PRISM :: Browsing by Author "Dukelow, Sean P."

Browsing by Author "Dukelow, Sean P."

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Open Access
A robot-based interception task to quantify upper limb impairments in proprioceptive and visual feedback after stroke
(2023-10-11) Park, Kayne; Ritsma, Benjamin R.; Dukelow, Sean P.; Scott, Stephen H.
Abstract Background A key motor skill is the ability to rapidly interact with our dynamic environment. Humans can generate goal-directed motor actions in response to sensory stimulus within ~ 60-200ms. This ability can be impaired after stroke, but most clinical tools lack any measures of rapid feedback processing. Reaching tasks have been used as a framework to quantify impairments in generating motor corrections for individuals with stroke. However, reaching may be inadequate as an assessment tool as repeated reaching can be fatiguing for individuals with stroke. Further, reaching requires many trials to be completed including trials with and without disturbances, and thus, exacerbate fatigue. Here, we describe a novel robotic task to quantify rapid feedback processing in healthy controls and compare this performance with individuals with stroke to (more) efficiently identify impairments in rapid feedback processing. Methods We assessed a cohort of healthy controls (n = 135) and individuals with stroke (n = 40; Mean 41 days from stroke) in the Fast Feedback Interception Task (FFIT) using the Kinarm Exoskeleton robot. Participants were instructed to intercept a circular white target moving towards them with their hand represented as a virtual paddle. On some trials, the arm could be physically perturbed, the target or paddle could abruptly change location, or the target could change colour requiring the individual to now avoid the target. Results Most participants with stroke were impaired in reaction time (85%) and end-point accuracy (83%) in at least one of the task conditions, most commonly with target or paddle shifts. Of note, this impairment was also evident in most individuals with stroke when performing the task using their unaffected arm (75%). Comparison with upper limb clinical measures identified moderate correlations with the FFIT. Conclusion The FFIT was able to identify a high proportion of individuals with stroke as impaired in rapid feedback processing using either the affected or unaffected arms. The task allows many different types of feedback responses to be efficiently assessed in a short amount of time.
Open Access
Cerebral Small Vessel Disease: Cognitive Reserve and Mediators of Cognitive Decline
(2021-09-24) Durrani, Romella; Smith, Eric E.; Ismail, Zahinoor; Hill, Michael D.; Monchi, Oury; Dukelow, Sean P.; Postuma, Ronald B.
Background: Cerebral small vessel disease (CSVD) is the most common type of cerebrovascular disease that contributes to cognitive decline and dementia. However, persons with the same burden of CSVD often have different cognitive outcomes. Cognitive reserve, defined as the ability to tolerate or adapt to pathology, has been suggested to explain these variations. There are limited studies on cognitive reserve in CSVD, as most studies have focused on Alzheimer’s disease (AD). These studies have also focused on education as the proxy of cognitive reserve, with only a few studies looking at other proxies, such as occupation and leisure activities. Additionally, few studies of cognitive reserve have examined other measures of cerebrovascular disease, beyond white matter hyperintensities (WMH). Objectives: Determine whether cognitive reserve mitigates the deleterious effects of CSVD on cognition, and determine the degree to which cerebral amyloid angiopathy (CAA) biomarkers mediate the effects of CAA on cognition.Methods: Data were analyzed from four multicenter, cross-sectional cohorts. Measures of cerebrovascular disease included: brain infarcts, non-lacunar covert brain infarcts (CBI), WMH, vascular lesion burden, and CAA. Measures of cognitive reserve included: education, occupation, social involvement, physical activity, leisure physical activity, household income, marital status, height, stress, and multilingualism. CAA biomarkers included: WMH, cerebrovascular reactivity (CVR), peak width of skeletonized mean diffusivity (PSMD), mean cortical thickness, and mean cortical thickness in an AD meta-region of interest.Results: WMH, non-lacunar CBI, vascular lesion burden, and CAA were associated with lower cognition. Proxies of cognitive reserve were associated with higher cognition. However, cognitive reserve did not modify the association between CSVD and cognition. CVR, PSMD, and mean cortical thickness in regions typically affected by AD accounted for half of the effects of CAA on cognition; PSMD was the largest contributor.Conclusions: This forms the largest body of work on cognitive reserve within CSVD. Strategies to prevent CSVD-related cognitive decline and dementia include: 1) preventing CSVD, 2) enhancing cognitive reserve, thereby independently increasing cognition---however, this does not mitigate the deleterious effects of CSVD on cognition, and 3) in CAA, maintaining white matter integrity and restoring normal cerebrovascular reactivity.
Open Access
Correction: Virtual Arm Boot Camp (V-ABC): study protocol for a mixed-methods study to increase upper limb recovery after stroke with an intensive program coupled with a grasp count device
(2022-03-11) Simpson, Lisa A.; Barclay, Ruth; Bayley, Mark T.; Dukelow, Sean P.; MacIntosh, Bradley J.; MacKay-Lyons, Marilyn; Menon, Carlo; Mortenson, W. B.; Peng, Tzu-Hsuan; Pollock, Courtney L.; Pooyania, Sepideh; Teasell, Robert; Yang, Chieh-ling; Yao, Jennifer; Eng, Janice J.
Open Access
The Impact of Severity, Timing, and Sex on Outcomes of Inpatient Stroke Rehabilitation
(2020-01-08) Tanlaka, Eric Fover; King-Shier, Kathryn M.; Dukelow, Sean P.; Venturato, Lorraine; King-Shier, Kathryn M.; Dukelow, Sean P.; Green, Theresa L.; Seneviratne, Cydnee C.; Ewashen, Carol J.; Teasell, Robert
Stroke severity and time to rehabilitation admission are important factors in influencing stroke rehabilitation outcomes. We aimed to determine the impact of: (1) stroke severity and timing to inpatient rehabilitation admission on length of stay, functional gains, and discharge destination; and (2) age and sex differences in time to rehabilitation, length of stay in rehabilitation, and discharge destination for stroke patients in Alberta. The first manuscript offers a discussion of post-positivist critical multiplism and its value for nursing research and describes the steps for conducting critical multiplist nursing research using stroke rehabilitation as an example. We identify that post-positivist critical multiplism offers a useful, rigorous approach that relies on a step-by-step method and a collaboration with a team of scholars who offer different perspectives, open questioning and critique, and rigorous attention to minimize biases throughout the research process. We examined a large retrospective cohort to address the research aims. In the second paper, we identified that length of time to rehabilitation admission was not significantly different between stroke severities. Individuals with moderate and severe stroke made significantly larger FIM gains than mild stroke during inpatient rehabilitation. LOS was longer with increasing stroke severity. Time to inpatient rehabilitation admission had small, but significant impacts on functional gains and LOS. Patients with shorter times to rehabilitation admission and those with mild stroke were more likely to be discharged home without needing health services. In the third paper, we identified that mean length of time from acute care admission to inpatient rehabilitation admission was not significantly different between males and females. There was no significant difference in mean FIM change between males and females during inpatient rehabilitation. Mean LOS in rehabilitation was slightly longer among females compared to males. Male patients and those of younger age were more likely than females and those of older age to be discharged home without needing homecare. In conclusion, stroke severity had a significant impact on the conduct of inpatient rehabilitation. The impact of timing on functional gains and LOS was small. Differences in LOS and discharge destination based on sex and age were significant.
Open Access
Impairments of the ipsilesional upper-extremity in the first 6-months post-stroke
(2023-08-14) Smith, Donovan B.; Scott, Stephen H.; Semrau, Jennifer A.; Dukelow, Sean P.
Abstract Background Ipsilesional motor impairments of the arm are common after stroke. Previous studies have suggested that severity of contralesional arm impairment and/or hemisphere of lesion may predict the severity of ipsilesional arm impairments. Historically, these impairments have been assessed using clinical scales, which are less sensitive than robot-based measures of sensorimotor performance. Therefore, the objective of this study was to characterize progression of ipsilesional arm motor impairments using a robot-based assessment of motor function over the first 6-months post-stroke and quantify their relationship to (1) contralesional arm impairment severity and (2) stroke-lesioned hemisphere. Methods A total of 106 participants with first-time, unilateral stroke completed a unilateral assessment of arm motor impairment (visually guided reaching task) using the Kinarm Exoskeleton. Participants completed the assessment along with a battery of clinical measures with both ipsilesional and contralesional arms at 1-, 6-, 12-, and 26-weeks post-stroke. Results Robotic assessment of arm motor function revealed a higher incidence of ipsilesional arm impairment than clinical measures immediately post-stroke. The incidence of ipsilesional arm impairments decreased from 47 to 14% across the study period. Kolmogorov–Smirnov tests revealed that ipsilesional arm impairment severity, as measured by our task, was not related to which hemisphere was lesioned. The severity of ipsilesional arm impairments was variable but displayed moderate significant relationships to contralesional arm impairment severity with some robot-based parameters. Conclusions Ipsilesional arm impairments were variable. They displayed relationships of varying strength with contralesional impairments and were not well predicted by lesioned hemisphere. With standard clinical care, 86% of ipsilesional impairments recovered by 6-months post-stroke.
Open Access
Improving symptom burden in adults with persistent post-concussive symptoms: a randomized aerobic exercise trial protocol
(2020-02-05) Mercier, Leah J.; Fung, Tak S.; Harris, Ashley D.; Dukelow, Sean P.; Debert, Chantel T.
Abstract Background Persistent post-concussive symptoms (PPCS) affect up to 30% of individuals following mild traumatic brain injury. PPCS frequently includes exercise intolerance. Sub-symptom threshold aerobic exercise has been proposed as a treatment option for symptom burden and exercise intolerance in this population. The primary aim of this study is to evaluate whether a progressive, sub-symptom threshold aerobic exercise program can alleviate symptom burden in adults with PPCS. Methods Fifty-six adults (18–65) with PPCS (>3mos-5 yrs) will be randomized into two groups: an immediate start 12-week aerobic exercise protocol (AEP) or delayed start 6-week placebo-like stretching protocol (SP), followed by AEP. Aerobic or stretching activities will be completed 5x/week for 30 mins during the intervention. Online daily activity logs will be submitted. Exercise prescriptions for the AEP will be 70–80% of heart rate at the point of symptom exacerbation achieved on a treadmill test with heart rate monitoring. Exercise prescription will be updated every 3-weeks with a repeat treadmill test. The Rivermead Post-concussion Symptom Questionnaire will be the primary outcome measure at 6 and 12-weeks of intervention. Secondary outcomes include assessments of specific symptoms (headache, quality of life, mood, anxiety, fatigue, dizziness, sleep parameters, daytime sleepiness) in addition to blood biomarkers and magnetic resonance imaging and spectroscopy data for quantification of brain metabolites including γ-aminobutyric acid (GABA), glutathione, glutamate and N-acetyl aspartate (NAA) all measured at 6 and 12-weeks of intervention. Discussion This trial will evaluate the use of aerobic exercise as an intervention for adults with PPCS, thus expanding our knowledge of this treatment option previously studied predominantly for adolescent sport-related concussion. Trial registration ClinicalTrials.gov - NCT03895450 (registered 2019-Feb-11).
Open Access
The independence of deficits in position sense and visually guided reaching following stroke
(BioMed Central, 2012-10-04) Dukelow, Sean P.; Herter, Troy M; Bagg, Stephen D; Scott, Stephen H
Open Access
Inhibitory Control Deficits in Children with Tic Disorders Revealed by Object-Hit-and-Avoid Task
(2021-07-02) Cothros, Nicholas; Medina, Alex; Martino, Davide; Dukelow, Sean P.; Hawe, Rachel L.; Kirton, Adam; Ganos, Christos; Nosratmirshekarlou, Elaheh; Pringsheim, Tamara
Background. Tic disorders may reflect impaired inhibitory control. This has been evaluated using different behavioural tasks, yielding mixed results. Our objective was to test inhibitory control in children with tics through simultaneous presentation of multiple, mobile stimuli. Methods. Sixty-four children with tics (mean age 12.4 years; 7.5-18.5) were evaluated using a validated robotic bimanual exoskeleton protocol (Kinarm) in an object-hit-and-avoid task, in which target and distractor objects moved across a screen and participants aimed to hit only the targets while avoiding distractors. Performance was compared to 146 typically developing controls (mean age 13 years; 6.1-19.9). The primary outcome was the percentage of distractors struck. Results. ANCOVA (age as covariate) showed participants struck significantly more distractors (participants without comorbid ADHD, 22.71% [SE 1.47]; participants with comorbid ADHD, 23.56% [1.47]; and controls, 15.59% [0.68]). Participants with comorbid ADHD struck significantly fewer targets (119.74 [2.77]) than controls, but no difference was found between participants without comorbid ADHD (122.66 [2.77]) and controls (127.00 [1.28]). Participants and controls did not differ significantly in movement speed and movement area. Just over 20% of participants with tics fell below the age-predicted norm in striking distractors, whereas fewer than 10% fell outside age-predicted norms in other task parameters. Conclusions. In children with tics (without comorbid ADHD), acting upon both targets and distractors suggests reduced ability to suppress responses to potential triggers for action. This may be related to increased sensorimotor noise or abnormal sensory gating.
Open Access
Machine Learning-based Tools for Predicting Neurological Deterioration in Non-operative Degenerative Cervical Myelopathy Patients
(2024-06-27) Al-Shawwa, Abdul-Jawwad; Cadotte, David W.; Anderson, David W.; Casha, Steven; Dukelow, Sean P.
Background Degenerative cervical myelopathy (DCM) is the most common form of atraumatic spinal cord injury globally. DCM is characterized by the progressive compression of the cervical spinal cord as a result of vertebral column spondylotic degeneration. While surgery is currently the only effective treatment of DCM, clinical guidelines remain unclear on the benefit of surgery for patients with mild forms of DCM. This thesis utilizes machine learning based tools to elucidate clinical and imaging indicators of neurological deterioration in non-operative DCM patients. This thesis is comprised of two independent studies, one focussing on clustering patient groups at risk of deteriorating and the second focusing on developing a supervised machine learning (ML) model capable of predicting neurological deterioration. Methods DCM patients recruited from 2016-2023 underwent MRI scans, including T2w, diffusion tensor imaging (DTI), and magnetization transfer (MT) scans, along with a series of clinical metrics. These were collected every six months, resulting in 124 overall entries. T2w imaging scans were assessed for spinal cord compression, and cervical spinal canal diameter (SCD) was measured. Clustering was achieved through PaCMAP dimensionality reduction and K-Means clustering for the first study. Logistic regressions, support vector classifiers, and random forest classifiers were trained and tested for the second study. Findings We elucidated five patient groups with their associated risks of deterioration, according to both SCD range and cord compression pattern. Furthermore, we found that the compression pattern is unimportant at SCD extremes (≤14.5 mm or >15.75mm). Our best-performing supervised ML model had a testing balanced accuracy of 0.830 and ROC-AUC of 0.87. The three most important metrics for predicting neurological deterioration based on the model were MT ratio above the maximally compressed cervical level in the dorsal and ventral funiculi, and moderate tingling in the arm, shoulder, or hand (quickDASH item 10). Significance and Conclusion SCD and focal cord compression alone do not reliably predict an increased risk of neurological deterioration, their combination does. Furthermore, MT and DTI scans improve the prediction of neurological deterioration in non-operative mild DCM patients.
Open Access
Novel Functional Magnetic Resonance Imaging Analysis Approaches for Investigations of the Dynamics of Resting-State Functional Connectivity
(2018-08-23) Sojoudi, Alireza; Goodyear, Bradley G.; Smith, Michael Richard; Dukelow, Sean P.; MacIntosh, Bradley; MacMaster, Frank P.; Sotero Díaz, Roberto
Spontaneous fluctuations of blood-oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) signals are highly synchronous between brain regions that serve similar functions. This provides a means to investigate functional networks of the human brain; however, most data analysis techniques assume functional connections are constant over time. This is problematic when studying brain processes associated with aging or neurological disease, where functional connections may become highly variable. Proposed methods of examining moment-to-moment changes in the strength of functional connections over an imaging session (so called dynamic connectivity) are not well established, and there are several pitfalls in current analysis approaches. In this thesis, novel analysis frameworks are developed to address several issues associated with dynamic resting-state fMRI analysis techniques. These techniques are then used to analyze the dynamics of functional connectivity within long-range and local brain networks. Specifically, a hierarchical observation modeling approach is proposed to permit statistical inference of the presence of dynamic connectivity at any point in time. Also, a sliding-window regional homogeneity approach is developed to examine the dynamics of local functional connectivity, to gain even further insight into the global functional organization of the human brain. Finally, the proposed methods are used in a study to determine resting-state local and long-range connectivity changes related to healthy aging, and further, how these changes demonstrate that age changes the proportion of time the brain occupies certain functional states. The studies in this thesis greatly further our understanding of the functional architecture of the human brain, in terms of how local and long-distance interactions are organized both in space and time. This thesis also helps establish a framework for dynamic resting-state fMRI analysis with consistency and reliability.
Open Access
The PSTIM Trial: Pediatric Transcranial Static Magnetic Field Stimulation to Improve Motor Learning
(2019-05-30) Hollis, Asha; Kirton, Adam; Zewdie, Ephrem Takele; Condliffe, Elizabeth G.; Dukelow, Sean P.
Non-invasive neuromodulation is an emerging therapy for children with early brain injury but is difficult to apply to preschoolers where windows of developmental plasticity are optimal. Transcranial static magnetic field stimulation (tSMS) decreases motor cortex excitability in adults but effects on the developing brain are unstudied. We aimed to determine the effects of tSMS on primary motor cortex (M1) excitability and motor learning in healthy children. Our randomized, sham-controlled, double-blinded, 3-arm, cross-over interventional trial enrolled 24 typically developing school-aged children. We used a linear mixed effects model to examine intervention effects over time. Our results demonstrated that tSMS modulates motor learning. Contralateral (right) tSMS inhibited early motor learning in the trained hand (p<0.01) while ipsilateral (left) tSMS facilitated later stages of motor learning (p<0.01). We did not observe changes in cortical excitability as assessed by transcranial magnetic stimulation (TMS) generated motor-evoked potential (MEP) amplitudes and intracortical neurophysiology paradigms. We demonstrated the feasibility, safety, and favourable tolerability of tSMS in a pediatric population. We conclude that tSMS over motor cortex can modulate motor learning in children with effects specific to both the hemisphere of stimulation and stage of learning. Our findings suggest therapeutic potential for tSMS neuromodulation in young children with cerebral palsy (CP).
Open Access
Quantitative Assessment of Gait During Rehabilitation Using an Instrumented Treadmill
(2023-09-22) Fitzsimons, Karson; Bertram, John E.A.; Dukelow, Sean P.; Condliffe, Elizabeth G.; Schroeder, Ryan T.; Manocha, Ranita H.
Kinetic gait analysis of subacute stroke is a relatively unexplored area of study. Chronic stroke literature on the subject is extensive but does not capture the time period where the extent of recovery is greatest. Translating methods of gait analysis seen in research to a clinical setting is subject to many additional requirements which have previously prevented such investigations. The work presented in this thesis represents the first investigation using NeuroRecoVR, a new instrumented treadmill facility located within an inpatient rehabilitation gym. Working directly with inpatient physiotherapists, this study examines kinetic based gait parameters to quantify levels of impairment in subacute stroke. Recovery is most readily seen in changes in the walking speed of an individual, with many other gait parameters changing alongside walking speed. Therefor the relationships for all parameters of interest to walking speed are investigated in both neurologically intact controls (n = 14) and those undergoing rehabilitation for subacute stroke (n = 15). Parameters including spatiotemporal measures, forces, impulses, center of mass trajectory, center of pressure variability, and measures of symmetry were calculated for both groups. Subacute stroke participants have higher levels of asymmetry, increased instability, and altered gait dynamics compared to neurologically intact controls. The extent of recovery for each parameter was examined in a subset of stroke patients who took part in instrumented treadmill training over 1-2 months of rehabilitation (n = 4; mean ±SD age = 65 ±17; mean ±SD days post stroke at first session = 79 ±67). These participants showed improvements in stability, walking speed, and symmetry over the course of rehabilitation. These results show the benefit and potential for the use of kinetic analysis for aspects of both research and rehabilitation
Open Access
Quantitatively assessing aging effects in rapid motor behaviours: a cross-sectional study
(2022-07-26) Moulton, Richard H.; Rudie, Karen; Dukelow, Sean P.; Scott, Stephen H.
Abstract Background An individual’s rapid motor skills allow them to perform many daily activities and are a hallmark of physical health. Although age and sex are both known to affect motor performance, standardized methods for assessing their impact on upper limb function are limited. Methods Here we perform a cross-sectional study of 643 healthy human participants in two interactive motor tasks developed to quantify sensorimotor abilities, Object-Hit (OH) and Object-Hit-and-Avoid (OHA). The tasks required participants to hit virtual objects with and without the presence of distractor objects. Velocities and positions of hands and objects were recorded by a robotic exoskeleton, allowing a variety of parameters to be calculated for each trial. We verified that these tasks are viable for measuring performance in healthy humans and we examined whether any of our recorded parameters were related to age or sex. Results Our analysis shows that both OH and OHA can assess rapid motor behaviours in healthy human participants. It also shows that while some parameters in these tasks decline with age, those most associated with the motor system do not. Three parameters show significant sex-related effects in OH, but these effects disappear in OHA. Conclusions This study suggests that the underlying effect of aging on rapid motor behaviours is not on the capabilities of the motor system, but on the brain’s capacity for processing inputs into motor actions. Additionally, this study provides a baseline description of healthy human performance in OH and OHA when using these tasks to investigate age-related declines in sensorimotor ability.
Open Access
Sensorimotor robotic changes of tDCS and HD-tDCS enhanced motor learning in children
(2018-07-06) Cole, Lauran; Kirton, Adam; Dukelow, Sean P.; Emery, Carolyn A.
Non-invasive brain stimulation, such as transcranial direct-current stimulation (tDCS), can alter cortical excitability and human behavior but investigations to date have been limited in pediatrics. Emerging neurostimulation technologies such as high-definition tDCS (HD-tDCS) are unstudied in the developing brain. Application of tDCS can safely enhance motor skill acquisition in children but mechanisms are poorly understood. Robotics can objectively quantify sensorimotor function and may examine functional changes associated with motor learning and neurostimulation. We aimed to characterize the effects of tDCS and HD-tDCS on motor learning in healthy children. Our randomized, blinded, sham-controlled five day interventional trial demonstrated that both tDCS and HD-tDCS can enhance motor learning with medium to large effect sizes, lasting effects, and favorable safety and tolerability. To explore changes in sensorimotor function accompanying enhanced motor learning, a validated robotic protocol was performed before and after the trial. Motor training was associated with changes in sensory and motor function with less evident effects of stimulation. Both tDCS and HD-tDCS enhance motor learning in children while robotics can explore associated behavioural mechanisms, both of which promise to advance neurorehabilitation strategies in disabled children.
Open Access
Sensorimotor Robotic Measures of tDCS- and HD-tDCS-Enhanced Motor Learning in Children
(2018-12-18) Cole, Lauran; Dukelow, Sean P.; Giuffre, Adrianna; Nettel-Aguirre, Alberto; Metzler, Megan J.; Kirton, Adam
Transcranial direct-current stimulation (tDCS) enhances motor learning in adults. We have demonstrated that anodal tDCS and high-definition (HD) tDCS of the motor cortex can enhance motor skill acquisition in children, but behavioral mechanisms remain unknown. Robotics can objectively quantify complex sensorimotor functions to better understand mechanisms of motor learning. We aimed to characterize changes in sensorimotor function induced by tDCS and HD-tDCS paired motor learning in children within an interventional trial. Healthy, right-handed children (12–18 y) were randomized to anodal tDCS, HD-tDCS, or sham targeting the right primary motor cortex during left-hand Purdue pegboard test (PPT) training over five consecutive days. A KINARM robotic protocol quantifying proprioception, kinesthesia, visually guided reaching, and an object hit task was completed at baseline, posttraining, and six weeks later. Effects of the treatment group and training on changes in sensorimotor parameters were explored. Twenty-four children (median 15.5 years, 52% female) completed all measures. Compared to sham, both tDCS and HD-tDCS demonstrated enhanced motor learning with medium effect sizes. At baseline, multiple KINARM measures correlated with PPT performance. Following training, visually guided reaching in all groups was faster and required less corrective movements in the trained arm ((2) = 9.250, ). Aspects of kinesthesia including initial direction error improved across groups with sustained effects at follow-up ((2) = 9.000, ). No changes with training or stimulation were observed for position sense. For the object hit task, the HD-tDCS group moved more quickly with the right hand compared to sham at posttraining ((2) = 6.255, ). Robotics can quantify complex sensorimotor function within neuromodulator motor learning trials in children. Correlations with PPT performance suggest that KINARM metrics can assess motor learning effects. Understanding how tDCS and HD-tDCS enhance motor learning may be improved with robotic outcomes though specific mechanisms remain to be defined. Exploring mechanisms of neuromodulation may advance therapeutic approaches in children with cerebral palsy and other disabilities.
Open Access
The independence of impairments in proprioception and visuomotor adaptation after stroke
(2024-05-18) Moore, Robert T.; Piitz, Mark A.; Singh, Nishita; Dukelow, Sean P.; Cluff, Tyler
Abstract Background Proprioceptive impairments are common after stroke and are associated with worse motor recovery and poor rehabilitation outcomes. Motor learning may also be an important factor in motor recovery, and some evidence in healthy adults suggests that reduced proprioceptive function is associated with reductions in motor learning. It is unclear how impairments in proprioception and motor learning relate after stroke. Here we used robotics and a traditional clinical assessment to examine the link between impairments in proprioception after stroke and a type of motor learning known as visuomotor adaptation. Methods We recruited participants with first-time unilateral stroke and controls matched for overall age and sex. Proprioceptive impairments in the more affected arm were assessed using robotic arm position- (APM) and movement-matching (AMM) tasks. We also assessed proprioceptive impairments using a clinical scale (Thumb Localization Test; TLT). Visuomotor adaptation was assessed using a task that systematically rotated hand cursor feedback during reaching movements (VMR). We quantified how much participants adapted to the disturbance and how many trials they took to adapt to the same levels as controls. Spearman’s rho was used to examine the relationship between proprioception, assessed using robotics and the TLT, and visuomotor adaptation. Data from healthy adults were used to identify participants with stroke who were impaired in proprioception and visuomotor adaptation. The independence of impairments in proprioception and adaptation were examined using Fisher’s exact tests. Results Impairments in proprioception (58.3%) and adaptation (52.1%) were common in participants with stroke (n = 48; 2.10% acute, 70.8% subacute, 27.1% chronic stroke). Performance on the APM task, AMM task, and TLT scores correlated weakly with measures of visuomotor adaptation. Fisher’s exact tests demonstrated that impairments in proprioception, assessed using robotics and the TLT, were independent from impairments in visuomotor adaptation in our sample. Conclusion Our results suggest impairments in proprioception may be independent from impairments in visuomotor adaptation after stroke. Further studies are needed to understand factors that influence the relationship between motor learning, proprioception and other rehabilitation outcomes throughout stroke recovery.
Open Access
The use of machine learning and deep learning techniques to assess proprioceptive impairments of the upper limb after stroke
(2023-01-27) Hossain, Delowar; Scott, Stephen H.; Cluff, Tyler; Dukelow, Sean P.
Abstract Background Robots can generate rich kinematic datasets that have the potential to provide far more insight into impairments than standard clinical ordinal scales. Determining how to define the presence or absence of impairment in individuals using kinematic data, however, can be challenging. Machine learning techniques offer a potential solution to this problem. In the present manuscript we examine proprioception in stroke survivors using a robotic arm position matching task. Proprioception is impaired in 50–60% of stroke survivors and has been associated with poorer motor recovery and longer lengths of hospital stay. We present a simple cut-off score technique for individual kinematic parameters and an overall task score to determine impairment. We then compare the ability of different machine learning (ML) techniques and the above-mentioned task score to correctly classify individuals with or without stroke based on kinematic data. Methods Participants performed an Arm Position Matching (APM) task in an exoskeleton robot. The task produced 12 kinematic parameters that quantify multiple attributes of position sense. We first quantified impairment in individual parameters and an overall task score by determining if participants with stroke fell outside of the 95% cut-off score of control (normative) values. Then, we applied five machine learning algorithms (i.e., Logistic Regression, Decision Tree, Random Forest, Random Forest with Hyperparameters Tuning, and Support Vector Machine), and a deep learning algorithm (i.e., Deep Neural Network) to classify individual participants as to whether or not they had a stroke based only on kinematic parameters using a tenfold cross-validation approach. Results We recruited 429 participants with neuroimaging-confirmed stroke (< 35 days post-stroke) and 465 healthy controls. Depending on the APM parameter, we observed that 10.9–48.4% of stroke participants were impaired, while 44% were impaired based on their overall task score. The mean performance metrics of machine learning and deep learning models were: accuracy 82.4%, precision 85.6%, recall 76.5%, and F1 score 80.6%. All machine learning and deep learning models displayed similar classification accuracy; however, the Random Forest model had the highest numerical accuracy (83%). Our models showed higher sensitivity and specificity (AUC = 0.89) in classifying individual participants than the overall task score (AUC = 0.85) based on their performance in the APM task. We also found that variability was the most important feature in classifying performance in the APM task. Conclusion Our ML models displayed similar classification performance. ML models were able to integrate more kinematic information and relationships between variables into decision making and displayed better classification performance than the overall task score. ML may help to provide insight into individual kinematic features that have previously been overlooked with respect to clinical importance.
Open Access
Treatment of Persistent Headache Attributed to Mild Traumatic Injury to the Head in Patients with Persistent Post Concussion Symptoms using Repetitive Transcranial Magnetic Stimulation
(2019-05-07) Stilling, Joan M.; Monchi, Oury; Debert, Chantel T.; Amoozegar, Farnaz; Dukelow, Sean P.
Persistent post-traumatic headache (PTH) following a mild traumatic brain injury (mTBI) is one of the most prominent and highly-reported persistent post-concussion symptoms (PPCS). Non-pharmacologic treatment alternatives, including non-invasive neurostimulation technologies, have been proposed for use. After a systematic review investigating transcranial magnetic and direct current stimulation (TMS/tDCS) for management of headache, we designed a double-blind, sham-controlled, randomized trial investigating repetitive TMS (rTMS) for treatment of persistent PTH in patients with PPCS. Our primary outcome was a change in headache frequency and severity at one-month post-treatment. Twenty participants underwent rTMS therapy to the left dorsolateral prefrontal cortex (DLPFC). Headache diaries and clinical questionnaires assessing function, cognition, and mood were completed. Headache severity demonstrated a significant time effect, while headache frequency demonstrated a reduction across all time points for both the real and sham groups, based on descriptive analysis. Secondary outcomes demonstrated improvements in function, reduced PPCS, and depression in the real-treatment group, with no serious adverse effects. A phase II study is warranted.
Embargo
Understanding Stroke Rehabilitation Progression in a Robotic Rehabilitation Trial
(2020-05-29) Keeling, Alexa Brianne; Dukelow, Sean P.; Cluff, Tyler; Hill, Michael D.
Stroke is one of the leading causes of adult disability worldwide, leaving many individuals requiring rehabilitation to regain independence. A critical component to any rehabilitation program is progression, which is the ability of therapy program to change according to patient improvement. Currently, there is little known about therapy progression, which negatively impacts the optimization of rehabilitation programs. Therefore, the purpose of this thesis was to better understand how stroke survivor’s kinematics change throughout therapy in order to inform future rehabilitation programs. The first step in answering this question was to understand how motor learning contributes to recovery after stroke, which is explored in Chapter Two. Next, a therapy program was needed in order to study how stroke survivors progress during rehabilitation. The motor learning and stroke recovery principles discussed in Chapter Two were then used to inform the development of tasks for a robotic rehabilitation program for stroke survivors. The development, and subsequent testing, of the tasks are discussed in Chapter Three. It was found that this robotic therapy program was feasible after stroke and has the potential to improve clinical outcomes when compared only to standard of care. Using the results from this pilot study, the robotic therapy tasks were refined, as well as the study protocol, and gave rise to a Phase II Clinical Trial (RESTORE). As discussed in Chapter Four, subacute stroke patients were recruited to receive 20 days of robotic therapy for 1 or 2-hours a day, beginning either 5-9 days or 21-25 days post-stroke. Following completion of the intervention, changes in the participants’ kinematics measuring speed, accuracy, and smoothness of movements were examined. It was found that kinematics of directional error and hand path ratio (measures of accuracy), as well as smoothness, predominantly increased during the first 5 days of the intervention. Movement speed and percent time in target (a measure of accuracy), on the other hand, continued to improve throughout the intervention. These findings should be interpreted with caution due to small sample size but may be used to inform the progression of future robotic rehabilitation tasks.
Open Access
Utilization of early supported discharge and outpatient rehabilitation services following inpatient stroke rehabilitation
(2024-05-30) Razavilar, Negar; Tran, Dat T.; Dukelow, Sean P.; Round, Jeff
Abstract Background Studies examining factors associated with patient referral to early supported discharge (ESD)/outpatient rehabilitation (OPR) programs and utilization of ESD/OPR services after discharge from inpatient stroke rehabilitation (IPR) are scarce. Accordingly, we examined utilization of ESD/OPR services following discharge from IPR and patient factors associated with service utilization. Methods Stroke patients discharged from IPR facilities in Alberta between April 2014 and March 2016 were included and followed for one year for ESD/OPR service utilization. Multivariable linear and negative binomial regressions were used to examine association of patients’ factors with ESD/OPR use. Results We included 752 patients (34.4% of 2,187 patients discharged from IPR) who had 40,772 ESD/OPR visits during one year of follow-up in the analysis. Mean and median ESD/OPR visits were 54.2 and 36 visits, respectively. Unadjusted ESD/OPR visits were lower in females and patients aged ≥ 60 years but were similar between urban and rural areas. After adjustment for patient factors, patients in urban areas and discharged home after IPR were associated with 83.5% and 61.9%, respectively, increase in ESD/OPR visits, while having a right-body stroke was associated with 23.5% increase. Older patients used ESD/OPR less than their younger counterparts (1.4% decrease per one year of older age). Available factors explained 12.3% of variation in ESD/OPR use. Conclusion ESD/OPR utilization after IPR in Alberta was low and varied across age and geographic locations. Factors associated with use of ESD/OPR were identified but they could not fully explain variation of ESD/OPR use.