scholarly journals Laryngeal and swallow dysregulation following acute cervical spinal cord injury

2021 ◽  
Author(s):  
Teresa Pitts ◽  
Kimberly E Iceman ◽  
Alyssa Huff ◽  
M Nicholas Musselwhite ◽  
Michael L Frazure ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Upper Airway ◽  
Emg Activity ◽  
Post Injury ◽  
Percent Change ◽  
Cord Injury ◽  
Posterior Cricoarytenoid ◽  
Diaphragm Activity

Proper function of the larynx is vital to airway protection, including swallow. While the swallow reflex is controlled by the brainstem, patients with cervical spinal cord injuries (cSCI) are likely at increased risk of disordered swallow (dysphagia) and pneumonia, and the underlying mechanisms are unknown. We aimed to determine if acute spinal cord injury would disrupt swallow function in animal models. We hypothesized that 1) loss of descending efferent information to the diaphragm would affect swallow and breathing differently, and that 2) loss of ascending spinal afferent information would alter central swallow regulation to change motor drive to the upper airway. We recorded amplitudes of laryngeal and inspiratory muscle electromyograms (EMGs), submental and pharyngeal muscle EMGs, and cardiorespiratory measures in freely breathing pentobarbital-anesthetized cats and rats. First, we assessed the effect of a lateral hemisection at the second cervical level (C2) in cats during breathing. Posterior cricoarytenoid (laryngeal abductor) EMG activity during inspiration increased nearly two-fold, indicating that inspiratory laryngeal drive increased following cSCI. Ipsilateral to the injury, the crural diaphragm EMG was significantly reduced during breathing (62 ± 25 percent change post-injury), but no animal had a complete termination of all activity; 75% of animals had an increase in contralateral diaphragm recruitment after cSCI, but this did not reach significance. Next, we assessed the effect of C2 lateral hemisection in cats during swallow. The thyroarytenoid (laryngeal adductor) and thyropharyngeus (pharyngeal constrictor) both increased EMG activity during swallow, indicating increased upper airway drive during swallow following cSCI. There was no change in the number of swallows stimulated per trial. We also found that diaphragm activity during swallow (schluckatmung) was bilaterally suppressed after lateral C2 hemisection, which was unexpected because this injury did not suppress contralateral diaphragm activity during breathing. Swallow-breathing coordination was also affected by cSCI, with more post-injury swallows occurring during early expiration. Finally, because we wanted to determine if the chest wall is a major source of feedback for laryngeal regulation, we performed T1 total transections in rats. As in the cat C2 lateral hemisection, a similar increase in inspiratory laryngeal activity (posterior cricoarytenoid) was the first feature noted after rat T1 complete spinal cord transection. In contrast to the cat C2 lateral hemisection, diaphragmatic respiratory drive increased after T1 transection in every rat (215 ± 63 percent change), and this effect was significant. Overall, we found that spinal cord injury alters laryngeal drive during swallow and breathing, and alters swallow-related diaphragm activity. Our results show behavior-specific effects, suggesting that swallow may be more affected than breathing is by cSCI, and emphasizing the need for additional studies on laryngeal function during breathing and swallow after spinal cord injury.

scholarly journals Intraspinal microstimulation and diaphragm activation after cervical spinal cord injury

2017 ◽  
Vol 117 (2) ◽  
pp. 767-776 ◽  
Author(s):  
L. M. Mercier ◽  
E. J. Gonzalez-Rothi ◽  
K. A. Streeter ◽  
S. S. Posgai ◽  
A. S. Poirier ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Emg Activity ◽  
Motor Nucleus ◽  
Adult Rats ◽  
Intraspinal Microstimulation ◽  
Emg Signal ◽  
Cord Injury ◽  
Diaphragm Activity

Intraspinal microstimulation (ISMS) using implanted electrodes can evoke locomotor movements after spinal cord injury (SCI) but has not been explored in the context of respiratory motor output. An advantage over epidural and direct muscle stimulation is the potential of ISMS to selectively stimulate components of the spinal respiratory network. The present study tested the hypothesis that medullary respiratory activity could be used to trigger midcervical ISMS and diaphragm motor unit activation in rats with cervical SCI. Studies were conducted after acute (hours) and subacute (5–21 days) C2 hemisection (C2Hx) injury in adult rats. Inspiratory bursting in the genioglossus (tongue) muscle was used to trigger a 250-ms train stimulus (100 Hz, 100–200 μA) to the ventral C4 spinal cord, targeting the phrenic motor nucleus. After both acute and subacute injury, genioglossus EMG activity effectively triggered ISMS and activated diaphragm motor units during the inspiratory phase. The ISMS paradigm also evoked short-term potentiation of spontaneous inspiratory activity in the previously paralyzed hemidiaphragm (i.e., bursting persisting beyond the stimulus period) in ∼70% of the C2Hx animals. We conclude that medullary inspiratory output can be used to trigger cervical ISMS and diaphragm activity after SCI. Further refinement of this method may enable “closed-loop-like” ISMS approaches to sustain ventilation after severe SCI. NEW & NOTEWORTHY We examined the feasibility of using intraspinal microstimulation (ISMS) of the cervical spinal cord to evoke diaphragm activity ipsilateral to acute and subacute hemisection of the upper cervical spinal cord of the rat. This proof-of-concept study demonstrated the efficacy of diaphragm activation, using an upper airway respiratory EMG signal to trigger ISMS at the level of the ipsilesional phrenic nucleus during acute and advanced postinjury intervals.

Impact of cervical spinal cord injury on the relationship between the metabolism and ventilation in rats

2021 ◽  
Author(s):  
Tzu-Ting Chiu ◽  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Tidal Volume ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Male Rats ◽  
Whole Body ◽  
Post Injury ◽  
Chronic Injury ◽  
Cord Injury

Cervical spinal cord injury typically results in respiratory impairments. Clinical and animal studies have demonstrated that respiratory function can spontaneously and partially recover over time after injury. However, it remains unclear whether respiratory recovery is associated with alterations in metabolism. The present study was designed to comprehensively examine ventilation and metabolism in a rat model of spinal cord injury. Adult male rats received sham (i.e., laminectomy) or unilateral mid-cervical contusion injury (height of impact rod: 6.25 or 12.5 mm). Breathing patterns and whole-body metabolism (O2 consumption and CO2 production) were measured using a whole-body plethysmography system conjugated with flow controllers and gas analyzer at the acute (1 day post-injury), subchronic (2 weeks post-injury), and chronic (8 weeks post-injury) injury stages. The results demonstrated that mid-cervical contusion caused a significant reduction in the tidal volume. Although the tidal volume of contused animals can gradually recover, it remains lower than that of uninjured animals at the chronic injury stage. While O2 consumption and CO2 production were similar between uninjured and contused animals at the acute injury stage, these two metabolic parameters were significantly reduced in contused animals at the subchronic to chronic injury stages. Additionally, the relationships between ventilation, metabolism, and body temperature were altered by cervical spinal cord injury. These results suggest that cervical spinal cord injury causes a complicated reconfiguration of ventilation and metabolism that may enable injured animals to maintain a suitable homeostasis for adapting to the pathophysiological consequences of injury.

scholarly journals Serial plasma DNA levels as predictors of outcome in patients with acute traumatic cervical spinal cord injury

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Hung-Chen Wang ◽  
Yu-Tsai Lin ◽  
Shih-Yuan Hsu ◽  
Nai-Wen Tsai ◽  
Yun-Ru Lai ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Japanese Orthopaedic Association ◽  
Cervical Spinal Cord Injury ◽  
Acute Injury ◽  
Control Group ◽  
Plasma Dna ◽  
Post Injury ◽  
Cord Injury

Abstract Background Acute traumatic cervical spinal cord injury (SCI) is a leading cause of disability in adolescents and young adults worldwide. Evidence from previous studies suggests that circulating cell-free DNA is associated with severity following acute injury. The present study determined whether plasma DNA levels in acute cervical SCI are predictive of outcome. Methods In present study, serial plasma nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) levels were obtained from 44 patients with acute traumatic cervical SCI at five time points from day 1 to day 180 post-injury. Control blood samples were obtained from 66 volunteers. Results Data showed a significant increase in plasma nDNA and mtDNA concentrations at admission in SCI patients compared to the control group. Plasma nDNA levels at admission, but not plasma mtDNA levels, were significantly associated with the Japanese Orthopaedic Association (JOA) score and Injury Severity Score in patients with acute traumatic cervical SCI. In patients with non-excellent outcomes, plasma nDNA increased significantly at days 1, 14 and 30 post-injury. Furthermore, its level at day 14 was independently associated with outcome. Higher plasma nDNA levels at the chosen cutoff point (> 45.6 ng/ml) predicted poorer outcome with a sensitivity of 78.9% and a specificity of 78.4%. Conclusions These results indicate JOA score performance and plasma nDNA levels reflect the severity of spinal cord injury. Therefore, the plasma nDNA assays can be considered as potential neuropathological markers in patients with acute traumatic cervical SCI.

scholarly journals Trihydroxyethyl Rutin Provides Neuroprotection in Rats With Cervical Spinal Cord Hemi-Contusion

2021 ◽  
Vol 15 ◽  
Author(s):  
Yapu Liu ◽  
Qi Liu ◽  
Zhou Yang ◽  
Rong Li ◽  
Zhiping Huang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Evoked Potentials ◽  
Grip Strength ◽  
Cervical Spinal Cord ◽  
Microvascular Density ◽  
Post Injury ◽  
Neuroprotective Effects ◽  
Injury Group ◽  
Cord Injury

Objective: To investigate the neuroprotective effects of trihydroxyethyl rutin in rats with cervical spinal cord hemi-contusion.Methods: Adult male Sprague–Dawley rats were subjected to hemi-contusion at a stroke depth of 1.2 mm, and then intraperitoneally injected with 50 or 100 mg/kg trihydroxyethyl rutin per day for 12 weeks (T50 and T100 groups, respectively). Changes in somatosensory evoked potentials (SEPs), motor evoked potentials (MEPs), and behavior were continuously monitored. At 12 weeks post-injury, immunohistochemical staining was performed to assess changes in cervical spinal cord microvascular morphology. Magnetic resonance imaging (MRI) scans were performed to examine end-stage injury in the cervical spinal cord, and Eriochrome cyanine-stained slices of spinal cord tissue were evaluated for injury.Results: There were no significant differences in biomechanical parameters among the spinal cord injury, T50 and T100 rat groups. At 3 days-post-injury, there was a significant decrease in grip strength. At 12 weeks post-injury, grip strength recovery was significantly better in the T50 and T100 groups than in the injury group. Compared with the injury group, the total limb placement frequency was significantly higher in the T50 group at 2, 4, 6, 10, and 12 weeks post-injury and in the T100 group at 2, 6, 8, and 10 weeks post-injury. Ipsilateral SEPs and MEPs were dynamic, increasing in latency and decreasing in amplitude in the injury compared with sham group. MRI scanning demonstrated that the coronal, sagittal, and transversal lesion areas were smaller in the T50 and T100 groups than in the injury group. Microvascular density showed a greater reduction in the injury group compared with the T50 and T100 groups. Eriochrome cyanine staining showed that the ipsilateral side, residual parenchyma, and gray matter areas were larger in the T50 and T100 groups than in the injury group.Conclusion: Trihydroxyethyl rutin exhibits robust neuroprotective effects, improving limb motor function and nerve electrophysiological parameters after spinal cord injury, maintaining microvascular density, and reducing the area of injury and degree of demyelination.

scholarly journals Timely Intubation With Early Prediction of Respiratory Exacerbation in Acute Traumatic Cervical Spinal Cord Injury

2021 ◽  
Author(s):  
Takafumi Yonemitsu ◽  
Azuna Kinoshita ◽  
Keiji Nagata ◽  
Mika Morishita ◽  
Tomoyuki Yamaguchi ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Post Injury ◽  
Airway Control ◽  
Airway Secretion ◽  
Respiratory Management ◽  
Cord Injury ◽  
Treatment Data

Abstract Background: Early routine intubation in motor-complete cervical spinal cord injury (CSCI) above the C5 level is a conventional protocol to prevent unexpected respiratory exacerbation (RE). However, in context of the recent advances in multidisciplinary respiratory management, the absolute indication for intubation in CSCI patients based on initial neurologic assessment is controversial because of the drawbacks of intubation. This study aimed to redetermine the most important predictor of RE following CSCI after admission without routine intubation among patients admitted with motor-complete injury and/or injury above the C5 level to ensure timely intubation. Methods: We performed a retrospective review of patients with acute traumatic CSCI admitted to our hospital without an initial routine intubation protocol from January 2013 to December 2017. CSCI patients who developed RE (defined as unexpected emergent intubation for respiratory resuscitation) were compared with those who did not. Baseline characteristics and severity of trauma data were collected. Univariate analyses were performed to compare treatment data and clinical outcomes between the two groups. Further, multivariate logistic regressions were performed with clinically important independent variables: motor-complete injury, neurologic level above C5, atelectasis, and copious airway secretion (CAS). Results: Among the analyzed 58 patients with CSCI, 35 (60.3%) required post-injury intubation and 1 (1.7%) died during hospitalization. Thirteen (22.4%) had RE in 3.5 days (mean) post-injury; 3 (37.5%) of eight motor-complete CSCI patients above C5 developed RE. Eleven of the 27 (40.7%) patients with motor-complete injury and five of the 22 (22.7%) patients with neurologic injury above C5 required emergency intubation at RE. Three of the eight CSCI patients with both risk factors (motor-complete injury above C5) resulted in emergent RE intubation (37.5%). CAS was an independent predictor for RE (odds ratio 7.19, 95% confidence interval 1.48–42.72, P=0.0144) in multivariate analyses. Conclusion: Timely intubation post-CSCI based on close attention to CAS during the acute 3-day phase may prevent RE and reduce unnecessary invasive airway control even without immediate routine intubation in motor-complete injury above C5.

scholarly journals The experiences of individuals with cervical spinal cord injury and their family during post-injury care in non-specialised and specialised units in UK

2020 ◽  
Author(s):  
Jackie McRae ◽  
Christina Smith ◽  
Anton Emmanuel ◽  
Suzanne Beeke
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Family Members ◽  
Cervical Spinal Cord Injury ◽  
Specialist Care ◽  
Structured Interviews ◽  
Post Injury ◽  
Experience Of Care ◽  
Cord Injury

Abstract Background Individuals with acute cervical spinal cord injury require specialised interventions to ensure optimal clinical outcomes especially for respiratory, swallowing and communication impairments. This study explores the experiences of post-injury care for individuals with cervical spinal cord injury and their family members during admissions in specialised and non-specialised units in the United Kingdom.Methods Semi-structured interviews were undertaken with individuals with a cervical spinal cord injury and their family member, focussing on the experience of care across units. Eight people with spinal cord injury levels from C2 to C6, were interviewed in their current care settings. Six participants had family members present to support them. Interviews were audio-recorded and transcribed with data inputted into NVivo for thematic analysis.Results The study identified six themes from the participant interviews that highlighted different experiences of care in non-specialised and specialised settings. A number of these were related to challenges with the system, whilst others were about the personal journey of recovery. The themes were titled as: adjustment, transitions, “the golden opportunity”, “when you can’t eat”, communication, and “in the hands of the nurses and doctors”.Conclusions Whilst participants reported being well cared for in non-specialised units, they felt that they did not receive specialist care and this delayed their rehabilitation. Participants were dependent on healthcare professionals for information and care and at times lost hope for recovery. Staff in non-specialised units require training and guidance to help provide support for those with dysphagia and communication difficulties, as well as reassurance to patients and families whilst they wait for transfer to specialised units.

scholarly journals Cardio-centric hemodynamic management improves spinal cord oxygenation and mitigates hemorrhage in acute spinal cord injury

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexandra M. Williams ◽  
Neda Manouchehri ◽  
Erin Erskine ◽  
Keerit Tauh ◽  
Kitty So ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Cardiac Contractility ◽  
Left Ventricular ◽  
Vasopressor Therapy ◽  
Post Injury ◽  
Doppler Flowmetry ◽  
Hemodynamic Management ◽  
Cord Injury

Abstract Chronic high-thoracic and cervical spinal cord injury (SCI) results in a complex phenotype of cardiovascular consequences, including impaired left ventricular (LV) contractility. Here, we aim to determine whether such dysfunction manifests immediately post-injury, and if so, whether correcting impaired contractility can improve spinal cord oxygenation (SCO2), blood flow (SCBF) and metabolism. Using a porcine model of T2 SCI, we assess LV end-systolic elastance (contractility) via invasive pressure-volume catheterization, monitor intraparenchymal SCO2 and SCBF with fiberoptic oxygen sensors and laser-Doppler flowmetry, respectively, and quantify spinal cord metabolites with microdialysis. We demonstrate that high-thoracic SCI acutely impairs cardiac contractility and substantially reduces SCO2 and SCBF within the first hours post-injury. Utilizing the same model, we next show that augmenting LV contractility with the β-agonist dobutamine increases SCO2 and SCBF more effectively than vasopressor therapy, whilst also mitigating increased anaerobic metabolism and hemorrhage in the injured cord. Finally, in pigs with T2 SCI survived for 12 weeks post-injury, we confirm that acute hemodynamic management with dobutamine appears to preserve cardiac function and improve hemodynamic outcomes in the chronic setting. Our data support that cardio-centric hemodynamic management represents an advantageous alternative to the current clinical standard of vasopressor therapy for acute traumatic SCI.

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