Baseline Predictors of Response to Repetitive Task Practice in Chronic Stroke

Abstract

Background Repetitive task practice reduces mean upper extremity motor impairment in populations of patients with chronic stroke, but individual response is highly variable. A method to predict meaningful reduction in impairment in response to training based on biomarkers and other data collected prior to an intervention is needed to establish realistic rehabilitation goals and to effectively allocate resources. Objectives To identify prognostic factors and better understand the biological substrate for reductions in arm impairment in response to repetitive task practice among patients with chronic (≥6 months) post-stroke hemiparesis. Methods The intervention is a form of repetitive task practice using a combination of robot-assisted therapy and functional arm use in real-world tasks. Baseline measures include the Fugl-Meyer Assessment, Wolf Motor Function Test, Action Research Arm Test, Stroke Impact Scale, questionnaires on pain and expectancy, MRI, transcranial magnetic stimulation, kinematics, accelerometry, and genomic testing. Results Mean increase in FM-UE was 4.6 ± 1.0 SE, median 2.5. Approximately one-third of participants had a clinically meaningful response to the intervention, defined as an increase in FM ≥ 5. The selected logistic regression model had a receiver operating curve with AUC = .988 (Std Error = .011, 95% Wald confidence limits: .967–1) showed little evidence of overfitting. Six variables that predicted response represented impairment, functional, and genomic measures. Conclusion A simple weighted sum of 6 baseline factors can accurately predict clinically meaningful impairment reduction after outpatient intensive practice intervention in chronic stroke. Reduction of impairment may be a critical first step to functional improvement. Further validation and generalization of this model will increase its utility in clinical decision-making.

Therapies Targeting Stroke Recovery

“…Cramer et al 37 conducted a secondary analysis of the ICARE clinical trial (Interdisciplinary Comprehensive Arm Rehabilitation Evaluation) data, showing that, across 216 participants, there was no association of either the brain-derived neurotrophic factor val 66 met or ApoE ε4 polymorphism with month-12 outcomes poststroke, although the brain-derived neurotrophic factor val 66 met polymorphism was associated with greater cerebral atrophy at baseline, echoing findings in healthy subjects. Findings form Dimyan et al 38 suggest that variations in klotho genotype may be among variables useful for predicting arm motor gains in response to treatment among patients with chronic stroke.…”

Opportunities and challenges in the development of exoskeletons for locomotor assistance

“…Warm-starting HIL algorithms with baseline data may enable devices to adapt to exoskeleton users as their gait changes across environments or with time. It may also be possible to predict the impact of robotic exoskeleton training before completing a full protocol, although such approaches have been validated only in the upper limb 252 . Ideally, the rehabilitation goals set by patients and clinicians will be achieved by automatic tuning of wearable-device settings.…”

Considerations for at-home upper-limb rehabilitation technology following stroke: Perspectives of stroke survivors and therapists

“… 9 However, there is evidence that stroke survivors can still experience recovery in the chronic phase. 10 – 12 …”

“…9 However, there is evidence that stroke survivors can still experience recovery in the chronic phase. [10][11][12] A stroke survivor's recovery process is determined by the health system of their country and region. In Ontario, Canada, following acute care where the stroke itself is treated, patients are discharged to a variety of destinations based in large part on their post-stroke functional status as well as their social situation.…”