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Malone IG, Nosacka RL, Nash MA, Otto KJ, Dale EA. Electrical epidural stimulation of the cervical spinal cord: implications for spinal respiratory neuroplasticity after spinal cord injury. J Neurophysiol 2021; 126:607-626. [PMID: 34232771 PMCID: PMC8409953 DOI: 10.1152/jn.00625.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 06/07/2021] [Accepted: 06/27/2021] [Indexed: 01/15/2023] Open
Abstract
Traumatic cervical spinal cord injury (cSCI) can lead to damage of bulbospinal pathways to the respiratory motor nuclei and consequent life-threatening respiratory insufficiency due to respiratory muscle paralysis/paresis. Reports of electrical epidural stimulation (EES) of the lumbosacral spinal cord to enable locomotor function after SCI are encouraging, with some evidence of facilitating neural plasticity. Here, we detail the development and success of EES in recovering locomotor function, with consideration of stimulation parameters and safety measures to develop effective EES protocols. EES is just beginning to be applied in other motor, sensory, and autonomic systems; however, there has only been moderate success in preclinical studies aimed at improving breathing function after cSCI. Thus, we explore the rationale for applying EES to the cervical spinal cord, targeting the phrenic motor nucleus for the restoration of breathing. We also suggest cellular/molecular mechanisms by which EES may induce respiratory plasticity, including a brief examination of sex-related differences in these mechanisms. Finally, we suggest that more attention be paid to the effects of specific electrical parameters that have been used in the development of EES protocols and how that can impact the safety and efficacy for those receiving this therapy. Ultimately, we aim to inform readers about the potential benefits of EES in the phrenic motor system and encourage future studies in this area.
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Affiliation(s)
- Ian G Malone
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida
- Breathing Research and Therapeutics Center (BREATHE), University of Florida, Gainesville, Florida
| | - Rachel L Nosacka
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Marissa A Nash
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
| | - Kevin J Otto
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida
- Breathing Research and Therapeutics Center (BREATHE), University of Florida, Gainesville, Florida
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
- Department of Neuroscience, University of Florida, Gainesville, Florida
- Department of Neurology, University of Florida, Gainesville, Florida
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Erica A Dale
- Breathing Research and Therapeutics Center (BREATHE), University of Florida, Gainesville, Florida
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Department of Neuroscience, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
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Spontaneous Functional Recovery in a Paralyzed Hemidiaphragm Following Upper Cervical Spinal Cord Injury in Adult Rats. Neurorehabil Neural Repair 2016. [DOI: 10.1177/154596839901300404] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Previous studies have shown that latent respiratory pathways can be activated by as phyxia or systemic theophylline administration to restore function to a hemidiaphragm paralyzed by C2 spinal cord hemisection in adult female rats. Based on this premise, electrophysiologic recording techniques were employed in the present investigation to first determine qualitatively whether latent respiratory pathways are activated spon taneously following prolonged post hemisection periods (4-16 weeks) without any therapeutic intervention. Our second objective in a separate group of hemisected an imals was to quantitate any documented functional recovery under the following stan dardized recording conditions: bilateral vagotomy, paralysis with pancuronium bro mide, artificial ventilation, and constant PCO2(maintained at 25 mmHg).
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Mateika JH, Komnenov D. Intermittent hypoxia initiated plasticity in humans: A multipronged therapeutic approach to treat sleep apnea and overlapping co-morbidities. Exp Neurol 2016; 287:113-129. [PMID: 27170208 DOI: 10.1016/j.expneurol.2016.05.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/18/2016] [Accepted: 05/03/2016] [Indexed: 10/21/2022]
Abstract
Over the past three decades exposure to intermittent hypoxia (IH) has generally been considered a stimulus associated with a number of detrimental outcomes. However, there is sufficient evidence to link IH to many beneficial outcomes but they have largely been ignored, particularly in the field of sleep medicine in the United States. Recent reviews have postulated that this apparent contradiction is related to the severity and duration of exposure to IH; mild forms of IH initiate beneficial outcomes while severe forms of IH are coupled to detrimental consequences. In the present review we explore the role that IH has in initiating respiratory plasticity and the potential this form of plasticity has to mitigate obstructive sleep apnea (OSA) in humans. In taking this approach, we address the possibility that IH could serve as an adjunct therapy coupled with continuous positive airway pressure (CPAP) to treat OSA. Our working hypothesis is that exposure to mild IH leads to respiratory plasticity that manifests in increased stability of the upper airway, which could ultimately reduce the CPAP required to treat OSA. In turn, this reduction could increase CPAP compliance and extend the length of treatment each night, which might improve the magnitude of outcome measures. Improved treatment compliance coupled with the direct effect that IH has on numerous overlapping conditions (i.e. asthma, chronic obstructive pulmonary disease, spinal cord injury) may well lead to substantial improvements that exceed outcomes following treatment with CPAP alone. Overall, this review will consider evidence from the published literature which suggests that IH could serve as an effective multipronged therapeutic approach to treat sleep apnea and its overlapping co-morbidities.
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Affiliation(s)
- Jason H Mateika
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, United States; Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, United States; Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI 48201, United States.
| | - Dragana Komnenov
- John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, United States; Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, United States
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A center's experience: pulmonary function in spinal cord injury. Lung 2014; 192:339-46. [PMID: 24723067 DOI: 10.1007/s00408-014-9575-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/10/2014] [Indexed: 01/24/2023]
Abstract
Traumatic spinal cord injury (SCI) is associated with significant psychological and physical challenges. A multidisciplinary approach to management is essential to ensure recovery during the acute phase, and comprehensive rehabilitative strategies are necessary to foster independence and quality of life throughout the chronic phase of injury. Complications that beset these individuals are often a unique consequence of SCI, and knowledge of the effects of SCI upon organ systems is essential for appropriate management. According to the National SCI Statistical Center (NSCISC), as of 2010 there were an estimated 265,000 persons living with SCI in the United States, with approximately 12,000 incidence cases annually. Although life expectancy for newly injured individuals with SCI is markedly reduced, persons with chronic SCI are expected to live about as long as individuals without SCI; however, longevity varies inversely with level of injury. Since 2005, 56 % of persons with SCI are tetraplegic, and due to paralysis of respiratory muscles, these individuals may be especially prone to pulmonary complications, which remain a major cause of mortality among persons with chronic SCI. We at the VA Rehabilitation Research and Development Center of Excellence for the Medical Consequences of SCI at the James J. Peters VA Medical Center have devoted more than 25 years to the study of secondary medical conditions that complicate SCI. Herein, we review pulmonary research at the Center, both our past and future endeavors, which form an integral part of our multidisciplinary approach toward achieving a greater understanding of and improving care for veterans with SCI.
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Bauman WA, Korsten MA, Radulovic M, Schilero GJ, Wecht JM, Spungen AM. 31st g. Heiner sell lectureship: secondary medical consequences of spinal cord injury. Top Spinal Cord Inj Rehabil 2012; 18:354-78. [PMID: 23459498 PMCID: PMC3584784 DOI: 10.1310/sci1804-354] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Persons with spinal cord injury (SCI) have secondary medical consequences of paralysis and/or the consequences of extreme inactivity. The metabolic changes that result from reduced activity include insulin resistance with carbohydrate disorders and dyslipidemia. A higher prevalence of coronary artery calcification was found in persons with SCI than that in matched able-bodied controls. A depression in anabolic hormones, circulating testosterone and growth hormone, has been described. Adverse soft tissue body composition changes of increased adiposity and reduced skeletal muscle are appreciated. Immobilization is the cause for sublesional disuse osteoporosis with an associated increased risk of fragility fracture. Bowel dysmotility affects all segments of the gastrointestinal tract, with an interest in better defining and addressing gastroesophageal reflux disease and difficulty with evacuation. Developing and testing more effective approaches to cleanse the bowel for elective colonoscopy are being evaluated. The extent of respiratory dysfunction depends on the level and completeness of SCI. Individuals with higher spinal lesions have both restrictive and obstructive airway disease. Pharmacological approaches and expiratory muscle training are being studied as interventions to improve pulmonary function and cough strength with the objective of reducing pulmonary complications. Persons with spinal lesions above the 6th thoracic level lack both cardiac and peripheral vascular mechanisms to maintain blood pressure, and they are frequently hypotensive, with even worse hypotension with upright posture. Persistent and/or orthostatic hypotension may predispose those with SCI to cognitive impairments. The safety and efficacy of anti-hypotensive agents to normalize blood pressure in persons with higher level cord lesions is being investigated.
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Affiliation(s)
- William A Bauman
- VA RR&D National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center , Bronx, New York ; Medical Service, James J. Peters VA Medical Center , Bronx, New York ; Department of Medicine, The Mount Sinai School of Medicine , New York, New York ; Department of Rehabilitation Medicine, The Mount Sinai School of Medicine , New York, New York
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Schilero GJ, Spungen AM, Bauman WA, Radulovic M, Lesser M. Pulmonary function and spinal cord injury. Respir Physiol Neurobiol 2009; 166:129-41. [PMID: 19442929 DOI: 10.1016/j.resp.2009.04.002] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Revised: 03/31/2009] [Accepted: 04/01/2009] [Indexed: 11/30/2022]
Abstract
Injury to the cervical and upper thoracic spinal cord disrupts function of inspiratory and expiratory muscles, as reflected by reduction in spirometric and lung volume parameters and static mouth pressures. In association, subjects with tetraplegia have decreased chest wall and lung compliance, increased abdominal wall compliance, and rib cage stiffness with paradoxical chest wall movements, all of which contribute to an increase in the work of breathing. Expiratory muscle function is more compromised than inspiratory muscle function among subjects with tetraplegia and high paraplegia, which can result in ineffective cough and propensity to mucus retention and atelectasis. Subjects with tetraplegia also demonstrate heightened vagal activity with reduction in baseline airway caliber, findings attributed to loss of sympathetic innervation to the lungs. Significant increase in airway caliber following inhalation of ipratropium bromide, an anticholinergic agent, suggests that reduction in airway caliber is not due to acquired airway fibrosis stemming from repeated infections or to abnormal hysteresis secondary to chronic inability of subjects to inhale to predicted total lung capacity. Reduced baseline airway caliber possibly explains why subjects with tetraplegia exhibit airway hyperresponsiveness to methacholine and ultrasonically nebulized distilled water. While it has been well demonstrated that bilateral phrenic nerve pacing or stimulation through intramuscular diaphragmatic electrodes improves inspiratory muscle function, it remains unclear if inspiratory muscle training improves pulmonary function. Recent findings suggest that expiratory muscle training, electrical stimulation of expiratory muscles and administration of a long-acting beta(2)-agonist (salmeterol) improve physiological parameters and cough. It is unknown if baseline bronchoconstriction in tetraplegia contributes to respiratory symptoms, of if the chronic administration of a bronchodilator reduces the work of breathing and/or improves respiratory symptoms. Less is known regarding the benefits of treatment of obstructive sleep apnea, despite evidence indicating that the prevalence of this condition in persons with tetraplegia is far greater than that encountered in able-bodied individuals.
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Affiliation(s)
- Gregory J Schilero
- Rehabilitation Research and Development Center of Excellence for the Medical Consequences of Spinal Cord Injury, The James J. Peters VA Medical Center, Bronx, NY 10468, USA.
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Stolzmann KL, Gagnon DR, Brown R, Tun CG, Garshick E. Longitudinal change in FEV1 and FVC in chronic spinal cord injury. Am J Respir Crit Care Med 2008; 177:781-6. [PMID: 18202346 DOI: 10.1164/rccm.200709-1332oc] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Although respiratory dysfunction is common in chronic spinal cord injury (SCI), determinants of longitudinal change in FEV(1) and FVC have not been assessed. OBJECTIVES Determine factors that influence longitudinal lung function decline in SCI. METHODS A total of 174 male participants (mean age of 49 and 17 yr after injury) completed a respiratory questionnaire and underwent spirometry over an average follow-up of 7.5 years (range, 4-14 yr). MEASUREMENTS AND MAIN RESULTS In multivariate models, longitudinal decline in FEV(1) was significantly related to continued smoking, persistent wheeze, an increase in body mass index, and respiratory muscle strength. Aging was associated with an accelerated decline in FEV(1) (for ages <40, 40-60, >60 yr: -27, -37, and -71 ml/yr, respectively). Similar effects were observed for FVC. CONCLUSIONS Longitudinal change in FEV(1) and FVC was not directly related to level and severity of SCI, but was attributable to potentially modifiable factors in addition to age. These results suggest that weight control, smoking cessation, trials directed at the recognition and treatment of wheeze, and efforts to improve respiratory muscle strength may slow lung function decline after SCI.
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Affiliation(s)
- Kelly L Stolzmann
- VA Boston Healthcare System, Pulmonary and Critical Care Medicine Section, 1400 VFW Parkway, West Roxbury, MA 02132, USA
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Chu D, Bakaeen FG, Shenaq SA, Ribati M, Atluri PV, Holmes SA, Berger DH, Huh J. Open-heart operations in patients with a spinal cord injury. Am J Surg 2007; 194:663-7. [PMID: 17936431 DOI: 10.1016/j.amjsurg.2007.07.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 07/08/2007] [Accepted: 07/30/2007] [Indexed: 11/26/2022]
Abstract
BACKGROUND The objective of our study was to evaluate the outcomes of open-heart surgery in patients with a spinal cord injury. METHODS A retrospective analysis of all patients (n = 8) with a spinal cord injury who underwent open-heart operations in a single institution from April 1994 to November 2006 was conducted. RESULTS All patients had a permanent spinal cord injury with levels ranging from T3 to L2 with a mean age of 62 years (range, 47-72). Seven coronary artery bypass operations and 2 aortic valve replacements were performed. The mean cardiac ejection fraction was 44% (range, 20-60). Seventy-five percent of the patients were extubated within 24 hours of the operation. A decubitus ulcer occurred in only 1 patient. The acute hospital stay averaged 14 days (range, 6-36). One patient died from multiorgan failure on postoperative day 13 giving an in-hospital 30-day mortality of 12.5%. The 5-year survival was 75% with a mean follow-up of 67 months (range, .5-129). CONCLUSIONS Open-heart operations in patients with a spinal cord injury can be performed safely with acceptable early and late outcomes.
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Affiliation(s)
- Danny Chu
- Division of Cardiothoracic Surgery, Michael E. DeBakey Veterans Affairs Medical Center, Baylor College of Medicine, 2002 Holcombe Blvd, OCL 112, Houston, TX 77030, USA.
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Jain NB, Brown R, Tun CG, Gagnon D, Garshick E. Determinants of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC in chronic spinal cord injury. Arch Phys Med Rehabil 2006; 87:1327-33. [PMID: 17023241 PMCID: PMC1896316 DOI: 10.1016/j.apmr.2006.06.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Accepted: 06/21/2006] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To assess factors that influence pulmonary function, because respiratory system dysfunction is common in chronic spinal cord injury (SCI). DESIGN Cross-sectional cohort study. SETTING Veterans Affairs Boston SCI service and the community. PARTICIPANTS Between 1994 and 2003, 339 white men with chronic SCI completed a respiratory questionnaire and underwent spirometry. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and FEV(1)/FVC. RESULTS Adjusting for SCI level and completeness, FEV(1) (-21.0 mL/y; 95% confidence interval [CI], -26.3 to -15.7 mL/y) and FVC (-17.2 mL/y; 95% CI, -23.7 to -10.8 mL/y) declined with age. Lifetime cigarette use was also associated with a decrease in FEV(1) (-3.8 mL/pack-year; 95% CI, -6.5 to -1.1 mL/pack-year), and persistent wheeze and elevated body mass index were associated with a lower FEV(1)/FVC. A greater maximal inspiratory pressure (MIP) was associated with a greater FEV(1) and FVC. FEV(1) significantly decreased with injury duration (-6.1 mL/y; 95% CI, -11.7 to -0.6 mL/y), with the greatest decrement in the most neurologically impaired. The most neurologically impaired also had a greater FEV(1)/FVC, and their FEV(1) and FVC were less affected by age and smoking. CONCLUSIONS Smoking, persistent wheeze, obesity, and MIP, in addition to SCI level and completeness, were significant determinants of pulmonary function. In SCI, FEV(1), FVC, and FEV(1)/FVC may be less sensitive to factors associated with change in airway size and not reliably detect the severity of airflow obstruction.
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Affiliation(s)
- Nitin B Jain
- Research Service, VA Boston Healthcare System, West Roxbury, MA 02132, USA
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Le Foll-de Moro D, Tordi N, Lonsdorfer E, Lonsdorfer J. Ventilation efficiency and pulmonary function after a wheelchair interval-training program in subjects with recent spinal cord injury. Arch Phys Med Rehabil 2005; 86:1582-6. [PMID: 16084811 DOI: 10.1016/j.apmr.2005.03.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To study the effect of a wheelchair interval-training program on the ventilatory function of subjects with recent spinal cord injury (SCI). DESIGN Evaluation trial before and after a training program. SETTING Center of reeducation and university hospital. PARTICIPANTS Six subjects (5 men, 1 woman) hospitalized after a recent SCI. INTERVENTION On a wheelchair ergometer, subjects with SCI performed 30 minutes of interval training 3 times a week for 6 weeks. The training program was part of their reeducation program. MAIN OUTCOME MEASURES Spirometric values at rest and dynamic ventilatory responses were studied before and after this training program with a spirometric test, a maximal exercise test that increased by 5W every 2 minutes, and a submaximal test. RESULTS Spirometric values at rest did not change after training. At maximal exercise, peak ventilation (Vepeak, 7.5%), peak breathing frequency (f peak) (-13.4%), peak tidal volume (Vtpeak +28.9%), and the ventilatory reserve (12.9%) improved after training. The oxygen cost of Ve decreased significantly (-20%) after training. We observed for the wheelchair tests that, at the same workload after training, Ve and f decreased and Vt increased. CONCLUSIONS After 6 weeks of our interval-training program in subjects with recent SCI, the increase of Vt and the decrease of oxygen cost of Ve indicated better ventilatory efficiency.
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Affiliation(s)
- Déborah Le Foll-de Moro
- Service de Physiologie Clinique et des Explorations Fonctionnelles, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
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Nantwi KD, Goshgarian HG. Adenosinergic mechanisms underlying recovery of diaphragm motor function following upper cervical spinal cord injury: potential therapeutic implications. Neurol Res 2005; 27:195-205. [PMID: 15829183 DOI: 10.1179/016164105x21977] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES In adult rats, a latent respiratory motor pathway can be pharmacologically activated with 1,3-dimethylxanthine (theophylline) to restore respiratory-related activity to a hemidiaphragm paralysed by an ipsilateral upper cervical (C2) spinal cord hemisection. The purpose of this review is to describe mechanisms that underlie theophylline-induced recovery of respiratory-related function following C2 hemisection and to underscore the therapeutic potential of theophylline therapy in spinal cord injured patients with respiratory deficits. METHODS Theophylline mediates recovery of respiratory-related activity via antagonism of central adenosine A(1) receptors. When administered chronically, the drug restores and maintains recovered function. Since theophylline is an adenosine receptor antagonist with affinity for both the adenosine A(1) and A(2) receptors, we assessed the relative contributions of each receptor to functional recovery. While A(1) receptor antagonism plays a predominant role, activation of the A(2) receptors by specific agonists subserves the A(1) receptor-mediated actions. That is, when an adenosine A(2) receptor agonist is administered first, it primes the system such that subsequent administration of the A(1) antagonist induces a greater degree of recovered respiratory activity than when the antagonist alone is administered. RESULTS Chronic oral administration of theophylline in C2 hemisected animals demonstrates that even when animals have been weaned from the drug, theophylline-induced recovered respiratory actions persist. This suggests that in clinical application, it may not be necessary to maintain patients on long-term theophylline. We have shown that recovery of respiratory-related activity in the ipsilateral phrenic nerve can occur spontaneously 3-4 months after C2 hemisection. Theophylline administration after this post-injury period obliterates/negates the recovery function. This indicates strongly that there is therapeutic window (more acutely after injury) for the initiation of theophylline therapy. We have also demonstrated that peripheral (carotid bodies) adenosine A(1) receptors can be selectively activated to modulate theophylline-induced CNS actions. Blocking central adenosine receptors while simultaneously activating peripheral adenosine receptors minimizes the potential of respiratory muscle fatigue with theophylline. DISCUSSION The significance of the current findings lies in the potential clinical application of theophylline therapy in spinal cord injured patients with respiratory deficits. The ultimate goal of theophylline therapy is to wean ventilator-dependent patients off ventilatory support. Thus far, our animal studies suggest that the onset of theophylline therapy must be soon after injury.
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Affiliation(s)
- Kwaku D Nantwi
- Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, MI 48201, USA.
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Goshgarian HG. The crossed phrenic phenomenon: a model for plasticity in the respiratory pathways following spinal cord injury. J Appl Physiol (1985) 2003; 94:795-810. [PMID: 12531916 DOI: 10.1152/japplphysiol.00847.2002] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
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.
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Affiliation(s)
- Harry G Goshgarian
- Department of Anatomy/Cell Biology, Wayne State University, Detroit, Michigan 48201, USA.
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Mackenzie CF, Geisler FH. Management of cervical spine injury. Best Pract Res Clin Anaesthesiol 1999. [DOI: 10.1053/bean.1999.0053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Claxton AR, Wong DT, Chung F, Fehlings MG. Predictors of hospital mortality and mechanical ventilation in patients with cervical spinal cord injury. Can J Anaesth 1998; 45:144-9. [PMID: 9512849 DOI: 10.1007/bf03013253] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE The objective of this study was to identify predictors of death and mechanical ventilation in patients with traumatic cervical spinal cord injury. METHODS From 1981 to 1994, 72 patients with traumatic cervical spinal cord injury resulting in neurological deficits were identified in this retrospective study. For each patient, neurological and associated injuries, physiological variables, complications, hospital mortality and the need for mechanical ventilation were recorded. Univariate and multivariate logistic regression analyses were done to identify predictors of mortality and the need for mechanical ventilation. RESULTS Fifteen patients (21%) died in the first three months after injury. Univariate analyses identified age, heart disease, neurological level at C4 and above, GCS < or = 13, forced vital capacity and cough, to be associated with mortality. Multivariate logistic regression identified age (P = 0.01), neurological level (P = 0.03) and GCS (P = 0.05) as independent predictors of mortality. In 41 patients (57%), the lungs were mechanically ventilated. Univariate analyses identified. The following predictors of the need for mechanical ventilation: neurological level at C5 and above, complete cord lesions, copious sputum, pneumonia and lung collapse. Multivariate logistic regression identified copious sputum (P = 0.01) and pneumonia (P = 0.01) as independent predictors of the need for mechanical ventilation. CONCLUSION Age, neurological level and GCS are independent predictors of mortality in patients with traumatic cervical spinal cord injury. Copious sputum and pneumonia are independent predictors of the need for mechanical ventilation.
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Affiliation(s)
- A R Claxton
- Department of Anaesthesia, University of Toronto, Ontario, Canada
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Roth EJ, Lu A, Primack S, Oken J, Nusshaum S, Berkowitz M, Powley S. Ventilatory function in cervical and high thoracic spinal cord injury. Relationship to level of injury and tone. Am J Phys Med Rehabil 1997; 76:262-7. [PMID: 9267184 DOI: 10.1097/00002060-199707000-00002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Weakness and spasticity of chest wall muscles are known to adversely affect pulmonary function in spinal cord-injured patients. To test the assertion that impaired strength and increased tone contribute to ventilation deficits, 52 patients with recent acute traumatic cervical and high thoracic spinal cord injury underwent complete pulmonary function testing. Regression analyses were performed to determine relationships between spinal cord injury level and pulmonary function test results and between Ashworth scale tone ratings and pulmonary function test results. Level of injury was found to be significantly correlated with expiratory reserve volume (and percent predicted expiratory reserve volume), residual volume/total lung capacity ratio, and negative inspiratory pressure but not with vital capacity, forced expiratory volume in one second, forced expiratory volume in one second/vital capacity ratio, inspiratory capacity, total lung capacity, functional residual capacity, residual volume, or positive expiratory pressure. There were significant correlations between Ashworth Scale tone ratings and negative inspiratory pressure but not between tone ratings and any of the other pulmonary function test results. It appears that muscle strength may be a more important factor than muscle tone in determining pulmonary function in spinal cord-injured patients and that both strength and tone are closely related to negative inspiratory pressure.
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Affiliation(s)
- E J Roth
- Department of Physical Medicine and Rehabilitation, Northwestern University Medical School, Chicago, Illinois, USA
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Singas E, Lesser M, Spungen AM, Bauman WA, Almenoff PL. Airway hyperresponsiveness to methacholine in subjects with spinal cord injury. Chest 1996; 110:911-5. [PMID: 8874244 DOI: 10.1378/chest.110.4.911] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Previously, we found that never-smokers with quadriplegia were hyperresponsive to aerosolized methacholine. To further explore the phenomenon, we compared responsiveness to methacholine in never-smokers with that of smokers and ex-smokers. We also evaluated responsiveness in subjects with high paraplegia (lesions at T-1 to T-6) or low paraplegia (lesions at T-7 and below). We found that smokers and ex-smokers with quadriplegia were hyperresponsive to methacholine (provocative concentration causing a 20% fall in FEV1 = 1.9 mg/mL), and that the response was comparable to that found in never-smokers, revealing that hyperresponsiveness among never-smokers cannot be attributed to preinjury airway hyperreactivity that precluded cigarette use. In contrast, subjects with low paraplegia were not hyperresponsive to methacholine. Among subjects with high paraplegia, the three subjects demonstrating airway hyperresponsiveness had significantly lower FEV1 (percent predicted). The findings support the hypothesis that airway hyperresponsiveness in subjects with quadriplegia represents loss of sympathetic innervation of the lung, thereby leaving intact unopposed bronchoconstrictor cholinergic activity. However, reduced lung volumes in these subjects also suggest the possibility that airway hyperresponsiveness is due to loss of ability to stretch airway smooth muscle by deep breathing.
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Affiliation(s)
- E Singas
- Pulmonary Section, Bronx (NY) Veterans Affairs Medical Center 10468, USA
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17
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Abstract
BACKGROUND The risk of heart disease in patients with spinal cord injury is similar to that in the general population. The physiologic derangements raise special problems in patients with SCI having coronary operations. METHODS From January 1980 to May 1995, we performed coronary artery bypass procedures on 20 patients with SCI; 4 were tetraplegic and the remainder were paraplegic. The indication for operation was angina: unstable (13), exertional (4), or postinfarctional (3). Bowel and bladder care was given immediately before operation; operating room tables were double padded and a pelvic wrap was used to protect the back. Electric wheelchairs were used for early mobilization. RESULTS Vasomotor instability from cardiopulmonary bypass was not present in patients with SCI. Pharmacologic support was required in the operating room by 4 patients for low vascular resistance, but in only one case in the intensive care unit. One patient required ventilation support for more than 24 hours. All patients were able to cough effectively. No thoracic wound complications occurred. There were three operative deaths, all in patients with multiple risk factors. The acute hospital stay averaged 9.3 days; patients were then transferred to an SCI unit for rehabilitation, were upper-extremity weight bearing was restricted for 2 to 4 weeks. CONCLUSIONS Patients should not be denied coronary artery bypass procedures because of an SCI, but their special needs must be managed properly.
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Affiliation(s)
- W A Walker
- Department of Surgery, The University of Tennessee, College of Medicine, Memphis, USA
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18
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Frisbie JH, Brown R. Waist and neck enlargement after quadriplegia. THE JOURNAL OF THE AMERICAN PARAPLEGIA SOCIETY 1994; 17:177-8. [PMID: 7869061 DOI: 10.1080/01952307.1994.11735933] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Changes in waist and neck size in quadriplegic patients after paralysis, noted clinically, were assessed systematically. Twenty quadriplegic men, aged 60 +/- 13 years (mean +/- 1 SD) and 20 neurologically intact men, aged 63 +/- 17 years, selected by absence of weight gain, were questioned about changes in their waist and shirt collar sizes since the onset of paralysis (20 +/- 13 years) or during the previous 20 years for control subjects. Waist size expanded 7.0 +/- 0.3 inches for quadriplegic and 1.7 +/- 1.7 inches for control subjects (p < 0.001). Changes in neck size of 0.7 +/- 1.1 inches for quadriplegic and 0 +/- 0.7 inches for control subjects were found (p < 0.02). We conclude that quadriplegia is often followed by increased waist and neck size. These changes may relate to the impaired breathing mechanisms in quadriplegia.
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Affiliation(s)
- J H Frisbie
- Spinal Cord Injury Service, Department of Veterans Affairs Medical Center, Brockton, MA 02401
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19
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Dicpinigaitis PV, Spungen AM, Bauman WA, Absgarten A, Almenoff PL. Bronchial hyperresponsiveness after cervical spinal cord injury. Chest 1994; 105:1073-6. [PMID: 8162727 DOI: 10.1378/chest.105.4.1073] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Cervical spinal cord injury results in interruption of sympathetic airway innervation, which originates from the upper thoracic spine, whereas parasympathetic nerve supply, arising in the vagal nuclei of the brainstem, remains intact. To assess the effect of such an altered neural environment on airway reactivity, bronchoprovocation testing was performed on eight subjects with nonacute traumatic lesions of the cervical spine, all of whom were lifetime nonsmokers without history of respiratory symptoms prior to their injury. Bronchial challenge was subsequently repeated after pretreatment with the anticholinergic agent, ipratropium bromide, an inhibitor of airway muscarinic receptors. All subjects demonstrated hyperresponsiveness to methacholine (the concentration of methacholine producing a fall in FEV1 of 20 percent from baseline [PC20] = 1.42 +/- 1.61 [SD] mg/ml). Airway hyperreactivity was completely blocked by pretreatment with inhaled ipratropium bromide (mean PC20 > 25 mg/ml [p < 0.0001]). The bronchial hyperresponsiveness observed in this population most likely reflects the loss of sympathetic airway innervation and resultant unopposed cholinergic bronchoconstrictor tone which results from transection of the cervical spine. Blockade of methacholine hyperresponsiveness with ipratropium bromide suggests a muscarinic receptor-mediated phenomenon.
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Affiliation(s)
- P V Dicpinigaitis
- Division of Pulmonary and Critical Care Medicine, Mt. Sinai School of Medicine, New York, NY
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20
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Ashba J, Garshick E, Tun CG, Lieberman SL, Polakoff DF, Blanchard JD, Brown R. Spirometry--acceptability and reproducibility in spinal cord injured subjects. THE JOURNAL OF THE AMERICAN PARAPLEGIA SOCIETY 1993; 16:197-203. [PMID: 8270915 DOI: 10.1080/01952307.1993.11735901] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The American Thoracic Society (ATS) has formulated guidelines for spirometry. We hypothesized that individuals with SCI (SCI), as a result of weak respiratory muscles, would exhibit poor test acceptability and reproducibility. Seventy-eight SCI subjects (39 with complete SCI) answered a respiratory questionnaire and performed spirometry. Of those with complete SCI, the proportion of subjects which met ATS criteria decreased with higher levels of injury. Poor test performance was not associated with age, respiratory symptoms or muscle fatigue. The most common reason for failing to meet ATS criteria for acceptability was excessive back extrapolated volumes (EBEV). Individuals with efforts that were acceptable except for EBEV and/or for exhalation of less than six seconds had values for forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) that were reproducible. If ATS criteria for acceptable spirometry were used in studying subjects with SCI, individuals producing otherwise reproducible values for FVC and FEV1 would be excluded. We found reproducibility similar to what has been reported in other cohorts and conclude that longitudinal study of respiratory function in SCI is feasible.
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Affiliation(s)
- J Ashba
- Pulmonary Section, Medical Service, Geriatric Research Education and Clinical Center, Boston, MA
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21
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Abstract
Breathing is a complicated act that requires sophisticated control mechanisms. The nervous system coordinates 3 fundamentally important components of respiration. The central nervous system has a central pattern generator that, along with appropriate feedback mechanisms, establishes both the resiratory rate and the depth of respirations. The peripheral nervous system facilitates transmission of these respiratory commands to the ventilatory muscles. The nervous system also contributes to the control of airway size. Laryngeal function is coordinated with inspiration, and local nerves in the lung have a major role in determining bronchial patency. Finally, the nervous system acts in incompletely understood ways to regulate perfusion of the lungs and to match local pulmonary blood flow with ventilation. Failure of the nervous system to adequately control these 3 different aspects of respiration may result in lifethreatening illness. Understanding how the nervous system affects control of ventilation, airway patency, and pulmonary perfusion therefore will enable intensivists to recognize and manage the pulmonary complications of neurological disease.
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Affiliation(s)
- Gene L. Colice
- Department of Medicine, Dartmouth Medical School, Hanover, NH
- Chief, Pulmonary Division, VA Medical Center, White River Junction, VT
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Segal JL, Patel J, Gordon SK, Eltorai IM. Theophylline pharmacokinetics in spinal cord injury: a preliminary report. THE JOURNAL OF THE AMERICAN PARAPLEGIA SOCIETY 1985; 8:23-4. [PMID: 3842977 DOI: 10.1080/01952307.1985.11785930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Fugl-Meyer AR, Grimby G. Respiration in tetraplegia and in hemiplegia: a review. INTERNATIONAL REHABILITATION MEDICINE 1984; 6:186-90. [PMID: 6396267 DOI: 10.3109/03790798409165962] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Impairment of respiratory function is one of the most serious complications of both complete cervical cord injury and stroke with hemiplegia. This review updates the information first gathered 15 years ago. The overall improvement in prognosis is documented and the methods of treatment, including diaphragmatic pacing and physiotherapy are discussed.
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