar spine: identification and management

Fifteen percent of spinal injuries occur in the lumbosacral region. Damage to the spinal cord or cauda equina is a possible complication. Thorough assessment of all trauma patients for such injuries will result in early diagnosis and optimal outcome can be achieved. This article looks at the identification and management of injuries to the lumbar spine.

Management of posttraumatic vertigo

OBJECTIVE

To evaluate patients after blunt trauma of the head, neck, and craniocervical junction (without fractures) with vertigo and to report the results of treatment after extensive diagnostics.

STUDY DESIGN

Prospective study of consecutive new cases with vertigo after trauma at different periods of onset. During 2000-2002, 63 patients were examined and treated.

SETTING

Regional trauma medical center for the greater Berlin Area, tertiary referral unit.

RESULTS

The primary disorders included labyrinthine concussion (18), rupture of the round window membrane (6), and cervicogenic vertigo (12). The secondary disorders included otolith disorders (5), delayed endolymphatic hydrops (12), and canalolithiasis (9). The patients were free of vertigo symptoms (except cervicogenic and otolith disorder) after treatment, which consisted of habituation training, medical and surgical therapy options. The follow-up was 1 year.

CONCLUSION

Posttraumatic vertigo can be treated with a high success rate once the underlying disorder has been identified. The extent of the neurotological test battery determines the precision and quality of diagnostics. Surgical measures should be an integral part of treatment modalities if conservative treatment is not effective.

SIGNIFICANCE

Minor trauma of the head, neck, and craniocervical junction can have major impact on the vestibular system at different sites. Patients need to be carefully diagnosed, even if the onset of vertigo occurs a few weeks or months after the initial trauma.

Management of birth injuries

Birth injuries are a significant cause of neonatal morbidity and mortality. Although often associated with traumatic delivery, birth injuries often occur in normal spontaneous deliveries in the absence of any risk factors. This article discusses the diagnosis and management of the most common birth injuries that are encountered by health care providers who care for newborns.

Pediatric hand trauma

Hand injuries in infants are an exciting challenge for those who treat pediatric trauma patients. We will review different hand injuries and provide basic rules for their treatment and followup. We will compare our experience with published results. When compared with adults, two main differences arise in treatment of pediatric hand injuries: children have an exceptional regenerative ability that allows procedures to be used that would not be useful in older patients (eg, replantation after avulsion injuries) and children have a high degree of cooperation with physicians. The main goal of treatment should be to have children return quickly to their daily leisure and academic activities.

Critical care requirements after mass toxic agent release

There is an increasing risk of mass exposure of civil populations after release of toxic agents. These include military chemical warfare agents or industrial compounds, some of which have been used as a chemical. The traditional military divisions among chemical agents, toxins, and biologic agents may be viewed as a continuous spectrum of hazards. Each of these has four specific qualities (toxicity, latency, persistency, and transmissibility), which determine management of casualties and the toxic release. Toxic hazards may be released accidentally or deliberately, producing potentially large numbers of casualties. Previous incidents have shown that many of these require extended hospital care. This article reviews aspects of the nature of the toxic agents, the pathophysiology they produce, and therapeutic measures. The central and peripheral nervous systems and the respiratory systems are particularly vulnerable and may lead to fatal results unless early action is taken. Specific antidotes and life support care is required at all levels of prehospital and hospital management. Critical care management is required for severe cases, and this must combine continuing antidote, ventilatory and supportive therapy.

Controlled Autoimmunity in CNS Maintenance and Repair: Naturally Occurring CD4+CD25+ Regulatory T-Cells at the Crossroads of Health and Disease

T-cells directed to self-antigens ("autoimmune" T-cells) have traditionally been perceived as tending to attack the body's own tissues, and likely to exert their destructive effects unless they undergo deletion in the thymus during ontogeny. Naturally occurring CD4+CD25+ regulatory T-cells were viewed as thymus-derived cells that constitutively suppress any autoimmune T-cells that escaped thymic deletion. Studies in recent years suggest, however, that some autoimmune T-cells are necessary, at least in the central nervous system for neural maintenance and repair, possibly in part by rendering the resident microglia capable of fighting off adverse conditions, as well as for neural maintenance and repair. In line with this notion, the regulatory T-cells are thought to allow autoimmunity to exist in healthy individuals without causing an autoimmune disease. This proposed immune scenario and its implications for therapy are discussed.

The effect of neural embryonic stem cell therapy in a rat model of cavernosal nerve injury

OBJECTIVE

To isolate embryonic stem cells that have differentiated along the neuronal cell line, and to assess whether injecting these neural stem cells into the corpus cavernosum influences cavernosal nerve regeneration and functional status.

MATERIALS AND METHODS

Embryonic neural stem cells were obtained; 26 male Sprague-Dawley rats were divided into four groups: five had a sham operation; eight (controls) had a bilateral cavernosal nerve crush and injection of culture medium into the corpora cavernosa; four had an injection of neural embryonic stem (NES) cells into the major pelvic ganglion (MPG); and nine had bilateral cavernosal nerve crush and injection of NES cells into the corpora cavernosa. Erectile response was assessed by cavernosal nerve electrostimulation at 3 months, and penile tissue samples were evaluated histochemically for nitric oxide synthase (NOS)-containing fibres, tyrosine hydroxylase and neurofilament staining.

RESULTS

The groups injected with NES cells into the MPG and corpora cavernosa had significantly higher intracavernosal pressures than the control group. Immunohistochemical staining also revealed differences in the quality of the NOS-containing nerve fibres. Neurofilament staining was significantly better in the experimental groups injected with NES cells.

CONCLUSION

We were able to isolate embryonic stem cells that had differentiated along the neural cell line and, using these NES cells intracavernosally, showed improved erectile function in a rat model of neurogenic impotence.

Management of birth injuries

Birth injuries are a significant cause of neonatal morbidity and mortality. Although they are frequently associated with traumatic delivery, birth injuries often occur in normal spontaneous deliveries in the absence of any risk factors. This article discusses the diagnosis and management of the most common birth injuries encountered by health care providers caring for newborns.