scholarly journals Neuroprotective and Neurorestorative Processes after Spinal Cord Injury: The Case of the Bulbospinal Respiratory Neurons

2016 ◽  
Vol 2016 ◽  
pp. 1-15
Author(s):  
Anne Kastner ◽  
Valéry Matarazzo
Keyword(s):  
Spinal Cord ◽  
Molecular Mechanisms ◽  
Spinal Cord Injuries ◽  
Cervical Spinal Cord ◽  
Axon Growth ◽  
Respiratory Neurons ◽  
Partial Recovery ◽  
Respiratory Drive ◽  
Phrenic Motoneurons ◽  
Cord Injury

High cervical spinal cord injuries interrupt the bulbospinal respiratory pathways projecting to the cervical phrenic motoneurons resulting in important respiratory defects. In the case of a lateralized injury that maintains the respiratory drive on the opposite side, a partial recovery of the ipsilateral respiratory function occurs spontaneously over time, as observed in animal models. The rodent respiratory system is therefore a relevant model to investigate the neuroplastic and neuroprotective mechanisms that will trigger such phrenic motoneurons reactivation by supraspinal pathways. Since part of this recovery is dependent on the damaged side of the spinal cord, the present review highlights our current understanding of the anatomical neuroplasticity processes that are developed by the surviving damaged bulbospinal neurons, notably axonal sprouting and rerouting. Such anatomical neuroplasticity relies also on coordinated molecular mechanisms at the level of the axotomized bulbospinal neurons that will promote both neuroprotection and axon growth.

5-Hydroxytryptophan-induced respiratory recovery after cervical spinal cord hemisection in rats

2000 ◽  
Vol 89 (4) ◽  
pp. 1528-1536 ◽  
Author(s):  
Shi-Yi Zhou ◽  
Harry G. Goshgarian
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Phrenic Nerve ◽  
Serotonin Receptor ◽  
Cervical Spinal Cord ◽  
Respiratory Drive ◽  
Respiratory Pathway ◽  
Cord Injury ◽  
Respiratory Recovery ◽  
Spinal Cord Hemisection

The present study investigates the role of serotonin in respiratory recovery after spinal cord injury. Experiments were conducted on C2 spinal cord hemisected, anesthetized, vagotomized, paralyzed, and artificially ventilated rats in which end-tidal CO2 was monitored and maintained. Before drug administration, the phrenic nerve ipsilateral to hemisection showed no respiratory-related activity due to the disruption of the descending bulbospinal respiratory pathways by spinal cord hemisection. 5-Hydroxytryptophan (5-HTP), a serotonin precursor, was administrated intravenously. 5-HTP induced time- and dose-dependent increases in respiratory recovery in the phrenic nerve ipsilateral to hemisection. Although the 5-HTP-induced recovery was initially accompanied by an increase in activity in the contralateral phrenic nerve, suggesting an increase in descending respiratory drive, the recovery persisted well after activity in the contralateral nerve returned to predrug levels. 5-HTP-induced effects were reversed by a serotonin receptor antagonist, methysergide. Because experiments were conducted on animals subjected to C2 spinal cord hemisection, the recovery was most likely mediated by the activation of a latent respiratory pathway spared by the spinal cord injury. The results suggest that serotonin is an important neuromodulator in the unmasking of the latent respiratory pathway after spinal cord injury. In addition, the results also suggest that the maintenance of 5-HTP-induced respiratory recovery may not require a continuous enhancement of central respiratory drive.

scholarly journals Novel cytokine-loaded PCL-PEG scaffold composites for spinal cord injury repair

RSC Advances ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 6306-6314 ◽  
Author(s):  
Pangbo Wang ◽  
Hufei Wang ◽  
Kang Ma ◽  
Shi Wang ◽  
Chuanyan Yang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Extracellular Matrix ◽  
Spinal Cord Injuries ◽  
Composite Scaffold ◽  
Axon Growth ◽  
Injury Repair ◽  
Promising Strategy ◽  
Cord Injury

This “five-in-one” composite scaffold has been considered as a promising strategy to direct the axon growth, mimic the properties of natural extracellular matrix and finally be used to repair the spinal cord injuries.

Recurrent Asystole Resulting from High Cervical Spinal Cord Injuries

2006 ◽  
Vol 72 (6) ◽  
pp. 525-529 ◽  
Author(s):  
D.L. Franga ◽  
M.L. Hawkins ◽  
R.S. Medeiros ◽  
D. Adewumi
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Cervical Spinal Cord ◽  
Cardiac Pacemakers ◽  
Cord Injury ◽  
Pacemaker Placement ◽  
Level I ◽  
High Cervical ◽  
Short Time ◽  
Injured Patients

Cervical spinal cord injury is a highly morbid condition frequently associated with cardiovascular instability. This instability may include bradyarrhythmias, as well as hypotension, and usually resolves in a relatively short time. However, over a 3-year period (January 2003–December, 2005), 5 of 30 patients with complete cervical spinal cord injuries seen at our Level I trauma center required placement of permanent cardiac pacemakers for recurrent bradycardia/asystolic events. Strong consideration for pacemaker placement should be given for those spinal cord-injured patients with symptomatic bradyarrhythmic events still occurring 2 weeks after injury.

scholarly journals Targeted, activity-dependent spinal stimulation produces long-lasting motor recovery in chronic cervical spinal cord injury

2015 ◽  
Vol 112 (39) ◽  
pp. 12193-12198 ◽  
Author(s):  
Jacob G. McPherson ◽  
Robert R. Miller ◽  
Steve I. Perlmutter
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neural Plasticity ◽  
Enhanced Recovery ◽  
Cervical Spinal Cord ◽  
Spike Timing ◽  
Neurological Injury ◽  
Partial Recovery ◽  
Cord Injury ◽  
Activity Dependent

Use-dependent movement therapies can lead to partial recovery of motor function after neurological injury. We attempted to improve recovery by developing a neuroprosthetic intervention that enhances movement therapy by directing spike timing-dependent plasticity in spared motor pathways. Using a recurrent neural–computer interface in rats with a cervical contusion of the spinal cord, we synchronized intraspinal microstimulation below the injury with the arrival of functionally related volitional motor commands signaled by muscle activity in the impaired forelimb. Stimulation was delivered during physical retraining of a forelimb behavior and throughout the day for 3 mo. Rats receiving this targeted, activity-dependent spinal stimulation (TADSS) exhibited markedly enhanced recovery compared with animals receiving targeted but open-loop spinal stimulation and rats receiving physical retraining alone. On a forelimb reach and grasp task, TADSS animals recovered 63% of their preinjury ability, more than two times the performance level achieved by the other therapy groups. Therapeutic gains were maintained for 3 additional wk without stimulation. The results suggest that activity-dependent spinal stimulation can induce neural plasticity that improves behavioral recovery after spinal cord injury.

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 Insertion of magnetically controlled growing rods in a patient with a diaphragmatic pacemaker: case report

2017 ◽  
Vol 43 (4) ◽  
pp. E14 ◽  
Author(s):  
Andrew C. Vivas ◽  
Steven W. Hwang ◽  
Joshua M. Pahys
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Muscle Tone ◽  
Cervical Spinal Cord ◽  
Young Patients ◽  
Growing Rods ◽  
Growing Rod ◽  
Cord Injury ◽  
High Cervical ◽  
Magnetically Controlled Growing Rods

Phrenic stimulators offer an alternative to standard mechanical ventilation as well as the potential for ventilator independence in select patients with chronic respiratory failure. Young patients (< 10 years old) with high cervical spinal cord injuries often develop paralytic scoliosis due to loss of muscle tone caudal to their spinal cord lesion. Growing rod systems allow for stabilization of spinal deformity while permitting continued growth of the spine and thoracic cavity. Magnetically controlled growing rods (MCGRs) offer the advantage of noninvasive expansion, as opposed to the operative expansion required in traditional growing rod systems. To the authors’ knowledge, this is the first reported case of MCGRs in a patient with a diaphragmatic pacemaker (DP). A 7-year-old boy with ventilator dependence after a high cervical spinal cord injury presented to the authors’ institution with paralytic scoliosis that progressed to > 120°. The patient had previously undergone insertion of phrenic nerve stimulators for diaphragmatic pacing. The decision was made to insert MCGRs bilaterally to stabilize his deformity, because the planned lengthening surgeries that are necessary with traditional growing rods would be poorly tolerated in this patient. The patient’s surgery and postoperative course were uneventful. The DP remained functional after insertion and lengthening of the MCGRs by using the external magnet. The DP had no effect on the expansion capability of the MCGRs. In conclusion, the MCGRs appear to be compatible with the DP. Further studies are needed to validate the long-term safety and compatibility of these 2 devices.

Invited Review: The crossed phrenic phenomenon: a model for plasticity in the respiratory pathways following spinal cord injury

2003 ◽  
Vol 94 (2) ◽  
pp. 795-810 ◽  
Author(s):  
Harry G. Goshgarian
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Mammalian Species ◽  
Respiratory Muscles ◽  
Respiratory Drive ◽  
Respiratory Pathway ◽  
Physiological Basis ◽  
Cord Injury ◽  
Crossed Phrenic Phenomenon

Hemisection of the cervical spinal cord rostral to the level of the phrenic nucleus interrupts descending bulbospinal respiratory pathways, which results in a paralysis of the ipsilateral hemidiaphragm. In several mammalian species, functional recovery of the paretic hemidiaphragm can be achieved by transecting the contralateral phrenic nerve. The recovery of the paralyzed hemidiaphragm has been termed the “crossed phrenic phenomenon.” The physiological basis for the crossed phrenic phenomenon is as follows: asphyxia induced by spinal hemisection and contralateral phrenicotomy increases central respiratory drive, which activates a latent crossed respiratory pathway. The uninjured, initially latent pathway mediates the hemidiaphragm recovery by descending into the spinal cord contralateral to the hemisection and then crossing the midline of the spinal cord before terminating on phrenic motoneurons ipsilateral and caudal to the hemisection. The purpose of this study is to review work conducted on the crossed phrenic phenomenon and to review closely related studies focusing particularly on the plasticity associated with the response. Because the review deals with recovery of respiratory muscles paralyzed by spinal cord injury, the clinical relevance of the reviewed studies is highlighted.

scholarly journals Combined medical and surgical treatment after acute spinal cord injury: results of a prospective pilot study to assess the merits of aggressive medical resuscitation and blood pressure management

1999 ◽  
Vol 6 (1) ◽  
pp. E6 ◽  
Author(s):  
Fernando L. Vale ◽  
Jennifer Burns ◽  
Amie B. Jackson ◽  
Mark N. Hadley
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Cervical Spinal Cord ◽  
Bladder Function ◽  
Thoracic Spinal Cord ◽  
Arterial Blood ◽  
Thoracic Spinal ◽  
Cord Injury

The optimal management of acute spinal cord injuries remains to be defined. The authors prospectively applied resuscitation principles of volume expansion and blood pressure maintenance to 77 patients who presented with acute neurological deficits as a result of spinal cord injuries occurring from C-1 through T-12 in an effort to maintain spinal cord blood flow and prevent secondary injury. According to the Intensive Care Unit protocol, all patients were managed by Swan-Ganz and arterial blood pressure catheters and were treated with immobilization and fracture reduction as indicated. Intravenous fluids, colloid, and vasopressors were administered as necessary to maintain mean arterial blood pressure above 85 mm Hg. Surgery was performed for decompression and stabilization, and fusion in selected cases. Sixty-four patients have been followed at least 12 months postinjury by means of detailed neurological assessments and functional ability evaluations. Sixty percent of patients with complete cervical spinal cord injuries improved at least one Frankel or American Spinal Injury Association (ASIA) grade at the last follow-up review. Thirty percent regained the ability to walk and 20% had return of bladder function 1 year postinjury. Thirty-three percent of the patients with complete thoracic spinal cord injuries improved at least one Frankel or ASIA grade. Approximately 10% of the patients regained the ability to walk and had return of bladder function. As of the 12-month follow-up review, 92% of patients demonstrated clinical improvement after sustaining incomplete cervical spinal cord injuries compared to their initial neurological status. Ninety-two percent regained the ability to walk and 88% regained bladder function. Eighty-eight percent of patients with incomplete thoracic spinal cord injuries demonstrated significant improvements in neurological function 1 year postinjury. Eighty-eight percent were able to walk and 63% had return of bladder function. The authors conclude that the enhanced neurological outcome that was observed in patients after spinal cord injury in this study was in addition to, and/or distinct from, any potential benefit provided by surgery. Early and aggressive medical management (volume resuscitation and blood pressure augmentation) of patients with acute spinal cord injuries optimizes the potential for neurological recovery after sustaining trauma.

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