Spinal Cord Injury Participants Research Articles

Dietary intake relative to cardiovascular disease risk factors in individuals with chronic spinal cord injury: a pilot study.

The relationship between cardiovascular disease (CVD) risk factors and dietary intake is unknown among individuals with spinal cord injury (SCI). To investigate the relationship between consumption of selected food groups (dairy, whole grains, fruits, vegetables, and meat) and CVD risk factors in individuals with chronic SCI. A cross-sectional substudy of individuals with SCI to assess CVD risk factors and dietary intake in comparison with age-, gender-, and race-matched able-bodied individuals enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary history, blood pressure, waist circumference (WC), fasting blood glucose, high-sensitivity C-reactive protein (hs-CRP), lipids, glucose, and insulin data were collected from 100 SCI participants who were 38 to 55 years old with SCI >1 year and compared to 100 matched control participants from the CARDIA study. Statistically significant differences between SCI and CARDIA participants were identified in WC (39.2 vs 36.2 in.; P < .001) and high-density lipoprotein cholesterol (HDL-C; 39.2 vs 47.5 mg/dL; P < .001). Blood pressure, total cholesterol, triglycerides, glucose, insulin, and hs-CRP were similar between SCI and CARDIA participants. No significant relation between CVD risk factors and selected food groups was seen in the SCI participants. SCI participants had adverse WC and HDL-C compared to controls. This study did not identify a relationship between consumption of selected food groups and CVD risk factors.

Dietary intake and adherence to the 2010 Dietary Guidelines for Americans among individuals with chronic spinal cord injury: A pilot study

ObjectiveTo investigate dietary intake and adherence to the 2010 Dietary Guidelines for Americans in individuals with chronic spinal cord injury (SCI) and able-bodied individuals.DesignA pilot study of dietary intake among a sample of individuals with SCI >1 year ago from a single site compared with able-bodied individuals.Participants/methodsOne hundred black or white adults aged 38–55 years old with SCI >1 year and 100 age-, sex-, and race-matched adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary intake was assessed by the CARDIA dietary history. Linear regression analysis was used to compare dietary intake between the subjects with SCI and those enrolled in the CARDIA study. Further, adherence to the 2010 Dietary Guidelines for dairy, fruits, and vegetables, and whole-grain foods was assessed.ResultsCompared with CARDIA participants, participants with SCI consumed fewer daily servings of dairy (2.10 vs. 5.0, P < 0.001), fruit (2.01 vs. 3.64, P = 0.002), and whole grain foods (1.20 vs. 2.44 P = 0.007). For each food group, fewer participants with SCI met the recommended servings compared with the CARDIA participants. Specifically, the participants with SCI and in CARDIA who met the guidelines were, respectively: dairy, 22% vs. 54% (P < 0.001), fruits and vegetables 39% vs. 70% (P = 0.001), and whole-grain foods 8% vs. 69.6% (P = 0.001).ConclusionsCompared with able-bodied individuals, SCI participants consumed fewer daily servings of fruit, dairy, and whole grain foods than proposed by the 2010 Dietary Guideline recommendations. Nutrition education for this population may be warranted.

Effectiveness of Bisphosphonate Analogues and Functional Electrical Stimulation on Attenuating Post-Injury Osteoporosis in Spinal Cord Injury Patients- a Systematic Review and Meta-Analysis

BackgroundVarious pharmacologic and non-pharmacologic approaches have been applied to reduce sublesional bone loss after spinal cord injury (SCI), and the results are inconsistent across the studies. The objective of this meta-analysis was to investigate whether the two most-studied interventions, bisphosphonate analogues and functional electrical stimulation (FES), could effectively decrease bone mineral density (BMD) attenuation and/or restore lost BMD in the SCI population. MethodsRandomized controlled trials, quasi-experimental studies, and prospective follow-up studies employing bisphosphonates or FES to treat post-SCI osteoporosis were identified in PubMed and Scopus. The primary outcome was the percentage of BMD change from baseline measured by dual-energy X-ray absorptiometry (DEXA) or computed tomography (CT). Data were extracted from four points: the 3rd, 6th, 12th, and 18th month after intervention. ResultsA total of 19 studies were included in the analysis and involved 364 patients and 14 healthy individuals. Acute SCI participants treated with bisphosphonate therapy demonstrated a trend toward less bone loss than participants who received placebos or usual care. A significant difference in BMD decline was noted between both groups at the 3rd and 12th month post-medication. The subgroup analysis failed to show the superiority of intravenous bisphosphonate over oral administration. Regarding FES training, chronic SCI patients had 5.96% (95% CI, 2.08% to 9.84%), 7.21% (95%CI, 1.79% to 12.62%), and 9.56% (95% CI, 2.86% to 16.26%) increases in BMD at the 3rd, 6th, and 12th months post-treatment, respectively. The studies employing FES ≥5 days per week were likely to have better effectiveness than studies using FES ≤3 days per week. ConclusionsOur meta-analysis indicated bisphosphonate administration early following SCI effectively attenuated sublesional bone loss. FES intervention for chronic SCI patients could significantly increase sublesional BMD near the site of maximal mechanical loading.

Motor-related cortical activity after cervical spinal cord injury: Multifaceted EEG analysis of isometric elbow flexion contractions

Electroencephalographic (EEG) studies have well established that motor cortex (M1) activity ~20Hz decreases during muscular contraction and increases as soon as contraction stops, which are known as event-related desynchronization (ERD) and event-related synchronization (ERS), respectively. ERD is supposed to reflect M1 activation, sending information to recruited muscles, while the process underlying ERS is interpreted either as active cortical inhibition or as processing of sensory inputs. Investigation of the process behind ERD/ERS in people with spinal cord injury (SCI) would be particularly relevant since their M1 remains effective despite decreased sensorimotor abilities. In this study, we recorded net joint torque and EEG in 6 participants with cervical SCI and 8 healthy participants who performed isometric elbow flexion at 3 force levels. Multifaceted EEG analysis was introduced to assess ERD/ERS according to their amplitude, frequency range and duration. The results revealed that net joint torque increased with the required force level for all participants and time to contraction inhibition was longer in the SCI group. At the cortical level, ERD/ERS frequency ranges increased with the required force level in all participants, indicating that the modulation of cortical activity with force level is preserved after SCI. However, ERS amplitude decreased only in SCI participants, which may be linked to delayed contraction inhibition. All in all, cortical modulation of frequency range and amplitude could reflect two different kinds of neural communication.

The Influence of Self-Efficacy on Mood States in People with Spinal Cord Injury

Objective. Negative mood is prevalent in people with a neurological injury such as spinal cord injury (SCI). However, research is needed for determining those people with SCI who are vulnerable to negative mood states, as well as establishing the influence of self-efficacy, that is, expectations of their control over their lives. The objective of this research was to investigate the protective role that self-efficacy may play in adult people with SCI compared to able-bodied controls. Methods. Participants included 41 adults with SCI living in the community and 41 able-bodied controls similar in age, sex ratio, and education. All participants completed a psychological assessment regimen in a relaxed environment. Measures consisted of validated measures of self-efficacy and negative mood states. Results. The SCI group was found to have significantly elevated levels of depressive mood, anxiety, stress, and poor self-efficacy. SCI participants with low levels of self-efficacy were shown to have significantly elevated levels of depressive mood and anxiety in comparison to those SCI participants with high levels of self-efficacy and able-bodied controls. Conclusions. People with a neurological injury such as SCI are vulnerable to experiencing clinically elevated negative mood states if they have poor expectations of control over their lives. Implications for SCI rehabilitation are discussed.

Detection of abnormal muscle activations during walking following spinal cord injury (SCI)

In order to identify optimal rehabilitation strategies for spinal cord injury (SCI) participants, assessment of impaired walking is required to detect, monitor and quantify movement disorders. In the proposed assessment, ten healthy and seven SCI participants were recruited to perform an over-ground walking test at slow walking speeds. SCI participants were given assistance from physiotherapists, if required, while they were walking. In agreement with other research, larger cadence and smaller step length and swing phase of SCI gait were observed as a result of muscle weakness and resultant gait instability. Muscle activation patterns of seven major leg muscles were collected. The EMG signal was processed by the RMS in frequency domain to represent the muscle activation power, and the distribution of muscle activation was compared between healthy and SCI participants. The alternations of muscle activation within the phases of the gait cycle are highlighted to facilitate our understanding of the underlying muscular activation following SCI. Key differences were observed (p-value=0.0006) in the reduced activation of tibialis anterior (TA) in single stance phase and rectus femoris (RF) in swing phase (p-value=0.0011). We can then conclude that the proposed assessment approach of gait provides valuable information that can be used to target and define therapeutic interventions and their evaluation; hence impacting the functional outcome of SCI individuals.

Influence of visual inputs on quasi-static standing postural steadiness in individuals with spinal cord injury

Postural steadiness while standing is impaired in individuals with spinal cord injury (SCI) and could be potentially associated with increased reliance on visual inputs. The purpose of this study was to compare individuals with SCI and able-bodied participants on their use of visual inputs to maintain standing postural steadiness. Another aim was to quantify the association between visual contribution to achieve postural steadiness and a clinical balance scale. Individuals with SCI (n=15) and able-bodied controls (n=14) performed quasi-static stance, with eyes open or closed, on force plates for two 45s trials. Measurements of the centre of pressure (COP) included the mean value of the root mean square (RMS), mean COP velocity (MV) and COP sway area (SA). Individuals with SCI were also evaluated with the Mini-Balance Evaluation Systems Test (Mini BESTest), a clinical outcome measure of postural steadiness. Individuals with SCI were significantly less stable than able-bodied controls in both conditions. The Romberg ratios (eyes open/eyes closed) for COP MV and SA were significantly higher for individuals with SCI, indicating a higher contribution of visual inputs for postural steadiness in that population. Romberg ratios for RMS and SA were significantly associated with the Mini-BESTest. This study highlights the contribution of visual inputs in individuals with SCI when maintaining quasi-static standing posture.

Operation of a brain-computer interface walking simulator for individuals with spinal cord injury

BackgroundSpinal cord injury (SCI) can leave the affected individuals with paraparesis or paraplegia, thus rendering them unable to ambulate. Since there are currently no restorative treatments for this population, novel approaches such as brain-controlled prostheses have been sought. Our recent studies show that a brain-computer interface (BCI) can be used to control ambulation within a virtual reality environment (VRE), suggesting that a BCI-controlled lower extremity prosthesis for ambulation may be feasible. However, the operability of our BCI has not yet been tested in a SCI population.MethodsFive participants with paraplegia or tetraplegia due to SCI underwent a 10-min training session in which they alternated between kinesthetic motor imagery (KMI) of idling and walking while their electroencephalogram (EEG) were recorded. Participants then performed a goal-oriented online task, where they utilized KMI to control the linear ambulation of an avatar while making 10 sequential stops at designated points within the VRE. Multiple online trials were performed in a single day, and this procedure was repeated across 5 experimental days.ResultsClassification accuracy of idling and walking was estimated offline and ranged from 60.5% (p = 0.0176) to 92.3% (p = 1.36×10−20) across participants and days. Offline analysis revealed that the activation of mid-frontal areas mostly in the μ and low β bands was the most consistent feature for differentiating between idling and walking KMI. In the online task, participants achieved an average performance of 7.4±2.3 successful stops in 273±51 sec. These performances were purposeful, i.e. significantly different from the random walk Monte Carlo simulations (p<0.01), and all but one participant achieved purposeful control within the first day of the experiments. Finally, all participants were able to maintain purposeful control throughout the study, and their online performances improved over time.ConclusionsThe results of this study demonstrate that SCI participants can purposefully operate a self-paced BCI walking simulator to complete a goal-oriented ambulation task. The operation of the proposed BCI system requires short training, is intuitive, and robust against participant-to-participant and day-to-day neurophysiological variations. These findings indicate that BCI-controlled lower extremity prostheses for gait rehabilitation or restoration after SCI may be feasible in the future.

Does the force level modulate the cortical activity during isometric contractions after a cervical spinal cord injury?

ObjectiveThis study investigated the effects of a cervical spinal cord injury (SCI) on the modulation of cortical desynchronization (ERD) during isometric contractions at different force levels. MethodsFor 8 able-bodied (AB) and 6 cervical SCI participants, the net joint moment and electroencephalographic activities were recorded during isometric contractions of the right elbow in flexion and in extension at 3 force levels, that is, during intact and altered muscle contractions for SCI participants. The mean net moment and ∼20Hz ERD from C3 electroencephalographic electrode were compared between AB and SCI participants. ResultsIn flexion, that is, during intact contractions for all participants, the mean net moment and the ERD increased with the required force level. In extension, that is, during altered contractions, the mean net moment increased for 3 SCI participants while it was almost zero for 3 other SCI participants. The associated ERD increased with the required force level for all participants. ConclusionThe cortical desynchronization was modulated by the intent to modulate the force level rather than the actual modulation of the force production. SignificanceThese results provide a better understanding of the modulation of the cortical desynchronization following SCI. Potential applications could include the control of neuroprostheses.

Reduction of spinal sensory transmission by facilitation of 5-HT1B/D receptors in noninjured and spinal cord-injured humans

Activation of receptors by serotonin (5-HT1) and norepinephrine (α2) on primary afferent terminals and excitatory interneurons reduces transmission in spinal sensory pathways. Loss or reduction of descending sources of serotonin and norepinephrine after spinal cord injury (SCI) and the subsequent reduction of 5-HT1/α2 receptor activity contributes, in part, to the emergence of excessive motoneuron activation from sensory afferent pathways and the uncontrolled triggering of persistent inward currents that depolarize motoneurons during muscle spasms. We tested in a double-blind, placebo-controlled study whether facilitating 5-HT1B/D receptors with the agonist zolmitriptan reduces the sensory activation of motoneurons during an H-reflex in both noninjured control and spinal cord-injured participants. In both groups zolmitriptan, but not placebo, reduced the size of the maximum soleus H-reflex with a peak decrease to 59% (noninjured) and 62% (SCI) of predrug values. In SCI participants we also examined the effects of zolmitriptan on the cutaneomuscular reflex evoked in tibialis anterior from stimulation to the medial arch of the foot. Zolmitriptan, but not placebo, reduced the long-latency, polysynaptic component of the cutaneomuscular reflex (first 200 ms of reflex) by ∼50%. This ultimately reduced the triggering of the long-lasting component of the reflex (500 ms poststimulation to end of reflex) known to be mediated by persistent inward currents in the motoneuron. These results demonstrate that facilitation of 5-HT1B/D receptors reduces sensory transmission in both monosynaptic and polysynaptic reflex pathways to ultimately reduce long-lasting reflexes (spasms) after SCI.

Motor Recovery after Spinal Cord Injury Enhanced by Strengthening Corticospinal Synaptic Transmission

The corticospinal tract is an important target for motor recovery after spinal cord injury (SCI) in animals and humans. Voluntary motor output depends on the efficacy of synapses between corticospinal axons and spinal motoneurons, which can be modulated by the precise timing of neuronal spikes. Using noninvasive techniques, we developed tailored protocols for precise timing of the arrival of descending and peripheral volleys at corticospinal-motoneuronal synapses of an intrinsic finger muscle in humans with chronic incomplete SCI. We found that arrival of presynaptic volleys prior to motoneuron discharge enhanced corticospinal transmission and hand voluntary motor output. The reverse order of volley arrival and sham stimulation did not affect or decreased voluntary motor output and electrophysiological outcomes. These findings are the first demonstration that spike timing-dependent plasticity of residual corticospinal-motoneuronal synapses provides a mechanism to improve motor function after SCI. Modulation of residual corticospinal-motoneuronal synapses may present a novel therapeutic target for enhancing voluntary motor output in motor disorders affecting the corticospinal tract.

Manual movement coordination adapted to spinal cord injury and low back pain

Spinal cord injury (SCI) and low back pain (LBP) significantly limit personal and occupational activities. Since upper body movements are crucial to extend hand reach envelopes and maintain postural balance, coordinated control of torso and hand movements is essential. In this study, adapted patterns of coordination were investigated in SCI, LBP and control participants performing seated manual material handling tasks, in which a load was transferred with both hands from a home location to one of 4 targets in the mid-sagittal plane.Torso peak velocities are larger and delayed for the SCI when compared to the control group, while hand peak velocities are comparable. However, hand peak velocities are smaller in the LBP than control group. Hand movements generally precede torso movements for all groups, but more prominently for the SCI than the other groups. Furthermore, for SCIs torso movements were suppressed until the hands were aligned with target elevation.These results indicate that SCI individuals have developed a unique coordination pattern to compensate for their limited balance control, although this strategy may reduce their effective workspace and overload the upper extremities. In contrast, LBPs seem to have reduced movement speed while their coordination patterns are generally similar to those in the control group. Relevance to industryThis study analyzed movements of persons with spinal cord injury or low back pain in manual material handling tasks. Assessing their adapted movement strategies would help to improve workspace design to accommodate workers with limited capacities and to provide quantifiable evidence and guidelines on the effectiveness of occupational rehabilitation programs.

Corticomotor representation to a human forearm muscle changes following cervical spinal cord injury

Functional imaging studies, using blood oxygen level-dependent signals, have demonstrated cortical reorganization of forearm muscle maps towards the denervated leg area following spinal cord injury (SCI). The extent of cortical reorganization was predicted by spinal atrophy. We therefore expected to see a similar shift in the motor output of corticospinal projections of the forearm towards more denervated lower body parts in volunteers with cervical injury. Therefore, we used magnetic resonance imaging-navigated transcranial magnetic stimulation (TMS) to non-invasively measure changes in cortical map reorganization of a forearm muscle in the primary motor cortex (M1) following human SCI. We recruited volunteers with chronic cervical injuries resulting in bilateral upper and lower motor impairment and severe cervical atrophy and healthy control participants. All participants underwent a T1-weighted anatomical scan prior to the TMS experiment. The motor thresholds of the extensor digitorum communis muscle (EDC) were defined, and its cortical muscle representation was mapped. The centre of gravity (CoG), the cortical silent period (CSP) and active motor thresholds (AMTs) were measured. Regression analysis was used to investigate relationships between trauma-related anatomical changes and TMS parameters. SCI participants had increased AMTs (P = 0.01) and increased CSP duration (P = 0.01). The CoG of the EDC motor-evoked potential map was located more posteriorly towards the anatomical hand representation of M1 in SCI participants than in controls (P = 0.03). Crucially, cord atrophy was negatively associated with AMT and CSP duration (r(2) ≥ 0.26, P < 0.05). In conclusion, greater spinal cord atrophy predicts changes at the cortical level that lead to reduced excitability and increased inhibition. Therefore, cortical forearm motor representations may reorganize towards the intrinsic hand motor representation to maximize output to muscles of the impaired forearm following SCI.

Effects Of Wheelchair Tai Chi On Selected Physical Functional Abilities For Individuals With SCI

PURPOSE: The purpose of this study was to implement a 3-month pilot Wheelchair Tai Chi Modified 10- form (WTC10) intervention for individuals with Spinal Cord Injury (SCI) and examine the effects of the WTC10 intervention on selected physical functional abilities. METHODS: A convenience sample of 17 subjects with spinal cord injury between the ages of 49 and 78 were recruited from the Atlanta VA Medical Center to participate in this study; 12 subjects completed the study. The study was approved by the university and VA Medical Center IRBs. The subjects signed the informed consent forms and participated in the WTC10 intervention over a 3-month duration, consisting of 20 sessions each lasting an hour. Subjects were assessed before and immediately after the Tai Chi intervention using the following outcome measures: active joint range of motion of the upper extremities and trunk, vital capacity and respiratory function, and the Pain Self Efficacy Questionnaire (PSEQ). Paired t-tests were used to determine (p<.05) the change of the selected physical functional abilities before and after the intervention. RESULTS: After 20 sessions of the intervention, improvements were found in active range of motion at all joints tested with significant improvements in left shoulder flexion (pretest 118.420+28.00 vs posttest 132.200+25.22, p<.020), right elbow flexion (pre 131.920+11.29 vs post 141.360+10.06, p<.001), right elbow extension (pre -13.140+8.49 vs post-7.860+5.61, p<.001), and bilateral trunk rotation (right pre 20.420+10.79 vs right post 30.530+, p<.003) (left pre 22.530+8.31 vs left post 38.700+11.98, p<.001). Significant improvement was also found in expiratory vital capacity (EVC) (pre 1.39lit+1.34 vs post 2.45lit+0.80, p<.046). No significant changes were observed for the PSEQ. CONCLUSIONS: The modified WTC10 program is feasible for SCI participants to learn and practice and is effective for improving respiratory function and active range of motion in the upper extremity and trunk for individuals with SCI. This project was supported by Paralyzed Veterans of America (Grant #:592)

Cerebral activation is correlated to regional atrophy of the spinal cord and functional motor disability in spinal cord injured individuals

Recovery of function following lesions in the nervous system requires adaptive changes in surviving circuitries. Here we investigate whether changes in cerebral activation are correlated to spinal cord atrophy and recovery of functionality in individuals with incomplete spinal cord injury (SCI).19 chronic SCI individuals and 7 age-comparable controls underwent functional magnetic resonance imaging (fMRI) while performing rhythmic dorsiflexion of the ankle. A significant negative correlation was found between the activation in the ipsilateral motor (M1) and bilateral premotor cortex (PMC) on one hand and the functional ability of the SCI participants measured by the clinical motor score on the other. There was no significant correlation between activation in any other cerebral area and the motor score.Activation in ipsilateral somatosensory cortex (S1), M1 and PMC was negatively correlated to the width of the spinal cord in the left–right direction, where the corticospinal tract is located, but not in the antero-posterior direction. There was a tendency for a negative correlation between cerebral activation in ipsilateral S1, M1 and PMC and the amplitude of motor evoked potentials in the tibialis anterior muscle elicited by transcranial magnetic stimulation, but this did not reach statistical significance. There was no correlation between motor score or spinal cord dimensions and the volume of the cortical motor areas.The observations show that lesion of descending tracts in the lateral part of the spinal cord results in increased activation in ipsilateral motor and sensory areas, which may help to compensate for the functional deficit following SCI.

Adaptation of Torso Movement Strategies in Persons With Spinal Cord Injury or Low Back Pain

Controlled laboratory study. Statistical regression and between-group comparisons. To characterize functional limitation and adaptive strategies in seated manual transport tasks for spinal cord injury (SCI), low back pain (LBP), and control participants. People with SCI are known to have adapted electromyographic activities and slow hand movement velocity, while those with LBP have reduced range of motion and lumbar joint contribution. However, their resultant outcome in torso movements has not been systematically quantified. Seated participants performed either 2- or 1-handed loaded transports to 1 of 6 targets 49 cm above the hip-point, at 0 degrees, 45 degrees, and 90 degrees azimuths, at close and far distance. Three-dimensional torso movements were modeled by combinations of B-spine base functions. The SCI and LBP participants exhibit smaller torso flexion and axial rotation than control participants. The SCI participants tend to move the torso away from the target to maintain upper body balance. These differences among groups are significantly reduced in the 1-handed transport condition and/or transports to the frontal target. The movement patterns suggest that SCI participants may have adapted torso movement strategies to compensate for the limited control of upper body balance, while LBP participants may limit torso motion to avoid pain.

Effects of autonomic blockade on nonlinear heart rate dynamics

Analysis of nonlinear heart rate (HR) dynamics may provide greater insight into neurocardiac influences during exercise and disease than traditional HR variability. However, the physiological basis of nonlinear HR dynamics has not been investigated in individuals with spinal cord injury (SCI). The purpose of this study was to compare the effects of autonomic blockade in SCI and able-bodied participants. Five participants (42 +/- 13 years) with SCI (C4-C7, AIS B-D, 13 +/- 13 years post-injury) and four able-bodied controls (33 +/- 8 years) underwent beta(1)-adrenergic and vagal blockade in the supine and cardiovascular stress positions. Cardiovascular stress consisted of 40 degrees tilt plus sustained isometric jaw contraction and cold water submersion of the right hand. In both SCI and able-bodied participants, vagal blockade significantly increased HR (p < 0.05) and resulted in significant reductions in sample entropy and correlation dimension in the supine and cardiovascular stress positions (p < 0.05). During the cardiovascular stress position, baseline sample entropy (p < 0.05) and correlation dimension (p < 0.05) were lower in participants with SCI. Nonlinear measures were also significantly correlated with HR (p < 0.05). The results suggest that vagal modulations are a primary modulator of nonlinear HR signals in both SCI and able-bodied participants, while the role of the beta(1)-adrenergic system remains less defined. Further study is required to elucidate the role of the autonomic nervous system in nonlinear HR dynamics in both SCI and able-bodied populations.

Right Bundle Branch Block as a Screening Test for Pulmonary Embolism in Chronic Spinal Cord Injury

Frisbie JH, Sharma GVRK. Right bundle branch block as a screening test for pulmonary embolism in chronic spinal cord injury. Objectives To evaluate right bundle branch block (RBBB) on electrocardiograms (ECGs) as a screening tool for the diagnosis of pulmonary embolism (PE) in a chronic spinal cord injury (SCI) population and to determine the prevalence of PE. Design Retrospective analysis. Setting Boston Veterans Affairs Healthcare System. Participants Consecutive SCI participants (N=112) who were followed at this institution until death between 1999 and 2005 at an average age of 71 years, a duration of paralysis of 31 years, with a tetraplegic level in 62%, and no useful motor function in 84%. Intervention Not applicable. Main Outcome Measures PE, as a cause of RBBB, was diagnosed by autopsy, a source of thromboembolism, imaging, or other ECG signs of PE. Chronic obstructive lung disease was diagnosed by pulmonary function tests and myocardial infarction by ECG or echocardiogram. Results Twenty-nine participants (26%) had RBBB (6 with incomplete RBBB). Evidence that PE caused RBBB was found in 21 (72%), with 4 (3 massive) found by autopsy, 4 by the presence of an embolic source, 3 by imaging, 2 by the intermittent course of RBBB, 1 by abrupt onset of RBBB before death, and 7 by other ECG signs. RBBB represented chronic obstructive lung disease or myocardial infarction in the remaining 8. The onset of RBBB occurred either within months of SCI in 5 (1 before SCI) or years after SCI in 24 (6–50y, median 32y). RBBB was constant in 27 and intermittent in 2. The duration of RBBB ranged from 20 minutes to 31 years, median 4 years. Conclusions RBBB may be a useful initial screening test for PE complicating chronic SCI. PE, often recurrent and sometimes fatal, is prevalent in chronic SCI.

Current coronary heart disease risk assessment tools may underestimate risk in community-dwelling persons with chronic spinal cord injury

Cross-sectional, observational study. To quantify, in adults with chronic spinal cord injury (SCI): (1) presence of metabolic syndrome versus the general North American population (GP) and (2) 10-year coronary heart disease (CHD) risk using Framingham risk scoring (FRS). Ontario, Canada. Fasting anthropometric and biochemical data were collected from 75 adults with chronic SCI. Metabolic syndrome was determined using four internationally recognized definitions and FRS using the most recent (2001) algorithm. Prevalence of metabolic syndrome was up to 5.4 times lower in SCI participants compared to GP, and FRS categorized 3.1% of participants as being at high 10-year CHD risk. However, high-sensitivity C-reactive protein (CRP) values indicated 36.7% of participants as being at high CHD risk. Current metabolic syndrome definitions and FRS may underestimate true CHD risk in people with SCI. Tools that better identify CHD risk require validation in the SCI population. CRP may be a potential factor to consider in the development of SCI-specific screening tools.

ALTERED BRAIN WAVE ACTIVITY IN PERSONS WITH CHRONIC SPINAL CORD INJURY

This study investigated brain wave activity associated with spinal cord injury (SCI). Electroencephalograms (EEG) were compared between 10 individuals with SCI and 10 age and sex matched able-bodied controls using a 64-channel EEG montage. SCI participants had chronic (>12 months) paraplegic clinically complete injuries. The 64 channels of EEG data were spread diffusely over the cortex and were compared for delta (2–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and beta (13–30 Hz) wave components of the EEG frequency spectra. No significant magnitude or directional changes were found in the delta (2–4 Hz) or theta (4–8 Hz) wave frequency bands between these two groups. However, significant and consistent decreased alpha wave (8–13 Hz) and increased beta wave activity (13–30 Hz) were found in the SCI participants across the cortex compared to the able-bodied control group. These findings suggest that the SCI group have increased neural processing compared to the able-bodied individuals, which may be related to ongoing reorganization of brain structures following SCI.