Cardiovascular Alterations After Spinal Cord Injury: An Overview

Usefulness of D-dimer and Ultrasonography Screening for Detecting Deep Vein Thrombosis in Patients with Spinal Cord Injury Undergoing Rehabilitation

Patients with spinal cord injury (SCI) are at an increased risk of deep vein thrombosis (DVT). This study aims at assessing usefulness of D-dimer and compressive Doppler ultrasonography (CDUS) for detecting DVT in patients undergoing rehabilitation at various time-points post-SCI. One-hundred forty-five patients were divided into three groups based on time elapsed since SCI: I (≥3 weeks to 3 months), II (≥3 to 6 months), and III (≥6 months). On admission, D-dimer plasma level measurement and CDUS of the lower limbs venous system were performed. DVT was diagnosed using CDUS in 15 patients (10.3% of entire group), more frequently in group I (22.2% of group) and II (11.7%) compared to group III (1.5%). Most DVT patients received thromboprophylaxis (80%) and were asymptomatic or mildly symptomatic (60%). Median D-dimer was elevated in patients with DVT from all groups, and also patients without DVT from groups I and II, but not group III. D-dimers were higher in patients with DVT than without DVT in the entire group (p = 0.001) and group I (p = 0.02), but not in groups II and III. The risk of DVT in SCI patients undergoing rehabilitation and thromboprophylaxis including asymptomatic or mildly symptomatic cases, is high within 6 months post-injury, and especially within 3 months. Measurement of D-dimer level should be complemented by routine CDUS for detecting DVT within 6 months post-SCI. Over 6 months, the usefulness of D-dimer screening alone is better for DVT detection.

Effects of 16-Form Wheelchair Tai Chi on the Autonomic Nervous System among Patients with Spinal Cord Injury

Objective

This study aims to investigate the effects of 16-form Wheelchair Tai Chi (WCTC16) on the autonomic nervous system among patients with spinal cord injury (SCI).

Methods

Twenty patients with chronic complete thoracic SCI were recruited. Equivital life monitoring system was used to record and analyze heart rate variability (HRV) of patients for five minutes before and after five consecutive sets of WCTC16, respectively. The analysis of HRV in the time domain included RR intervals, the standard deviation of all normal RR intervals (SDNN), and the root mean square of the differences between adjacent NN intervals (RMSSD). The analysis of HRV in the frequency domain included total power (TP), which could be divided into very-low-frequency area (VLFP), low-frequency area (LFP), and high-frequency area (HFP). The LF/HF ratio as well as the normalized units of LFP (LFPnu) and HFP (HFPnu) reflected the sympathovagal balance.

Results

There was no significant difference in RR interval, SDNN, RMSSD, TP, HEP, VLFP, and LFP of SCI patients before and after WCTC16 exercise (P > 0.05). LFPnu and HF peak decreased, while HFPnu and LF/HF increased in SCI patients after WCTC16 exercise. The differences were statistically significant (P < 0.001).

Conclusion

WCTC16 can enhance vagal activity and decrease sympathetic activity so that patients with chronic complete thoracic SCI can achieve the balanced sympathovagal tone.

Effects of an Overground Walking Program With a Robotic Exoskeleton on Long-Term Manual Wheelchair Users With a Chronic Spinal Cord Injury: Protocol for a Self-Controlled Interventional Study

BACKGROUND

In wheelchair users with a chronic spinal cord injury (WUSCI), prolonged nonactive sitting time and reduced physical activity-typically linked to this mode of mobility-contribute to the development or exacerbation of cardiorespiratory, musculoskeletal, and endocrine-metabolic health complications that are often linked to increased risks of chronic pain or psychological morbidity. Limited evidence suggests that engaging in a walking program with a wearable robotic exoskeleton may be a promising physical activity intervention to counter these detrimental health effects.

OBJECTIVE

This study's overall goals are as follows: (1) to determine the effects of a 16-week wearable robotic exoskeleton-assisted walking program on organic systems, functional capacities, and multifaceted psychosocial factors and (2) to determine self-reported satisfaction and perspectives with regard to the intervention and the device.

METHODS

A total of 20 WUSCI, who have had their injuries for more than 18 months, will complete an overground wearable robotic exoskeleton-assisted walking program (34 sessions; 60 min/session) supervised by a physiotherapist over a 16-week period (one to three sessions/week). Data will be collected 1 month prior to the program, at the beginning, and at the end as well as 2 months after completing the program. Assessments will characterize sociodemographic characteristics; anthropometric parameters; sensorimotor impairments; pain; lower extremity range of motion and spasticity; wheelchair abilities; cardiorespiratory fitness; upper extremity strength; bone architecture and mineral density at the femur, tibia, and radius; total and regional body composition; health-related quality of life; and psychological health. Interviews and an online questionnaire will be conducted to measure users' satisfaction levels and perspectives at the end of the program. Differences across measurement times will be verified using appropriate parametric or nonparametric analyses of variance for repeated measures.

RESULTS

This study is currently underway with active recruitment in Montréal, Québec, Canada. Results are expected in the spring of 2021.

CONCLUSIONS

The results from this study will be essential to guide the development, implementation, and evaluation of future evidence-based wearable robotic exoskeleton-assisted walking programs offered in the community, and to initiate a reflection regarding the use of wearable robotic exoskeletons during initial rehabilitation following a spinal cord injury.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03989752; https://clinicaltrials.gov/ct2/show/NCT03989752.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/19251.

Development of Cardiometabolic Health indicators to advance the quality of spinal cord injury rehabilitation: SCI-High Project

Context: Spinal cord injury or disease (SCI/D) leads to unchanged low-density lipoprotein and cholesterol, very low high-density lipoprotein a form of dyslipidemia and physical inactivity which combine to increase risk of morbidity and mortality from cardiometabolic disease. Herein, we describe the selection of structure, process and outcome indicators for adults in the first 18 months post-SCI/D rehabilitation admission. Methods: A Pan-Canadian Cardiometabolic Health Working Group was formed to develop a construct definition. Cardiometabolic risk factors were summarized in a Driver diagram. Release of the Paralyzed Veterans of America "Identification and Management of Cardiometabolic Risk after Spinal Cord Injury" and the International Scientific Exercise Guidelines: "Evidence-based scientific exercise guidelines for adults with spinal cord injury", informed the group's focus on prevention strategies to advance this Domain of rehabilitation admission. Results: The structure indicator identifies during rehabilitation the presence of appropriate time and resources for physical exercise prescription. Process indicators are lipid profile assessment at rehabilitation admission and documented exercise prescriptions prior to discharge. The outcome indicators track patient's knowledge retention regarding exercise prescription at discharge, current exercise adherence and lipid status 18 months after rehabilitation discharge. Conclusion: Routine national implementation of these indicators at the specified time points will enhance efforts to detect dyslipidemia and assure routine participation in endurance exercise. These indicators align with international initiatives to improve cardiometabolic health through interventions targeting modifiable risk factors specifically endurance exercising and optimal lipid profiles, crucial to augmenting cardiometabolic health after SCI/D.

Accuracy of Impedance Cardiography for Hemodynamic Assessment During Rest and Exercise in Wheelchair Rugby Players

Purpose: The aim of the study was to analyze the accuracy of impedance cardiography (ICG) for hemodynamic assessment in wheelchair rugby players during rest and exercise. Method: The study included 21 players (mean age 33.0 ± 5.4, 86% male) with posttraumatic tetraplegia. ECG, echocardiography, and gas exchange analysis during rest and exercise were used to obtain heart rate (HR), stroke volume (SV), and cardiac output (CO) for comparison with PhysioFlow®. Results: There was a good correlation between reference methods and ICG for HR, SV, CO at rest and CO at peak exercise (r = 0.69-0.77, p < .001) and a very good correlation for peak HR (r = 0.91, p < .0001). ICG overestimated SV at rest, CO at rest, and peak CO, which resulted in low intraclass correlation coefficients (ICC = 0.250 and 0.570). Conclusions: ICG can serve as a good estimate of basic hemodynamic parameters during rest and exercise in wheelchair rugby players but overestimates stroke volume and cardiac output.

Identification of critical genes associated with spinal cord injury based on the gene expression profile of spinal cord tissues from trkB.T1 knockout mice

The present study aimed to identify the genes and underlying mechanisms critical to the pathology of spinal cord injury (SCI). Gene expression profiles of spinal cord tissues of trkB.T1 knockout (KO) mice following SCI were accessible from the Gene Expression Omnibus database. Compared with trkB.T1 wild type (WT) mice, the differentially expressed genes (DEGs) in trkB.T1 KO mice following injury at different time points were screened out. The significant DEGs were subjected to function, co-expression and protein-protein interaction (PPI) network analyses. A total of 664 DEGs in the sham group and SCI groups at days 1, 3, and 7 following injury were identified. Construction of a Venn diagram revealed the overlap of several DEGs in trkB.T1 KO mice under different conditions. In total, four modules (Magenta, Purple, Brown and Blue) in a co-expression network were found to be significant. Protein tyrosine phosphatase, receptor type C (PTPRC), coagulation factor II, thrombin (F2), and plasminogen (PLG) were the most significant nodes in the PPI network. ‘Fc γ R-mediated phagocytosis’ and ‘complement and coagulation cascades’ were the significant pathways enriched by genes in the PPI and co-expression networks. The results of the present study identified PTPRC, F2 and PLG as potential targets for SCI treatment, which may further improve the general understanding of SCI pathology.

Exercise and Health-Related Risks of Physical Deconditioning After Spinal Cord Injury

A sedentary lifestyle occurring soon after spinal cord injury (SCI) may be in contrast to a preinjury history of active physical engagement and is thereafter associated with profound physical deconditioning sustained throughout the lifespan. This physical deconditioning contributes in varying degrees to lifelong medical complications, including accelerated cardiovascular disease, insulin resistance, osteopenia, and visceral obesity. Unlike persons without disability for whom exercise is readily available and easily accomplished, exercise options for persons with SCI are more limited. Depending on the level of injury, the metabolic responses to acute exercise may also be less robust than those accompanying exercise in persons without disability, the training benefits more difficult to achieve, and the risks of ill-considered exercise both greater and potentially irreversible. For exercise to ultimately promote benefit and not impose additional impairment, an understanding of exercise opportunities and risks if exercise is undertaken by those with SCI is important. The following monograph will thus address common medical challenges experienced by persons with SCI and typical modes and benefits of voluntary exercise conditioning.

Early Systemic Alterations in Severe Spinal Cord Injury: An Experimental Study on the Impact of Injury Level on Renal Function

STUDY DESIGN

An experimental model of spinal cord injury (SCI) intended to characterize changes in renal function.

OBJECTIVE

The aim of this study was to evaluate the possible influence of SCI level on renal function during spinal shock.

SUMMARY OF BACKGROUND DATA

SCI triggers multiple systemic and metabolic alterations. Among them, renal dysfunction stands out. Although several variables have been related to its extent, the impact of the cord injury level on renal function has not been clearly stated, particularly during the spinal shock.

METHODS

Anesthetized adult Sprague-Dawley rats were subjected to severe spinal cord contusion at low (T8) and high (T1) thoracic levels using the weight-drop method. Glomerular filtration rate (GFR) and tubular secretion (TS) were estimated 24 hours after injury, using a validated method based on the determination of plasma concentrations of iopamidol and p-aminohippuric acid by high-performance liquid chromatography.

RESULTS

GFR, fell to 33% (95% CI [24%, 43%]) and 10% (8%, 13%) of the sham-injured controls, whereas TS, decreased to 59% (95% CI [47%, 71%]), and 25% (18%, 32%) of the sham-injured controls, in T8 and T1 injury levels, respectively. Comparisons between cords injured and control rats, as well as between low and high-injured levels, were statistically significant (P < 0.01).

CONCLUSION

Renal dysfunction occurs early after severe SCI. The damage is greater in high compared to low injuries. These findings could have important implications in the acute management of patients with high thoracic and cervical injuries, especially in pharmacotherapy using drugs eliminated by the kidney.

LEVEL OF EVIDENCE

N/A.

Implications of altered autonomic control on sports performance in athletes with spinal cord injury

It is well known that athletes with spinal cord injury (SCI) may experience altered autonomic physiology that impacts their exercise capacity and sports performance. This is particularly relevant given the ever-increasing number of individuals with SCI who are actively engaged in sports at all levels, from community-based adaptive sports to elite Paralympic competitions. As such, the purpose of this article is to review the present literature regarding the implications of altered autonomic control on the safety and performance of athletes with SCI. A particular emphasis will be placed on the autonomic aspects of cardiovascular and thermoregulatory control in the athlete population, as well as the implications of autonomic dysreflexia in enhancing sports performance. Further research is needed to understand the autonomic factors that influence athletes with SCI in order to ensure optimal and safe sports competition. Additionally, this information is crucially relevant to the coaches, sports administrators, and team medical staff who work closely with athletes with SCI.

Hemodynamic Adaptations to Regular Exercise in People With Spinal Cord Injury

Objective

To investigate the real-time cardiovascular response to the progressive overload exercise in different levels of spinal cord injury (SCI), and to find out whether regular exercise has effect on these cardiovascular responses.

Methods

The study enrolled 8 able-bodied individuals in the control group plus 15 SCI subjects who were divided into two groups by their neurological level of injury: high-level SCI group (T6 or above) and low-level SCI group (T7 or below). Also, subjects were divided into exercise group and non-exercise group by usual exercise habits. We instructed the subjects to perform exercises using arm ergometer according to the protocol and checked plethysmograph for the real time assessment of blood pressure, heart rate, and cardiac output.

Results

Six subjects were included in high-level SCI group (3 cervical, 3 thoracic injuries), 9 subjects in low-level SCI group (9 thoracic injuries), and 8 able-bodied individuals in control group. During arm ergometer-graded exercise, mean arterial pressure (MAP) was significantly lower in high-level SCI subjects of non-exercise group, compared with high-level SCI subjects of exercise group. In addition, HR was significantly higher in low-level SCI group compared with control group.

Conclusion

There are significant differences in mean arterial pressure of high-level SCI group according to usual exercise habits. We discovered that even in non-athlete high-level SCI, regular exercise can bring cardiac modulation through blood pressure control.

Deep venous thrombosis in patients with chronic spinal cord injury

CONTEXT/OBJECTIVE

Deep venous thrombosis (DVT) is a well-known complication of an acute spinal cord injury (SCI). However, the prevalence of DVT in patients with chronic SCI has only been reported in a limited number of studies. The aim of our study was to examine the prevalence of DVT in patients with SCI beyond three months after injury.

DESIGN

Cross-sectional study.

SETTING

Rehabilitation Department at the Bydgoszcz University Hospital in Poland.

PARTICIPANTS

Sixty-three patients with SCI that were more than 3 months post injury. The patients, ranging in age from 13 to 65 years, consisted of 15 women and 48 men; the mean age of the patients was 32.1 years. The time from injury varied from 4 to 124 months.

OUTCOME MEASURES

Clinical assessment, D-dimer and venous duplex scan.

RESULTS

The venous duplex scan revealed DVT in 5 of the 63 patients. The post-injury time in four of the patients varied between 4 and 5 months; one patient was 42 months post-injury.

CONCLUSION

DVT occurred in patients with chronic SCI, mainly by the 6th post injury month.

Arm Crank and Wheelchair Ergometry Produce Similar Peak Oxygen Uptake but Different Work Economy Values in Individuals with Spinal Cord Injury

Objective. To study whether values for peak oxygen uptake (VO_2peak) and work economy (WE) at a standardized workload are different when tested by arm crank ergometry (ACE) and wheelchair ergometry (WCE). Methods. Twelve paraplegic men with spinal cord injury (SCI) in stable neurological condition participated in this cross-sectional repeated-measures study. We determined VO_2peak and peak power output (PO_peak) values during ACE and WCE in a work-matched protocol. Work economy was tested at a standardized workload of 30 Watts (W) for both ACE and WCE. Results. There were no significant differences in VO_2peak (mL·kg⁻¹·min⁻¹) between ACE (27.3 ± 3.2) and WCE (27.4 ± 3.8) trials, and a Bland-Altman plot shows that findings are within 95% level of agreement. WE or oxygen consumption at 30 W (VO_2-30W) was significantly lower during WCE compared to ACE (P < 0.039). Mean (95% CI) PO_peak (W) were 130 (111–138) and 100 (83–110) during ACE and WCE, respectively. Conclusion. The findings in the present study support the use of both ACE and WCE for testing peak oxygen uptake. However, WE differed between the two test modalities, meaning that less total energy is used to perform external work of 30 W during wheelchair exercise when using this WCE (VP100 Handisport ergometer). Clinical Trials Protocol Record is NCT00987155/4.2007.2271.

Preserved cardiac autonomic dynamics during sleep in subjects with spinal cord injuries

BACKGROUND

Spinal cord injuries (SCI) are associated with altered cardiovascular autonomic control (CAC). Sleep is characterized by modifications of autonomic control across sleep stages; however, no data are available in SCI subjects on CAC during sleep. We aim to assess cardiac autonomic modulation during sleep in subjects with SCI.

PATIENTS AND METHODS

27 participants with a neurological and radiological diagnosis of cervical (Cerv, n = 12, ie, tetraplegic) and thoracic SCI (Thor, n = 15, ie, paraplegic) and healthy subjects (Controls) were enrolled. Overnight polysomnographic (PSG) recordings were obtained in all participants. Electrocardiography and respiration were extracted from PSG, divided into sleep stages [wakefulness (W), non-REM sleep (NREM) and REM] for assessment of CAC, using symbolic analysis (SA) and corrected conditional entropy (CCE). SA identified indices of sympathetic and parasympathetic modulation and CCE evaluated the degree of complexity of the heart period time series.

RESULTS

SA revealed a reduction of sympathetic and predominant parasympathetic control during NREM compared to W and REM in SCI patients, independent of the level of the lesion, similar to the Controls. In all three groups, complexity of autonomic regulation was higher in NREM compared to W and REM.

CONCLUSIONS

In subjects with SCI, cardiac autonomic control changed across sleep stages, with a reduction of sympathetic and an increase of parasympathetic modulation during NREM compared to W and REM, and a parallel increase of complexity during NREM, which was similar to the Controls. Cardiac autonomic dynamics during sleep are maintained in SCI, independent of the level of the lesion.

The effect of alpha-lipoic acid (ALA) supplementation on cardiovascular risk factors in men with chronic spinal cord injury: a clinical trial

STUDY DESIGN

A randomized, double-blind, placebo-controlled clinical trial.

OBJECTIVE

To assess the effect of alpha-lipoic acid (ALA) supplementation on IL-6, hs-CRP, FBS, anthropometric indices, food intake and blood pressure in male patients with chronic spinal cord injury (SCI).

SETTING

Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran.

METHODS

Fifty-eight men with chronic SCI participated in the study. Participants were divided in two groups: one group received 600 mg of supplemental ALA (n=28) and the other group received placebo (n=30) for 12 weeks. At the beginning and end of the study, biochemical parameters, anthropometric indices, blood pressure and dietary intakes were measured. Dietary intake was measured using N4 software, and statistical analyses were carried out using SPSS16.

RESULTS

No significant reduction was found in IL-6 (P=0.97) and hs-CRP levels (P=0.23). There was significant reduction in fasting blood sugar (P=0.001), body weight (P=0.001), BMI (P=0.001), waist circumference (P=0.001) and blood pressure (P=0.001). Dietary intake was significantly reduced, including fat (P=0.001), carbohydrate (P=0.001), protein (P=0.002) and energy intakes (P=0.001).

CONCLUSION

Lipoic acid supplementation had no significant effect on the measured inflammatory markers but it reduces fasting blood sugar, anthropometric parameters, food intake and blood pressure in men with chronic SCI.

The association between spinal cord injury and acute myocardial infarction in a nationwide population-based cohort study

STUDY DESIGN

A spinal cord injury (SCI) retrospective cohort study was derived from the National Health Insurance Research Database of Taiwan.

OBJECTIVE

We evaluated risk of acute myocardial infarction (AMI) in patients newly diagnosed with SCI.

SUMMARY OF BACKGROUND DATA

According to information of the World Health Organization, cardiovascular diseases are the most frequent causes of death in patients with SCI compared with those in the general population.

METHODS

We obtained claims data from the National Health Insurance Research Database for this cohort study. The SCI group comprised 22,197 patients with a diagnosis of SCI. Case and control patients were based on risk-set sampling in a 1:4 ratio, and we excluded patients with a prior diagnosis of AMI. Comorbidities were categorized as the proportion of prior illnesses in the SCI and non-SCI groups. We used the Cox proportion model to explore adjusted hazard ratio (aHR) for developing AMI between case and control patients.

RESULTS

Patients with SCI were significantly more likely to exhibit pre-existing illnesses associated with AMI than patients without SCI. Patients with a diagnosis of SCI exhibited significantly higher aHRs for developing AMI than patients without SCI (aHR=1.17; P<0.05). Patients with SCI, compared with patients without SCI, were associated with a subsequent AMI risk (aHR=1.17; P<0.05). Several comorbidities, such as cardiovascular disease (aHR=1.29; P<0.05), chronic obstructive pulmonary disease (aHR=1.51; P<0.05), hypertension (aHR=1.34; P<0.01), and renal disease (aHR=1.76; P<0.05), were associated with an increased AMI risk. Furthermore, T-spine SCI was significantly associated with an AMI risk (aHR=1.38; P<0.05).

CONCLUSION

Patients with as diagnosis of SCI exhibited an increased risk of AMI compared with patients without SCI. These findings have broad implications for surveillance among patients with SCI, and future studies should evaluate whether risk factor modification can decrease AMI risk among patients with SCI.

LEVEL OF EVIDENCE

3.

Heart rate response during underwater treadmill training in adults with incomplete spinal cord injury

BACKGROUND

Walking on a submerged treadmill can improve mobility in persons displaying lower limb muscle weakness and balance deficits. Little is known, however, regarding the effect of water treadmill exercise on cardiac performance in persons with incomplete spinal cord injury (iSCI).

OBJECTIVE

To assess heart rate response during underwater treadmill training (UTT) in adults with iSCI.

METHODS

Seven males and 4 females with iSCI (age = 48 ± 13 years; 5 ± 8 years after injury) completed 8 weeks of UTT (3 sessions per week; 3 walks per session) incorporating individually determined walking speeds, personalized levels of body weight unloading, and gradual, alternating increases in speed and duration. Heart rate was monitored during the last 15 seconds of the final 2 minutes of each walk.

RESULTS

Over the course of 3 biweekly periods in which walking speed remained constant, heart rate fell by 7% (7 ± 1 b•min(-1); P < .001) in weeks 2 and 3, 14% (17 ± 6 b•min(-1); P < .001) in weeks 4 and 5, and 17% (21 ± 11 b•min(-1); P < .001) in weeks 6 and 7.

CONCLUSION

In adults with iSCI, progressively greater absolute and relative reductions in submaximal exercise heart rate occurred after 2 months of UTT featuring a systematic increase in training volume.

Spinal cord injury increases the risk of type 2 diabetes: a population-based cohort study

BACKGROUND CONTEXT

Previous studies on the risk and prevalence of diabetes among spinal cord injury (SCI) patients are limited and controversial.

PURPOSE

To compare the risk and incidence rate (IR) of Type 2 diabetes in SCI and non-SCI patients.

STUDY DESIGN

This is a population-based retrospective cohort study.

PATIENT SAMPLE

Data from Taiwan's National Health Insurance Research Database for the period 1997 to 2010 were analyzed. Patients aged 20 years and older newly identified with SCIs during this period were included in the SCI cohort. A non-SCI comparison cohort was randomly selected from National Health Insurance beneficiaries and matched with the SCI cohort based on age, sex, and index date.

OUTCOME MEASURES

Both cohorts were followed until the first of the following occurred: the diagnosis of Type 2 diabetes (International Classification of Disease, Ninth Revision, Clinical Modification codes 250), withdrawal from the insurance system, the end of 2010, or death.

METHODS

A Cox proportional hazards regression analysis was used to estimate the risk of developing diabetes.

RESULTS

Taiwan possesses an older SCI population, with a mean age of 51.6 years. The IR for diabetes in patients with and without SCIs was 22.1 per 10,000 person-years and 17.2 per 10,000 person-years, respectively. The adjusted hazard ratio (HR) for diabetes was 1.33 times higher in patients with SCIs than in those without SCIs. In patients with SCIs, men (adjusted HR=1.23, 95% confidence interval (CI)=1.04-1.44), older people (adjusted HR=4.26 in patients older than 65 years, 95% CI=3.16-5.74), patients with comorbidity (adjusted HR=1.36, 95% CI=1.14-1.62), and patients with a complete thoracic SCI (T-spine injury) (adjusted HR=2.13, 95% CI=0.95-4.79) were more likely to be diagnosed with diabetes than other patient subgroups.

CONCLUSIONS

Our findings may facilitate the prioritizing of preventive health strategies and planning of long-term care for SCI patients.

Lower extremity functional electrical stimulation cycling promotes physical and functional recovery in chronic spinal cord injury

OBJECTIVE

To examine the effect of long-term lower extremity functional electrical stimulation (FES) cycling on the physical integrity and functional recovery in people with chronic spinal cord injury (SCI).

DESIGN

Retrospective cohort, mean follow-up 29.1 months, and cross-sectional evaluation.

SETTING

Washington University Spinal Cord Injury Neurorehabilitation Center, referral center.

PARTICIPANTS

Twenty-five people with chronic SCI who received FES during cycling were matched by age, gender, injury level, and severity, and duration of injury to 20 people with SCI who received range of motion and stretching.

INTERVENTION

Lower extremity FES during cycling as part of an activity-based restorative treatment regimen.

MAIN OUTCOME MEASURE

Change in neurological function: motor, sensory, and combined motor-sensory scores (CMSS) assessed by the American Spinal Injury Association Impairment scale. Response was defined as ≥ 1 point improvement.

RESULTS

FES was associated with an 80% CMSS responder rate compared to 40% in controls. An average 9.6 CMSS point loss among controls was offset by an average 20-point gain among FES subjects. Quadriceps muscle mass was on average 36% higher and intra/inter-muscular fat 44% lower, in the FES group. Hamstring and quadriceps muscle strength was 30 and 35% greater, respectively, in the FES group. Quality of life and daily function measures were significantly higher in FES group.

CONCLUSION

FES during cycling in chronic SCI may provide substantial physical integrity benefits, including enhanced neurological and functional performance, increased muscle size and force-generation potential, reduced spasticity, and improved quality of life.

Urodynamic results, clinical efficacy, and complication rates of sacral intradural deafferentation and sacral anterior root stimulation in patients with neurogenic lower urinary tract dysfunction resulting from complete spinal cord injury

AIMS

To investigate the outcome and complications of sacral deafferentation (SDAF) and sacral anterior root stimulation (SARS) in patients with neurogenic lower urinary tract dysfunction (NLUTD) resulting from complete spinal cord injury (SCI).

METHODS

Retrospective chart analysis of 137 patients who underwent SDAF/SARS at a single institution. Patients were categorized as being at risk of renal damage when the maximum detrusor pressure was >40 cmH2 O or detrusor compliance was <20 ml/cmH2 O.

RESULTS

After a mean follow-up time of 14.8 ± 5.3 years, SDAF/SARS treatment significantly (P < 0.001) reduced the number of patients suffering from elevated detrusor pressure from 65 to 2, and from low detrusor compliance from 62 to 13, respectively. Mean bladder capacity significantly (P < 0.001) improved from 272.4 ± 143.0 to 475.0 ± 82.7 ml. The mean number of symptomatic UTI also decreased significantly (P < 0.001) from 6.2 ± 4.5 to 2.5 ± 2.6 per year. The number of patients suffering from incontinence had significantly (P < 0.001) decreased from 70 to 44. At the last follow-up visit, 107 (78.1%) patients were still using the stimulator. A total of 84 complications requiring surgical revision were observed. Defects of the stimulator cables or the receiver plate were the most common events (n = 38). The retrospective design pertains to the limitations of the study.

CONCLUSIONS

Sacral deafferentation and SARS are an effective treatment option for refractory NLUTD in patients with complete SCI, despite a substantial long-term complication rate.

Avaliação da potência aeróbia de praticantes de Rugby em Cadeira de Rodas através de um teste de quadra

O presente estudo teve por finalidade estimar a potência aeróbia em atletas com LME praticantes de RCR, correlacionar os níveis de VO2máx com a classificação funcional (CF) dos atletas e analisar o comportamento da FC antes e pós-teste. A amostra foi composta por 10 atletas com LME, do sexo masculino e idade média de 29,6±6,5anos. Os atletas foram submetidos ao teste de corrida de 12 minutos e monitorados com o frequêncimetro cardíaco. A média do VO2máx foi de 18,3±8,1ml(kg.min)-1 e da FCmáx de 114,6±25,3bpm. Os valores de VO2máx obtidos no estudo são classificados como médio para a população com tetraplegia. Observou-se que existe correlação moderada (r=0,77) entre a CF e o VO2máx entre atletas praticantes de RCR e por fim, observou-se baixos valores de FC frente á um teste submáximo, fato que pode estar relacionado à diminuição da atuação simpática após LME.

Changes in renal function during acute spinal cord injury: implications for pharmacotherapy

STUDY DESIGN

Laboratory investigation in rats submitted to experimental spinal cord injury (SCI).

OBJECTIVE

To characterize changes in renal function during acute SCI.

METHODS

Sprague Dawley rats were subjected to severe spinal cord contusion at T8 level or to laminectomy as control. Twenty-four hours after spine surgery, clearance assessments of a single dose of iohexol (120 mg kg(-1)) or of p-aminohippuric acid (PAH, 100 mg kg(-1)) were used to evaluate glomerular filtration rate (GFR) and tubular secretion (TS), respectively. Blood sampling was used to determine concentrations of both compounds by high-performance liquid chromatography for pharmacokinetic measurements.

RESULTS

Iohexol clearance decreased significantly after injury, which resulted in increased concentrations and half-life of iohexol in blood; PAH clearance remained unchanged.

CONCLUSION

GFR but not TS is altered during spinal shock. These observations should be of interest to professionals caring for early cord-injured patients, in order to prevent toxicity and therapeutic failure when administering drugs eliminated by the kidney.

Hemodynamic effects of L-threo-3,4-dihydroxyphenylserine (Droxidopa) in hypotensive individuals with spinal cord injury

OBJECTIVES

To determine the effect of an escalating dose of droxidopa (100, 200, and 400 mg) compared with placebo on seated blood pressure (BP) in hypotensive individuals with spinal cord injury (SCI). Secondarily, we aimed to determine the effect of droxidopa on (1) supine BP and heart rate, (2) the change in BP and heart rate when these individuals were transferred from the supine to the seated position, and (3) adverse event (AE) reporting.

DESIGN

Open-label dose titration trial.

SETTING

A Veterans Administration Medical Center.

PARTICIPANTS

Participants with SCI (C3-T12) (N=10) were studied during 4 laboratory visits. Subjects visited the laboratory for about 5 hours on each visit, which incorporated a 30-minute seated baseline, a 30- to 60-minute supine, and a 4-hour seated postdrug observation.

INTERVENTIONS

Placebo on visit 1, droxidopa 100 mg on visit 2, droxidopa 200 mg on visit 3, and droxidopa 400 mg on visit 4.

MAIN OUTCOME MEASURES

BP and heart rate changes from baseline to the postdrug period, orthostatic heart rate and BP responses, and subjective AE reporting.

RESULTS

Seated BP was significantly elevated with 400 mg droxidopa compared with placebo and 100 mg droxidopa for 3 hours and was elevated for 2 hours compared with 200 mg droxidopa. Increase in supine BP was not worsened following droxidopa, and the expected fall in BP when transferred to the seated position was prevented with droxidopa 200 and 400 mg. There were no significant differences in the heart rate response or AE reporting among the study visits.

CONCLUSIONS

Our preliminary findings suggest that droxidopa, at the doses tested, does not cause excessive increases in supine BP and the 400-mg dose appears to be effective at increasing seated BP for up to 3 hours in persons with SCI.

Lower extremity functional electrical stimulation cycling promotes physical and functional recovery in chronic spinal cord injury

OBJECTIVE

To examine the effect of long-term lower extremity functional electrical stimulation (FES) cycling on the physical integrity and functional recovery in people with chronic spinal cord injury (SCI).

DESIGN

Retrospective cohort, mean follow-up 29.1 months, and cross-sectional evaluation.

SETTING

Washington University Spinal Cord Injury Neurorehabilitation Center, referral center.

PARTICIPANTS

Twenty-five people with chronic SCI who received FES during cycling were matched by age, gender, injury level, and severity, and duration of injury to 20 people with SCI who received range of motion and stretching.

INTERVENTION

Lower extremity FES during cycling as part of an activity-based restorative treatment regimen.

MAIN OUTCOME MEASURE

Change in neurological function: motor, sensory, and combined motor-sensory scores (CMSS) assessed by the American Spinal Injury Association Impairment scale. Response was defined as ≥ 1 point improvement.

RESULTS

FES was associated with an 80% CMSS responder rate compared to 40% in controls. An average 9.6 CMSS point loss among controls was offset by an average 20-point gain among FES subjects. Quadriceps muscle mass was on average 36% higher and intra/inter-muscular fat 44% lower, in the FES group. Hamstring and quadriceps muscle strength was 30 and 35% greater, respectively, in the FES group. Quality of life and daily function measures were significantly higher in FES group.

CONCLUSION

FES during cycling in chronic SCI may provide substantial physical integrity benefits, including enhanced neurological and functional performance, increased muscle size and force-generation potential, reduced spasticity, and improved quality of life.

Increasing patient engagement during virtual reality-based motor rehabilitation

OBJECTIVE

To investigate the influence of different design characteristics of virtual reality exercises on engagement during lower extremity motor rehabilitation.

DESIGN

Correlational study.

SETTING

Spinal cord injury (SCI) rehabilitation center.

PARTICIPANTS

Subjects with SCI (n=12) and control subjects (n=10).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Heart rate and electromyographic activity from both legs at the tibialis anterior, the gastrocnemius medialis, the rectus femoris, and the biceps femoris were recorded.

RESULTS

Interactivity (ie, functionally meaningful reactions to motor performance) was crucial for the engagement of subjects. No significant differences in engagement were found between exercises that differed in feedback frequency, explicit task goals, or aspects of competition.

CONCLUSIONS

Functional feedback is highly important for the active participation of patients during robotic-assisted rehabilitation. Further investigations on the design characteristics of virtual reality exercises are of great importance. Exercises should thoroughly be analyzed regarding their effectiveness, while user preferences and expectations should be considered when designing virtual reality exercises for everyday clinical motor rehabilitation.

Acute spinal cord injury induces genetic damage in multiple organs of rats

Spinal cord injury (SCI) is a devastating condition with important functional and psychological consequences. However, the underlying mechanisms by which these alterations occur are still not fully understood. The aim of this study was to analyze genomic instability in multiple organs in the acute phase of SCI by means of single cell gel (comet) assay. Rats were randomly distributed into two groups (n = 5): a SHAM and a SCI group killed 24 h after cord transection surgery. The results pointed out genetic damage in blood cells as depicted by the tail moment results. DNA breakage was also detected in liver and kidney cells after SCI. Taken together, our results suggest that SCI induces genomic damage in multiple organs of Wistar rats.

Cardiovascular and urological dysfunction in spinal cord injury

OBJECTIVE

A spinal cord injury (SCI) above the sixth thoracic vertebra interrupts the supraspinal control of the sympathetic nervous system causing an imbalance between the sympathetic and the parasympathetic nervous system. This article focuses on the symptoms, treatment and examination of autonomic disturbances of the cardiovascular and the urinary system after a SCI.

METHODS

A non-systematic literature search in the PubMed database.

RESULTS

Frequent complications in the acute phase of cervical and high thoracic SCI are bradyarrhythmias, hypotension, hypothermia/hyperthermia, increased neurogenic shock, vagovagal reflex, supraventricular/ventricular ectopic beats, vasodilatation and congestion. Serious complications in the chronic phase of SCI are orthostatic hypotension, impaired cardiovascular reflexes, autonomic dysreflexia (AD), reduced sensation of cardiac pain, loss of reflex cardiac acceleration, quadriplegic cardiac atrophy due to loss of left ventricular mass and pseudo-myocardial infarction. AD is associated with a sudden, uncontrolled sympathetic response, triggered by stimuli below the injury. It may cause mild symptoms like skin rash or slight headache, but also severe hypertension, cerebral haemorrhage and death. Early recognition and prompt treatment are important. Urinary autonomic dysfunctions include hyperreflexia or areflexia of detrusor and/or sphincter of the bladder.

CONCLUSIONS

Patients with SCI have a high risk of cardiovascular complications, AD and urinary autonomic dysfunction both in the acute phase and later, affecting their prognosis and quality of life. Knowledge of cardiovascular and urological complications after SCI is important for proper diagnosis and treatment.

Inhibition of Ras-GTPase farnesylation and the ubiquitin-proteasome system or treatment with angiotensin-(1-7) attenuates spinal cord injury-induced cardiac dysfunction

Cardiovascular diseases are one of the principal causes of death and disability in people with spinal cord injury (SCI). The present study was designed to investigate if acute treatment with FPTIII (an inhibitor of Ras-GTPase farnesylation) or MG132 (an inhibitor of ubiquitin-proteasome pathway [UPS]) or administration of angiotensin-(1-7), also known as Ang-(1-7), (a known inhibitor of cardiac NF-kB) would be cardioprotective. The weight drop technique produced a consistent contusive injury of the spinal cord at the T13 segment. Hearts were isolated from rats either 6 months (SCI-6) or 12 months (SCI-12) after SCI. Hearts were perfused for 30 min and then subjected to 30 min ischemia followed by 30 min reperfusion (I/R). Recovery of cardiac function after I/R was measured as left ventricular developed pressure (P(max)) and coronary flow (CF). Drugs were given during perfusion before hearts were exposed to ischemia and reperfusion. Percent recovery (%R) in P(max) and CF in hearts from control animals were 48±6 and 50±5, respectively, whereas none of the hearts from animals with SCI recovered after 30 min of ischemia. Treatment with FPTIII, MG 132, or Ang-(1-7) before ischemia for 30 min led to significant recovery of heart function following ischemia in SCI-6 but not in SCI-12 animals. Thus we have shown that acute treatments with FPTIII, MG132, or Ang-(1-7) improve cardiac recovery following ischemic insult in animals with SCI and may represent novel therapeutic agents for preventing ischemia-induced cardiac dysfunction in patients with SCI.

Spinal cord injury sequelae alter drug pharmacokinetics: an overview

STUDY DESIGN

Literature review.

OBJECTIVES

Critical review of the literature published on the physiological alterations caused by spinal cord injury (SCI) and their effect on the pharmacokinetic parameters of commonly employed drugs. The review introduces the most recent treatment protocols of a variety of drugs, enabling the modern clinician to apply efficacious and cost-effective solutions to the pharmacological treatment of SCI patients.

METHODS

Studies published in international indexed journals up to January 2011 were selected from the PubMed database.

RESULTS

The review evaluated the sequelae of SCI and their effect on pharmacological processes. The results demonstrated that these alterations affected the pharmacokinetics of drugs commonly administered to SCI patients, such as antibiotics, muscle relaxants, immunosuppressants and analgesics.

CONCLUSION

There are multiple etiologies to SCI and patients present with varying degrees of impairment. Factors such as level of injury and completeness of the injury create a very heterogeneous population within the SCI community. The heterogeneity of this population creates a problem when trying to standardize pharmacokinetic (PK) parameters. It is because of this that specific physiological alterations must be linked to changes in PK and be identified within the clinical setting. This relationship between physiology and PK enables the clinician to be alert for possible pharmacological complications in individual patients based on their clinical manifestations. Future research should aim to develop rigorous therapeutic guidelines tailored to the diverse manifestations of SCI so as to provide effective, affordable and safe pharmacotherapy.

The correlation between ventricular repolarization and clinical severity of spinal cord injuries

BACKGROUND

Alteration in ventricular repolarization has been reported in patients with spinal cord injuries (SCIs). However, its clinical impact remains unclear.

OBJECTIVE

The purpose of this study was to investigate the correlation between SCIs and ventricular repolarization and the associated clinical impact.

METHODS

One hundred forty-four patients with an SCI were retrospectively reviewed and were divided into two groups (SCI level ≤ T6, n = 110; SCI level >T6, n = 34). The electrocardiograms were reviewed during acute phase (at emergency room) and chronic phase (>1 year).

RESULTS

There were no differences in the underlying diseases or in ASIA score between the two groups, except there were more patients with tetraplegia among those with an SCI level ≤ T6. For the electrophysiological parameters from the electrocardiograms, the patients with an SCI level ≤ T6 had longer QTc and PR interval than those with an SCI level >T6 during acute phase. In the chronic phase, there were no differences in the electrophysiological parameters between the two groups. Only in patients with an SCI level ≤ T6 did a Kaplan-Meier analysis show that QTc prolongation could predict 30-day mortality after the acute injury. After multivariate Cox regression analysis, only tetraplegia and QTc prolongation were independent predictors of 30-day mortality (odds ratios 7.85 and 34.62, respectively). In patients with an SCI level ≤ T6, the QTc intervals were shorter in the chronic phase than those during the acute phase.

CONCLUSION

QTc interval was associated with the level of acute SCI and predicted the 30-day mortality.

Aerobic exercise during early rehabilitation for cervical spinal cord injury

BACKGROUND AND PURPOSE

People with spinal cord injuries (SCIs), particularly those with injuries causing tetraplegia, are at risk for cardiovascular illnesses. There is a compelling need to address poor cardiovascular health as early as possible after cervical SCI. The purpose of this case report is to illustrate the process of aerobic exercise prescription during inpatient rehabilitation for cervical SCI.

CASE DESCRIPTION

The patient was a 22-year-old man who had sustained a complete C5 SCI during a swimming accident 12 weeks before he participated in an aerobic exercise program. The program was developed to facilitate aerobic capacity while minimizing muscular fatigue. The patient attended 18 sessions over a 2-month period.

OUTCOMES

The patient's exercise tolerance increased in terms of both exercise duration and exercise intensity. Measurements of cardiovascular health, taken before and after training, revealed substantial increases in peak oxygen uptake (20%) and orthostatic tolerance over the course of the program.

DISCUSSION

The patient experienced typical complications associated with acute SCI (eg, orthostatic hypotension, urinary tract infections). He exhibited several signs of improved exercise tolerance and wheelchair mobility during the 2-month program, indicating potential cardiovascular and functional improvements from the exercise training.

Serial compression B-scan and Doppler sonography for the screening of deep venous thrombosis in patients with spinal cord injuries

PURPOSE

To evaluate the usefulness of serial compression B-scan and Doppler sonography (US) in screening for deep venous thrombosis (DVT) of the lower extremities in patients with spinal cord injuries.

METHOD

Patients with paraplegia and tetraplegia due to spinal cord injuries were screened by a serial compression B-scan and Doppler US protocol for DVT of the bilateral lower extremities within the first 36 hours after admission, at day 7 and at day 21. In patients with DVT, a follow-up US examination was performed 3 weeks after diagnosis to assess thrombi distribution.

RESULTS

Between January 2007 and March 2008, a total of 115 patients (75 males, 40 females), aged 19 to 85 years, were included. The first US examination documented a DVT in 44 cases (38.3%). After an initial negative scan, sonography after 7 days and 21 days showed DVT in 6 patients and 2 patients, respectively. Cumulative rate of DVT after the first 3 weeks was 45.2% (n=52). Follow-up US after 3 weeks in patients with DVT documented a complete recanalization in 19 patients (36.5%), no change in 12 patients (23.1%), and residual thrombi with partial recanalization in 21 patients (40.4%).

CONCLUSION

Our study supports the use of serial compression B-scan and Doppler US as a screening tool for DVT of the lower extremities in patients with spinal cord injuries early after injury.

Do not forget the distal lower limb veins in screening patients with spinal cord injuries for deep venous thromboses

In this prospective study, we aimed to document the rate and localization of deep venous thromboses in patients with spinal cord injuries. Patients with paraplegia or tetraplegia were screened by a serial color duplex sonography protocol for deep venous thrombosis within the first 36 hours after admission, at day 7, and at day 21. Sonography was performed by a complete scan including the veins below the knee. A total of 139 patients were included (19-90 years, 63.5% male). Cumulative rate of deep venous thrombosis after 3 duplex scans was 45.3% (n = 63). In 71.4% (n = 45), thromboses were localized below the knee. Because of the relevant number of distal vein thromboses, inclusion of the calf veins during screening scans is suggested. Further studies are needed to analyze the clinical benefit of diagnosing and treating distal vein thromboses.

Acute, subacute and chronic effect of cyclosporin-A on mean arterial pressure of rats with severe spinal cord contusion

Cyclosporin-A (CsA) protects and regenerates the neural tissue after spinal cord (SC) injury. These beneficial effects are achieved when CsA is administered at a dose of 2.5mg/kg/12h during the first 2 days after lesion. In view of these observations, it is realistic to envision that, CsA could be tested in SC-clinical trials. Since CsA is a drug strongly related to hypertension, results imperative to evaluate experimentally the effect of the above CsA-dose regimen on blood pressure. For this purpose, one hundred and twenty adult rats were subjected (10 groups) or not (10 groups) to SC-injury. Five injured and five Sham-operated groups received CsA. The remaining groups received only vehicle. Mean arterial pressure (MAP) was recorded from these animals at acute (6 and 24h post surgery; p.s.), subacute (96h), or chronic (30 days) stages of injury. In the latter, the therapy (CsA or vehicle) was administered only during the first 2 days p.s. or daily during 30 days of follow-up. The results of this study showed that SC-injury by itself induces a significant decrease of MAP during the acute and subacute phases of injury. CsA therapy was able to reestablish MAP parameters to control values in these phases. Regardless the therapy, a reestablishment of MAP was observed in chronic stages. Only the daily administration of CsA induced a significant increase in MAP, however; such variation remained into the normal ranges of MAP for rats. The potential benefits offered by CsA support its usefulness after SC-injury.

L-arginine reverses alterations in drug disposition induced by spinal cord injury by increasing hepatic blood flow

High hepatic extraction drugs--such as phenacetin, methylprednisolone, and cyclosporine--exhibit an increased bioavailability after acute spinal cord injury (SCI) due to an impaired clearance. For these drugs, metabolic clearance depends on hepatic blood flow. Thus, it is possible that pharmacokinetic alterations can be reversed by increasing liver perfusion. Therefore, we evaluated the effect of L-arginine, a nitric oxide precursor, on the pharmacokinetics of a prototype drug with high hepatic extraction, and on hepatic microvascular blood flow (MVBF) after acute SCI. Pharmacokinetics of i.v. phenacetin was studied in rats 24 h after a severe T-5 spinal cord contusion; animals being pretreated with L-arginine 100 mg/kg i.v. or vehicle. MVBF was assessed under similar experimental conditions using laser Doppler flowmetry. SCI significantly altered phenacetin pharmacokinetics. Clearance was significantly reduced, resulting in a prolonged half-life and an increase in bioavailability, while volume of distribution was decreased. Pharmacokinetic alterations were reversed when injured rats were pretreated with L -arginine. It was also observed that L-arginine significantly increased hepatic MVBF in injured rats, notwithstanding it exhibited a limited effect on sham-injured animals. Our data hence suggest that L-arginine is able to reverse SCI-induced alterations in phenacetin pharmacokinetics due to an impaired hepatic MVBF, likely by increased nitric oxide synthesis leading to vasodilation. Further studies are warranted to examine the potential usefulness of nitric oxide supplementation in a clinical setting.