Browsing by Author "Dukelow, Sean"
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- ItemOpen AccessA Multimodal Approach to Understanding Motor Impairment in Developmental Coordination Disorder(2020-07-13) Grohs, Melody N.; Dewey, Deborah, M.; Dukelow, Sean; Lebel, Catherine; Kirton, Adam; Graham, Susan; Hands, BethAbstractThe ability to learn, execute and adapt motor skills is fundamental to childhood development and promotes independence in daily living. Yet children with developmental coordination disorder (DCD), demonstrate difficulties acquiring and executing motor skills. DCD is a motor disorder that occurs in 5-6% of school-aged children. Motor impairment manifests as clumsy, slow and inaccurate motor performance adversely affecting the physical, academic and social outcomes of affected children. The pervasive negative impact of motor impairment on daily life in children with DCD, highlights the importance of early diagnosis and intervention. However, the motor deficits common among children with DCD remain unclear, making both screening and intervention difficult. There is a need for research with a priority focus on characterizing the motor deficits present in children with DCD. Evidence is growing, which suggests that poor motor performance in DCD is associated with motor control and motor learning deficits, however, findings are inconsistent across published studies. The current thesis used a three-pronged approach to investigate motor control and motor learning in children with diagnosed DCD, between the ages of 8 to 12 years: (1) two robotic behavioral tasks were employed to objectively quantify motor control abilities, (2) motor learning over five consecutive days of skill training and the potential of non-invasive brain stimulation to modulate rates of motor learning were explored, and (3) neuroimaging was used to investigate brain morphology of regions pertinent to motor control and motor learning. Spatial-temporal differences in reaching performance were observed in children with DCD, supporting the presence of motor control deficits. Preserved motor learning was also seen in the same sample of children. Non-invasive brain stimulation was unsuccessful in modulating the rate of motor learning. Finally, limited brain structural differences were observed in our DCD group compared to healthy controls. However, preliminary findings of reduced subcortical thalamic and pallidal volumes in our DCD group warrants further study, particularly given that these brain structures play critical roles in motor control and motor learning. Taken together, these findings suggest that the motor difficulties observed in children with DCD may be associated with compromised motor control systems.
- ItemOpen AccessEffect of mobile application types on stroke rehabilitation: a systematic review(2023-01-24) Szeto, Stephen G.; Wan, Hoyee; Alavinia, Mohammad; Dukelow, Sean; MacNeill, HeatherAbstract Background Stroke is a significant contributor of worldwide disability and morbidity with substantial economic consequences. Rehabilitation is a vital component of stroke recovery, but inpatient stroke rehabilitation programs can struggle to meet the recommended hours of therapy per day outlined by the Canadian Stroke Best Practices and American Heart Association. Mobile applications (apps) are an emerging technology which may help bridge this deficit, however this area is understudied. The purpose of this study is to review the effect of mobile apps for stroke rehabilitation on stroke impairments and functional outcomes. Specifically, this paper will delve into the impact of varying mobile app types on stroke rehabilitation. Methods This systematic review included 29 studies: 11 randomized control trials and 18 quasi-experimental studies. Data extrapolation mapped 5 mobile app types (therapy apps, education apps, rehab videos, reminders, and a combination of rehab videos with reminders) to stroke deficits (motor paresis, aphasia, neglect), adherence to exercise, activities of daily living (ADLs), quality of life, secondary stroke prevention, and depression and anxiety. Results There were multiple studies supporting the use of therapy apps for motor paresis or aphasia, rehab videos for exercise adherence, and reminders for exercise adherence. For permutations involving other app types with stroke deficits or functional outcomes (adherence to exercise, ADLs, quality of life, secondary stroke prevention, depression and anxiety), the results were either non-significant or limited by a paucity of studies. Conclusion Mobile apps demonstrate potential to assist with stroke recovery and augment face to face rehabilitation, however, development of a mobile app should be carefully planned when targeting specific stroke deficits or functional outcomes. This study found that mobile app types which mimicked principles of effective face-to-face therapy (massed practice, task-specific practice, goal-oriented practice, multisensory stimulation, rhythmic cueing, feedback, social interaction, and constraint-induced therapy) and education (interactivity, feedback, repetition, practice exercises, social learning) had the greatest benefits. Protocol registration PROPSERO (ID CRD42021186534). Registered 21 February 2021
- ItemEmbargoEvaluating Aerobic Exercise to Improve Symptom Burden and Quality of Life in Adults with Persistent Post-Concussive Symptoms(2023-06) Mercier, Leah Jordan; Dukelow, Sean; Debert, Chantel; Esser, Michael; Schneider, KathrynAdults who sustain a mild traumatic brain injury (mTBI) and go on to develop persistent post-concussive symptoms (PPCS) struggle to manage their symptoms and return to pre-morbid activity. There are few evidence-based treatments that have shown benefit in improving PPCS. Prescription of sub-symptom threshold aerobic exercise following mTBI has gained attention in recent years; however, the literature has largely focused on adolescents with sport-related mTBI despite the potential role of aerobic exercise in the treatment of adults with PPCS. This thesis begins by characterizing physical activity (PA) and sedentary behavior and their associations with symptom burden and quality of life (QoL) in adults with PPCS. Next, a systematic review describes the evidence for autonomic dysfunction, namely through evaluation of heart rate variability (HRV), following mTBI. Limitations of the literature including confounding variables that may influence interpretation of results are discussed. The next chapter is the protocol of a randomized clinical trial evaluating a sub-symptom threshold aerobic exercise intervention for improvement in symptom burden, QoL, specific symptom outcomes and sleep. In the following chapter, the results of the trial are presented. The thesis goes on to evaluate changes in heart rate, HRV, blood pressure and cardiac baroreceptor sensitivity between adults with PPCS and age/sex-matched controls. In the PPCS group, longitudinal changes in autonomic metrics following an aerobic exercise intervention are also presented. This work builds on our knowledge of PA and sedentary behavior in adults with PPCS and how aerobic exercise may play a role in the treatment of this patient population. Significant improvements in symptom burden, QoL and other specific symptom outcomes were observed following 6-weeks of aerobic exercise. These outcomes did not significantly improve following 6-weeks of stretching. Lower resting HRV in adults with PPCS compared to age/sex-matched controls and blunted response to postural change provides evidence of cardiovascular autonomic dysfunction in this cohort, although improvement in these outcomes was not observed with the exercise intervention. This thesis provides data to suggest adults with PPCS can benefit from sub-symptom threshold exercise and prescription of aerobic exercise should be considered in the chronic phase of injury despite persistence of symptoms.
- ItemEmbargoExamining the Rate of Recovery Across Movement Parameters Post-Stroke(2023-06) Cowan-Nelson, Emilee; Dukelow, Sean; Kirton, Adam; Demchuk, AndrewStroke is one of the leading causes of disability worldwide. Following a stroke, many individuals suffer from upper limb motor impairment which can hinder their ability to complete daily tasks. It has been suggested that recovery of the upper limb is greatest within the first three months post-stroke, as measured by clinical scores, after which recovery reaches a plateau. Kinematic measures of motor recovery however suggest that recovery is not only greatest within the first six weeks post-stroke, but continues well beyond the suggested three month plateau. Further, data from our lab suggests that certain spatial and temporal movement parameters may show different patterns of recovery. The purpose of this thesis was to examine patterns of spatial and temporal motor recovery in subacute stroke survivors using a Kinarm robotic exoskeleton. Chapter Two of this thesis is comprised of a manuscript which details this project. Our results suggest that the greatest recovery in spatial and temporal parameters of movement occurs within 1- to 6-weeks post-stroke. Additionally, spatial and temporal movement parameters appear to follow similar patterns of motor recovery overall. With a better understanding of motor recovery post-stroke, therapists can tailor rehabilitation practices to ensure movement parameters are targeted at the appropriate time, allowing patients to achieve better recovery outcomes.
- ItemOpen AccessExperience of Young Stroke Survivors in a Community-Based Peer Support Group(2023-04-28) Morin, Tiffany Danette; Milaney, Katrina; Rankin, Joanna; Dukelow, SeanPurpose: The purpose of this study was to explore the experiences of young stroke survivors (YSS) participating in a community-based peer support program in Calgary, Alberta. There is a lack of research on peer support groups facilitated by YSS themselves, and on the impact of peer support on the health and wellbeing of stroke survivors under the age of 50. Methods: This qualitative case study project was guided by Critical Disability Studies and included five semi-structured interviews with YSS in Calgary, Alberta. Participants were between the ages of 18-50 and had attended at least two YSS peer support activities in the past three years. Following the principles of community-based research, support for this research was provided by the Stroke Recovery Association of Calgary to co-create the research question, methods, recruitment, and analysis of results, along with guiding the development of the implications and recommendations. Results: Three main themes and six sub-themes were identified from the interviews as follows: 1) Feeling normal; 1a) What is normal anyways?; 1b) Why does there need to be a new normal?; 2) Connection through lived experience; 2a) Shared life and stroke experiences; 2b) Mixed feelings when meeting with other survivors; and 3) Perceived benefits of attending the peer support group; 3a) Being accepted by others; 3b) Opportunities for social interaction. Conclusion: This case study demonstrated that there continues to be value in recommending peer support to YSS, especially grassroots groups that are led and facilitated by those with lived experience. Participants experienced connection through shared experiences, as well as supported each other to navigate a world that caters to people who fit societal norms and often leaves them feeling isolated and alone. Keywords: young stroke survivors, stroke, peer support, community engagement
- ItemOpen AccessFeedback Responses Must Disengage from Postural Control to Initiate Rapid Movements(2021-09) Yeung, Natalie; Cluff, Tyler; Peters, Ryan; Herzog, Walter; Dukelow, SeanThe nervous system enables humans to respond to changes in the environment, and when necessary, update the course of an ongoing action. The process of initiating a new motor action when the task changes suddenly appears to carry a delay or time cost. Electrophysiological recordings suggest this time cost may arise from neural processing related to engaging in a new motor action. We know little about this time cost and when it arises following changes in task demands. Here we examine the time required to respond to a change in the goal of ongoing upper limb motor tasks. In 3 experiments, we applied visual perturbations while a total of 47 participants (22 females) maintained upper limb postural control (Experiment 1), performed reaching movements or maintained a fixed upper limb posture (Experiment 2), and transitioned from holding a fixed posture to initiating a reaching movement (Experiment 3). When applied in postural control, visual disturbances (‘cursor jumps’) required participants to disengage from holding a fixed limb position before initiating a rapid corrective response to drive the cursor back to the target. The same perturbations require a corrective response but do not impose a change in goal when the nervous system is already engaged in movement. Rapid muscle responses emerged as early as ~105 ms when responding to the visual perturbations during upper limb reaching movements compared to postural control. In some postural control conditions, the nervous system required ~270 ms to update muscle activity when responding to the same visual disturbances. The findings highlight slower corrective responses when required to disengage from maintaining a fixed limb position to initiate a corrective response. Taken together, our results emphasize a direct time cost when responding to changes in the goal of the task.
- ItemOpen AccessIntervention-Related Changes in Motor Cortex GABA in Children with Perinatal Stroke(2024-04-15) Hart, Paulina Marie Byers; Kirton, Adam; Carlson, Helen; Dukelow, Sean; Lebel, CatherinePerinatal stroke (PS) is a focal, vascular brain injury that often damages the motor system and can leave patients with lifelong motor disability in the form of hemiparetic cerebral palsy. Current treatment is limited to waiting for the appearance of clinical signs and rehabilitation therapy; however, non-invasive brain stimulation is an emerging area of interest for this population. Transcranial direct current stimulation (tDCS) is a safe, non-invasive method of applying weak electrical current to the brain to enhance motor learning. How tDCS may alter motor cortex chemistry is unclear, however magnetic resonance spectroscopy (MRS) allows us to study brain metabolites and their changes in vivo. It is unknown how γ-aminobutyric acid (GABA), a primary inhibitory neurotransmitter may be altered in the motor cortices of children with PS and how it may change following intervention. Our study investigated the underlying neurochemical changes in children with perinatal stroke following intensive motor therapy and non-invasive brain stimulation interventions. Of those who were recruited and completed the Stimulation for Optimizing Perinatal Stroke Optimizing Recovery Trajectories (SPORT) Trial, data from 49 participants was used in this study. Trial participants (6-18 years) attended a two-week day-camp which included intensive individual motor therapy as well as were randomized to receive either active cathodal or sham tDCS. Motor function assessments and neuroimaging using MRI, including MRS, was completed at baseline, post-intervention, and 6-months following intervention. At baseline and post-intervention, GABA between hemispheres were different (p<0.001; p=0.044 respectively), and at the 6-month follow-up GABA was not different. Motor function significantly increased following the camp (p<0.001), however there was no correlation of GABA to the objective measures of motor function. There was no observed effect of tDCS on GABA over time. This project contributes to an understanding of GABA levels and other brain metabolites in children with perinatal stroke at baseline and following intensive motor therapy and tDCS interventions. Our results support the use of motor therapy for improving motor function in children with PS, however the potential effects of tDCS intervention warrant further investigation.
- ItemEmbargoMotor Learning after Stroke(2023-05-10) Moore, Robert Taylor; Cluff, Tyler; Dukelow, Sean; Kirton, Adam; Hill, MichaelMotor learning is a pillar of stroke rehabilitation. Indeed, many therapeutic protocols and interventions are based on principles of motor learning. One of the assumptions made in rehabilitation is that motor learning remains intact after stroke and can be leveraged to facilitate recovery. However, a growing body of evidence has shown that motor learning can be impaired after stroke. Our understanding of how stroke influences the neural and behavioural processes that support motor learning is incomplete. This raises questions about how well our current understanding of motor learning, derived predominantly from studies in healthy adults, applies to stroke rehabilitation. The following dissertation describes four studies that examine reaching movements and a specific type of motor learning known as motor adaptation. This type of learning encompasses the processes that help to maintain accurate movements amidst changes in the body, environment, and task demands. Across three experiments in healthy adults (Chapter Two) and three experiments in participants with stroke (Chapters Three, Four, and Five), we characterized motor adaptation in health and disease. Overall, the works in this dissertation demonstrate the utility of robotics for quantifying motor adaptation. Impaired adaptation after stroke was associated with several clinical variables including: the side of the stroke affected limb (i.e., dominant versus non-dominant), time post-stroke, movement performance, proprioceptive abilities, and clinical assessments of motor impairment and functional independence. Notably these variables accounted for only a small portion of the variance in motor adaptation after stroke, suggesting that other clinical variables (e.g., lesion characteristics or other types of impairments) may be associated with adaptation after stroke. Our results reveal widespread impairments in visuomotor adaptation after stroke and generate numerous questions about the basic mechanisms underlying motor adaptation and how adaptation applies to stroke rehabilitation.
- ItemOpen AccessMovement Biomechanics and Personalized Exercise Interventions in Individuals with Hip Osteoarthritis(2016) Leigh, Ryan; Ferber, Reed; Dukelow, Sean; Culos-Reed, Nicole; Duffett-Leger, LindaHip osteoarthritis (OA) is a prevalent musculoskeletal disorder that results in increased patient morbidity and dysfunction. While exercise is a common therapeutic modality employed in the management of this disorder, effect sizes remain small. Given this finding, the overarching aim of this thesis was to better understand the 3-dimensioanl (3D) gait biomechanics of this clinical population and subsequently test novel exercise interventions to improve clinical outcomes in individuals with mild-to-moderate hip OA. Following the Introduction, Chapter 2 explored whether tester experience influenced the reliability with which 3D gait data can be collected. This study was important since 3D gait collections would be a major part of the final two chapters. Using a coefficient of multiple correlation (CMC) statistic to estimate within-tester reliability, we found that within-tester CMC values exceeded 0.90 for both novice and experienced testers across all kinematic variables. Chapter 3 summarized the current hip OA and exercise literature and determined whether land-based exercise is an effective intervention in hip OA subjects not awaiting surgery. Pooled data from 7 studies demonstrated exercise had no effect on pain or self-reported function immediately post intervention and the overall effect sizes remained small. Chapter 4 characterized the 3D kinematic gait patterns of individuals with mild-to-moderate hip OA considering that to this point, the lower extremity kinematics of hip OA patients had not been fully described. We reported that hip OA subjects walked with greater peak hip abduction, reduced peak hip extension, and greater peak hip external rotation compared to age and body mass index (BMI) matched healthy controls. Whether these subtle biomechanical abnormalities could be used as treatment targets was explored in the capstone investigation. In Chapter 5, we targeted these 3D gait abnormalities with a novel tailored exercise intervention in mild-to-moderate hip OA subjects. This exercise protocol was compared to a tailored intervention that was based on a standard clinical assessment. No significant improvements in pain were found across either group at 8-weeks follow-up and a 3D gait derived exercise program did not result in improved clinical outcomes.
- ItemOpen AccessNeural Correlates of Proprioception After Stroke(2019-05-15) Findlater, Sonja E; Dukelow, Sean; Demchuk, Andrew; Pike, Bruce; Kirton, AdamProprioception, one’s sense of limb and body position (position sense) and movement (kinesthesia), is impaired in up to 64% of individuals after stroke. Proprioceptive deficits in the arm result in poor coordination of multiple joints, leading to decreased reaching accuracy and poor fine motor coordination. After stroke, these impairments have been associated with longer hospital stays and poorer functional recovery. Despite consensus that proprioception contributes to efficient arm movement, relatively little is known about it in comparison to the motor system. The goal of this thesis was to investigate the structural anatomy underlying proprioceptive awareness after stroke and provide a foundation upon which targeted interventions for proprioceptive deficits may be built. In chapter two, a literature review was conducted that examined subcomponents, assessments, and interventions of proprioception. This review identified that few proprioceptive assessments or interventions exist and highlighted considerations that might guide intervention development. In chapter three, a lesion analysis was conducted in a large cohort. Lesions in the parietal lobe, somatosensory association areas, and white matter pathways that connect the parietal, temporal and frontal lobes were associated with poor performance on a robotic proprioceptive matching task at approximately six months post-stroke. In chapter four, a diffusion tractography study was conducted to examine whether altered microstructure of the dorsal column-medial lemniscus (DCML) tract, the postcentral gyrus to supramarginal gyrus (POCG-SMG) association tract, or the postcentral gyrus to Heschl’s gyrus (POCG-HG) association tract was related to poor proprioception after stroke. A moderate correlation was observed between the POCG-SMG and POCG-HG and proprioceptive impairment at one month post-stroke. These findings provided support to those from chapter 3 that identified the supramarginal and Heschl’s gyri as important regions for perceiving proprioceptive information. In chapter five, the association between corticospinal tract damage and motor or proprioceptive impairments was examined. Corticospinal tract damage was significantly associated with both motor and proprioceptive deficits after stroke. Together these results further our understanding of the structural correlates underlying proprioceptive impairments after stroke.
- ItemOpen AccessNeuroimaging and Robotic Assessment of Proprioceptive Impairments Post-Stroke(2017) Kenzie, Jeffrey; Dukelow, Sean; Goodyear, Bradley; Hill, MichaelBackground: Proprioception is the sense of position (position sense) and movement (kinesthesia) of our limbs and body. It is important for performing coordinated volitional movements, and is often affected after stroke, leading to worse functional recovery. Proprioception is difficult to reliably assess with current clinical measures. This thesis performed proprioceptive assessments in subjects with recent stroke using a robotic exoskeleton called a KINARM. Chapter Two identified specific lesion locations in a sample of subjects with recent stroke (n=142) that were associated with impairments in different aspects of kinesthesia (e.g. speed, direction, and amplitude of movement perception). Lesions to frontal, parietal and temporal cortices, and the insula were associated with impairments in kinesthesia. Chapter Three incorporated multiple measures from position sense and kinesthesia robotic tasks into a single composite score of proprioception. Proprioceptive impairments were common (over 60%, n=285) after stroke, and were correlated with clinical measures of functional independence. This composite score will have utility in monitoring proprioceptive impairments in future rehabilitation clinical trials. Next, Chapters Four and Five utilized functional MRI (fMRI) to identify disruptions in brain activity related to proprioceptive impairments. Chapter Four used a position-matching device and task during fMRI to identify brain areas associated with impaired proprioception. The ipsilesional supramarginal and superior temporal gyri as well as bilateral supplementary motor and ipsilesional premotor cortices were associated with impaired proprioception in subjects with recent stroke (n=16). Chapter Five measured resting-state functional connectivity in subjects with stroke (n=17) using fMRI. Changes in functional connectivity were computed in relation to impaired proprioception (measured using the KINARM). Impaired proprioception was associated with decreased functional connectivity between 1) contralesional opercular area 1 (seed) and ipsilesional temporal and parietal areas, and 2) supplementary motor/premotor areas (seed) and ipsilesional SI and supramarginal gyrus. Conclusions: We have developed an objective and reproducible robotic-based outcome measure of upper limb proprioception. Proprioception in the human brain appears to involve primary sensorimotor structures (e.g. SI, MI) and higher-level association areas such as superior and inferior parietal cortices, supplementary motor and premotor cortices.
- ItemOpen AccessRobotic and Imaging Biomarkers of Sensorimotor Dysfunction in Hemiparetic Children after Perinatal Stroke(2017) Kuczynski, Andrea; Kirton, Adam; Dukelow, Sean; Lebel, Catherine; Demchuk, Andrew; Boyd, Lara; Cluff, TylerPerinatal ischemic stroke results from focal cerebral arterial or venous occlusion and usually causes lifelong disability. Perinatal stroke is the leading cause of hemiparetic cerebral palsy, and may result in impairment in both sensory and motor function. A major limitation in assessing sensory and motor function following stroke is a lack of objective, sensitive measurement tools which are required to advance personalized therapeutic strategies. In this study, we used a novel robotic exoskeleton (KINARM) to assess sensory and motor function in hemiparetic children with perinatal stroke. Using diffusion tensor imaging, we further sought to better understand changes in sensorimotor pathway microstructure following perinatal stroke and their relationship with behaviour. We studied 50 children with perinatal stroke (arterial or venous) and 150 typically developing children aged 6 to 19 years. Children with perinatal stroke demonstrated diverse impairments in both sensory and motor function relative to controls. Mean group differences were greater for arterial strokes compared to venous. Proprioceptive deficits included dysfunction in both robotic position-matching and kinesthesia tasks that correlated poorly with beside sensory tests. Both stroke groups demonstrated impaired motor reaching in the contralesional limb, with greater deficits in the arterial group. The ipsilesional, “unaffected” arm of arterial cases also often showed impairments. Robotic sensory and motor performance was often associated with the structural connectivity of the corresponding lesioned tract as measured by diffusion tensor imaging. Our findings contribute to a better understanding of how sensory and motor systems develop following unilateral perinatal injury and how these relate to clinical function. We add new components to emerging developmental plasticity models of perinatal stroke including detailed functional outcomes of both upper extremities and measures of structural connectivity in related major tracts. Such knowledge can inform emerging neuromodulation trials towards personalized neurorehabilitation and improved outcomes for hemiparetic children.
- ItemOpen AccessStudy of an At-home Upper-extremity Stroke Rehabilitation System(2021-09) Khan, Alhamd; Smith, Mike; Dukelow, Sean; Vyas, Rushi; Ferber, ReedIncreased awareness of the signs of stroke and better stroke management has increased survival rate close to 90% in Canada. However, this means each year close to 4000 Albertans require rehabilitation to re-learn skills for performing daily activities. A major challenge for therapists carrying out rehabilitation is the assessment of motor and sensory functions, especially of the upper extremities. Assessment tools range from therapists using simplistic observer based ordinal scales to more quantitative research-based tools such as the NEOFECT data gloves, using which patients can perform virtual reality-based exercises displayed on a computer screen or using virtual reality headsets. However, existing smart-gloves are marketed towards a clinic, not home, environment. Apart from their high initial $15,000USD cost, they require additional interfacing including costly and precise installation of cameras/base-stations for position tracking in addition to headsets to interact with the virtual reality environments. We propose a prototype of a data glove and arm tracking system with a variety of low-cost, position, orientation, and feedback sensors to supplement clinic assessments, and enable their continued use at home. Preliminary results for gamified rehabilitation exercises to encourage participation in a wider variety of motor and sensory tasks using smart-glove monitoring will be presented. Covid-19 restrictions have limited the ability to evaluate the accuracy and effectiveness of the glove monitoring by comparison to existing assessment approaches for both simplistic and complex therapeutic activities in the clinic. An initial optimization of the real-time capture of smart-glove measurements will initiate our longer term research goal of implementing machine learning models for user’s hand performance evaluation. We believe our prototype has the potential to lead to a new device that could assist therapists, patients, and families by enabling an adjunctive route for monitoring and evaluating stroke rehabilitation and recovery of the post-stroke hand when used in home-based environments.
- ItemEmbargoThe Clinical Utility of a Novel Multi-Modal Assessment Battery for Acute Sport-Related Concussion(2024-04-19) Bertagnolli, Jalena Ashley; Benson, Brian; Dukelow, Sean; Smith, David; Richer, LawrenceObjective: To determine the clinical utility of a novel, multimodal, assessment battery in detecting acute post-concussion impairment relative to baseline performance. Study Design: Prospective observational cohort study. Subjects: Four hundred thirty-one elite ice hockey, alpine and freestyle ski, artistic swimming and luge athletes (mean age: 15.7 years (range: 14-36 years), male: 349, female: 82) over one athletic season (2022-2023). Observation Technique: Standardized multimodal baseline assessments including electroencephalography (EEG) utilizing the NeuroCatch® 1.0 device, postural sway using the tri-axial accelerometer Protxx® device, cardiovascular exercise from a bicycle ergometer and sustained handgrip strength were completed in the pre-season and then repeated for any athlete sustaining a sport-related concussion within seven days of injury. Outcome Measures: Directional bootstrap paired t-tests and binomial tests adjusting for multiplicity using Bonferroni correction were used to assess changes in performance between baseline and post-concussion test results for the following four primary assessments of interest: 1) quantitative EEG event-related potentials (N100, P300, and N400 amplitude and latency) (NeuroCatch), 2) quantitative assessment of postural sway with eyes open and eyes closed using a physiological vibration acceleration (phybrata) sensor (Protxx), 3) concussion symptom exacerbation (≥1 on a 10-point visual analogue rating scale) during a submaximal bicycle ergometer assessment, and 4) change in heart rate during a 30-second, 30% maximal handgrip strength contraction. Results: Forty-six athletes were diagnosed with a concussion by a sport medicine physician during the study period. Neither amplitude nor latency for N100, P300 or N400 event-related potentials demonstrated a significant group difference between baseline and post-concussion assessments. Athletes demonstrated a significant group difference in postural sway between baseline and post-concussion timepoints using the phybrata sensor for sway power ratio, with a moderate effect size (dav= 0.491) (baseline: 1.4 ±0.5W, post-concussion: 1.9 ±1.4W, p=0.005). Fifteen (68.2%) of the 22 athletes completing post-concussion exercise assessments experienced worsening symptoms, with two additional athletes unable to initiate exercise due to significant symptom burden (p<0.001, large effect size PR= 0.972). Furthermore, no significant difference was observed for change in heart rate during the handgrip strength task. Conclusions: A novel phybrata motion sensor objectively evaluating postural sway and standardized submaximal cardiovascular assessment evaluating symptom exacerbation demonstrated significant clinical utility in detecting impairment within seven days of an acute sport-related concussion, while event-related potentials (N100, P300, N400) and heart rate change during a sustained handgrip task did not.
- ItemOpen AccessThe Development and Clinical Application of the Dextrometer for Measuring Hand Function in Acute Stroke Patients(2013-01-25) Dew, Michael; Johnston, Jamie; Dukelow, SeanHand function after stroke is clinically assessed by using observation and coarse, ordinal scales to classify impairment severity. Researchers have postulated that these assessment tools may be unable to detect small but clinically relevant differences in impairment. The purpose of this study was to develop an assessment tool, the Dextrometer, that accurately measures and identifies aberrant multi-digit force production patterns produced by stroke patients. To address this goal, acute stroke patients were asked to produce maximum voluntary force with their stroke-affected and unaffected hands in both the extension and flexion directions while forces were recorded from all digits. The results show that the Dextrometer successfully identified unique patterns of digit interactions in the affected hand and also distinguished between different levels of impairment. This study provides justification for the use of the Dextrometer and force production measures for discriminating impairments in hand function.
- ItemOpen AccessThe Neuroanatomical Correlates of Impaired Position Sense After Stroke(2013-10-02) Findlater, Sonja; Dukelow, SeanProprioception describes our sense of self-position and movement without vision. It plays a key role in the production and control of movement. Affected in 50% of stroke patients, impairment in proprioception is correlated with poor motor recovery, functional outcomes, and extended hospitalization. Proprioception-targeted rehabilitation is lacking. To contribute to improved understanding of the anatomical regions underlying proprioception, this study aimed to identify brain areas responsible for impaired position sense post-stroke. Voxel-based lesion-symptom mapping compared lesion location and performance on quantitative robotic position sense assessment. This and region of interest analyses revealed that the hypothesized areas: the thalamus; posterior limb of the internal capsule; postcentral gyrus; posterior parietal association area were associated with poor position sense in addition to non-hypothesized areas: insula; lingual, inferior frontal, superior temporal, and middle temporal gyri. Position sense appears to be a multi-dimensional construct, processed via a distributed network of brain regions.
- ItemOpen AccessUnderstanding Brain Signal Variability and Why it Matters in Maturation from Childhood to Adulthood(2023-01-16) Wang, Hongye; Protzner, Andrea; Iaria, Giuseppe; Dukelow, Sean; Borowsky, Ron; Kopala-Sibley, DanielBlood oxygen level dependent (BOLD) signal variability characterizes the inherently time-varying features of brain signal and has provided complementary perspectives into aging research. As a strong age predictor, age-related brain patterns that are associated with BOLD SD barely overlap with those from the mean BOLD signal. The three studies in this thesis elucidate what BOLD signal variability (quantified by standard deviation (SD) of BOLD time series) can tell us about brain structure and function relationships across the lifespan from childhood to adulthood. Study 1 explored the association between BOLD SD, age, and white matter development during early childhood. Across- and within-participant analyses demonstrated that white matter maturation was closely linked to alterations in brain function as measured by BOLD SD. Study 2 examined the relationship between age and brain function for healthy men and women using a context memory task. Although men and women performed equally well behaviorally, neurotypical aging showed different trajectories between the sexes; BOLD SD in women showed age vs performance trade-offs in widespread cortical and subcortical regions, whereas in men, BOLD SD patterns associated with age and performance were orthogonal and task-specific. To better understand how BOLD SD relates to other, more commonly used measures of brain function, Study 3 related BOLD SD to other metrics, some of them reflecting brain dynamics, e.g., BOLD signal complexity (quantified by multi-scale entropy), functional connectivity and dynamic functional connectivity. This work suggests that the relationship between BOLD SD and complexity is time scale dependent, with a positive correlation at fine scales but a negative one at coarse scale. The link between BOLD SD and dynamic functional connectivity preserved only part of the associations between BOLD SD and static functional connectivity, which revealed how brain signal and brain functional connectivity co-evolved over time. Taken together, these studies suggest that BOLD SD can be used to elucidate maturational-, aging- and sex-associated differences in brain structure and function. Relating BOLD SD to other measures of brain function may improve our understanding of how the dynamic features of brain states evolve across the lifespan.