Introduction: Pulmonary complications are among the major causes of death in persons with spinal cord injury (SCI). Therefore, improving the management of pulmonary dysfunction is highly prioritized in SCI care. The objectives of the study are to describe structural and functional changes in the pulmonary system among middle-aged persons with chronic, traumatic, high-level SCI, investigate associations between structural and functional changes, sociodemographics and injury characteristics, and to compare the findings with matched controls from the general population.

Methods: Cross-sectional study in a community and tertiary hospital setting in southern Sweden. Data from the Swedish SPinal Cord Injury Study on Cardiopulmonary and Autonomic Impairment (SPICA), including 5 women and 20 men (mean age 58 years, mean time since injury 28 years, injury levels C1-T6, American Spinal Injury Association Impairment Scale A-C). Structural changes in the lungs were assessed with computed tomography. The lung function was assessed with spirometry, impulse oscillometry (IOS) and diffusing capacity. Controls (ratio 4:1), matched for age, gender, height and smoking status, were obtained from the Swedish CArdioPulmonary BioImage Study (SCAPIS). SCAPIS is a study designed to improve risk prediction and to study disease mechanisms of cardiovascular disease and chronic obstructive pulmonary disease in a cohort of 30 000 persons. Controls performed lung function tests 15 min after the inhalation of 400 µg salbutamol. Associations between variables were investigated using regression analyses.

Results: In total, 75% of the participants had structural findings, of which linear scars of atelectasis were the most common. There were no significant associations between structural and functional changes. A lower level of injury (i.e. each level C1-T6) was significantly associated with lower occurrence of structural findings (OR=0.65, p=0.02). Older age was significantly associated with greater occurrence of linear scars of atelectasis (OR=1.40, p=0.03). No significant differences were found between all participants and controls regarding structural findings. However, when subgroup analyses were performed, structural findings were significantly more common in participants with tetraplegia compared to controls (OR=6.79, p=0.03). The percent of predicted vital capacity (VC), predicted forced expiratory volume in 1 s (FEV1), FEV1/forced VC (%) and predicted maximal expiratory flow at 50% (MEF50) increased significantly with each lower level of injury, indicating better pulmonary function. Compared to controls, the percent of predicted diffusing capacity of lung for carbon monoxide was 27.7 lower in all participants with SCI, and 31.9 lower in participants with tetraplegia. The corresponding decreases of the carbon monoxide transfer coefficient were 9.6 and 16.4. The same pattern, with more pronounced pathology in participants with tetraplegia compared to controls, was found for all the IOS parameters (R5 0.05 vs 0.09, R20 0.03 vs 0.06, X5 -0.04 vs -0.05, AX 0.29 vs 0.41 and resonant frequency 2.8 vs 3.6).

Conclusions: Structural and functional changes in the pulmonary system are common in middle-aged persons with chronic high-level SCI, and depend to a large extent on the level of injury. As persons with tetraplegia are particularly vulnerable, this group should receive particular attention in the clinical context.

Background: Gunshot wounds (GSW) are the third most common source of the 17,700 new US spinal cord injuries. According to the National Spinal Cord Injury Statistics, there has been a significant decline in survival from 2010 to 2018 for a 20 year old SCI on mechanical ventilation (MV) from 17.1 years to 11.3 years. MV during the initial hospitalization leads to a 60% ventilator associated pneumonia rate and contributed to delayed rehabilitation. Diaphragm Pacing (DP) can replace MV. Recent reports demonstrate that DP is associated with a significant decrease in short term mortality of 15% to 3% (Kerwin et al, 2018) and improved median long term survival to 22.2 years (Onders et al, 2018). This report analyzes cervical GSW with respiratory compromise.
Methods: This is a single site retrospective review of prospective IRB protocols and trauma registry identifying of all patients with GSW cervical spine injuries and respiratory compromise.
Results: A total of 17 patients met inclusion criteria. Six patients died within 24 hours of admission. Eleven patients were evaluated for DP, nine of whom were taken to the OR. Of the two not taken to the operating room: one had extension of infarction of his spinal cord injury to his brainstem expiring at 10 days and the second one deferred DP in trying to wean but expired at 12 weeks while still on MV. Two had non stimulable diaphragms in the OR and were not implanted. Seven patients underwent laparoscopic implantation of DP electrodes. Of the 7 patients who were implanted, 4 achieved full time pacing and successfully replaced their mechanical ventilators. One patient was able to wean up to 4 hours off the vent and two patients had no success with weaning. For all patients who survived the first 24 hours only 36%(4/11) were able to be completely liberated from MV. The only successfully weaned patients used DP.
Conclusion: With acts of violence primarily from GSW involving 13.5% of SCI, it is unfortunate the results of DP only approaches 44% (4/9) when patients explored laparoscopically. This is due to the blast effect and the infarction of the phrenic motor neurons causing loss of the diaphragm motor units so there cannot be stimulation. Early use of nerve grafts with DP could help these patients, who would otherwise be on chronic MV with decreased quality of life and increased mortality.

Introduction: Swallowing dysfunction, which may cause aspiration pneumonia, is one of the most important complications of cervical spinal cord injury (CSCI) treatment. Early detection of dysphagia is necessary to ensure sufficient nutritional intake and avoid aspiration pneumonia. Dysphagia following acute traumatic CSCI has recently been reported, but the mechanism is not well understood. No previous studies have reported the association between morphological changes of the soft tissue and dysphagia. Videofluoroscopic and videoendoscopic swallowing studies often show food retention in the pharynx in individuals with dysphagia following CSCI. We hypothesized that the morphological changes of the pharynx situated right in front of the injured cervical spine result in the swallowing dysfunction. The objective of this study was to examine the factors associated with the severity of dysphagia to elucidate its mechanism.
Methods: We conducted a prospective analysis of patients with acute traumatic CSCI who were admitted within 2 weeks of the injury from October 2015 to August 2018. Dysphagia was evaluated using the Dysphagia Severity Scale (1 = saliva aspiration; 2 = food aspiration; 3 = water aspiration; 4 = occasional aspiration; 5 = oral problems; 6 = minimum problems; and 7 = within normal limits) 2 weeks after the injury. The widths of the retropharyngeal (level C2) and retrotracheal spaces (level C6) were measured to assess the soft tissue damage due to the injury using sagittal computed tomography. In addition, we assessed the patient age, surgery of the injured cervical spine, presence of tracheostomy, osteophyte behind the pharynx, level of injury on magnetic resonance imaging, and American Spinal Injury Association (ASIA) motor score 2 weeks after the injury. The factors affecting DSS were evaluated using a multiple regression analysis.
Results: Of the 161 patients admitted to our hospital within 2 weeks from the injury, we excluded 16 who changed hospitals because of the deterioration in their general condition and 9 with mild paresis who were discharged early. Finally, 136 individuals (mean age±standard deviation: 65.1±14.1 years) were evaluated in this study. Among the individuals with acute CSCI, 1, 8, 11, 24, 40, 46, and 6 had DSS grades of 1, 2, 3, 4, 5, 6, and 7, respectively. As 44 individuals were categorized under grades less than 5, which were defined as different types of aspiration, the incidence of aspiration was 32%. Multiple regression analysis revealed that age, ASIA motor score, tracheostomy, and retropharyngeal space were significantly associated with DSS (t-value/p-value: -3.7/<0.001, 9.1/<0.001, -4.5/<0.001, -2.6/<0.01, respectively).
Conclusion: A prospective analysis for dysphagia was performed on 136 individuals with CSCI. The incidence of aspiration following CSCI was 32%. Severe paresis, tracheostomy, old age, and swelling of the retropharyngeal space were significantly affected by dysphagia following CSCI. Morphological changes of the pharynx, which is situated right behind the larynx, following the injury affects the mechanism of dysphagia.

Introduction:
Individuals with cervical spinal cord injury (CSCI) have identified upper limb function as one of the most relevant factors for the improvement of quality of life. Arm and hand function in CSCI shows a great heterogeneity. To date, the impact of the lower motor neuron (LMN) status (intact versus damaged) on upper limb function in CSCI has been less evaluated. The objectives of this study were: (1) to evaluate the LMN integrity of five selected hand and forearm muscles, within the first 9 weeks after CSCI, and (2) to investigate the impact of the LMN status of these muscles on upper limb function.
Methods:
Longitudinal prospective study in individuals with CSCI. Assessments were performed at T1 (7-14 days), T2 (21-28 days), T3 (56-63 days) and T4 (3 months after CSCI). Surface electrical nerve stimulation was used to evaluate the LMN integrity of five hand- and forearm muscles (M. extensor carpi radialis, M extensor digitorum communis, M. flexor pollicis longus, M. extensor pollicis longus, M. flexor digitorum profundus) between T1-T3. The LMN status at T3 was related to measures of the manual muscle testing (MMT), the distance measured from the middle finger pad to the palm of the hand and the qualitative grasping and quantitative grasping subtests of the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) at T4. The Mann-Whitney-U Test was used to detect significant differences between intact and damaged LMN regarding our defined outcome measures.
Results:
18 individuals (36 arms) with CSCI were included and analyzed. The statistical analyses showed (1) stable findings over time (T1-T3) both in individuals with intact and damaged LMN. However partially intact LMN often changed into an intact or damaged LMN between T1-T3, (2) a large variability regarding relation to upper limb function at T4 was found within the intact as well as the damaged LMN group, (3) individuals with CSCI and damaged LMN of the M. extensor digitorum communis did not show a shorter distance from the middle finger pad to the palm of the hand compared to individuals with CSCI and intact LMN, (4) finally in some muscles, voluntary motor contraction was detected, however, these muscles did not respond to electrical stimulation. Conclusion:
The optimal time point to assess the LMN status is between the 21st and 63rd day after CSCI. Nerve electrical stimulation seems less sensitive to distinguish if muscles have a damaged or partially damaged LMN. Therefore, the impact of the LMN status, assessed with electrical stimulation, on the development of a tenodesis grasp and upper limb function in CSCI has to be considered with caution.

Introduction:

Paired associative stimulation (PAS), a combination of non-invasive transcranial magnetic stimulation (TMS) with peripheral nerve stimulation (PNS), is emerging as a promising tool for alleviation of motor deficits in neurological disorders. We have shown previously that PAS employing 50 Hz PNS enhances motor performance in chronic spinal cord injury patients and induces robust motor-evoked potential (MEP) potentiation in healthy subjects. Specifically, we have shown that PAS leads to improved motor function in hands of individuals with incomplete traumatic tetraplegia and such a paired stimulation is more effective than PNS alone.

The effectiveness and feasibility of PAS protocols are essential for their use in clinical practice. Plasticity induction by conventional PAS can be variable and unstable. Protocols effective in challenging clinical conditions are needed.

Spinal cord injuries (SCIs) can be caused by neurological diseases. Cellular and molecular mechanisms behind neurological SCI can differ dramatically from those of traumatic SCI, and it is not self-evident that treatments that are effective for traumatic SCI would also work in disease-provoked injuries.

Methods:

Here we investigated whether the effectiveness of PAS can be further enhanced. Potentiation of MEPs up to 60 minutes after PAS with PNS frequencies of 25, 50, and 100 Hz was tested in ten healthy subjects. We also tested our most effective protocol in the condition mimicking the situation in patients whose optimal TMS target in the cortex cannot be precisely identified.

After identifying most effective protocol, we tested long-term PAS approach in patients with nontraumatic neurological SCI. Five patients with nontraumatic tetraplegia received PAS to the weaker upper limb 3-5 times per week for 6 weeks. Patients were evaluated with manual muscle testing (MMT) before and immediately after the therapy as well as at 1- and 6-month follow-ups. Patients were also evaluated for spasticity, hand mechanical and digital dynamometry, pinch and Box and Blocks tests.

Results

PAS with 100 Hz PNS was more effective than 50 (P=0.009) and 25 Hz (P=0.016) protocols. Moreover, when administered for 3 days, PAS with 100 Hz led to significant MEP potentiation on the 3rd day (P=0.043) even when the TMS target was selected suboptimally (modelling cases where finding an optimal site for TMS is problematic due to a neurological disease).

All patients with neurological SCI had improved MMT values at all post-PAS evaluations. The average MMT increase was 1.44±0.37 points (p=0.043) immediately after PAS, 1.57±0.4 points (p=0.043) at the one-month follow-up and 1.71±0.47 points (p=0.043) at the 6-month follow-up. The pinch, digital dynamometry values and Box and Blocks test results also improved in all patients.

Conclusions

PAS with 100 Hz PNS is the most effective protocol and feasible for clinical applications. Long-term PAS can be a safe and effective treatment for improving hand function in patients with nontraumatic tetraplegia. This is the first report demonstrating the therapeutic potential of PAS for neurological SCI. Further studies with larger number of patients and at the subacute stage of SCI are justified.

Introduction: More than half of all people who sustain a spinal cord injury (SCI) experience some degree of impairment in the upper extremity. Functional use of the arm and hand is of paramount importance to these individuals. Fortunately, options for improving upper extremity function after tetraplegia have increased as a result of advancing science and technology. These advancements focus on acute spinal decompression, neural repair and neuroprotection, activity-based rehabilitation, and surgical reconstruction including electrical stimulation devices that are surgically implanted. Unfortunately, while reconstructive procedures have demonstrated functional improvements for people with cervical SCI, they are not universally available and are therefore under-utilized. A common measure for evaluating the impact of upper limb interventions such as those targeting neurorecovery is the upper extremity motor score (UEMS) of the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI). Historically, the impact of UE reconstructive procedures, including implanted neuroprostheses, has not been reported as changes in the ISNCSCI UEMS. The purpose of this paper is to demonstrate the step-wise incremental changes in UEMS after reconstructive surgery and implantation of UE neuroprostheses.

Methods: A retrospective analysis was conducted of 25 individuals with motor compete C5 and C6 SCI who received reconstructive procedures such as tendon transfers and an implanted neuroprosthesis at least one-year post-injury. Data included manual muscle test (MMT) scores obtained prior to intervention, and three months post-surgery. Post-surgical strength was measured with the neuroprosthesis off (reflecting impact of tendon transfers) and on (reflecting the impact of tendon transfers and the neuroprosthesis). All participants were enrolled in a clinical trial for an upper extremity neuroprosthesis at the time of data collection.

Results: Large incremental improvements in UEMS were observed as a result of UE reconstructive procedures and neuroprosthesis implantation. The median UEMS prior to any intervention was 8/25 (range 4-8). The median UEMS after UE reconstruction with the neuroprosthesis off was 11/25 (range 4-15) (p=0.0109), reflecting the impact of tendon transfers. The median UEMS including UE neuroprostheses was 18/25 (range 14-23) (p<0.0001). Additionally, all participants gained strength in thumb flexion post-surgery (median MMT grade 4), which is not captured by UEMS.

Conclusion: Reconstructive surgeries including tendon transfers and implanted neuroprostheses effect significant changes in UEMS. A 10-point UEMS increase in a neurologically stable population surpasses the effects of other clinical and research interventions currently available for people with chronic, cervical SCI. These strong effects are further underestimated as the UEMS does not include changes in function at the thumb. The functional impact of these changes in strength have been reported in the literature. Currently, there are no other interventions that provide this level of function for people with chronic, cervical SCI. This is a call to action for expanding opportunities for UE reconstruction and increasing access to implanted technology for a segment of the SCI community that often has few other options for functional restoration.