Published Research

Some recent papers published by ICORD researchers are listed below. Links to each of our researchers’ most recent publications are included at the bottom of their respective researcher profile.

Clinicians’ perspective of the current diagnostic criteria for myofascial pain syndrome

Authors: Grosman-Rimon L, Clarke H, Mills PB., Chan AK, Kumbhare D.
Published inJ Back Musculoskelet Rehabil. 2016 Nov 11. [Epub ahead of print]
About: Myofascial pain syndrome (MPS) is one of the most common chronic musculoskeletal pain disorders. However, MPS is often under-diagnosed. The purpose of this study was to characterize practicing clinicians’ perspectives of the current diagnostic criteria for MPS.

Physical activity outside of structured therapy during inpatient spinal cord injury rehabilitation

Authors: Zbogar D, Eng JJMiller WCKrassioukov AV, Verrier MC.
Published inJ Neuroeng Rehabil. 2016 Nov 15;13(1):99.
About: Little information exists on the content of inpatient rehabilitation stay when individuals with spinal cord injury (SCI) are not engaged in structured rehabilitation therapy sessions. Investigation of inpatient therapy content is incomplete without the context of activities outside of this time. We sought to quantify physical activity occurring outside of physical therapy (PT) and occupational therapy (OT) sessions during inpatient SCI rehabilitation and examine how this activity changes over time from admission to discharge.

Data logger technologies for manual wheelchairs: A scoping review

Authors: Routhier F, Lettre J, Miller WC, Borisoff JF, Keetch K, Mitchell IM, CanWheel Research Team.
Published inAssist Technol. 2016 Nov 15. [Epub ahead of print].
About: In recent years, studies have increasingly employed data logger technologies to record objective driving and physiological characteristics of manual wheelchair users. However, the technologies used offer significant differences in characteristics such as measured outcomes, ease of use and level of burden. In order to identify and describe the extent of published research activity that relies on data logger technologies for manual wheelchair users, we performed a scoping review of the scientific and grey literature. Five databases were searched: Medline, Compendex, CINAHL, EMBASE and Google Scholar. The 119 retained papers document a wide variety of logging devices and sensing technologies measuring a range of outcomes. The most commonly used technologies were accelerometers installed on the user (18.8%), odometers installed on the wheelchair (12.4%), accelerometers installed on the wheelchair (9.7%) and heart monitors (9.7%). Not surprisingly, the most reported outcomes were distance, mobility events, heart rate, speed/velocity, acceleration and driving time. With decreasing costs and technological improvements, data loggers are likely to have future widespread clinical (and even personal) use. Future research may be needed to assess the usefulness of different outcomes and to develop methods more appropriate to wheelchair users, in order to optimize the practicality of wheelchair data loggers.

Optimizing finite element predictions of local subchondral bone structural stiffness using neural network-derived density-modulus relationships for proximal tibial subchondral cortical and trabecular bone

Authors: Nazemi SM, Amini M, Kontulainen SA, Milner JS, Holdsworth DW, Masri BA, Wilson DR, Johnston JD.
Published inClin Biomech (Bristol, Avon). 2016 Oct 27;41:1-8. doi: 10.1016/j.clinbiomech.2016.10.012. [Epub ahead of print].
About: Quantitative computed tomography based subject-specific finite element modeling has potential to clarify the role of subchondral bone alterations in knee osteoarthritis initiation, progression, and pain. However, it is unclear what density-modulus equation(s) should be applied with subchondral cortical and subchondral trabecular bone when constructing finite element models of the tibia. Using a novel approach applying neural networks, optimization, and back-calculation against in situ experimental testing results, the objective of this study was to identify subchondral-specific equations that optimized finite element predictions of local structural stiffness at the proximal tibial subchondral surface.

Long-Term Plasticity in Reflex Excitability Induced by Five Weeks of Arm and Leg Cycling Training after Stroke

Authors: Klarner T, Barss TS, Sun Y, Kaupp C, Loadman PM, Zehr EP.
Published inBrain Sci. 2016 Nov 3;6(4). pii: E54.
About: Neural connections remain partially viable after stroke, and access to these residual connections provides a substrate for training-induced plasticity. The objective of this project was to test if reflex excitability could be modified with arm and leg (A & L) cycling training. Nineteen individuals with chronic stroke (more than six months postlesion) performed 30 min of A & L cycling training three times a week for five weeks. Changes in reflex excitability were inferred from modulation of cutaneous and stretch reflexes. A multiple baseline (three pretests) within-subject control design was used. Plasticity in reflex excitability was determined as an increase in the conditioning effect of arm cycling on soleus stretch reflex amplitude on the more affected side, by the index of modulation, and by the modulation ratio between sides for cutaneous reflexes. In general, A & L cycling training induces plasticity and modifies reflex excitability after stroke.

Increased Central Arterial Stiffness after Spinal Cord Injury: Contributing Factors, Implications and Possible Interventions

Authors: Lee AH, Phillips AA, Krassioukov AV.
Published inJ Neurotrauma. 2016 Nov 8. [Epub ahead of print]
About: Individuals with spinal cord injury (SCI) experience life-threatening cardiovascular events and various autonomic consequences in addition to the well-appreciated motor and neurological impairments. As a result, cardiovascular disease is a major cause of death after SCI, corresponding to a 2-4 fold increased risk of cardiovascular events. A combination of neuroanatomical changes, unstable blood pressure, and rapid deconditioning as a result of decreased physical activity likely contributes to accelerated cardiovascular disease progression in after SCI. Aortic pulse wave velocity (aPWV) is considered the gold-standard technique for evaluating central arterial stiffness, which itself is a correlate for greater cardiovascular disease risk in healthy individuals and a plethora of clinical conditions. In this review we discuss central arterial stiffness after SCI, and demonstrate it is consistently elevated in this population 2-3 m/s, which corresponds to a 30-45% increased risk of cardiovascular mortality and an approximately 40 year acceleration of age-related cardiovascular decline. We also discuss the potential factors contributing to increased central arterial stiffness are reviewed in light of the available literature, including autonomic disruptions, blood pressure instability, metabolic changes and physical inactivity. Furthermore, measurement techniques, risk factors, cardiac dysfunction, and differences in arterial stiffness from able-bodied populations are discussed. Finally, potential therapeutic interventions for preventing or improving central arterial stiffening are also explored including dietary, physical activity and pharmacological strategies.

Autoregressive transitional ordinal model to test for treatment effect in neurological trials with complex endpoints

Authors: Tanadini LG, Steeves JD, Curt A, Hothorn T.
Published in: BMC Med Res Methodol. 2016 Nov 8;16(1):149.
About: A number of potential therapeutic approaches for neurological disorders have failed to provide convincing evidence of efficacy, prompting pharmaceutical and health companies to discontinue their involvement in drug development. Limitations in the statistical analysis of complex endpoints have very likely had a negative impact on the translational process.

Eye movement accuracy determines natural interception strategies

Authors: Fooken J, Yeo SH, Pai DK, Spering M.
Published inJ Vis. 2016 Nov 1;16(14):1. doi: 10.1167/16.14.1.
About: Eye movements aid visual perception and guide actions such as reaching or grasping. Most previous work on eye-hand coordination has focused on saccadic eye movements. Here we show that smooth pursuit eye movement accuracy strongly predicts both interception accuracy and the strategy used to intercept a moving object. We developed a naturalistic task in which participants (n = 42 varsity baseball players) intercepted a moving dot (a “2D fly ball”) with their index finger in a designated “hit zone.” Participants were instructed to track the ball with their eyes, but were only shown its initial launch (100-300 ms). Better smooth pursuit resulted in more accurate interceptions and determined the strategy used for interception, i.e., whether interception was early or late in the hit zone. Even though early and late interceptors showed equally accurate interceptions, they may have relied on distinct tactics: early interceptors used cognitive heuristics, whereas late interceptors’ performance was best predicted by pursuit accuracy. Late interception may be beneficial in real-world tasks as it provides more time for decision and adjustment. Supporting this view, baseball players who were more senior were more likely to be late interceptors. Our findings suggest that interception strategies are optimally adapted to the proficiency of the pursuit system.

Targeted Messages Increase Dairy Consumption in Adults: a Randomized Controlled Trial

Authors: Jung ME, Latimer-Cheung AE, Bofurne JE, Martin Ginis KA.
Published inAnn Behav Med. 2016 Oct 28. [Epub ahead of print]
About: Dairy consumption amongst North Americans aged 30-50 has been declining. Targeted messages have been identified as a cost-efficient method through which to increase health-enhancing behavior, such as dairy intake. The aim of this study is to assess the utility of targeted, framed, efficacy-enhancing messages on calcium consumption from dairy in adults aged 30-50 in a randomized controlled trial.

A systematic review of review articles addressing factors related to physical activity participation among children and adults with physical disabilities

Authors: Martin Ginis KA, Ma JK, Latimer-Cheung AE, Rimmer JH.
Published inHealth Psychol Rev. 2016 Dec;10(4):478-494. Epub 2016 Jun 29.
About: Dozens of published papers cite factors related to leisure-time physical activity (LTPA) participation among people with physical disabilities. Unfortunately, there has been little effort to synthesise this literature in a manner that is accessible and useful to the sectors (e.g., health care, recreation) responsible for LTPA promotion in disability populations. In this systematic review, over 200 factors were extracted from 22 review articles addressing barriers and facilitators to LTPA in children and adults with physical disabilities. Factors were grouped according to common themes, classified into five levels of a social ecological model, and coded according to whether they could be affected by the health-care and/or recreation sectors. Findings are discussed with regard to key factors to target in LTPA-enhancing interventions, relevant theories and models in which to frame interventions, the levels at which the interventions can be implemented, and intervention priorities. The synthesis provides a blueprint and a catalyst for researchers and practitioners to shift focus from conducting studies that merely describe LTPA barriers and facilitators, to developing and delivering strategies to increase LTPA among persons with physical disabilities.

High- and low-intensity exercise do not improve cognitive function after stroke: A randomized controlled trial

Authors: Tang A, Eng JJ, Krassioukov AV, Tsang TS, Liu-Ambrose T.
Published inJ Rehabil Med. 2016 Nov 11;48(10):841-846. doi: 10.2340/16501977-2163.
About: The objective of this study is to determine the effects of high versus low-intensity exercise on cognitive function following stroke.

The Development of a Universally Accepted Sacral Fracture Classification: A Survey of AOSpine and AOTrauma Members

Authors: Ming W, Palidis DJ, Spering M, McKeown MJ.
Published inInvest Ophthalmol Vis Sci. 2016 Oct 1;57(13):5696-5704. doi: 10.1167/iovs.16-20025.
About: Visual impairments are frequent in Parkinson’s disease (PD) and impact normal functioning in daily activities. Visual contrast sensitivity is a powerful nonmotor sign for discriminating PD patients from controls. However, it is usually assessed with static visual stimuli. Here we examined the interaction between perception and eye movements in static and dynamic contrast sensitivity tasks in a cohort of mildly impaired, early-stage PD patients.

The Development of a Universally Accepted Sacral Fracture Classification: A Survey of AOSpine and AOTrauma Members

Authors: Schroeder GD, Kurd MF1, Kepler CK, Krieg JC, Wilson JR, Kleweno CP, Firoozabadi R, Bellabarba C, Kandizoria F, Schnake KJ, Rajesekaran S, Dvorak MF, Chapman JR, Vialle LR, Oner FC, Vaccaro AR.
Published in: Global Spine J. 2016 Nov;6(7):686-694. Epub 2016 Mar 17.
About: The objective of this study is to determine the global perspective on controversial aspects of sacral fracture classifications.

The prevalence and effect of problematic spasticity following traumatic spinal cord injury

Authors: Holtz KA, Lipson R, Noonan VK, Kwon BK, Mills PB.
Published in: Arch Phys Med Rehabil. 2016 Oct 22. pii: S0003-9993(16)31162-5. doi: 10.1016/j.apmr.2016.09.124. [Epub ahead of print]
About: The objective of this study is to evaluate the prevalence and impact of spasticity following traumatic spinal cord injury (SCI).

MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI

Authors: Thiessen JD, Shams E, Stortz G, Schellenberg G, Bishop D, Khan MS, Kozlowski P, Retière F, Sossi V, Thompson CJ, Goertzen AL.
Published in: Phys Med Biol. 2016 Nov 21;61(22):7934-7956. Epub 2016 Oct 25.
About: A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding. MR-compatibility measurements included field mapping of the static magnetic field (B 0) and the time-varying excitation field (B 1) as well as acquisitions with multiple pulse sequences: spin echo (SE), rapid imaging with refocused echoes (RARE), fast low angle shot (FLASH) gradient echo, and echo planar imaging (EPI). B 0 field maps revealed a small degradation in the mean homogeneity (+0.1 ppm) when the PET insert was installed and operating. No significant change was observed in the B 1 field maps or the image homogeneity of various MR images, with a 9% decrease in the signal-to-noise ratio (SNR) observed only in EPI images acquired with the PET insert installed and operating. PET detector flood histograms, photopeak amplitudes, and energy resolutions were unchanged in individual PET detector modules when acquired during MRI operation. There was a small baseline shift on the PET detector signals due to the switching amplifiers used to power MRI gradient pulses. This baseline shift was observable when measured with an oscilloscope and varied as a function of the gradient duty cycle, but had no noticeable effect on the performance of the PET detector modules. Compact front-end electronics and effective RF shielding led to minimal cross-interference between the PET and MRI systems. Both PET detector and MRI performance was excellent, whether operating as a standalone system or a hybrid PET/MRI.

Comparison of specimen-specific vertebral body finite element models with experimental digital image correlation measurements

Authors: Gustafson HM, Cripton PA, Ferguson SJ, Helgason B.
Published inJ Mech Behav Biomed Mater. 2016 Oct 7;65:801-807. doi: 10.1016/j.jmbbm.2016.10.002. [Epub ahead of print]
About: The purpose of this study was to load cadaveric vertebral bodies (n=6) in compression and compare the response, measured with digital image correlation (DIC) on the cortex, with the predicted response from specimen-specific vertebral finite element (FE) models. Five modulus-density relationships were evaluated, and for the strongest modulus-density relationship, the correlation between the DIC and FE displacements had R^2 values from 0.75 to 0.93. The stiffnesses derived from the DIC measurements were strongly predicted by the FE stiffnesses (R^2=0.90). DIC provides full-field measurements of surface displacement, eliminating the influence of system compliance, for validation of specimen-specific models.

Older Adults’ Online Dating Profiles and Successful Aging

Authors: Wada M, Mortenson WB, Hurd Clarke L.
Published in: Can J Aging. 2016 Oct 24:1-12. [Epub ahead of print]
About: This study examined how relevant Rowe and Kahn’s three criteria of successful aging were to older adults’ self-portrayals in online dating profiles: low probability of disease and disability, high functioning, and active life engagement. In this cross-sectional study, 320 online dating profiles of older adults were randomly selected and coded based on the criteria. Logistic regression analyses determined whether age, gender, and race/ethnicity predicted self-presentation. Few profiles were indicative of successful aging due to the low prevalence of the first two criteria; the third criterion, however, was identified in many profiles. Native Americans were significantly less likely than other ethnic groups to highlight the first two criteria. Younger age predicted presenting the first criterion. Women’s presentation of the third criterion remained significantly high with age. The findings suggest that the criteria may be unimportant to older adults when seeking partners, or they may reflect the exclusivity of this construct.

Morphology based anisotropic finite element models of the proximal femur validated with experimental data

Authors: Enns-Bray WS, Ariza O, Gilchrist S, Widmer Soyka RP, Vogt PJ, Palsson H, Boyd SK, Guy P, Cripton PA, Ferguson SJ, Helgason B.
Published inMed Eng Phys. 2016 Nov;38(11):1339-1347. doi: 10.1016/j.medengphy.2016.08.010. Epub 2016 Sep 15.
About: Finite element analysis (FEA) of bones scanned with Quantitative Computed Tomography (QCT) can improve early detection of osteoporosis. The accuracy of these models partially depends on the assigned material properties, but anisotropy of the trabecular bone cannot be fully captured due to insufficient resolution of QCT. The inclusion of anisotropy measured from high resolution peripheral QCT (HR-pQCT) could potentially improve QCT-based FEA of the femur, although no improvements have yet been demonstrated in previous experimental studies. This study analyzed the effects of adding anisotropy to clinical resolution femur models by constructing six sets of FE models (two isotropic and four anisotropic) for each specimen from a set of sixteen femurs that were experimentally tested in sideways fall loading with a strain gauge on the superior femoral neck. Two different modulus-density relationships were tested, both with and without anisotropy derived from mean intercept length analysis of HR-pQCT scans. Comparing iso- and anisotropic models to the experimental data resulted in nearly identical correlation and highly similar linear regressions for both whole bone stiffness and strain gauge measurements. Anisotropic models contained consistently greater principal compressive strains, approximately 14% in magnitude, in certain internal elements located in the femoral neck, greater trochanter, and femoral head. In summary, anisotropy had minimal impact on macroscopic measurements, but did alter internal strain behavior. This suggests that organ level QCT-based FE models measuring femoral stiffness have little to gain from the addition of anisotropy, but studies considering failure of internal structures should consider including anisotropy to their models.

Aerobic exercise and vascular cognitive impairment: A randomized controlled trial

Authors: Liu-Ambrose T, Best JR, Davis JC, Eng JJ, Lee PE, Jacova C, Boyd LA, Brasher PM, Munkacsy M, Cheung W, Hsiung GR.
Published inNeurology. 2016 Oct 19. pii: 10.1212/WNL.0000000000003332. [Epub ahead of print]
About: The objective of this study is to assess the efficacy of a progressive aerobic exercise training program on cognitive and everyday function among adults with mild subcortical ischemic vascular cognitive impairment (SIVCI).

The technical quality of online leisure time physical activity resources for people with physical disabilities

Authors: Shaw RB, Mallory KD, Arkell J, Martin Ginis KA.
Published in: Disabil Health J. 2016 Sep 13. pii: S1936-6574(16)30129-7. doi: 10.1016/j.dhjo.2016.09.002. [Epub ahead of print]
About: The internet is an important information source for people with disabilities. Unfortunately, little is known about the quality of online leisure time physical activity resources provided for people with physical disabilities. The objective of this study is to assess the quality of leisure time physical activity resources available online for people with physical disabilities.

Neuromechanical interactions between the limbs during human locomotion: an evolutionary perspective with translation to rehabilitation

Authors: Zehr EP, Barss TS, Dragert K, Frigon A, Vasudevan EV, Haridas C, Hundza S, Kaupp C, Klarner T, Klimstra M, Komiyama T, Loadman PM, Mezzarane RA, Nakajima T, Pearcey GE, Sun Y.
Published in: Exp Brain Res. 2016 Nov;234(11):3059-3081. Epub 2016 Jul 15.
About: During bipedal locomotor activities, humans use elements of quadrupedal neuronal limb control. Evolutionary constraints can help inform the historical ancestry for preservation of these core control elements support transfer of the huge body of quadrupedal non-human animal literature to human rehabilitation. In particular, this has translational applications for neurological rehabilitation after neurotrauma where interlimb coordination is lost or compromised. The present state of the field supports including arm activity in addition to leg activity as a component of gait retraining after neurotrauma.

The relationship between lower limb proprioceptive sense and locomotor skill acquisition

Authors: Qaiser T, Chisholm AE, Lam T.
Published in: Exp Brain Res. 2016 Nov;234(11):3185-3192. Epub 2016 Jul 5.
About: Sensorimotor integration is essential for controlling movement and acquiring new motor tasks in humans. The aim of this project was to understand how lower limb proprioceptive sense contributes to the acquisition of a skilled walking task. We assessed lower limb joint position and movement detection sense in healthy human subjects using the Lokomat robotic exoskeleton. Subjects walked on a treadmill to practice a skilled motor task (200 trials) requiring them to match their foot height during the swing phase to the height of a virtual obstacle displayed on a monitor in front of them. Subjects were given visual feedback on their error relative to the obstacle height after it was crossed. Lower limb joint position sense was related to the final performance error, but not the learning rate of the skilled walking task. The findings from this study support the role of lower limb proprioceptive sense on locomotor skill performance in healthy adult subjects.

Movement repetitions in physical and occupational therapy during spinal cord injury rehabilitation

Authors: Zbogar D, Eng JJ, Miller WC, Krassioukov AV, Verrier MC.
Published inSpinal Cord. 2016 Oct 18. doi: 10.1038/sc.2016.129. [Epub ahead of print]
About: The objective of this study is to quantify the amount of upper- and lower-extremity movement repetitions (that is, voluntary movements as part of a functional task or specific motion) occurring during inpatient spinal cord injury (SCI), physical (PT) and occupational therapy (OT), and examine changes over the inpatient rehabilitation stay.

Emergency management of autonomic dysreflexia with neurologic complications

Authors: Squair JW, Phillips AA, Harmon M, Krassioukov AV.
Published inCMAJ. 2016 Oct 18;188(15):1100-1103. Epub 2016 May 24.

Listening to music during sprint interval exercise: The impact on exercise attitudes and intentions

Authors: Stork MJ, Martin Ginis KA.
Published inJ Sports Sci. 2016 Oct 15:1-7. [Epub ahead of print]
About: This study investigated the impact of listening to music during exercise on perceived enjoyment, attitudes and intentions towards sprint interval training (SIT). Twenty men (24.8 ± 4.5 years) and women (20.1 ± 2.6 years) unfamiliar with SIT exercise completed two acute sessions of SIT, one with and one without music. Perceived enjoyment, attitudes and intentions towards SIT were measured post-exercise for each condition. Attitudes and intentions to engage in SIT were also measured at baseline and follow-up. Post-exercise attitudes mediated the effects of enjoyment on intentions in the music condition (95% confidence interval [CI]: [0.01, 0.07], κ^2 = 0.36) and in the no music condition (95% CI: [0.01, 0.08], κ^2 = 0.37). Attitudes towards SIT were significantly more positive following the music than no music condition (P = 0.004), while intentions towards SIT were not (P = 0.29). Further, attitudes and intentions towards SIT did not change from baseline to follow-up (Ps > 0.05). These findings revealed that participants had relatively positive attitudes and intentions towards SIT, which did not become more negative despite experiencing intense SIT protocols. This study highlights the importance of acute affective responses to SIT exercise for influencing one’s attitudes and intentions towards participating in SIT exercise. Such factors could ultimately play a key role in determining whether an individual engages in SIT exercise in the long term.

Biomaterial Strategies for Delivering Stem Cells as a Treatment for Spinal Cord Injury

Authors: Agbay A, Edgar JM, Robinson M, Styan T, Wilson K, Schroll J, Ko J, Khadem Mohtaram N, Jun MB, Willerth SM.
Published in: Cells Tissues Organs. 2016;202(1-2):42-51. Epub 2016 Oct 5.
About: Ongoing clinical trials are evaluating the use of stem cells as a way to treat traumatic spinal cord injury (SCI). However, the inhibitory environment present in the injured spinal cord makes it challenging to achieve the survival of these cells along with desired differentiation into the appropriate phenotypes necessary to regain function. Transplanting stem cells along with an instructive biomaterial scaffold can increase cell survival and improve differentiation efficiency. This study reviews the literature discussing different types of instructive biomaterial scaffolds developed for transplanting stem cells into the injured spinal cord. We have chosen to focus specifically on biomaterial scaffolds that direct the differentiation of neural stem cells and pluripotent stem cells since they offer the most promise for producing the cell phenotypes that could restore function after SCI. In terms of biomaterial scaffolds, this article reviews the literature associated with using hydrogels made from natural biomaterials and electrospun scaffolds for differentiating stem cells into neural phenotypes. It then presents new data showing how these different types of scaffolds can be combined for neural tissue engineering applications and provides directions for future studies.

Sensorimotor integration of vision and proprioception for obstacle crossing in ambulatory individuals with spinal cord injury

Authors: Malik RN, Cote R, Lam T.
Published in: J Neurophysiol. 2016 Oct 12:jn.00169.2016. doi: 10.1152/jn.00169.2016. [Epub ahead of print]
About: Skilled walking, such as obstacle crossing, is an essential component of functional mobility. Sensorimotor integration of visual and proprioceptive inputs is important for successful obstacle crossing. The objective of this study was to understand how proprioceptive deficits affect obstacle-crossing strategies when controlling for variations in motor deficits in ambulatory individuals with spinal cord injury.

Mechanisms of action of an implementation intervention in stroke rehabilitation: a qualitative interview study

Authors: Connell LA, McMahon NE, Tyson SF, Watkins CL, Eng JJ.
Published inBMC Health Serv Res. 2016 Sep 30;16(1):534.
About: Despite best evidence demonstrating the effectiveness of increased intensity of exercise after stroke, current levels of therapy continue to be below those required to optimise motor recovery. We developed and tested an implementation intervention that aims to increase arm exercise in stroke rehabilitation. The aim of this study was to illustrate the use of a behaviour change framework, the Behaviour Change Wheel, to identify the mechanisms of action that explain how the intervention produced change.

Normative data for the segmental acquisition of contact heat evoked potentials in cervical dermatomes

Authors: Jutzeler CR, Rosner J, Rinert J, Kramer JL, Curt A.
Published inSci Rep. 2016 Oct 6;6:34660. doi: 10.1038/srep34660.
About: Contact heat evoked potentials (CHEPs) represent a neurophysiological approach to assess conduction in the spinothalamic tract. The aim of this study was to establish normative values of CHEPs acquired from cervical dermatomes (C4, C6, C8) and examine the potential confounds of age, sex, and height. 101 (49 male) healthy subjects of three different age groups (18-40, 41-60, and 61-80 years) were recruited. Normal (NB, 35-52 °C) followed by increased (IB, 42-52 °C) baseline stimulation protocols were employed to record CHEPs. Multi-variate linear models were used to investigate the effect of age, sex, and height on the CHEPs parameters (i.e., N2 latency, N2P2 amplitude, rating of perceived intensity). Compared to NB, IB stimulation reduced latency jitter within subjects, yielding larger N2P2 amplitudes, and decreased inter-subject N2 latency variability. Age was associated with reduced N2P2 amplitude and prolonged N2 latency. After controlling for height, male subjects had significantly longer N2 latencies than females during IB stimulation. The study provides normative CHEPs data in a large cohort of healthy subjects from segmentally examined cervical dermatomes. Age and sex were identified as important factors contributing to N2 latency and N2P2 amplitude. The normative data will improve the diagnosis of spinal cord pathologies.

Can concussion constrain the Caped Crusader?

AuthorsZehr EP, Wright B.
Published inBr J Sports Med. 2016 Oct 4. pii: bjsports-2016-096792. doi: 10.1136/bjsports-2016-096792. [Epub ahead of print]

Telerehabilitation in Stroke Recovery: A Survey on Access and Willingness to Use Low-Cost Consumer Technologies

Authors: Edgar MC, Monsees S, Rhebergen J, Waring J, Van der Star T, Eng JJ, Sakakibara BM.
Published in: Telemed J E Health. 2016 Oct 5. [Epub ahead of print]
About: Early telerehabilitation trials with stroke survivors have shown promising results, but there remains a lack of knowledge of what areas of rehabilitation people with stroke are interested and willing to receive using technology. The purpose of this study was to describe the access to low-cost consumer technologies and willingness to use them to receive rehabilitation services among stroke survivors.

Cardiac Consequences of Autonomic Dysreflexia in Spinal Cord Injury

Authors: West CR, Squair JW, McCracken L, Currie KD, Somvanshi R, Yuen V, Phillips AA, Kumar U, McNeill JH, Krassioukov AV.
Published in: Hypertension. 2016 Nov;68(5):1281-1289. Epub 2016 Oct 3.
About: Autonomic dysreflexia (AD), which describes episodic hypertension, is highly prevalent in people with spinal cord injury (SCI). In non-SCI, primary hypertension depresses cardiac contractile reserve via β-adrenergic mechanisms. In this study, we investigated whether AD contributes to the impairment in cardiac contractile function that accompanies SCI. We induced SCI in rodents and stratified them into sham, SCI, or SCI plus repetitive induction of AD. At 6-week post-SCI, we assessed cardiac function using in vivo (speckle-tracking echocardiography), ex vivo (working heart), and molecular approaches (Western blot). We also provide unique translational insight by comparing the relationship between the number of daily AD events and cardiac function in 14 individuals with cervical SCI. We found SCI and SCI plus repetitive induction of AD exhibited a reduction in left ventricular dimensions at 6-week post-SCI versus preinjury (P<0.049). Compared with sham, SCI exhibited a reduction in peak radial strain along with a down and rightward shift in the Starling curve (P<0.037), both of which were further depressed in SCI plus repetitive induction of AD (P<0.042). In response to β-adrenergic stimulation, SCI plus repetitive induction of AD exhibited an attenuated increase in contractile indices (P<0.001), despite no differences in β-receptor expression within the left ventricle. Our clinical data confirm our experimental findings by demonstrating significant associations between the number of daily AD events and markers of systolic and diastolic function along with left ventricular mechanics. Here, we provide the first evidence from a translational perspective that AD exerts insidious effects on cardiac function in rodents and humans with SCI.

Development and user validation of driving tasks for a power wheelchair simulator

Authors: Archambault PS, Blackburn É, Reid D, Routhier F, Miller WC.
Published in: Disabil Rehabil. 2016 Sep 27:1-8. [Epub ahead of print]
About: Mobility is important for participation in daily activities and a power wheelchair (PW) can improve quality of life of individuals with mobility impairments. A virtual reality simulator may be helpful in complementing PW skills training, which is generally seen as insufficient by both clinicians and PW users. To this end, specific, ecologically valid activities, such as entering an elevator and navigating through a shopping mall crowd, have been added to the McGill wheelchair (miWe) simulator through a user-centred approach.

Differences in health, participation and life satisfaction outcomes in adults following paediatric- versus adult-sustained spinal cord injury.

Authors: Ma JK, Post MW, Gorter JW, Martin Ginis KA.
Published in: Spinal Cord. 2016 Sep 20. [Epub ahead of print]
About: The objective of this study was to compare differences in self-reported health status, participation and life satisfaction outcomes between adults with a spinal cord injury (SCI) sustained during paediatric (P) versus adulthood (A) years. Regardless of time since injury, people who sustained a paediatric SCI reported better health and greater participation than those injured in adulthood. Nevertheless, both groups scored well below able-bodied normative values for all measures. The results highlight the importance of a comprehensive life-course approach to SCI rehabilitation, irrespective of age at the time of injury.

With Great Power Comes Great Responsibility-A Personal Philosophy for Communicating Science in Society

AuthorsZehr EP.
Published ineNeuro. 2016 Sep 8;3(5). pii: ENEURO.0200-16.2016.
About: Many think that communicating science is a necessary and rewarding activity. Yet finding compelling, relevant, and timely points of linkage between challenging scientific concepts and the experiences and interests of the general public can be difficult. Since science continues to influence more and more aspects of daily life and knowledge, there is a parallel need for communication about science in our society. Here I discuss the “middle-ground hypothesis” using popular culture for science communication and applying the “FUNnel model,” where popular culture is used as a lead-in and wrap-up when discussing science. The scientific knowledge we find in our hands does not belong to us-we just had it first. We can honor that knowledge best by sharing it as widely as possible using the most creative means at our disposal.

Morphology based anisotropic finite element models of the proximal femur validated with experimental data

Authors: Enns-Bray WS, Ariza O, Gilchrist S, Widmer Soyka RP, Vogt PJ, Palsson H, Boyd SK, Guy P, Cripton PA, Ferguson SJ, Helgason B.
Published inMed Eng Phys. 2016 Sep 15. pii: S1350-4533(16)30187-4.
About: Finite element analysis (FEA) of bones scanned with Quantitative Computed Tomography (QCT) can improve early detection of osteoporosis. The accuracy of these models partially depends on the assigned material properties, but anisotropy of the trabecular bone cannot be fully captured due to insufficient resolution of QCT. The inclusion of anisotropy measured from high resolution peripheral QCT (HR-pQCT) could potentially improve QCT-based FEA of the femur, although no improvements have yet been demonstrated in previous experimental studies. This study analyzed the effects of adding anisotropy to clinical resolution femur models by constructing six sets of FE models (two isotropic and four anisotropic) for each specimen from a set of sixteen femurs that were experimentally tested in sideways fall loading with a strain gauge on the superior femoral neck. Two different modulus-density relationships were tested, both with and without anisotropy derived from mean intercept length analysis of HR-pQCT scans. Comparing iso- and anisotropic models to the experimental data resulted in nearly identical correlation and highly similar linear regressions for both whole bone stiffness and strain gauge measurements. Anisotropic models contained consistently greater principal compressive strains, approximately 14% in magnitude, in certain internal elements located in the femoral neck, greater trochanter, and femoral head. In summary, anisotropy had minimal impact on macroscopic measurements, but did alter internal strain behavior. This suggests that organ level QCT-based FE models measuring femoral stiffness have little to gain from the addition of anisotropy, but studies considering failure of internal structures should consider including anisotropy to their models.

Reliability and validity of daily physical activity measures during inpatient spinal cord injury rehabilitation

Authors: Zbogar D, Eng JJMiller WCKrassioukov AV, Verrier MC.
Published in: SAGE Open Med. 2016 Sep 1;4:2050312116666941.
About: The objective of this study is to assess the test-retest reliability and convergent validity of daily physical activity measures during inpatient spinal cord injury rehabilitation. The test-retest reliability and convergent validity of the instrumented measures suggest that wrist and hip accelerometers are appropriate tools for use in research studies of daily physical activity in the spinal cord injury rehabilitation setting but are too variable for individual use.

Predicting recruitment feasibility for acute spinal cord injury clinical trials in Canada using national registry data

Authors: Thibault-Halman G, Rivers CS, Bailey C, Tsai E, Drew B, Noonan V, Fehlings M, Dvorak MF, Kuerban D, Kwon BK, Christie S.
Published in: J Neurotrauma. 2016 Sep 14. [Epub ahead of print]
About: Traumatic spinal cord injury (tSCI) represents a significant burden of illness, but is relatively uncommon and heterogeneous, making it challenging to achieve sufficient subject enrollment in clinical trials of therapeutic interventions for acute SCI. The Rick Hansen Spinal Cord Injury Registry (RHSCIR) is a national SCI Registry that enters SCI patients from acute-care centers across Canada. To predict the feasibility of conducting clinical trials of acute SCI within Canada, we have applied the inclusion/exclusion criteria of six previously conducted SCI trials to the RHSCIR dataset and generated estimates of how many Canadian individuals would theoretically have been eligible for enrollment in these studies. Data for SCI cases were prospectively collected for RHSCIR at 18 acute and 13 rehabilitation sites across Canada. RHSCIR cases enrolled between 2009-2013 who met the following key criteria were included: non-penetrating traumatic SCI; received acute care at a RHSCIR site; age >18- <75 years, and had complete admission single neurological level of injury data. Inclusion and exclusion criteria for the Minocycline in Acute Spinal Cord injury (Minocycline), Riluzole, Surgical Timing in Acute Spinal Cord Injury Study (STASCIS), Cethrin, Nogo antibody study (NOGO) and Sygen studies were applied retrospectively to this dataset. The numbers of patients eligible for each clinical trial were determined. 2166 of the initial 2714 cases (79.8%) met the key criteria and were included in the dataset. Projected annual numbers of eligible patients for each trial was: Minocycline 117 cases; Riluzole 62 cases; STASCIS 109 cases; Cethrin 101 cases; NOGO 82 cases; and Sygen 70 cases. An additional 8.0% of the sample had a major head injury (GCS≤ 12) and would have been excluded from the trials. RHSCIR provides a comprehensive national dataset which may serve as a useful tool in the planning of multicentre clinical SCI trials.

Online training improves paramedics’ knowledge of autonomic dysreflexia management guidelines

Authors: Martin Ginis KA, Tomasone JR, Welsford M, Ethans K, Sinden AR, Longeway M, Krassioukov AV.
Published in: Spinal Cord. 2016 Sep 13. [Epub ahead of print]
About: The objective of this study was to test the effects of the ‘ABCs of AD’ educational module on immediate and longer-term changes in paramedics’ knowledge and beliefs about using the autonomic dysreflexia clinical practice guidelines (AD-CPGs). ‘ABCs of AD’ has immediate and sustained effects on paramedics’ knowledge of attitudes toward and perceived pressure from patients to use the AD-CPGs. Updates to paramedic patient care guidelines and standards are needed to increase paramedics’ perceived control and self-efficacy to implement the guidelines, and their intentions to use the AD-CPGs.

Neuropathic pain following traumatic spinal cord injury: Models, measurement, and mechanisms

Authors: Kramer JL, Minhas NK, Jutzeler CR, Erskine EL, Liu LJ, Ramer MS.
Published in: J Neurosci Res. 2016 Sep 12. [Epub ahead of print]
About: Neuropathic pain following spinal cord injury (SCI) is notoriously difficult to treat and is a high priority for many in the SCI population. Resolving this issue requires animal models fidelic to the clinical situation in terms of injury mechanism and pain phenotype. This Review discusses the means by which neuropathic pain has been induced and measured in experimental SCI and compares these with human outcomes, showing that there is a substantial disconnection between experimental investigations and clinical findings in a number of features. Clinical injury level is predominantly cervical, whereas injury in the laboratory is modeled mainly at the thoracic cord. Neuropathic pain is primarily spontaneous or tonic in people with SCI (with a relatively smaller incidence of allodynia), but measures of evoked responses (to thermal and mechanical stimuli) are almost exclusively used in animals. There is even the question of whether pain per se has been under investigation in most experimental SCI studies rather than simply enhanced reflex activity with no affective component. This Review also summarizes some of the problems related to clinical assessment of neuropathic pain and how advanced imaging techniques may circumvent a lack of patient/clinician objectivity and discusses possible etiologies of neuropathic pain following SCI based on evidence from both clinical studies and animal models, with examples of cellular and molecular changes drawn from the entire neuraxis from primary afferent terminals to cortical sensory and affective centers.

Identification of a Chrysanthemic Ester as an Apolipoprotein E Inducer in Astrocytes

Authors: Fan J, Zareyan S, Zhao W, Shimizu Y, Pfeifer TA, Tak JH, Isman MB, Van den Hoven B, Duggan ME, Wood MW, Wellington CL, Kulic I.
Published inPLoS One. 2016 Sep 6;11(9):e0162384
About: The apolipoprotein E (APOE) gene is the most highly associated susceptibility locus for late onset Alzheimer’s Disease (AD), and augmenting the beneficial physiological functions of apoE is a proposed therapeutic strategy. In a high throughput phenotypic screen for small molecules that enhance apoE secretion from human CCF-STTG1 astrocytoma cells, we show the chrysanthemic ester 82879 robustly increases expressed apoE up to 9.4-fold and secreted apoE up to 6-fold and is associated with increased total cholesterol in conditioned media. Compound 82879 is unique as structural analogues, including pyrethroid esters, show no effect on apoE expression or secretion. 82879 also stimulates liver x receptor (LXR) target genes including ATP binding cassette A1 (ABCA1), LXRα and inducible degrader of low density lipoprotein receptor (IDOL) at both mRNA and protein levels. In particular, the lipid transporter ABCA1 was increased by up to 10.6-fold upon 82879 treatment. The findings from CCF-STTG1 cells were confirmed in primary human astrocytes from three donors, where increased apoE and ABCA1 was observed along with elevated secretion of high-density lipoprotein (HDL)-like apoE particles. Nuclear receptor transactivation assays revealed modest direct LXR agonism by compound 82879, yet 10 μM of 82879 significantly upregulated apoE mRNA in mouse embryonic fibroblasts (MEFs) depleted of both LXRα and LXRβ, demonstrating that 82879 can also induce apoE expression independent of LXR transactivation. By contrast, deletion of LXRs in MEFs completely blocked mRNA changes in ABCA1 even at 10 μM of 82879, indicating the ability of 82879 to stimulate ABCA1 expression is entirely dependent on LXR transactivation. Taken together, compound 82879 is a novel chrysanthemic ester capable of modulating apoE secretion as well as apoE-associated lipid metabolic pathways in astrocytes, which is structurally and mechanistically distinct from known LXR agonists.

Impact of bladder, bowel and sexual dysfunction on health status of people with thoracolumbar spinal cord injuries living in the community

Authors: Park SE, Elliott S, Noonan VK, Thorogood NP, Fallah N, Aludino A, Dvorak MF.
Published in: J Spinal Cord Med. 2016 Aug 31:1-12.
About: The disruption of autonomic function following a spinal cord injury (SCI) is common and can negatively affect quality of life. The objective of this study was to describe the prevalence of bladder/bowel incontinence and sexual dysfunction in community-dwelling individuals with a thoracolumbar SCI and examine the impact on general physical and mental health status.

Characterising the severity of autonomic cardiovascular dysfunction after spinal cord injury using a novel 24 hour ambulatory blood pressure analysis software

Authors: Popok D, West CR, Hubli M, Currie KD, Krassioukov AV.
Published inJ Neurotrauma. 2016 Aug 29. [Epub ahead of print]
About: Cardiovascular disease is one of the leading causes of morbidity and mortality in the spinal cord injury (SCI) population. SCI may disrupt autonomic cardiovascular homeostasis, which can lead to persistent hypotension, irregular diurnal rhythmicity and the development of Autonomic Dysreflexia (AD). There is currently no software available to perform automated detection and evaluation of cardiovascular autonomic dysfunction(s) such as those listed above from 24hr ambulatory blood pressure monitoring (ABPM) recordings in the clinical setting. The objective of the following study is to compare the efficacy of a novel 24 hour ABPM Autonomic Dysfunction (AD) Detection Software against manual detection and to use the software to demonstrate the relationships between level of injury and the degree of autonomic cardiovascular impairment in a large cohort of individuals. A total of 46 individuals with cervical (group 1, n =37) and high-thoracic (group 2, n=9) SCI participated in the study. Outcome measures included the frequency and severity of AD, frequency of hypotensive events, and diurnal variations in blood pressure and heart rate. There was good agreement between the Software and manual detection of AD events (Bland-Altman limits of agreement =±1.458 events). Cervical SCI presented with more frequent (p=0.0043) and severe AD (p=0.0343) vs. high thoracic SCI. Cervical SCI exhibited higher systolic and diastolic blood pressure during the night and lower heart rate during the day compared to high thoracic SCI. In conclusion, our ABPM AD Detection Software was equally as effective in detecting the frequency and severity of AD and hypotensive events as manual detection, suggesting this software can be used in the clinical setting to expedite ABPM analyses.

Cross-education of strength and skill: an old idea with applications in the aging nervous system

Authors: Barss TS, Pearcey GE, Zehr EP.
Published in: Yale J Biol Med. 2016 Mar 24;89(1):81-6.
About: Edward Wheeler Scripture’s 1894 work out of the Yale Psychological Laboratory has been influential in identifying the nervous system’s contribution to the bilateral improvements that are seen with unilateral strength and skill training. Scripture coined the term “cross-education” to describe this improvement in the untrained contralateral limb. While physiological changes accompany aging that may negatively affect the performance of physical tasks, far too much credit has been given to the natural aging process rather than the effects of inactivity. Emerging evidence indicates strength or skill training interventions induce significant neuroplasticity in an aging population. The model of unilateral training provides a unique approach in which to elicit such plasticity. This brief review highlights the innate ability of the nervous system to adapt to unilateral strength and skill training interventions, regardless of age, and provides a novel perspective on the robust plastic ability of the aging nervous system.

Short-Term Plasticity in a Monosynaptic Reflex Pathway to Forearm Muscles after Continuous Robot-Assisted Passive Stepping

Authors: Nakajima T, Kamibayashi K, Kitamura T, Komiyama T, Zehr EP, Nakazawa K.
Published inFront Hum Neurosci. 2016 Jul 22;10:368.
About: Both active and passive rhythmic limb movements reduce the amplitude of spinal cord Hoffmann (H-) reflexes in muscles of moving and distant limbs. This could have clinical utility in remote modulation of the pathologically hyperactive reflexes found in spasticity after stroke or spinal cord injury. However, such clinical translation is currently hampered by a lack of critical information regarding the minimum or effective duration of passive movement needed for modulating spinal cord excitability. We therefore investigated the H-reflex modulation in the flexor carpi radialis (FCR) muscle during and after various durations (5, 10, 15, and 30 min) of passive stepping in 11 neurologically normal subjects. Passive stepping was performed by a robotic gait trainer system (Lokomat(®)) while a single pulse of electrical stimulation to the median nerve elicited H-reflexes in the FCR. The amplitude of the FCR H-reflex was significantly suppressed during passive stepping. Although 30 min of passive stepping was sufficient to elicit a persistent H-reflex suppression that lasted up to 15 min, 5 min of passive stepping was not. The duration of H-reflex suppression correlated with that of the stepping. These findings suggest that the accumulation of stepping-related afferent feedback from the leg plays a role in generating short-term interlimb plasticity in the circuitry of the FCR H-reflex.

Left Ventricular Mechanics in Untrained and Trained Males with Tetraplegia

Authors: Currie KD, West CR, Stöhr EJ, Krassioukov AV.
Published inJ Neurotrauma. 2016 Sep 14. [Epub ahead of print]
About:Reduced left ventricular (LV) function is common in tetraplegia, yet it is unknown whether intrinsic myocardial function is attenuated. This study examined the effect of SCI and exercise-training status on LV mechanics (intrinsic function) and LV systolic/diastolic function by comparing untrained (UT) and trained (TT) individuals with tetraplegia and able-bodied (AB) individuals. Individuals with tetraplegia had a traumatic, chronic, motor-complete cervical spinal cord injury. Nine UT males (40 ± 10 years), 8 TT males (30 ± 5 years), and nine AB males (37 ± 9 years) participated in the study. LV indices were assessed using two-dimensional transthoracic echocardiography, with speckle-tracking analysis for the determination of LV mechanics. For systolic function, stroke volumes were lower in both UT (59 ± 9 mL; p < 0.001) and TT (63 ± 9 mL; p < 0.001) relative to AB (82 ± 11 mL), whereas systolic mechanics were similar across groups. Diastolic function was only reduced in UT, including a lower ratio of early-to-late transmitral filling velocity (1.55 ± 0.28) relative to TT (2.07 ± 0.42; p < 0.05) and AB (2.44 ± 0.61; p < 0.01) and longer isovolumetric relaxation times in UT (101 ± 7 ms) relative to TT (88 ± 11 ms; p < 0.05) and AB (85 ± 6 ms; p < 0.01). Diastolic mechanics (apical circumferential strain rate) were significantly enhanced in TT (3.03 ± 0.83 s-1) compared to AB (1.85 ± 0.65 s-1; p < 0.05). There was a trend (p = 0.062) for a between-group difference in apical radial diastolic strain rate (UT: -2.51 ± 0.83 s-1; TT: -3.92 ± 1.96 s-1; AB: -1.84 ± 0.46 s-1). In tetraplegia, attenuated LV systolic function is not attributed to intrinsic dysfunction, whereas exercise-training status appears to improve both global LV diastolic function and LV mechanics.

Cardiovascular response during urodynamics in individuals with spinal cord injury

Authors: Liu N, Zhou MW, Biering-Sørensen F, Krassioukov AV.
Published inSpinal Cord. 2016 Aug 2. [Epub ahead of print]
About: The objective of this study is to establish the frequency and severity of autonomic dysreflexia (AD) during urodynamics among individuals with chronic spinal cord injury (SCI) and to investigate the possible effect of the number of years since SCI on the severity of AD. Individuals with cervical SCI, DSD, poor bladder compliance or >2 years after SCI were associated with a higher possibility of developing AD during urodynamics. Furthermore, AD was more severe in complete (AIS A) individuals and was exacerbated with time after injury.

In with the new and out with the old: enter multivariate wavelet decomposition, exit transfer function

Authors: Phillips AA, Hansen A, Krassioukov AV.
Published inAm J Physiol Heart Circ Physiol. 2016 Sep 1;311(3):H735-7.
About: The human brain makes up only 2% of body weight, although it consumes more than 20% of oxygen and glucose at rest, with almost all adenosine triphosphate within the brain being produced by oxidative metabolism of glucose. In addition to a great need for substrate provision and by-product clearance, the metabolic circumstances in the brain are compromised by a limited intracellular capacity for energy storage. These two characteristics, combined with the paramount importance of brain function compared with other end organs, necessitate precise regulation of cerebral blood flow (CBF). Regulation of CBF is achieved through several factors including metabolic, myogenic, and neurogenic control, as well as systemic blood flow. Specifically, the primary controllers of CBF are partial pressure of arterial CO2, cerebral metabolism, cardiac output, and the autonomic nervous system. The role of the autonomic nervous system has been particularly difficult to assess due to a number of factors stemming from the redundant mechanisms at play involving a combination of neurovascular coupling, arterial blood gases, and systemic blood flow.

High Thoracic Contusion Model for the Investigation of Cardiovascular Function after Spinal Cord Injury

Authors: Squair JW, West CR, Popok D, Assinck P, Liu J, Tetzlaff WKrassioukov AV.
Published inJ Neurotrauma. 2016 Aug 25. [Epub ahead of print]
About: Cardiovascular disease is the leading cause of death for individuals with spinal cord injury (SCI). Because of a lack of a standardized and accessible animal model for cardiovascular disease after SCI, few laboratories have conducted pre-clinical trials aimed at reinstating descending cardiovascular control. Here, we utilized common contusion methodology applied to the midline of the upper-thoracic cord of adult Wistar rats accompanied with telemetric blood pressure monitoring and FluoroGold retrograde neuronal tracing, as well as lesion site and lumbrosacral afferent immunohistochemistry. We demonstrate widespread cardiovascular (i.e., impaired resting hemodynamics, autonomic dysreflexia) and hindlimb dysfunction at 1 month post-injury. Further, we provide a description of the neuroanatomical changes that accompany cardiovascular abnormalities. Specifically, we describe 1) the injury site including white matter sparing as well as lesion volume, and their correlations to cardiovascular as well as motor outcomes; 2) the severity of injury-dependent changes in sympathoexcitatory medullary neuron spinal connectivity, as measured using FluoroGold tracing; and 3) the extent of aberrant afferent plasticity within the lumbosacral region of the spinal cord, which has been linked to the development of autonomic dysreflexia. We believe that this model, which utilizes equipment common to numerous SCI laboratories, can serve as a research standard for studies specifically aimed at investigating autonomic neuroprotective and regenerative strategies following SCI.

Neuromechanical interactions between the limbs during human locomotion: an evolutionary perspective with translation to rehabilitation

AuthorsZehr EP, Barss TS, Dragert K, Frigon A, Vasudevan EV, Haridas C, Hundza S, Kaupp C, Klarner T, Klimstra M, Komiyama T, Loadman PM, Mezzarane RA, Nakajima T, Pearcey GE, Sun Y.
Published inExp Brain Res. 2016 Jul 15. [Epub ahead of print]
About: During bipedal locomotor activities, humans use elements of quadrupedal neuronal limb control. Evolutionary constraints can help inform the historical ancestry for preservation of these core control elements support transfer of the huge body of quadrupedal non-human animal literature to human rehabilitation. In particular, this has translational applications for neurological rehabilitation after neurotrauma where interlimb coordination is lost or compromised. The present state of the field supports including arm activity in addition to leg activity as a component of gait retraining after neurotrauma.

Exploiting Interlimb Arm and Leg Connections for Walking Rehabilitation: A Training Intervention in Stroke

Authors: Klarner T, Barss TS, Sun Y, Kaupp C, Loadman PM, Zehr EP.
Published in: Neural Plast. 2016;2016:1517968.
About: Rhythmic arm and leg (A&L) movements share common elements of neural control. The extent to which A&L cycling training can lead to training adaptations which transfer to improved walking function remains untested. The purpose of this study was to test the efficacy of A&L cycling training as a modality to improve locomotor function after stroke. Nineteen chronic stroke (>six months) participants were recruited and performed 30 minutes of A&L cycling training three times a week for five weeks. Changes in walking function were assessed with (1) clinical tests; (2) strength during isometric contractions; and (3) treadmill walking performance and cutaneous reflex modulation. A multiple baseline (3 pretests) within-subject control design was used. Data show that A&L cycling training improved clinical walking status increased strength by ~25%, improved modulation of muscle activity by ~25%, increased range of motion by ~20%, decreased stride duration, increased frequency, and improved modulation of cutaneous reflexes during treadmill walking. On most variables, the majority of participants showed a significant improvement in walking ability. These results suggest that exploiting arm and leg connections with A&L cycling training, an accessible and cost-effective training modality, could be used to improve walking ability after stroke.

Attitude to health risk in the Canadian population: a cross-sectional survey

Authors: Bansback N, Harrison M, Sadatsafavi M, Stiggelbout A, Whitehurst DG.
Published in: CMAJ Open. 2016 Jun 3;4(2):E284-91.
About: Risk is a ubiquitous part of health care. Understanding how people respond to risks is important for predicting how populations make health decisions. Our objective was to seek preliminary descriptive insights into the attitude to health risk in the Canadian population and factors associated with heterogeneity in risk attitude. We used a large market-research panel to survey (in English and French) a representative sample of the Canadian general population that reflected the age, sex and geography of the population. The survey included the Health-Risk Attitude Scale, which predicts how a person resolves risky health decisions related to treatment, prevention of disease and health-related behaviour. In addition, we assessed participants’ numeracy and risk understanding, as well as income band and level of education. We summarized the responses, and we explored the independent associations between demographics, numeracy, risk understanding and risk attitude in multivariable models. We concluded that in general, Canadians were averse to health risks, but we found that a sizeable, identifiable group of risk takers exists. Heterogeneity in preferences for risk can explain variations in health care utilization in the context of patient-centred care. Understanding risk preference heterogeneity can help guide policy and assist in patient-physician decisions

The relationship between lower limb proprioceptive sense and locomotor skill acquisition

Authors: Qaiser T, Chisholm AE, Lam T.
Published in: Exp Brain Res. 2016 Jul 5.
About: Sensorimotor integration is essential for controlling movement and acquiring new motor tasks in humans. The aim of this project was to understand how lower limb proprioceptive sense contributes to the acquisition of a skilled walking task. We assessed lower limb joint position and movement detection sense in healthy human subjects using the Lokomat robotic exoskeleton. Subjects walked on a treadmill to practice a skilled motor task (200 trials) requiring them to match their foot height during the swing phase to the height of a virtual obstacle displayed on a monitor in front of them. Subjects were given visual feedback on their error relative to the obstacle height after it was crossed. Lower limb joint position sense was related to the final performance error, but not the learning rate of the skilled walking task. The findings from this study support the role of lower limb proprioceptive sense on locomotor skill performance in healthy adult subjects.

Wheeled-mobility correlates of life-space and social participation in adult manual wheelchair users aged 50 and older

Authors: Sakakibara BM, Routhier F, Miller WC.
Published in: Disabil Rehabil Assist Technol. 2016 Jul 4:1-7.
About: The purpose of this study is to characterize the life-space mobility and social participation of manual wheelchair users using objective measures of wheeled mobility. Individuals (n = 49) were included in this cross-sectional study if they were aged 50 or older, community-dwelling and used their wheelchair on a daily basis for the past 6 months. Life-space mobility and social participation were measured using the life-space assessment and late-life disability instrument. The wheeled mobility variables (distance travelled, occupancy time, number of bouts) were captured using a custom-built data logger. The authors conclude that occupancy time and distance travelled are statistically significant predictors of life-space mobility. Lower occupancy time may be an indicative of travel to more distant life-spaces, whereas the distance travelled is likely a better reflection of mobility within each life-space. Occupancy time and number of bouts are significant predictors of participation frequency. Implications for rehabilitation Component measures of wheelchair mobility, such as distance travelled, occupancy time and number of bouts, are important predictors of life-space mobility and social participation in adult manual wheelchair users. Lower occupancy time is an indication of travel to more distant life-spaces, whereas distance travelled is likely a better reflection of mobility within each life-space. That lower occupancy time and greater number of bouts are associated with more frequent participation raises accessibility and safety issues for manual wheelchair users.

Universal disease-specific outcome instruments for spine trauma: a global perspective on relevant parameters to evaluate clinical and functional outcomes of thoracic and lumbar spine trauma patients.

Authors: Sadiqi S, Verlaan JJ, Mechteld Lehr A, Dvorak MF, Kandziora F, Rajasekaran S, Schnake KJ, Vaccaro AR, Oner FC.
Published in: Eur Spine J. 2016 Jul 2.
About: Besides a patient reported outcome measure, the AOSpine Knowledge Forum Trauma aims to develop a new concept of a surgeon reported outcome measure (SROM) for spine trauma patients. This study aims to identify parameters that spine surgeons consider relevant to evaluate clinical and functional outcomes of thoracic and lumbar spine trauma patients. An international cross-sectional web-based survey was conducted among spine surgeons from the five AOSpine International world regions. They were asked to evaluate the relevance of a compilation of 16 clinical and radiological parameters for thoracic and lumbar spine trauma patients, both for the short term (3 months-2 years) and long term (≥2 years), on a five-point scale. The responses were analyzed using descriptive statistics, frequency analysis, and Kruskal-Wallis test. Including a large and representative sample of spine trauma experts, this study identified parameters to evaluate clinical and functional outcomes of thoracic and lumbar spine trauma patients. The results form the basis for the development of a SROM for this specific patient population.

Does the method of botulinum neurotoxin injection for limb spasticity affect outcomes? A systematic review.

Authors: Chan AK, Finlayson H, Mills PB.
Published in: Clin Rehabil. 2016 Jul 1.
About: The objective of this study was to systematically review randomized controlled trials of botulinum neurotoxin for limb spasticity to determine whether different injection techniques affect spasticity outcomes. MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials electronic databases were searched for English language human randomized controlled trials from 1990 to 13 May 2016. Studies were assessed in duplicate for data extraction and risk of bias using the Physiotherapy Evidence Database scale and graded according to Sackett’s levels of evidence. Nine of 347 studies screened met selection criteria. Four categories of botulinum neurotoxin injection techniques were identified: (1) injection localization technique; (2) injection site selection; (3) injectate volume; (4) injection volume and site selection. There is level 1 evidence that: ultrasound, electromyography, and electrostimulation are superior to manual needle placement; endplate injections improve outcomes vs. multisite quadrant injections; motor point injections are equivalent to multisite injections; high volume injections are similar to low volume injections; and high volume injections distant from the endplate are more efficacious than low volumes closer to the endplate. The authors conclude that level 1 evidence exists for differences in treatment outcomes using specific botulinum neurotoxin injection techniques. Findings are based on single studies that require independent replication and further study.

Predicting peak oxygen uptake from submaximal exercise after spinal cord injury.

Authors: Totosy de Zepetnek JO, Au JS, Hol AT, Eng JJ, MacDonald MJ.
Published in: Appl Physiol Nutr Metab. 2016 Jul;41(7):775-81.
About: The purpose of this study was to determine the validity of the 6-min arm ergometry test (6MAT) in predicting peak oxygen consumption (V̇O2peak) in individuals with chronic spinal cord injury (SCI). Fifty-two individuals with chronic SCI (age, 38 ± 10 years; American Spinal Injury Association Impairment Scale (AIS), A-D; neurological level of injury (NLI), C1-L2; years post-injury (YPI), 13 ± 10 years) completed an incremental arm ergometry V̇O2peak test and a submaximal 6MAT. Oxygen consumption (V̇O2) data from both tests were used to create a predictive equation with regression analysis. Subsequently, a cross-validation group comprising an additional 10 individuals with SCI (age, 39 ± 13 years; AIS, A-D; NLI, C3-L3; YPI, 9 ± 9 years) were used to determine the predictive power of the equation. All participants were able to complete both the V̇O2peak and 6MAT assessments. Regression analysis yielded the following equation to predict V̇O2peak from end-stage 6MAT V̇O2: V̇O2peak (mL·kg(-1)·min(-1)) = 1.501(6MAT V̇O2) – 0.940. Correlation between measured and predicted V̇O2peak was excellent (r = 0.89). No significant difference was found between measured (17.41 ± 7.44 mL·kg(-1)·min(-1)) and predicted (17.42 ± 6.61 mL·kg(-1)·min(-1)) V̇O2peak (p = 0.97). When cross-validated with a sample of 10 individuals with SCI, correlation between measured and predicted V̇O2peak remained high (r = 0.89), with no differences between measured (18.81 ± 8.35 mL·kg(-1)·min(-1)) and predicted (18.73 ± 7.27 mL·kg(-1)·min(-1)) V̇O2peak (p = 0.75). Results suggest that 6MAT V̇O2 can be used to predict V̇O2peak among individuals with chronic SCI. The 6MAT should be used as a clinical tool for assessing aerobic capacity when peak exercise testing is not feasible.

Accelerating skin wound healing by M-CSF through generating SSEA-1 and -3 stem cells in the injured sites.

Authors: Li Y, Jalili RB, Ghahary A.
Published inSci Rep. 2016 Jul 1;6:28979.
About: Wound healing is a complicated process requiring the collaborative efforts of different cell lineages. Our recent studies have found that one subset of hematopoietic cells can be induced to dedifferentiate into multipotent stem cells by means of a proliferating fibroblast releasable factor, M-CSF. Understanding the importance of stem cells on skin wound healing, here we evaluate the biological significance of M-CSF on skin wound healing. In an in vivo mouse skin excisional wound model, we found that SSEA-positive stem cells were present in wounded but not normal skin. After isolating skin cells from either normal or wounded skin by collagenase digestion, and analyzing the SSEA-1 positive cells by flow cytometry, we found a significant increase in the number of SSEA-1 positive cells in wounded skin. Topical application of M-CSF in skin wounds accelerated healing remarkably, while application of M-CSF-neutralizing antibody slowed wound healing. Furthermore, injection of EGFP-labeled hematopoietic cell-derived stem cells generated from M-CSF treated splenocytes resulted in EGFP-labeled cells being enriched in the skin wound site and further differentiated into functional organ-specific cells. Together, these data demonstrated that M-CSF makes a significant contribution to the healing process by inducing hematopoietic cell dedifferentiation into stem cells.

The course of fatigue after acute spinal cord injury.

Authors: Anton HA, Miller WC, Townson AF, Imam B, Silverberg N, Forwell S.
Published inSpinal Cord. 2016 Jun 28.
About: The objective of this study was to determine the prevalence and course of fatigue following acute spinal cord injury (SCI) during rehabilitation and after discharge. Fifty-two patients with traumatic SCI were assessed after admission to rehabilitation and followed until 6-months post discharge into the community. Fatigue was measured using the Fatigue Severity Scale (FSS) and the Modified Fatigue Impact Scale for Spinal Cord Injury (MFIS-SCI) at admission, discharge and 6 months after discharge. The researchers concluded that fatigue is common in SCI patients admitted to rehabilitation. Fatigue remained stable during rehabilitation and after discharge into the community. Clinicians should consider early screening for fatigue and interventions to reduce the consequences of fatigue in people with SCI.

Cerebrospinal Fluid Biomarkers to Stratify Injury Severity and Predict Outcome in Human Traumatic Spinal Cord Injury.

Authors: Kwon BK, Streijger F, Fallah N, Noonan V, Belanger LM, Ritchie L, Paquette SJ, Ailon T, Boyd MC, Street J, Fisher CG, Dvorak MF.
Published in: J Neurotrauma. 2016 Jun 27.
About: Neurologic impairment after spinal cord injury (SCI) is currently measured and classified by functional examination. Biological markers that objectively classify injury severity and predict outcome would greatly facilitate efforts to evaluate acute SCI therapies. The purpose of this study was to determine how well inflammatory and structural proteins within the CSF of acute traumatic SCI patients predicted American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade conversion and motor score improvement over 6 months. Fifty acute SCI patients (29 AIS A, 9 AIS B, 12 AIS C; 32 cervical, 18 thoracic) were enrolled and CSF obtained through lumbar intrathecal catheters to analyze IL-6, IL-8, MCP-1, Tau, S100β, and GFAP at 24 hours post-injury. The levels of IL-6, tau, S100β, and GFAP were significantly different between patients with baseline AIS grades of A, B, or C. The levels of all proteins (IL-6, IL-8, MCP-1, tau, S100β, and GFAP) were significantly different between those who improved an AIS grade over 6 months and those who did not improve. Linear discrimant analysis modeling was 83% accurate in predicting AIS conversion. For AIS A patients, the concentrations of proteins such as IL-6 and S100β correlated with conversion to AIS B or C. Motor score improvement was also strongly correlated with the 24-hour post-injury CSF levels of all 6 biomarkers. The analysis of CSF can provide valuable biological information about injury severity and recovery potential after acute SCI. Such biological markers may be valuable tools for stratifying individuals in acute clinical trials where variability in spontaneous recovery requires large recruitment cohorts for sufficient power.

Keratinocyte-Releasable Factors Stimulate the Expression of Granulocyte Colony-Stimulating Factor in Human Dermal Fibroblasts

Authors: Carr MJ, Li Y, Rezakhanlou AM, Ghahary A.
Published in: J Cell Biochem. 2016 Jun 24.
About: Interaction between keratinocytes and fibroblasts plays a critical role in maintaining skin integrity under both normal and pathological conditions. We have previously demonstrated that keratinocyte-releasable factors influence the expression of key extracellular matrix components, such as collagen and matrix metalloproteinases in dermal fibroblasts. In this study, we utilized DNA microarray analysis to examine the effects of keratinocyte-releasable factors on the expression of several cytokines in human dermal fibroblasts. The results revealed significantly higher granulocyte colony-stimulating factor (G-CSF) expression in fibroblasts co-cultured with keratinocytes relative to mono-cultured cells, which was verified by RT-PCR and western blot. G-CSF is an important hematopoietic factor also thought to play a beneficial role in wound healing through stimulating keratinocyte proliferation. To partially characterize the keratinocyte-releasable factors responsible for stimulating G-CSF production, keratinocyte-conditioned medium (KCM) was subjected to thermal treatment and ammonium sulfate precipitation before treating fibroblasts. The results showed that keratinocyte-releasable G-CSF-stimulating factors remain stable at 56°C and upon 50% ammonium sulfate precipitation. Knowing that keratinocytes release IL-1, which stimulates G-CSF expression in various immune cells, several experiments were conducted to ask whether this might also be the case for fibroblasts. The results showed that the addition of recombinant IL-1 markedly increased G-CSF expression in fibroblasts; however, IL-1 receptor antagonist only partially abrogated KCM-stimulated G-CSF expression, indicating the role of additional keratinocyte-releasable factors. These findings underline the importance of cross-talk between keratinocytes and fibroblasts, suggesting that communication between these cells in vivo modulates the production of cytokines required for cutaneous wound healing and maintenance.

Case Series of a Knowledge Translation Intervention to Increase Upper Limb Exercise in Stroke Rehabilitation

Authors: Connell LA, McMahon NE, Tyson SF, Watkins CL, Eng JJ.
Published inPhys Ther. 2016 Jun 23
About: Current approaches to upper limb rehabilitation are not sufficient to drive neural reorganisation and maximise recovery after stroke. To address this evidence-practice gap we developed a knowledge translation intervention using the Behaviour Change Wheel. The intervention involves collaborative working with stroke therapy teams to change their practice, and increase therapy intensity by therapists prescribing supplementary self-directed arm exercise. The purposes of this case series are: (1) to provide an illustrative example of how a research-informed process changed clinical practice and (2) to report on staff and patients’ perceptions of the utility of the developed intervention. A participatory action research approach was used in three stroke rehabilitation units in the United Kingdom. The intervention aimed to change four therapist level behaviours: (i) screening patients for suitability for supplementary self-directed arm exercise, (ii) provision of exercises, (iii) involving family/carers in assisting with exercises and (iv) monitoring and progressing exercises. Data on changes in practice were collected by therapy teams using a bespoke audit tool. Utility of the intervention was explored in qualitative interviews with patients and staff. Components of the intervention were successfully embedded in two of the three stroke units. At these sites almost all admitted patients were screened for suitability for supplementary self-directed exercise. 77%, 70% and 88% of suitable patients across the three sites were provided exercises. Involving family/carers, and monitoring and progressing exercises, were not performed consistently. This study is an example of how a rigorous research-informed knowledge translation process resulted in practice change. Further research is needed to demonstrate that these changes can translate into increased intensity of upper limb exercise and affect patient outcomes.

Inter-Rater Reliability of the International Standards to Document Remaining Autonomic Function after Spinal Cord Injury.

Authors: Davidson RA, Carlson M, Fallah N, Noonan VK, Elliott SL, Joseph J, Smith KM, Krassioukov AV.
Published in: J Neurotrauma. 2016 Jul 8
About: The autonomic nervous system can be profoundly affected after spinal cord injury (SCI). Despite its importance to quality of life, autonomic function is rarely systematically assessed in the clinical setting. The International Standards to Document Remaining Autonomic Function after Spinal Cord Injury (ISAFSCI) is an assessment designed to determine which autonomic functions are intact, impaired, or lost after SCI. The psychometric properties of the ISAFSCI have not yet been reported. The objective of this study was to describe the inter-rater reliability of the ISAFSCI. Participants with chronic traumatic SCI (greater than 1 year) able to remain on the same medications for the study period and communicate clearly with the assessor were recruited for the study. A standard protocol minimized variation between the sites. During the first assessment, neurologic examination (ISNCSCI) was performed and ISAFSCI completed. After 10-14 days, the ISAFSCI was repeated. Inter-rater reliability was calculated using percentage agreement, kappa, and weighted kappa statistics. Participants (n = 48) had an average age of 45 ± 12 years. Forty-one (85.4%) were male, 38 (79.2%) had a SCI at or above the T6 level, 24 (50.0%) had a complete SCI. Inter-rater reliability within the general autonomic component was moderate with kappa values ranging 0.41-0.6 (p < 0.05). Within the Lower Urinary Tract, Bowel, and Sexual Function component, agreement was good-strong with weighted kappa values 0.62-0.88 (p < 0.05). Given the results, we conclude that the ISAFSCI can be considered to have at least moderate and up to strong inter-rater reliability, especially in the bladder, bowel, and sexual function component of the assessment.

Powered robotic exoskeletons in post-stroke rehabilitation of gait: a scoping review.

Authors: Louie DR, Eng JJ.
Published in: J Neuroeng Rehabil. 2016 Jun 8;13(1):53.
About: Powered robotic exoskeletons are a potential intervention for gait rehabilitation in stroke to enable repetitive walking practice to maximize neural recovery. As this is a relatively new technology for stroke, a scoping review can help guide current research and propose recommendations for advancing the research development. The aim of this scoping review was to map the current literature surrounding the use of robotic exoskeletons for gait rehabilitation in adults post-stroke. Five databases (Pubmed, OVID MEDLINE, CINAHL, Embase, Cochrane Central Register of Clinical Trials) were searched for articles from inception to October 2015. Reference lists of included articles were reviewed to identify additional studies. Articles were included if they utilized a robotic exoskeleton as a gait training intervention for adult stroke survivors and reported walking outcome measures. Of 441 records identified, 11 studies, all published within the last five years, involving 216 participants met the inclusion criteria. The study designs ranged from pre-post clinical studies (n = 7) to controlled trials (n = 4); five of the studies utilized a robotic exoskeleton device unilaterally, while six used a bilateral design. Participants ranged from sub-acute (<7 weeks) to chronic (>6 months) stroke. Training periods ranged from single-session to 8-week interventions. Main walking outcome measures were gait speed, Timed Up and Go, 6-min Walk Test, and the Functional Ambulation Category. Meaningful improvement with exoskeleton-based gait training was more apparent in sub-acute stroke compared to chronic stroke. Two of the four controlled trials showed no greater improvement in any walking outcomes compared to a control group in chronic stroke. In conclusion, clinical trials demonstrate that powered robotic exoskeletons can be used safely as a gait training intervention for stroke. Preliminary findings suggest that exoskeletal gait training is equivalent to traditional therapy for chronic stroke patients, while sub-acute patients may experience added benefit from exoskeletal gait training. Efforts should be invested in designing rigorous, appropriately powered controlled trials before powered exoskeletons can be translated into a clinical tool for gait rehabilitation post-stroke.

Polyvinyl alcohol-graft-polyethylene glycol hydrogels improve utility and biofunctionality of injectable collagen biomaterials..

Authors: Hartwell R, Chan B, Elliott K, Alnojeidi H, Ghahary A.
Published in: Biomed Mater. 2016 Jun 8;11(3):035013.
About: Collagen-based materials have become a staple in both research and the clinic. In wound care, collagen-based materials comprise a core gamut of biological dressings and therapeutic strategies. In research, collagen-based materials are employed in everything from 3D cultures to bioprinting. Soluble collagen is well characterized to undergo fibrillation at neutral pH and 37 °C. To remain stable, a neutralized collagen solution must be maintained at 4 °C. These physical characteristics of collagen impose limitations on its utility. In our previous work, we identified that the incorporation of a simple polyvinyl alcohol:borate hydrogel could improve the rate of collagen gel fibrillation. In this work we sought to further investigate the interactions of polyvinyl alcohol blend variants, as surfactant-like polymers, in comparison with known non-polymer surfactants. To conduct our investigations scaffold variants were created using increasing concentrations of polyvinyl alcohol, differing combinations of polymers, and non-polymer surfactants Tweens 20 and 80, and TritonX-100. Activation energy for collagen fibrillation was found to significantly decrease in the presence of polyvinyl alcohols (p  <  0.01) at and above 0.4%w/v concentration. Further, addition of polyvinyl alcohol-graft-polyethylene glycol had the greatest enhancement (2.02 fold) on the fibrillation kinetics (p  <  0.01), wetting properties and the stability of the collagen scaffolds post-freeze drying. Our results demonstrated that the addition of polyvinyl alcohol hydrogels to a collagen solution could stabilize collagen solution such that the solution could easily be lyophilized (at pH 7) and then reconstituted with water. Cells cultured in polyvinyl alcohol scaffolds also exhibited more organized F-actin, as well as a reduced abundance of pro-collagen and α-smooth actin. In conclusion, our results demonstrate for the first time that polyvinyl alcohol, preferably polyvinyl alcohol-graft-polyethylene glycol, directly affects the physical properties of collagen and the physiology of cells cultured within improving the utility of the combined material for both research and clinic needs.

An integrative review of standardized clinical evaluation tool utilization in anticholinergic drug trials for neurogenic lower urinary tract dysfunction.

Authors: Stothers L, Tsang B, Nigro M, Lazare D, Macnab A.
Published in: Spinal Cord. 2016 May 31.
About: The objective of this study was to review prospective and randomized trials studying anticholinergic therapy for neurogenic bladder in SCI to identify whether trials included standardized clinical evaluation tools and reporting measures now recognized to enhance clinical trial data. A systematic search via EMBASE, MEDLINE, CENTRAL, CINAHL (Cumulative Index to Nursing and Allied Health Literature), HTA (Health Technology Assessment), CMR (Comprehensive Microbial Resource), HAPI (Health and Psychosocial Instruments) and PsycINFO using the key term spinal cord injury crossed with oxybutynin, tolterodine, darifenacin, solifenacin, fesoterodine, trospium chloride, propiverine, propantheline and anticholinergic(s) for 1946-2015 inclusive. We then collated whether standardized clinical tools, measures and descriptors were used within each study identified: American Spine Injury Association (ASIA) impairment scale; symptom scores validated in SCI; technical methodology for urodynamics/video urodynamics; urinary diaries; and standardized urologic terminology. A total of 1225 entries with 610 unique articles were identified, 14 randomized and 16 prospective studies. In 6/30 the population comprised SCI patients with neurogenic bladder alone; the remainder included mixed neurogenic etiologies. Classification using the ASIA impairment scale was used in <10% of studies; none used symptom scores validated in SCI; <50% reported urodynamic test methodology fully, incorporated urinary diaries or used International Continence Society Standardization Subcommittee urinary tract terminology. Integrative review of trials from 1946 to 2015 identified infrequent use of standardized clinical evaluation tools and reporting measures. Data from future trials evaluating therapies for neurogenic bladder would likely be more applicable to specific SCI patients if current standardized classification and descriptors now available were used consistently: for example, the ASIA scale, symptom scores validated in SCI, standardized urodynamic methodology, urinary diaries and urinary tract terminology. Studies recruiting SCI patients exclusively would also provide additional benefit.Spinal Cord advance online publication, 31 May 2016; doi:10.1038/sc.2016.63.

Association Between Paraspinal Muscle Morphology, Clinical Symptoms and Functional Status in Patients With Degenerative Cervical Myelopathy.

Authors: Fortin M, Dobrescu O, Courtemanche M, Sparrey CJ, Santaguida C, Fehlings MG, Weber MH.
Published in: Spine (Phila Pa 1976). 2016 May 23.
About: The objective of this cross-sectional study was to assess fatty infiltration and asymmetry of the multifidus (MF), semispinalis cervicis (SCer), semispinalis capitis (SCap) and splenius capitis (SPL) muscles in patients with degenerative cervical myelopathy (DCM), and evaluate their correlations with clinical symptoms and functional scores. Cervical muscle alterations have been reported in patients with chronic neck pain, but the assessment of cervical muscle morphology has been overlooked in patients with DCM. Thirty-eight patients diagnosed with DCM and spinal cord compression at C4-C5 or C5-C6 (first level of compression) were included. Cervical muscle measurements of cross-sectional area (CSA) and ratio of functional CSA (fat free area, FCSA) to total CSA were obtained from T2-weighted axial images at the level above, same, and level below the most cranial level of spinal cord compression. Muscle fatty infiltration and asymmetry was assessed at every level and their associations with respect to clinical signs and symptoms and functional scores were investigated. There was a significant increase in fatty infiltration (decrease in FCSA/CSA ratio) of the MF (p = 0.001) and SPL (p < 0.001) muscles at the level below the spinal cord compression. A significant increase in MF CSA asymmetry was also observed at the level below the compression. Lower MF FCSA/CSA ratio was associated longer 30-meters walking test time. Lower SCer FCSA/CSA was associated with corticospinal distribution motor deficits and atrophy of the hands. Greater asymmetry in SCap CSA was associated with higher Neck Disability Index (NDI) scores while lower asymmetry in MF CSA was associated with a positive Hoffman sign and weakness. A significant increase in muscle fatty infiltration and CSA asymmetry at the level below the compression was observed in patients with DCM. Our results also suggest an association between cervical muscle morphology and DCM clinical symptoms and functional status.

Broadening the Conceptualization of ‘Participation’ of Persons with Physical Disabilities: A Configurative Review and Recommendations.

Authors: Martin Ginis KA, Evans MB, Mortenson WB, Noreau LM.
Published in: Arch Phys Med Rehabil. 2016 May 20.
About: Within the context of physical disability, participation has typically been conceptualized in terms of one’s performance of different roles and activities. This perspective, however, ignores the meanings and satisfactions that a person derives from participating. Without an accepted conceptualization of participation that accounts for people’s subjective perceptions and experiences, it is challenging for decision-makers and service-providers to design meaningful participation-enhancing services, programs, and policies. Accordingly, our objectives were to: (a) conduct a review of definitions and conceptualizations of participation that extend beyond performance and capture people’s subjective experiences of participating, and (b) identify key experiential aspects of participation that can be used as a basis for conceptualizing and operationalizing the concept more broadly. The project involved a systematic, configurative review of relevant literature. Ten relevant articles were identified. Information on characteristics associated with experiential aspects of participation was extracted and subjected to a thematic analysis. Six themes emerged: Autonomy, Belongingness, Challenge, Engagement, Mastery, and Meaning. Drawing on these findings, it is recommended that the individual’s subjective perceptions of autonomy, belongingness, challenge, engagement, mastery and meaning associated with participating be incorporated into conceptualizations and operationalizations of the participation construct. This recommendation provides a starting point for clinicians, researchers and policy makers to conceptualize and measure the participation concept more consistently and more broadly.

The influence of the modulus-density relationship and the material mapping method on the simulated mechanical response of the proximal femur in side-ways fall loading configuration.

Authors: Pakyari M, Farokhi A, Khosravi M, Kilani RT, Ghahary A, Brown E.
Published in: Wound Repair Regen. 2016 May 19.
About: Skin transplantation provides an excellent potential model to investigate the immunology of allograft rejection and tolerance induction. Despite the theoretical ease of performing skin transplantation, as well as the potential of directly observing the reaction to the transplanted tissue, the poor reliability of skin transplantation in the mouse has largely precluded the use of this model. Furthermore, there is controversy regarding the most appropriate skin graft donor site due to poor success of back skin transplantation, as compared to the thinner ear or tail skin. The current study demonstrates a reliable method to successfully perform skin grafts in a mouse model, as well as the clinical and histologic outcome of syngeneic grafts. A total of 287 grafts were performed (in 126 mice) utilizing donor skin from the ear, tail or back. No graft failure or postoperative mortality was observed. Comparison of the current technique with two previously established protocols of skin transplantation (5.0 absorbable Suture + tissue glue technique and no-suture technique) demonstrates the significant improvement in the engraftment success of the new technique. In summary, a new technique for murine skin grafting demonstrates improved reliability across donor site locations and strains, increasing the potential for investigating interventions to alter the rejection process.

The influence of the modulus-density relationship and the material mapping method on the simulated mechanical response of the proximal femur in side-ways fall loading configuration.

Authors: Helgason B, Gilchrist S, Ariza O, Vogt P, Enns-Bray W, Widmer RP, Fitze T, Pálsson H, Pauchard Y, Guy P, Ferguson SJ, Cripton PA.
Published in: Med Eng Phys. 2016 Jul;38(7):679-89.
About: Contributing to slow advance of finite element (FE) simulations for hip fracture risk prediction, into clinical practice, could be a lack of consensus in the biomechanics community on how to map properties to the models. Thus, the aim of the present study was first, to systematically quantify the influence of the modulus-density relationship (E-ρ) and the material mapping method (MMM) on the predicted mechanical response of the proximal femur in a side-ways fall (SWF) loading configuration and second, to perform a model-to-model comparison of the predicted mechanical response within the femoral neck for all the specimens tested in the present study, using three different modelling techniques that have yielded good validation outcome in terms of surface strain prediction and whole bone response according to the literature. We found the outcome to be highly dependent on both the E-ρ relationship and the MMM. In addition, we found that the three modelling techniques that have resulted in good validation outcome in the literature yielded different principal strain prediction both on the surface as well as internally in the femoral neck region of the specimens modelled in the present study. We conclude that there exists a need to carry out a more comprehensive validation study for the SWF loading mode to identify which combination of MMMs and E-ρ relationship leads to the best match for whole bone and local mechanical response. The MMMs tested in the present study have been made publicly available at

Effect of a tailored assistive technology intervention on older adults and their family caregiver: a pragmatic study protocol

Authors: Demers L, Mortenson WB, Fuhrer MJ, Jutai JW, Plante M, Mah J, DeRuyter F.
Published in: BMC Geriatr. 2016 May 13;16:103.
About: Many older adults with mobility limitations use assistive technology to help them perform daily activities. However, little attention has been paid to the impact on their family caregivers. This neglect produces an incomplete portrayal of the outcomes of assistive technology provision. This paper describes the protocol for a study that examines the impact of a tailored assistive technology intervention that is inclusive of assistance users and their family caregivers. This research will use a combination of quantitative and qualitative methods. The quantitative portion will be an experimental, single-blinded study in which participants are randomly assigned to either an experimental assistive technology intervention or a standard care group. We will enroll 240 participants (120 dyads) into the study from three Canadian sites. Participants will include older adults (>55) and family caregivers who provide ≥4 h per week of assistance with daily activities and social participation. The primary outcome measure for the older adults will be the Functional Autonomy Measurement System, and the primary outcome measure for the caregivers will be the Caregiver Assistive Technology Outcomes Measure. Qualitative data will be collected through detailed records of the therapists’ interventions, as well as through interviews with dyads and therapists following the interventions. Data collection will occur at baseline (T0) with follow-ups at 6 weeks (T1), 22 weeks (T2), and 58 weeks (T3) after baseline evaluation. The findings from this study will help service providers and clinicians to move forward with assistive technology recommendations that are more attuned to the needs of both older adults with mobility limitations and their family caregivers. Additionally, the study’s findings will enhance our conceptual understanding of the spectrum of assistive technology outcomes and set the stage for econometric studies assessing cost-effectiveness.

Development of a Nano-fibrous Wound Dressing with an Anti-fibrogenic Properties In Vitro and In Vivo model

Authors: Wellington CL, Frikke-Schmidt R.
Published inCurr Opin Lipidol. 2016 Jun;27(3):225-32.
About: This article evaluates recent experimental and human evidence regarding the involvement of lipids, lipoproteins, and apolipoproteins in neurodegenerative diseases, and reviews the current literature of the effects of cholesterol-lowering treatment on cognition. Plasma levels of traditional lipids and lipoproteins are not consistently associated with risk of dementia even though low plasma levels of apolipoprotein E, through unknown mechanisms, robustly predict future dementia. Experimental evidence suggests neuroprotective roles of several brain and cerebrospinal fluid apolipoproteins. Whether plasma levels of apolipoprotein E, or any other apolipoprotein with possible central nervous system and/or blood-brain barrier functions (apolipoproteins J, A-I, A-II, A-IV, D, C-I, and C-III) may become accessible biomarker components that improve risk prediction for dementia together with genetic risk variants and cardiovascular risk factors remains to be determined. Apolipoproteins with well established functions in peripheral lipid metabolism may play important roles for brain vascular health and Alzheimer’s disease pathophysiology. Experimental work on lipids, lipoproteins, and apolipoproteins in the central nervous system together with robust prospective human studies will help to substantiate the drug target potential of these lipid components.

Development of a Nano-fibrous Wound Dressing with an Anti-fibrogenic Properties In Vitro and In Vivo model

Authors: Poormasjedi-Meibod MS, Pakyari M, Jackson JK, Salimi Elizei S, Ghahary A.
Published in: J Biomed Mater Res A. 2016 May 3.
About: Dermal fibrosis, characterized by excessive extracellular matrix (ECM), is a pathological condition with limited effective therapeutic modalities. Lack of an anti-scarring dressing further impedes the preventive measures for this condition. Here we developed a novel anti-scarring dressing and investigated its potential as a slow-releasing vehicle for kynureninc acid (KynA), an anti-fibrotic agent. KynA was incorporated into polymethyl methacrylate (PMMA) nanofibers, containing increasing concentration of polyethylene glycol (PEG). Fibre morphology, water absorption capacity, surface hydrophilicity, in vitro drug release profile and in vivo anti-fibrotic effects were investigated. Increasing concentrations of PEG (1-20%) significantly increased surface hydrophilicity, water absorption capacity and drug release. Based on the obtained release profiles, PMMA+10%PEG was the preferred formulation for sustained KynA release up to 120 hours. In vitro studies confirmed the preservation of KynA anti-fibrotic properties during electrospinning, indicated by fibroblasts proliferation suppression and ECM expression modulation. In vivo application of KynA-incorporated films significantly inhibited collagen (23.89±4.79 vs. 6.99±0.41, Col-I/β-actin mRNA expression, control vs. treated) and fibronectin expression (7.18±1.09 vs. 2.31±0.05, Fibronectin/β-actin mRNA expression, control vs. treated) and enhanced the production of an ECM degrading enzyme (2.03±0.88 vs. 11.88±1.16 MMP-1/β-actin mRNA expression, control vs. treated). The fabricated KynA-incorporated films can be exploited as anti-fibrotic wound dressings.

Functionalizing Ascl1 with Novel Intracellular Protein Delivery Technology for Promoting Neuronal Differentiation of Human Induced Pluripotent Stem Cells

Authors: Robinson M, Chapani P, Styan T, Vaidyanathan R, Willerth SM.
Published in: Stem Cell Rev. 2016 May 2.
About: Pluripotent stem cells can become any cell type found in the body. Accordingly, one of the major challenges when working with pluripotent stem cells is producing a highly homogenous population of differentiated cells, which can then be used for downstream applications such as cell therapies or drug screening. The transcription factor Ascl1 plays a key role in neural development and previous work has shown that Ascl1 overexpression using viral vectors can reprogram fibroblasts directly into neurons. Here we report on how a recombinant version of the Ascl1 protein functionalized with intracellular protein delivery technology (Ascl1-IPTD) can be used to rapidly differentiate human induced pluripotent stem cells (hiPSCs) into neurons. We first evaluated a range of Ascl1-IPTD concentrations to determine the most effective amount for generating neurons from hiPSCs cultured in serum free media. Next, we looked at the frequency of Ascl1-IPTD supplementation in the media on differentiation and found that one time supplementation is sufficient enough to trigger the neural differentiation process. Ascl1-IPTD was efficiently taken up by the hiPSCs and enabled rapid differentiation into TUJ1-positive and NeuN-positive populations with neuronal morphology after 8 days. After 12 days of culture, hiPSC-derived neurons produced by Ascl1-IPTD treatment exhibited greater neurite length and higher numbers of branch points compared to neurons derived using a standard neural progenitor differentiation protocol. This work validates Ascl1-IPTD as a powerful tool for engineering neural tissue from pluripotent stem cells.

Social Media Representation of Chronic Cerebrospinal Venous Insufficiency Intervention for Multiple Sclerosis..

Authors: Ghahari S, Forwell SJ.
Published in: Int J MS Care. 2016 Mar-Apr;18(2):49-57.
About: We conducted a rigorous review of videos related to multiple sclerosis (MS) and chronic cerebrospinal venous insufficiency (CCSVI) treatment posted by people with MS on one social media website (YouTube) that describe symptoms before and after the surgical procedure, as well as videos presented by health-care professionals (HCPs). All relevant videos posted from December 2009 to July 2011 were downloaded, viewed, and systematically organized. Categorical data were classified, and dominant messages were gleaned. A total of 1789 videos were extracted. A total of 621 videos by people with MS and 238 by HCPs were included. Eighty-six percent of people with MS anecdotally reported experiencing some improvement in at least one symptom. The most common message was that “CCSVI is not a miracle but worth trying.” Most HCPs posting videos recommended the procedure but called for continued research. We conclude that social media are conveying an anecdotal favorable message about CCSVI treatment for MS. The relative absence of videos offering a negative or more balanced perspective is a concern. Social persuasion through these videos creates a strong positive impression of CCSVI treatment, but the videos do not acknowledge the lack of supporting scientific evidence and the possible role of the placebo effect. Given the strong influence of social media on health-care decision making, researchers and clinicians should actively use social media to reach out to people with MS and describe the state of the evidence for MS treatments, both positive and negative.

A comparison of the Wiltse versus midline approaches in degenerative conditions of the lumbar spine.

Authors: Street JT, Andrew Glennie R, Dea N, DiPaola C, Wang Z, Boyd M, Paquette SJ, Kwon BK, Dvorak MF, Fisher CG.
Published in: J Neurosurg Spine. 2016 Apr 22:1-7.
About: The objective of this study was to determine if there is a significant difference in surgical site infection (SSI) when comparing the Wiltse and midline approaches for posterior instrumented interbody fusions of the lumbar spine and, secondarily, to evaluate if the reoperation rates and specific causes for reoperation were similar for both approaches. A total of 358 patients who underwent 1- or 2-level posterior instrumented interbody fusions for degenerative lumbar spinal pathology through either a midline or Wiltse approach were prospectively followed between March 2005 and January 2011 at a single tertiary care facility. A retrospective analysis was performed primarily to evaluate the incidence of SSI and the incidence and causes for reoperation. Secondary outcome measures included intraoperative complications, blood loss, and length of stay. A matched analysis was performed using the Fisher’s exact test and a logistic regression model. The matched analysis controlled for age, sex, comorbidities, number of index levels addressed surgically, number of levels fused, and the use of bone grafting. All patients returned for follow-up at 1 year, and adverse events were followed for 2 years. The rate of SSI was greater in the midline group (8 of 103 patients; 7.8%) versus the Wiltse group (1 of 103 patients; 1.0%) (p = 0.018). Fewer additional surgical procedures were performed in the Wiltse group (p = 0.025; OR 0.47; 95% CI 0.23-0.95). Proximal adjacent segment failure requiring reoperation occurred more frequently in the midline group (15 of 103 patients; 14.6%) versus the Wiltse group (6 of 103 patients; 5.8%) (p = 0.048). Blood loss was significantly lower in the Wiltse group (436 ml) versus the midline group (703 ml); however, there was no significant difference between the 2 groups in intraoperative complications or length of stay. The patients who underwent the Wiltse approach had a decreased risk of wound breakdown and infection, less blood loss, and fewer reoperations than the midline patients. The risk of adjacent segment failure in short posterior constructs is lower with a Wiltse approach.

Health state descriptions, valuations and individuals’ capacity to walk: a comparative evaluation of preference-based instruments in the context of spinal cord injury.

Authors: Whitehurst DG, Mittmann N, Noonan VK, Dvorak MF, Bryan S.
Published in: Qual Life Res. 2016 Apr 20.
About: This study explores variation in health state descriptions and valuations derived from preference-based health-related quality of life instruments in the context of spinal cord injury (SCI). Individuals living with SCI were invited to complete a web-based, cross-sectional survey. The survey comprised questions regarding demographics, SCI classifications and characteristics, secondary health complications and conditions, quality of life and SCI-specific functioning in activities of daily living. Four preference-based health status classification systems were included; Assessment of Quality of Life 8-dimension questionnaire (AQoL-8D), EQ-5D-5L, Health Utilities Index (HUI) and SF-6D (derived from the SF-36v2). In addition to descriptive comparisons of index scores and item/dimension responses, analyses explored dimension-level correlation and absolute agreement (intraclass correlation coefficient (ICC)). Subgroup analyses examined the influence of individuals’ self-reported ability to walk. Of 609 invitations, 364 (60 %) individuals completed the survey. Across instruments, convergent validity was seen between pain and mental health dimensions, while sizeable variation pertaining to issues of mobility was observed. Mean index scores were 0.248 (HUI-3), 0.492 (EQ-5D-5L), 0.573 (AQoL-8D) and 0.605 (SF-6D). Agreement ranged from ‘slight’ (HUI-3 and SF-6D; ICC = 0.124) to ‘moderate’ (AQoL-8D and SF-6D; ICC = 0.634). Walking status had a markedly different impact on health state valuations across instruments. Variation in the way that individuals are able to describe their health state across instruments is not unique to SCI. Further research is necessary to understand the significant differences in index scores and, in particular, the implications of framing mobility-related questions in the context of respondents’ ability to walk.

Regionally distinct cutaneous afferent populations contribute to reflex modulation evoked by stimulation of the tibial nerve during walking.

Authors: Nakajima T, Suzuki S, Futatsubashi G, Ohtsuska H, Mezzarane RA, Barss TS, Klarner T, Zehr EP, Komiyama T.
Published in: J Neurophysiol. 2016 Apr 13:jn.01011.2015.
About: During walking, cutaneous reflexes in ankle flexor muscle (tibialis anterior: TA) evoked by tibial nerve (TIB) stimulation are predominantly facilitatory at early swing phase, but reverse to suppression at late swing phase. Although the TIB innervates a large portion of the skin of foot sole, the extent to which specific foot sole regions contribute to the reflex reversals during walking remains unclear. Therefore, we investigated regional cutaneous contributions from discrete portions of the foot sole on reflex reversal in TA following TIB stimulation during walking. Summation effects on reflex amplitudes when applying combined stimulation from foot sole regions with TIB were examined. Middle latency responses (MLRs: 70-120 ms) after TIB stimulation were strongly facilitated during the late stance to mid-swing phases and reversed to suppression just before heel strike. Both forefoot medial (f-M) and forefoot lateral (f-L) stimulation in foot sole induced facilitation during stance to swing transition phases, but heel (HL) stimulation evoked suppression during the late stance to the end of swing phases. At the stance to swing transition, a summation of MLR amplitude occurred only for combined f-M&TIB stimulation. However, the same was not true for the combined HL&TIB stimulation. At the swing to stance transition, there was a suppressive reflex summation only for HL&TIB stimulation. In contrast, this summation was not observed for the f-M&TIB stimulation. Our results suggest that reflex reversals evoked by TIB stimulation arise from distinct reflex pathways to TA produced by separate afferent populations innervating specific regions of the foot sole.

Differences in Left Ventricular Global Function and Mechanics in Paralympic Athletes with Cervical and Thoracic Spinal Cord Injuries.

Authors: Currie KD, West CR, Krassioukov AV.
Published in: Front Physiol. 2016 Mar 29;7:110.
About: Following a spinal cord injury, there are changes in resting stroke volume (SV) and its response to exercise. The purpose of the following study was to characterize resting left ventricular structure, function, and mechanics in Paralympic athletes with tetraplegia (TETRA) and paraplegia (PARA) in an attempt to understand whether the alterations in SV are attributable to inherent dysfunction in the left ventricle. This retrospective study compared Paralympic athletes with a traumatic, chronic (>1 year post-injury), motor-complete spinal cord injury (American Spinal Injury Association Impairment Scale A-B). Eight male TETRA wheelchair rugby players (34 ± 5 years, C5-C7) and eight male PARA alpine skiers (35 ± 5 years, T4-L3) were included in the study. Echocardiography was performed in the left lateral decubitus position and indices of left ventricular structure, global diastolic and systolic function, and mechanics were derived from the average across three cardiac cycles. Blood pressure was measured in the supine and seated positions. All results are presented as TETRA vs. PARA. There was no difference in left ventricular dimensions between TETRA and PARA. Additionally, indices of global diastolic function were similar between groups including isovolumetric relaxation time, early (E) and late (A) transmitral filling velocities and their ratio (E/A). While ejection fraction was similar between TETRA and PARA (59 ± 4 % vs. 61 ± 7 %, p = 0.394), there was evidence of reduced global systolic function in TETRA including lower SV (62 ± 9 ml vs. 71 ± 6 ml, p = 0.016) and cardiac output (3.5 ± 0.6 L/min vs. 5.0 ± 0.9 L/min, p = 0.002). Despite this observation, several indices of systolic and diastolic mechanics were maintained in TETRA but attenuted in PARA including circumferential strain at the level of the papillary muscle (-23 ± 4% vs. -15 ± 6%, p = 0.010) and apex (-36 ± 10% vs. -23 ± 5%, p = 0.010) and their corresponding diastolic strain rates (papillary: 1.90 ± 0.63 s(-1) vs. 1.20 ± 0.51 s(-1), p = 0.028; apex: 3.03 ± 0.71 s(-1) vs. 1.99 ± 0.69 s(-1), p = 0.009). All blood pressures were lower in TETRA. The absence of an association between reduced global systolic function and mechanical dysfunction in either TETRA or PARA suggests any reductions in SV are likely attributed to impaired loading rather than inherent left ventricular dysfunction.

Balance Confidence: A Predictor of Perceived Physical Function, Perceived Mobility, and Perceived Recovery 1 Year After Inpatient Stroke Rehabilitation.

Authors: Torkia C, Best KL, Miller WC, Eng JJ.
Published in: Arch Phys Med Rehabil. 2016 Apr 6.
About: The objective of this study was to estimate the effect of balance confidence measured at 1 month poststroke rehabilitation on perceived physical function, mobility, and stroke recovery 12 months later. Balance confidence at 1 month postdischarge from inpatient rehabilitation predicts perceived physical function (model 1), mobility (model 2), and recovery (model 3) 12 months later after adjusting for important covariates. The covariates included in model 1 were age, sex, basic mobility, and depression. The covariates selected for model 2 were age, sex, balance capacity, and anxiety, and the covariates in model 3 were age, sex, walking capacity, and social support. The amount of variance in perceived physical function, perceived mobility, and perceived recovery that balance confidence accounted for was 12%, 9%, and 10%, respectively. After discharge from inpatient rehabilitation poststroke, balance confidence predicts individuals’ perceived physical function, mobility, and recovery 12 months later. There is a need to address balance confidence at discharge from inpatient stroke rehabilitation.

Re-Establishment of Cortical Motor Output Maps and Spontaneous Functional Recovery via Spared Dorsolaterally Projecting Corticospinal Neurons after Dorsal Column Spinal Cord Injury in Adult Mice.

Authors: Hilton BJ, Anenberg E, Harrison TC, Boyd JD, Murphy TH, Tetzlaff W.
Published inJ Neurosci. 2016 Apr 6;36(14):4080-92.
About: Motor cortical plasticity contributes to spontaneous recovery after incomplete spinal cord injury (SCI), but the pathways underlying this remain poorly understood. We performed optogenetic mapping of motor cortex in channelrhodopsin-2 expressing mice to assess the capacity of the cortex to re-establish motor output longitudinally after a C3/C4 dorsal column SCI that bilaterally ablated the dorsal corticospinal tract (CST) containing ∼96% of corticospinal fibers but spared ∼3% of CST fibers that project via the dorsolateral funiculus. Optogenetic mapping revealed extensive early deficits, but eventual reestablishment of motor cortical output maps to the limbs at the same latency as preoperatively by 4 weeks after injury. Analysis of skilled locomotion on the horizontal ladder revealed early deficits followed by partial spontaneous recovery by 6 weeks after injury. To dissociate between the contributions of injured dorsal projecting versus spared dorsolateral projecting corticospinal neurons, we established a transient silencing approach to inactivate spared dorsolaterally projecting corticospinal neurons specifically by injecting adeno-associated virus (AAV)-expressing Cre-dependent DREADD (designer receptor exclusively activated by designer drug) receptor hM4Di in sensorimotor cortex and AAV-expressing Cre in C7/C8 dorsolateral funiculus. Transient silencing uninjured dorsolaterally projecting corticospinal neurons via activation of the inhibitory DREADD receptor hM4Di abrogated spontaneous recovery and resulted in a greater change in skilled locomotion than in control uninjured mice using the same silencing approach. These data demonstrate the pivotal role of a minor dorsolateral corticospinal pathway in mediating spontaneous recovery after SCI and support a focus on spared corticospinal neurons as a target for therapy.

Evidence for an Age-Dependent Decline in Axon Regeneration in the Adult Mammalian Central Nervous System.

Authors: Geoffroy CG, Hilton BJ, Tetzlaff W, Zheng B.
Published in: Cell Rep. 2016 Apr 12;15(2):238-46.
About: How aging impacts axon regeneration after CNS injury is not known. We assessed the impact of age on axon regeneration induced by Pten deletion in corticospinal and rubrospinal neurons, two neuronal populations with distinct innate regenerative abilities. As in young mice, Pten deletion in older mice remains effective in preventing axotomy-induced decline in neuron-intrinsic growth state, as assessed by mTOR activity, neuronal soma size, and axonal growth proximal to a spinal cord injury. However, axonal regeneration distal to injury is greatly diminished, accompanied by increased expression of astroglial and inflammatory markers at the injury site. Thus, the mammalian CNS undergoes an age-dependent decline in axon regeneration, as revealed when neuron-intrinsic growth state is elevated. These results have important implications for developing strategies to promote axonal repair after CNS injuries or diseases, which increasingly affect middle-aged to aging populations

Soleus Hoffmann reflex amplitudes are specifically modulated by cutaneous inputs from the arms and opposite leg during walking but not standing.

Authors: Suzuki S, Nakajima T, Futatsubashi G, Mezzarane RA, Ohtsuka H, Ohki Y, Zehr EP, Komiyama T..
Published in: Exp Brain Res. 2016 Mar 31.
About: Electrical stimulation of cutaneous nerves innervating heteronymous limbs (the arms or contralateral leg) modifies the excitability of soleus Hoffmann (H-) reflexes. The differences in the sensitivities of the H-reflex pathway to cutaneous afferents from different limbs and their modulation during the performance of motor tasks (i.e., standing and walking) are not fully understood. In the present study, we investigated changes in soleus H-reflex amplitudes induced by electrical stimulation of peripheral nerves. Selected targets for conditioning stimulation included the superficial peroneal nerve, which innervates the foot dorsum in the contralateral ankle (cSP), and the superficial radial nerve, which innervates the dorsum of the hand in the ipsilateral (iSR) or contralateral wrist (cSR). Stimulation and subsequent reflex assessment took place during the standing and early-stance phase of treadmill walking in ten healthy subjects. Cutaneous stimulation produced long-latency inhibition (conditioning-test interval of ~100 ms) of the H-reflex during the early-stance phase of walking, and the inhibition was stronger following cSP stimulation compared with iSR or cSR stimulation. In contrast, although similar conditioning stimulation significantly facilitated the H-reflex during standing, this effect remained constant irrespective of the different conditioning sites. These findings suggest that cutaneous inputs from the arms and contralateral leg had reversible effects on the H-reflex amplitudes, including inhibitions with different sensitivities during the early-stance phase of walking and facilitation during standing. Furthermore, the differential sensitivities of the H-reflex modulations were expressed only during walking when the locations of the afferent inputs were functionally relevant.

H-GRASP: the feasibility of an upper limb home exercise program monitored by phone for individuals post stroke.

Authors: Simpson LA, Eng JJ, Chan M.
Published in: Disabil Rehabil. 2016 Mar 26:1-9.
About: The purpose of this study was to investigate the feasibility of a phone-monitored home exercise program for the upper limb following stroke. A pre-post double baseline repeated measures design was used. Participants completed an 8-week home exercise program that included behavioural strategies to promote greater use of the affected upper limb. Participants were monitored weekly by therapists over the phone. The following feasibility outcomes were collected: Process (e.g. recruitment rate); Resources (e.g. exercise adherence rate); Management (e.g. therapist monitoring) and Scientific (e.g. safety, effect sizes). Clinical outcomes included: The Chedoke Arm and Hand Inventory, Motor Activity Log, grip strength and the Canadian Occupational Performance Measure. The authors conclude that community dwelling individuals with stroke may benefit from a phone-monitored upper limb home exercise program that includes behavioural strategies that promote transfer of exercise gains into daily upper limb use. Implications for Rehabilitation A repetitive, task-oriented home exercise program that utilizes telephone supervision may be an effective method for the treatment of the upper limb following stroke This program is best suited for individuals with mild to moderate level impairment and experience a sufficient level of challenge from the exercises An exercise program that includes behavioural strategies may promote transfer of exercise gains into greater use of the affected upper limb during daily activities.

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