Coordination Between Respiration and Swallowing in Patients With Dysphagia After Cervical Spinal Cord Injury: An Observational Case-Control Study.

PURPOSE: The purpose of the present study was to characterize the differences between respiration and swallowing in patients with dysphagia after cervical spinal cord injury (CSCI) and to explore the underlying physiological changes. METHOD: A total of 95 participants were recruited for bedside swallowing evaluation followed by a flexible endoscopic evaluation of swallowing and surface electromyography with a thermocouple nasal airflow sensor examination: 32 with dysphagia, 33 without dysphagia, and 30 healthy controls. The differences in respiratory patterns, swallowing apnea duration (SAD), inspiratory-expiratory ratio, and swallowing efficiency were observed among healthy adults, CSCI patients with and without dysphagia after CSCI. RESULTS: Compared with those of healthy controls and patients without dysphagia after CSCI, the postswallow respiratory pattern of patients with dysphagia after CSCI was an inspiratory pattern, and the SAD was significantly shorter in patients with dysphagia after CSCI (p < .001). Additionally, the expiratory time in patients with dysphagia was significantly shorter than the inspiratory time, and the swallowing efficiency was reduced, requiring multiple swallows. Moreover, the index of SAD was statistically significant for predicting the development of dysphagia in patients with CSCI (p < .001). CONCLUSION: Patients with CSCI have an inspiratory pattern after swallowing, and the SAD is significantly reduced; SAD can be used as the predictor of dysphagia in patients after CSCI; the pattern of coordination between respiration and swallowing in patients with dysphagia after CSCI is different from that of healthy controls and patients without dysphagia after CSCI. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.26524717.

Application of a novel nested ensemble algorithm in predicting motor function recovery in patients with traumatic cervical spinal cord injury.

Traumatic cervical spinal cord injury (TCSCI) often causes varying degrees of motor dysfunction, common assessed by the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI), in association with the American Spinal Injury Association (ASIA) Impairment Scale. Accurate prediction of motor function recovery is extremely important for formulating effective diagnosis, therapeutic and rehabilitation programs. The aim of this study is to investigate the validity of a novel nested ensemble algorithm that uses the very early ASIA motor score (AMS) of ISNCSCI examination to predict motor function recovery 6 months after injury in TCSCI patients. This retrospective study included complete data of 315 TCSCI patients. The dataset consisting of the first AMS at ≤ 24 h post-injury and follow-up AMS at 6 months post-injury was divided into a training set (80%) and a test set (20%). The nested ensemble algorithm was established in a two-stage manner. Support Vector Classification (SVC), Adaboost, Weak-learner and Dummy were used in the first stage, and Adaboost was selected as second-stage model. The prediction results of the first stage models were uploaded into second-stage model to obtain the final prediction results. The model performance was evaluated using precision, recall, accuracy, F1 score, and confusion matrix. The nested ensemble algorithm was applied to predict motor function recovery of TCSCI, achieving an accuracy of 80.6%, a F1 score of 80.6%, and balancing sensitivity and specificity. The confusion matrix showed few false-negative rate, which has crucial practical implications for prognostic prediction of TCSCI. This novel nested ensemble algorithm, simply based on very early AMS, provides a useful tool for predicting motor function recovery 6 months after TCSCI, which is graded in gradients that progressively improve the accuracy and reliability of the prediction, demonstrating a strong potential of ensemble learning to personalize and optimize the rehabilitation and care of TCSCI patients.

Assessing Functional Recovery of Eupneic Diaphragm Activity Following Unilateral Cervical Spinal Cord Injury in Rats.

Following cSCI, activation of the DIAm can be impacted depending on the extent of the injury. The present manuscript describes a unilateral C2 hemisection (C2SH) model of cSCI that disrupts eupneic ipsilateral diaphragm (iDIAm) electromyographic (EMG) activity during breathing in rats. To evaluate recovery of DIAm motor control, the extent of deficit due to C2SH must first be clearly established. By verifying a complete initial loss of iDIAm EMG during breathing, subsequent recovery can be classified as either absent or present, and the extent of recovery can be estimated using the EMG amplitude. Additionally, by measuring the continued absence of iDIAm EMG activity during breathing after the acute spinal shock period following C2SH, the success of the initial C2SH may be validated. Measuring contralateral diaphragm (cDIAm) EMG activity can provide information about the compensatory effects of C2SH, which also reflects neuroplasticity. Moreover, DIAm EMG recordings from awake animals can provide vital physiological information about the motor control of the DIAm after C2SH. This article describes a method for a rigorous, reproducible, and reliable C2SH model of cSCI in rats, which is an excellent platform for studying respiratory neuroplasticity, compensatory cDIAm activity, and therapeutic strategies and pharmaceuticals.

Classification of upper-limb dysfunction severity and prediction of independence in activities of daily living after cervical spinal-cord injury.

STUDY DESIGN: Prospective observational study. OBJECTIVES: Classification of spinal-cord injury and prediction of independence in activities of daily living (ADL) based on performance evaluations such as upper-limb function have not been reported. Therefore, this study aimed to establish a severity classification and calculate cutoff values for independence in ADL using the Capabilities of Upper Extremity Test (CUE-T) for individuals with cervical spinal-cord injury (CSCI). SETTING: A spinal-cord injury rehabilitation center in Japan. METHODS: This study included individuals with subacute CSCI. Collected data included the CUE-T and Spinal Cord Independence Measure III (SCIM III) scores. The severity classification was used for the hierarchical cluster analysis using the CUE-T. The cutoff values of CUE-T scores for independence in ADL were calculated using an adjustment model with logistic regression analysis. The dependent variable was binary (independent/non-independent) for each SCIM III Self-care item, and the independent variable was CUE-T. RESULTS: A total of 71 participants were included in the analysis. The severity of upper-limb dysfunction was classified into four categories using CUE-T. Significant differences in upper-limb function and ADL were observed between clusters. The cutoff values for CUE-T score for independence in ADL ranged from 37 to 91 points. All cutoff values showed good results in the internal validation, sensitivity analysis. CONCLUSIONS: This study determined the severity of upper limb function in CSCI and the cutoff values of CUE-T scores for independence in ADL. These results may help set criteria and goals for interventions in the clinical and research fields. SPONSORSHIP: None.

Sex differences in spontaneous respiratory recovery following chronic C2 hemisection.

Respiratory deficits after C2 hemisection (C2Hx) have been well documented through single-sex investigations. Although ovarian sex hormones enable enhanced respiratory recovery observed in females 2 wk post-C2Hx, it remains unknown if sex impacts spontaneous respiratory recovery at chronic time points. We conducted a longitudinal study to provide a comprehensive sex-based characterization of respiratory neuromuscular recovery for 8 wk after C2Hx. We recorded ventilation and chronic diaphragm electromyography (EMG) output in awake, behaving animals, phrenic motor output in anesthetized animals, and performed diaphragm muscle histology in chronically injured male and female rodents. Our results show that females expressed a greater recovery of tidal volume and minute ventilation compared with males during subacute and chronic time points. Eupneic diaphragm EMG amplitude during wakefulness and phrenic motor amplitude are similar between sexes at all time points after injury. Our data also suggest that females have a greater reduction in ipsilateral diaphragm EMG amplitude during spontaneous deep breaths (e.g., sighs) compared with males. Finally, we show evidence for atrophy and remodeling of the fast, fatigable fibers ipsilateral to injury in females, but not in males. To our knowledge, the data presented here represent the first study to report sex-dependent differences in spontaneous respiratory recovery and diaphragm muscle morphology following chronic C2Hx. These data highlight the need to study both sexes to inform evidence-based therapeutic interventions in respiratory recovery after spinal cord injury (SCI).NEW & NOTEWORTHY In response to chronic C2 hemisection, female rodents display increased tidal volume during eupneic breathing compared with males. Females show a greater reduction in diaphragm electromyography (EMG) amplitude during spontaneous deep breaths (e.g., sighs) and atrophy and remodeling of fast, fatigable diaphragm fibers. Given that most rehabilitative interventions occur in the subacute to chronic stages of injury, these results highlight the importance of considering sex when developing and evaluating therapeutics after spinal cord injury.

Temporal dynamics of gait function in acute cervical spinal cord injury.

BACKGROUND: Following spinal cord injury (SCI), gait function reaches a post-recovery plateau that depends on the paralysis severity. However, the plateau dynamics during the recovery period are not known. This study aimed to examine the gait function temporal dynamics after traumatic cervical SCI (CSCI) based on paralysis severity. METHODS: This retrospective cohort study included 122 patients with traumatic CSCI admitted to a single specialized facility within 2 weeks after injury. The Walking Index for Spinal Cord Injury II (WISCI II) was estimated at 2 weeks and 2, 4, 6, and 8 months postinjury for each American Spinal Injury Association Impairment Scale (AIS) grade, as determined 2 weeks postinjury. Statistical analysis was performed at 2 weeks to 2 months, 2-4 months, 4-6 months, and 6-8 months, and the time at which no significant difference was observed was considered the time at which the gait function reached a plateau. RESULTS: In the AIS grade A and B groups, no significant differences were observed at any time point, while in the AIS grade C group, the mean WISCI II values continued to significantly increase up to 6 months. In the AIS grade D group, the improvement in gait function was significant during the entire observation period. CONCLUSIONS: The plateau in gait function recovery was reached at 2 weeks postinjury in the AIS grade A and B groups and at 6 months in the AIS grade C group.

Corticospinal inhibition investigated in relation to upper extremity motor function in cervical spinal cord injury.

OBJECTIVE: Corticospinal inhibitory mechanisms are relevant to functional recovery but remain poorly understood after spinal cord injury (SCI). Post-injury characteristics of contralateral silent period (CSP), a measure of corticospinal inhibition evaluated using transcranial magnetic stimulation (TMS), is inconsistent in literature. We envisioned that investigating CSP across muscles with varying degrees of weakness may be a reasonable approach to resolve inconsistencies and elucidate the relevance of corticospinal inhibition for upper extremity function following SCI. METHODS: We studied 27 adults with chronic C1-C8 SCI (age 48.8 ± 16.1 years, 3 females) and 16 able-bodied participants (age 33.2 ± 11.8 years, 9 females). CSP characteristics were assessed across biceps (muscle power = 3-5) and triceps (muscle power = 1-3) representing stronger and weaker muscles, respectively. We assessed functional abilities using the Capabilities of the Upper Extremity Test (CUE-T). RESULTS: Participants with chronic SCI had prolonged CSPs for biceps but delayed and diminished CSPs for triceps compared to able-bodied participants. Early-onset CSPs for biceps and longer, deeper CSPs for triceps correlated with better CUE-T scores. CONCLUSIONS: Corticospinal inhibition is pronounced for stronger biceps but diminished for weaker triceps muscle in SCI indicating innervation relative to the level of injury matters in the study of CSP. SIGNIFICANCE: Nevertheless, corticospinal inhibition or CSP holds relevance for upper extremity function following SCI.

Increased intensity of unintended mirror muscle contractions after cervical spinal cord injury is associated with changes in interhemispheric and corticomuscular coherences.

Mirror contractions refer to unintended contractions of the contralateral homologous muscles during voluntary unilateral contractions or movements. Exaggerated mirror contractions have been found in several neurological diseases and indicate dysfunction or lesion of the cortico-spinal pathway. The present study investigates mirror contractions and the associated interhemispheric and corticomuscular interactions in adults with spinal cord injury (SCI) - who present a lesion of the cortico-spinal tract - compared to able-bodied participants (AB). Eight right-handed adults with chronic cervical SCI and ten age-matched right-handed able-bodied volunteers performed sets of right elbow extensions at 20% of maximal voluntary contraction. Electromyographic activity (EMG) of the right and left elbow extensors, interhemispheric coherence over cerebral sensorimotor regions evaluated by electroencephalography (EEG) and corticomuscular coherence between signals over the cerebral sensorimotor regions and each extensor were quantified. Overall, results revealed that participants with SCI exhibited (1) increased EMG activity of both active and unintended active limbs, suggesting more mirror contractions, (2) reduced corticomuscular coherence between signals over the left sensorimotor region and the right active limb and increased corticomuscular coherence between the right sensorimotor region and the left unintended active limb, (3) decreased interhemispheric coherence between signals over the two sensorimotor regions. The increased corticomuscular communication and decreased interhemispheric communication may reflect a reduced inhibition leading to increased communication with the unintended active limb, possibly resulting to exacerbated mirror contractions in SCI. Finally, mirror contractions could represent changes of neural and neuromuscular communication after SCI.

Lower Motor Neuron Abnormality in Chronic Cervical Spinal Cord Injury: Implications for Nerve Transfer Surgery.

Nerve transfer surgery (NT) constitutes an exciting option to improve upper limb functions in chronic spinal cord injury (SCI), but requires intact sublesional lower motor neuron (LMN) health. The purpose of this study was to characterize patterns of LMN abnormality in nerve-muscle groups that are the potential recipients of NT, using a standardized electrodiagnostic examination, in individuals with chronic SCI (injury duration >2 years, injury levels C4-T1). The LMN abnormality was determined using a semihierarchical approach, combining the amplitude compound muscle action potential (CMAP) and abnormal spontaneous activity on needle electromyography (EMG). Ten participants (46 potential recipient muscles) were included (median age, 42.5 years; six males and four females; median duration from injury, 15.5 years). A high frequency of LMN abnormality was observed (87%), although there was substantial variation within and between individuals. No statistically significant discordance was observed between LMN abnormality on CMAP and EMG (p = 0.24), however, 50% of muscles with normal CMAP demonstrated abnormal spontaneous activity. The high frequency of LMN abnormality in recipient nerve-muscle groups has implications to candidate selection for NT surgery in chronic SCI and supports the important role of the pre-operative electrodiagnostic examination. Our results further support the inclusion of both CMAP and needle EMG parameters for characterization of LMN health. Although the number of nerve-muscle groups with normal LMN health was small (13%), this underscores the neurophysiological potential of some patients with chronic injuries to benefit from NT surgery.

The Protein Kinase Inhibitor Midostaurin Improves Functional Neurological Recovery and Attenuates Inflammatory Changes Following Traumatic Cervical Spinal Cord Injury.

Traumatic spinal cord injury (SCI) impairs neuronal function and introduces a complex cascade of secondary pathologies that limit recovery. Despite decades of preclinical and clinical research, there is a shortage of efficacious treatment options to modulate the secondary response to injury. Protein kinases are crucial signaling molecules that mediate the secondary SCI-induced cellular response and present promising therapeutic targets. The objective of this study was to examine the safety and efficacy of midostaurin-a clinically-approved multi-target protein kinase inhibitor-on cervical SCI pathogenesis. High-throughput analyses demonstrated that intraperitoneal midostaurin injection (25 mg/kg) in C6/7 injured Wistar rats altered the local inflammasome and downregulated adhesive and migratory genes at 24 h post-injury. Treated animals also exhibited enhanced recovery and restored coordination between forelimbs and hindlimbs after injury, indicating the synergistic impact of midostaurin and its dimethyl sulfoxide vehicle to improve functional recovery. Furthermore, histological analyses suggested improved tissue preservation and functionality in the treated animals during the chronic phase of injury. This study serves as a proof-of-concept experiment and demonstrates that systemic midostaurin administration is an effective strategy for mitigating cervical secondary SCI damage.

Electrical epidural stimulation of the cervical spinal cord: implications for spinal respiratory neuroplasticity after spinal cord injury.

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.

Autonomic dysreflexia associated with cervical spinal cord gliofibroma: case report.

BACKGROUND: Autonomic dysreflexia (AD) is an abnormal reflex of the autonomic nervous system normally observed in patients with spinal cord injury from the sixth thoracic vertebra and above. AD causes various symptoms including paroxysmal hypertension due to stimulus. Here, we report a case of recurrent AD associated with cervical spinal cord tumor. CASE PRESENTATION: The patient was a 57-year-old man. Magnetic resonance imaging revealed an intramedullary lesion in the C2, C6, and high Th12 levels. During the course of treatment, sudden loss of consciousness occurred together with abnormal paroxysmal hypertension, marked facial sweating, left upward conjugate gaze deviation, ankylosis of both upper and lower extremities, and mydriasis. Seizures repeatedly occurred, with symptoms disappearing after approximately 30 min. AD associated with cervical spinal cord tumor was diagnosed. Histological examination by tumor biopsy confirmed the diagnosis of gliofibroma. Radiotherapy was performed targeting the entire brain and spinal cord. The patient died approximately 3 months after treatment was started. CONCLUSIONS: AD is rarely associated with spinal cord tumor, and this is the first case associated with cervical spinal cord gliofibroma. AD is important to recognize, since immediate and appropriate response is required.

The Restless Spinal Cord in Degenerative Cervical Myelopathy.

BACKGROUND AND PURPOSE: The spinal cord is subject to a periodic, cardiac-related movement, which is increased at the level of a cervical stenosis. Increased oscillations may exert mechanical stress on spinal cord tissue causing intramedullary damage. Motion analysis thus holds promise as a biomarker related to disease progression in degenerative cervical myelopathy. Our aim was characterization of the cervical spinal cord motion in patients with degenerative cervical myelopathy. MATERIALS AND METHODS: Phase-contrast MR imaging data were analyzed in 55 patients (37 men; mean age, 56.2 [SD,12.0] years; 36 multisegmental stenoses) and 18 controls (9 men, P = .368; mean age, 62.2 [SD, 6.5] years; P = .024). Parameters of interest included the displacement and motion pattern. Motion data were pooled on the segmental level for comparison between groups. RESULTS: In patients, mean craniocaudal oscillations were increased manifold at any level of a cervical stenosis (eg, C5 displacement: controls [n = 18], 0.54 [SD, 0.16] mm; patients [n = 29], monosegmental stenosis [n = 10], 1.86 [SD, 0.92] mm; P < .001) and even in segments remote from the level of the stenosis (eg, C2 displacement: controls [n = 18], 0.36 [SD, 0.09] mm; patients [n = 52]; stenosis: C3, n = 21; C4, n = 11; C5, n = 18; C6, n = 2; 0.85 [SD, 0.46] mm; P < .001). Motion at C2 differed with the distance to the next stenotic segment and the number of stenotic segments. The motion pattern in most patients showed continuous spinal cord motion throughout the cardiac cycle. CONCLUSIONS: Patients with degenerative cervical myelopathy show altered spinal cord motion with increased and ongoing oscillations at and also beyond the focal level of stenosis. Phase-contrast MR imaging has promise as a biomarker to reveal mechanical stress to the cord and may be applicable to predict disease progression and the impact of surgical interventions.

Effects of aerobic exercise training on muscle plasticity in a mouse model of cervical spinal cord injury.

Cervical spinal cord injury (SCI) results in permanent life-altering motor and respiratory deficits. Other than mechanical ventilation for respiratory insufficiency secondary to cervical SCI, effective treatments are lacking and the development of animal models to explore new therapeutic strategies are needed. The aim of this work was to demonstrate the feasibility of using a mouse model of partial cervical spinal hemisection at the second cervical metameric segment (C2) to investigate the impact of 6 weeks training on forced exercise wheel system on locomotor/respiratory plasticity muscles. To measure run capacity locomotor and respiratory functions, incremental exercise tests and diaphragmatic electromyography were done. In addition, muscle fiber type composition and capillary distribution were assessed at 51 days following chronic C2 injury in diaphragm, extensor digitorum communis (EDC), tibialis anterior (TA) and soleus (SOL) muscles. Six-week exercise training increased the running capacity of trained SCI mice. Fiber type composition in EDC, TA and SOL muscles was not modified by our protocol of exercise. The vascularization was increased in all muscle limbs in SCI trained group. No increase in diaphragmatic electromyography amplitude of the diaphragm muscle on the side of SCI was observed, while the contraction duration was significantly decreased in sedentary group compared to trained group. Cross-sectional area of type IIa myofiber in the contralateral diaphragm side of SCI was smaller in trained group. Fiber type distribution between contralateral and ipsilateral diaphragm in SCI sedentary group was affected, while no difference was observed in trained group. In addition, the vascularization of the diaphragm side contralateral to SCI was increased in trained group. All these results suggest an increase in fatigue resistance and a contribution to the running capacity in SCI trained group. Our exercise protocol could be a promising non-invasive strategy to sustain locomotor and respiratory muscle plasticity following SCI.

Serotonergic innervation of respiratory motor nuclei after cervical spinal injury: Impact of intermittent hypoxia.

Although cervical spinal cord injury (cSCI) disrupts bulbo-spinal serotonergic projections, partial recovery of spinal serotonergic innervation below the injury site is observed after incomplete cSCI. Since serotonin contributes to functional recovery post-injury, treatments to restore or accelerate serotonergic reinnervation are of considerable interest. Intermittent hypoxia (IH) was reported to increase serotonin innervation near respiratory motor neurons in spinal intact rats, and to improve function after cSCI. Here, we tested the hypotheses that spontaneous serotonergic reinnervation of key respiratory (phrenic and intercostal) motor nuclei: 1) is partially restored 12 weeks post C2 hemisection (C2Hx); 2) is enhanced by IH; and 3) results from sprouting of spared crossed-spinal serotonergic projections below the site of injury. Serotonin was assessed via immunofluorescence in male Sprague Dawley rats with and without C2Hx (12 wks post-injury); individual groups were exposed to 28 days of: 1) normoxia; 2) daily acute IH (dAIH28: 10, 5 min 10.5% O2 episodes per day; 5 min normoxic intervals); 3) mild chronic IH (IH28-5/5: 5 min 10.5% O2 episodes; 5 min intervals; 8 h/day); or 4) moderate chronic IH (IH28-2/2: 2 min 10.5% O2 episodes; 2 min intervals; 8 h/day), simulating IH experienced during moderate sleep apnea. After C2Hx, the number of ipsilateral serotonergic structures was decreased in both motor nuclei, regardless of IH protocol. However, serotonergic structures were larger after C2Hx in both motor nuclei, and total serotonin immunolabeling area was increased in the phrenic motor nucleus but reduced in the intercostal motor nucleus. Both chronic IH protocols increased serotonin structure size and total area in the phrenic motor nuclei of uninjured rats, but had no detectable effects after C2Hx. Although the functional implications of fewer but larger serotonergic structures are unclear, we confirm that serotonergic reinnervation is substantial following injury, but IH does not affect the extent of reinnervation.

Recruitment of upper-limb motoneurons with epidural electrical stimulation of the cervical spinal cord.

Epidural electrical stimulation (EES) of lumbosacral sensorimotor circuits improves leg motor control in animals and humans with spinal cord injury (SCI). Upper-limb motor control involves similar circuits, located in the cervical spinal cord, suggesting that EES could also improve arm and hand movements after quadriplegia. However, the ability of cervical EES to selectively modulate specific upper-limb motor nuclei remains unclear. Here, we combined a computational model of the cervical spinal cord with experiments in macaque monkeys to explore the mechanisms of upper-limb motoneuron recruitment with EES and characterize the selectivity of cervical interfaces. We show that lateral electrodes produce a segmental recruitment of arm motoneurons mediated by the direct activation of sensory afferents, and that muscle responses to EES are modulated during movement. Intraoperative recordings suggested similar properties in humans at rest. These modelling and experimental results can be applied for the development of neurotechnologies designed for the improvement of arm and hand control in humans with quadriplegia.

Association Between Magnetic Resonance Imaging-Based Spinal Morphometry and Sensorimotor Behavior in a Hemicontusion Model of Incomplete Cervical Spinal Cord Injury in Rats.

Aim: Structural connectivity in the reorganizing spinal cord after injury dictates functional connectivity and hence the neurological outcome. As magnetic resonance imaging (MRI)-based structural parameters are mostly accessible across spinal cord injury (SCI) patients, we studied MRI-based spinal morphological changes and their relationship to neurological outcome in the rat model of cervical SCI. Introduction: Functional connectivity assessments on patients with SCI rely heavily on MRI-based approaches to investigate the complete neural axis (both spinal cord and brain). Hence, underlying MRI-based structural and morphometric changes in the reorganizing spinal cord and their relationship to neurological outcomes is crucial for meaningful interpretation of functional connectivity changes across the neural axis. Methods: Young adult rats, aged 1.5 months, underwent a precise mechanical impact hemicontusion incomplete cervical SCI at the C4/C5 level, after which sensorimotor behavioral assessments were tracked during the reorganization period of 1-6 weeks, followed by MRI of the cervical spinal cord at 8 weeks after SCI. Results: A significant ipsilesional forelimb motor debilitation was observed from 1 to 6 weeks after injury. Heat sensitivity testing (Hargreaves) showed ipsilesional forelimb hypersensitivity at 5 and 6 weeks after SCI. MRI of the cervical spine showed ipsilateral T1- and T2-weighted lesions across all SCI rats compared with no significant lesions in sham rats. Morphometric assessments of the lesional and nonlesional changes showed the diverse nature of their interindividual variability in the SCI receiving rats. While the various T1 and T2 MRI lesional volumes associated weakly or moderately with neurological outcome, the nonlesional spinal morphometric changes associated much more strongly. The results have important implications for interpreting functional MRI-based functional connectivity after SCI by providing vital underlying structural changes and their relative neurological impact. Impact statement Functional connectivity assessments on patients with SCI relies heavily upon MRI based approaches. Hence, underlying MRI based structural and morphometric changes in the reorganizing spinal cord and its relationship to neurological outcomes is vital for meaningful interpretation of functional connectivity changes across the complete neural axis (both spinal cord and the brain).

Enabling respiratory control after severe chronic tetraplegia: an exploratory case study.

Respiratory dysfunction is one of the most debilitating effects of spinal cord injury (SCI) impacting the quality of life of patients and caregivers. In addition, breathing difficulties impact the rehabilitation routine a patient may potentially undergo. Transcutaneous electrical spinal cord neuromodulation (TESCoN) is a novel approach to reactivate and retrain spinal circuits after paralysis. We demonstrate that acute and chronic TESCoN therapy over the cervical spinal cord positively impacts the breathing and coughing ability in a patient with chronic tetraplegia. ln addition, we show that the improved breathing and coughing ability are not only observed in the presence of TESCoN but persisted for a few days after TESCoN was stopped.NEW & NOTEWORTHY Noninvasive spinal neuromodulation improves breathing and coughing in a patient with severe and complete tetraplegia.

Influence of early extensive posterior decompression on hyponatremia and cardiopulmonary dysfunction after severe traumatic cervical spinal cord injury: A clinical observational study.

Retrospective single institution observational study.The aim of the present study was to analyze the influence of early extensive posterior decompression on complications in patients with severe traumatic cervical spinal cord injury (tcSCI).Cervical SCI is associated with a high prevalence of hyponatremia and cardiopulmonary dysfunction. However, very few studies have focused on this exploration to reduce the incidence of SCI early complications.We reviewed the medical records of consecutive patients undergoing extensive posterior decompression within 24 h for severe tcSCI (American Spinal Injury Association Impairment Scale [AIS] A to C) admitted between January 2009 and January 2018. The data collected retrospectively included age, gender, mechanism, and level of SCI, AIS grade, fracture or dislocation, electrolyte, and cardiopulmonary complications.Of the 97 enrolled patients, the baseline AIS grade was AIS A in 14, AIS B in 31, and AIS C in 52. Improvement of at least two AIS grades was found in 26 (26.8%), and improvement of at least one grade was found in 80.4% of patients at discharge. Twenty-nine (29.9%) patients had mild hyponatremia, 8 (8.2%) had moderate hyponatremia, and 3 (3.1%) had severe hyponatremia during hospitalization. The incidences of hyponatremia, hypotension, and tracheotomy were 41.2%, 13.4%, and 6.2%, respectively. The mean forced vital capacity (FVC) on admission and at discharge was 1.34 ±â€Š0.46 L and 2.21 ±â€Š0.41 L (P < .0001), respectively. Five patients developed pneumonia.Our results suggest that early expansive posterior decompression significantly reduces the incidence of hyponatremia, hypotension, and tracheotomy by promoting recovery of spinal cord function after severe tcSCI.