Recovery of the pulmonary chemoreflex and functional role of bronchopulmonary C-fibers following chronic cervical spinal cord injury

2014 ◽  
Vol 117 (10) ◽  
pp. 1188-1198 ◽  
Author(s):  
Kun-Ze Lee ◽  
Yu-Shuo Chang
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Injury Severity ◽  
Spinal Cord Injuries ◽  
Breathing Pattern ◽  
Chronic Injury ◽  
C Fibers ◽  
Cord Injury ◽  
C Fiber

Persistent impairment of pulmonary defense reflexes is a critical factor contributing to pulmonary complications in patients with spinal cord injuries. The pulmonary chemoreflex evoked by activation of bronchopulmonary C-fibers has been reported to be abolished in animals with acute cervical hemisection (C2Hx). The present study examined whether the pulmonary chemoreflex can recover during the chronic injury phase and investigated the role of bronchopulmonary C-fibers on the altered breathing pattern after C2Hx. In the first protocol, bronchopulmonary C-fibers were excited by intrajugular capsaicin administration in uninjured and complete C2Hx animals 8 wk postsurgery. Capsaicin evoked pulmonary chemoreflexes in both groups, but the reflex intensity was significantly weaker in C2Hx animals. To examine whether spared spinal white matter tissue contributes to pulmonary chemoreflex recovery, the reflex was evaluated in animals with different extents of lateral injury. Linear regression analyses revealed that tidal volume significantly correlated with the extent of spared tissue; however, capsaicin-induced apnea was not related to injury severity when the ipsilateral-to-contralateral white matter ratio was <50%. In the second protocol, the influence of background bronchopulmonary C-fiber activity on respiration was investigated by blocking C-fiber conduction via perivagal capsaicin treatment. The rapid shallow breathing of C2Hx animals persisted after perivagal capsaicin treatment despite attenuation of pulmonary chemoreflexes. These results indicate that the pulmonary chemoreflex can recover to some extent following spinal injury, but remains attenuated even when there is moderate spinal tissue sparing, and that altered breathing pattern of C2Hx animals cannot be attributed to endogenous activation of bronchopulmonary C-fibers.

scholarly journals Exoskeletons, Rehabilitation and Bodily Capacities

2021 ◽  
pp. 1357034X2110256
Author(s):  
Denisa Butnaru
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Crucial Role ◽  
Spinal Cord Injuries ◽  
Main Task ◽  
Cerebrovascular Accidents ◽  
Complex Processes ◽  
Cord Injury ◽  
Neurological Conditions

Motility impairments resulting from spinal cord injuries and cerebrovascular accidents are increasingly prevalent in society, leading to the growing development of rehabilitative robotic technologies, among them exoskeletons. This article outlines how bodies with neurological conditions such as spinal cord injury and stroke engage in processes of re-appropriation while using exoskeletons and some of the challenges they face. The main task of exoskeletons in rehabilitative environments is either to rehabilitate or ameliorate anatomic functions of impaired bodies. In these complex processes, they also play a crucial role in recasting specific corporeal phenomenologies. For the accomplishment of these forms of corporeal re-appropriation, the role of experts is crucial. This article explores how categories such as bodily resistance, techno-inter-corporeal co-production of bodies and machines, as well as body work mark the landscape of these contemporary forms of impaired corporeality. While defending corporeal extension rather than incorporation, I argue against the figure of the ‘cyborg’ and posit the idea of ‘residual subjectivity’.

scholarly journals Important Role of Reverse Na+-Ca2+Exchange in Spinal Cord White Matter Injury at Physiological Temperature

2000 ◽  
Vol 84 (2) ◽  
pp. 1116-1119 ◽  
Author(s):  
Shuxin Li ◽  
Qiubo Jiang ◽  
Peter K. Stys
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Traumatic Injury ◽  
White Matter Injury ◽  
Mechanical Trauma ◽  
White Matter Tracts ◽  
Physiological Temperature ◽  
Cord Injury ◽  
Cellular Ca

Spinal cord injury is a devastating condition in which most of the clinical disability results from dysfunction of white matter tracts. Excessive cellular Ca2+ accumulation is a common phenomenon after anoxia/ischemia or mechanical trauma to white matter, leading to irreversible injury because of overactivation of multiple Ca2+-dependent biochemical pathways. In the present study, we examined the role of Na+-Ca2+ exchange, a ubiquitous Ca2+ transport mechanism, in anoxic and traumatic injury to rat spinal dorsal columns in vitro. Excised tissue was maintained in a recording chamber at 37°C and injured by exposure to an anoxic atmosphere for 60 min or locally compressed with a force of 2 g for 15 s. Mean compound action potential amplitude recovered to ≈25% of control after anoxia and to ≈30% after trauma. Inhibitors of Na+-Ca2+ exchange (50 μM bepridil or 10 μM KB-R7943) improved functional recovery to ≈60% after anoxia and ≈70% after traumatic compression. These inhibitors also prevented the increase in calpain-mediated spectrin breakdown products induced by anoxia. We conclude that, at physiological temperature, reverse Na+-Ca2+exchange plays an important role in cellular Ca2+ overload and irreversible damage after anoxic and traumatic injury to dorsal column white matter tracts.

scholarly journals White matter regeneration induced by aligned fibrin nanofiber hydrogel contributes to motor functional recovery in canine T12 spinal cord injury

2021 ◽  
Author(s):  
Zheng Cao ◽  
Weitao Man ◽  
Yuhui Xiong ◽  
Yi Guo ◽  
Shuhui Yang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Nerve Regeneration ◽  
Spinal Cord Injuries ◽  
Diffusion Tensor ◽  
Nerve Fibers ◽  
Functional Restoration ◽  
Large Animal ◽  
Cord Injury

Abstract A hierarchically aligned fibrin hydrogel (AFG) that possesses soft stiffness and aligned nanofiber structure has been successfully proven to facilitate neuroregeneration in vitro and in vivo. However, its potential in promoting nerve regeneration in large animal models that is critical for clinical translation has not been sufficiently specified. Here, the effects of AFG on directing neuroregeneration in canine hemisected T12 spinal cord injuries were explored. Histologically obvious white matter regeneration consisting of a large area of consecutive, compact, and aligned nerve fibers is induced by AFG, leading to a significant motor functional restoration. The canines with AFG implantation start to stand well with their defective legs from 3 to 4 weeks postoperatively and even effortlessly climb the steps from 7 to 8 weeks. Moreover, high-resolution multi-shot diffusion tensor imaging illustrates the spatiotemporal dynamics of nerve regeneration rapidly crossing the lesion within 4 weeks in the AFG group. Our findings indicate that AFG could be a potential therapeutic vehicle for spinal cord injury by inducing rapid white matter regeneration and restoring locomotion, pointing out its promising prospect in clinic practice.

scholarly journals Controversies in the Surgical Management of Spinal Cord Injuries

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ahmed M. Raslan ◽  
Andrew N. Nemecek
Keyword(s):  
Spinal Cord ◽  
Surgical Treatment ◽  
Surgical Management ◽  
Spinal Cord Injuries ◽  
Late Onset ◽  
Initial Step ◽  
Outcome Data ◽  
Cord Injury ◽  
The Usa

Traumatic spinal cord injury (SCI) affects over 200,000 people in the USA and is a major source of morbidity, mortality, and societal cost. Management of SCI includes several components. Acute management includes medical agents and surgical treatment that usually includes either all or a combination of reduction, decompression, and stabilization. Physical therapy and rehabilitation and late onset SCI problems also play a role. A review of the literature in regard to surgical management of SCI patients in the acute setting was undertaken. The controversy surrounding whether reduction is safe, or not, and whether prereduction magnetic resonance (MR) imaging to rule out traumatic disc herniation is essential is discussed. The controversial role of timing of surgical intervention and the choice of surgical approach in acute, incomplete, and acute traumatic SCI patients are reviewed. Surgical treatment is an essential tool in management of SCI patients and the controversy surrounding the timing of surgery remains unresolved. Presurgical reduction is considered safe and essential in the management of SCI with loss of alignment, at least as an initial step in the overall care of a SCI patient. Future prospective collection of outcome data that would suffice as evidence-based is recommended and necessary.

scholarly journals Hydrogels and Cell Based Therapies in Spinal Cord Injury Regeneration

2015 ◽  
Vol 2015 ◽  
pp. 1-24 ◽  
Author(s):  
Rita C. Assunção-Silva ◽  
Eduardo D. Gomes ◽  
Nuno Sousa ◽  
Nuno A. Silva ◽  
António J. Salgado
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Cell Survival ◽  
Spinal Cord Injuries ◽  
Human Stem Cells ◽  
Related Disorder ◽  
Cord Injury ◽  
Cell Carriers

Spinal cord injury (SCI) is a central nervous system- (CNS-) related disorder for which there is yet no successful treatment. Within the past several years, cell-based therapies have been explored for SCI repair, including the use of pluripotent human stem cells, and a number of adult-derived stem and mature cells such as mesenchymal stem cells, olfactory ensheathing cells, and Schwann cells. Although promising, cell transplantation is often overturned by the poor cell survival in the treatment of spinal cord injuries. Alternatively, the therapeutic role of different cells has been used in tissue engineering approaches by engrafting cells with biomaterials. The latter have the advantages of physically mimicking the CNS tissue, while promoting a more permissive environment for cell survival, growth, and differentiation. The roles of both cell- and biomaterial-based therapies as single therapeutic approaches for SCI repair will be discussed in this review. Moreover, as the multifactorial inhibitory environment of a SCI suggests that combinatorial approaches would be more effective, the importance of using biomaterials as cell carriers will be herein highlighted, as well as the recent advances and achievements of these promising tools for neural tissue regeneration.

Role of Microglia and Astrocytes in Spinal Cord Injury Induced Neuropathic Pain

2021 ◽  
pp. 097275312110463
Author(s):  
Gurwattan S. Miranpuri ◽  
Parul Bali ◽  
Justyn Nguyen ◽  
Jason J Kim ◽  
Shweta Modgil ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neuropathic Pain ◽  
Spinal Cord Injuries ◽  
Medical Condition ◽  
The United States ◽  
Current Treatment ◽  
Treatment Modalities ◽  
Cord Injury

Spinal cord injuries incite varying degrees of symptoms in patients, ranging from weakness and incoordination to paralysis. Common amongst spinal cord injury (SCI) patients, neuropathic pain (NP) is a debilitating medical condition. Unfortunately, there remain many clinical impediments in treating NP because there is a lack of understanding regarding the mechanisms behind SCI-induced NP (SCINP). Given that more than 450,000 people in the United States alone suffer from SCI, it is unsatisfactory that current treatments yield poor results in alleviating and treating NP. In this review, we briefly discussed the models of SCINP along with the mechanisms of NP progression. Further, current treatment modalities are herein explored for SCINP involving pharmacological interventions targeting glia cells and astrocytes. The studies presented in this review provide insight for new directions regarding SCINP alleviation. Given the severity and incapacitating effects of SCINP, it is imperative to study the pathways involved and find new therapeutic targets in coordination with stem cell research, and to develop a new gold-standard in SCINP treatment.

scholarly journals Longitudinal changes in DTI parameters of specific spinal white matter tracts correlate with behavior following spinal cord injury in monkeys

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Arabinda Mishra ◽  
Feng Wang ◽  
Li Min Chen ◽  
John C. Gore
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Spinal Cord Injuries ◽  
Diffusion Tensor ◽  
Cervical Spinal Cord ◽  
Human Subjects ◽  
Realistic Model ◽  
White Matter Tracts ◽  
Injured Side ◽  
Cord Injury

Abstract This study aims to evaluate how parameters derived from diffusion tensor imaging reflect axonal disruption and demyelination in specific white matter tracts within the spinal cord of squirrel monkeys following traumatic injuries, and their relationships to function and behavior. After a unilateral section of the dorsal white matter tract of the cervical spinal cord, we found that both lesioned dorsal and intact lateral tracts on the lesion side exhibited prominent disruptions in fiber orientation, integrity and myelination. The degrees of pathological changes were significantly more severe in segments below the lesion than above. The lateral tract on the opposite (non-injured) side was minimally affected by the injury. Over time, RD, FA, and AD values of the dorsal and lateral tracts on the injured side closely tracked measurements of the behavioral recovery. This unilateral section of the dorsal spinal tract provides a realistic model in which axonal disruption and demyelination occur together in the cord. Our data show that specific tract and segmental FA and RD values are sensitive to the effects of injury and reflect specific behavioral changes, indicating their potential as relevant indicators of recovery or for assessing treatment outcomes. These observations have translational value for guiding future studies of human subjects with spinal cord injuries.

scholarly journals Role of vagal fibers in the hypoxia-induced increases in end-expiratory lung volume and diaphragmatic activity

1997 ◽  
Vol 83 (3) ◽  
pp. 700-706 ◽  
Author(s):  
M. Bonora ◽  
M. Vizek
Keyword(s):  
Lung Volume ◽  
Breathing Pattern ◽  
Vagal Afferents ◽  
C Fibers ◽  
C Fiber ◽  
Before And After ◽  
Bilateral Vagotomy ◽  
Ventilatory Response To Hypoxia ◽  
Intact Rats

Bonora, M., and M. Vizek. Role of vagal fibers in the hypoxia-induced increases in end-expiratory lung volume and diaphragmatic activity. J. Appl. Physiol. 83(3): 700–706, 1997.—The possible role of pulmonary C fibers in the hypoxia-induced concomitant increases in end-expiratory lung volume (EELV) and in the activity of the diaphragm at the end of expiration (De) were evaluated by measuring the effects of hypoxia (10% O2) on ventilation, EELV, and De in eight chloralose-urethan anesthetized rats. Recordings were made before and after blocking vagal C fibers and after bilateral vagotomy. C-fiber conduction was blocked by applying capsaicin perineurally to the cervical vagi. The efficiency of C-fiber blockade was tested with intravenous capsaicin and its selectivity by the Hering-Breuer reflex. Perineural capsaicin abolished the reflex apnea induced by intravenous capsaicin and transiently reduced Hering-Breuer reflex. Perineural capsaicin affected neither ventilation, De, and EELV in air nor the hypoxia-induced increases in these parameters. Vagotomy caused the typical changes of breathing pattern in air, but the ventilatory response to hypoxia was unchanged. Vagotomy performed during hypoxia resulted in large decreases in De and EELV. Hypoxia increased De and EELV in vagotomized rats but less than in intact rats. We conclude that the hypoxia-induced increases in EELV and diaphragmatic activity are probably not mediated by vagal C fibers and that vagal afferents are involved but not fully responsible for this phenomenon.

Cervical Spinal Cord Injury Associated with Near-Drowning Does Not Increase Pneumonia Risk or Mortality

2011 ◽  
Vol 77 (4) ◽  
pp. 426-429
Author(s):  
Thomas Butler ◽  
Susanna Shin ◽  
Jay Collins ◽  
Rebecca C. Britt ◽  
Scott F. Reed ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Injury Severity ◽  
Spinal Cord Injuries ◽  
Cervical Spinal Cord ◽  
Demographic Data ◽  
Pulmonary Complications ◽  
Discharge Data ◽  
Near Drowning ◽  
Discharge Disposition ◽  
Cord Injury

Body surfing accidents (BSA) can cause cervical spinal cord injuries (CSCIs) that are associated with near-drowning (ND). The submersion injury from a ND can result in aspiration and predispose to pulmonary complications. We predicted a worse outcome (particularly the development of pneumonia) in patients with CSCIs associated with ND. A retrospective review was performed of patients who were treated at Eastern Virginia Medical School for a CSCI resulting from a blunt mechanism. Data collected included basic demographic data, data regarding injury and in-hospital outcomes, and discharge data, including discharge disposition. Statistics were performed using χ2 and Student t test. In 2003 to 2008, 141 patients were treated for CSCIs with inclusion criteria. Thirty patients (21%) had an associated ND (BSA) and 111 patients (79%) did not (BLT). The cohorts were similar in mean age (BSA, 45 years; BLT, 50 years; P = 0.16) and male gender distribution (BSA, 93%; BLT, 79%; P = 0.13). The cohorts were similar in injury severity using Injury Severity Score (BSA, 22; BLT, 24; P = 0.65). The cohorts were similar in rates of developing pneumonia (BSA, 3%; BLT, 12%; P = 0.31). The rate of infection was significantly higher in the cohort without an associated near-drowning (BSA, 10%; BLT, 32%; P = 0.033). The mean intensive care unit stay (BSA, 3.5 days; BLT, 11.3 days; P = 0.057) and the rate of mortality were similar (BSA, 10%; BLT, 10% P = 0.99). Those patients with an associated ND had a shorter hospital stay (BSA, 5.7 days; BLT, 22.2 days; P = 0.007) and a better chance of being discharged home (BSA, 57%; BLT, 27%; P = 0.004). CSCIs after a BSA do better than their counterparts without an associated ND. CSCIs associated with ND appear to be isolated injuries with minimal pulmonary involvement despite submersion injuries.

scholarly journals Brain White Matter Impairment in Patients with Spinal Cord Injury

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Weimin Zheng ◽  
Qian Chen ◽  
Xin Chen ◽  
Lu Wan ◽  
Wen Qin ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Injury Severity ◽  
Clinical Performance ◽  
Angular Gyrus ◽  
Precentral Gyrus ◽  
Transneuronal Degeneration ◽  
Brain White Matter ◽  
Cord Injury

It remains unknown whether spinal cord injury (SCI) could indirectly impair or reshape the white matter (WM) of human brain and whether these changes are correlated with injury severity, duration, or clinical performance. We choose tract-based spatial statistics (TBSS) to investigate the possible changes in whole-brain white matter integrity and their associations with clinical variables in fifteen patients with SCI. Compared with the healthy controls, the patients exhibited significant decreases in WM fractional anisotropy (FA) in the left angular gyrus (AG), right cerebellum (CB), left precentral gyrus (PreCG), left lateral occipital region (LOC), left superior longitudinal fasciculus (SLF), left supramarginal gyrus (SMG), and left postcentral gyrus (PostCG) (p<0.01, TFCE corrected). No significant differences were found in all diffusion indices between the complete and incomplete SCI. However, significantly negative correlation was shown between the increased radial diffusivity (RD) of left AG and total motor scores (uncorrectedp<0.05). Our findings provide evidence that SCI can cause not only direct degeneration but also transneuronal degeneration of brain WM, and these changes may be irrespective of the injury severity. The affection of left AG on rehabilitation therapies need to be further researched in the future.

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