The objective of this study is to develop Neuro-Intermuscular Coordination Enhancement (NICE) rehabilitation, a novel neuromuscular control signal-guided strategy that visually guides stroke patients to individually activate motor modules through human-machine interaction. Ultimately, the development will lead to better clinical motor recovery, better quality of life, and lowered healthcare costs associated with the impairment.
Stroke is the leading cause of severe long-term disability, affecting 9.4 million Americans. Each year around 800,000 people suffer a stroke even in the USA. Chronic upper extremity motor impairment is a major contributing factor to disability; functional use of the affected UE in daily life is a key factor for increased independence, return to work, and overall quality of life. Thus, effective and innovative treatment to address long-term disability is both a major public health need and an economic necessity. This study is an early-stage, randomized controlled rehabilitation trial designed to evaluate the clinical effects, feasibility, transfer of therapeutic gains, and exploratory neurophysiological correlates of Neuro-Intermuscular Coordination Enhancement (NICE) in individuals with chronic stroke and upper-extremity hemiparesis. Forty-eight participants will be enrolled to obtain a target analyzable sample of 40 participants. Eligible participants will be randomized to either: (1) NICE, a motor module-guided rehabilitation intervention using isometric human-machine interaction and real-time EMG-based visual feedback to retrain impaired intermuscular coordination patterns; or (2) an active comparator consisting of dose-matched EMG amplitude biofeedback exercise. Both interventions will be delivered three times per week for six weeks (18 total sessions). Participants will complete assessments at baseline, immediately post-intervention, and at 10- and 18-week follow-up time points. Outcomes will include standardized clinical measures of upper-extremity motor impairment and function, measures of intermuscular coordination derived from surface electromyography, kinematic measures obtained during untrained dynamic motor tasks, and EEG-based measures of brain activity and connectivity. The primary objective is to determine whether NICE improves upper-extremity motor impairment relative to the active comparator. Secondary objectives are to evaluate intervention-related changes in intermuscular coordination and transfer of therapeutic gains to untrained motor behaviors. Exploratory objectives are to characterize rehabilitation-associated neurophysiological changes and examine relationships among EEG-derived biomarkers, intermuscular coordination, and clinical recovery outcomes.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
48
Neuro-Intermuscular Coordination Enhancement (NICE) is a motor module-guided rehabilitation intervention designed to improve upper-extremity motor recovery after stroke by retraining impaired intermuscular coordination patterns. Participants perform isometric upper-extremity force-generation tasks using a human-machine interface while receiving real-time visual feedback derived from motor module recruitment signals calculated from surface electromyography (EMG). Individualized motor module targets are derived from the participant's less-affected upper extremity and used to guide selective recruitment of impaired coordination patterns in the more-affected upper extremity. Participants will complete 18 one-hour training sessions over six weeks (3 sessions/week). During training, participants perform repetitive target-matching tasks that require preferential recruitment of specific motor modules while minimizing unintended activation of non-target modules.
EMG Amplitude Biofeedback Exercise is an active comparator rehabilitation intervention designed to improve upper-extremity motor function after stroke through targeted muscle activation training. Participants perform isometric upper-extremity exercises using a human-machine interface with real-time EMG amplitude-based visual feedback. Individualized muscle activation targets derived from the less-affected upper extremity guide training of the more-affected upper extremity. Participants will complete 18 one-hour sessions over 6 weeks (3 sessions/week).
University of Houston
Houston, Texas, United States
Fugl-Meyer Assessment (FMA) score
Motor impairment after stroke will be measured by upper extremity FMA (UE-FMA). The maximum UE-FMA motor score is 66 (i.e., 0: complete motor impairment; 66: normal motor performance). Each item is scored on a 3-point scale (0 = cannot perform, 1 = performs partially, 2 = performs fully). The FMA score reflects the level of upper extremity motor impairment.
Time frame: Baseline, six- week, 10-week, and 18-week follow-ups.
Similarity Score of Intermuscular Coordination Patterns (or Motor Modules)
Surface EMGs will be recorded from 8 key arm muscles during a 54-target isometric force generation task. A dimensionality reduction method (non-negative matrix factorization (NNMF)) will be applied to identify intermuscular coordination patterns - operational definition of motor modules in the field of motor neuroscience. They are mathematically 8-dimensional unit vectors. Similarity score is the scalar product (or dot product) between a pair of intermuscular coordination patterns in comparison (i.e., motor modules). We compute the similarity score between the less-affected and the more-affected arms. Also, surface EMGs will be recorded from 8 key arm muscles during 3D dynamic reaching tasks. NNMF will be applied to EMGs to identify and compare intermuscular coordination patterns. Similarity score is the scalar product between motor modules (i.e., intermuscular coordination patters) of the more-affected arm in stroke group and dominant arm in healthy group.
Time frame: Baseline, six- week, 10-week, and 18-week follow-ups.
Kinematic Synergy Similarity Score
Kinematic synergies are a representation of multi-joint coordination. It will be identified using NNMF algorithm applied to the joint kinematic data obtained from 3D dynamic point-to-point reaching tasks. Kinematic synergy similarity between stroke and healthy will be calculated using their scalar product.
Time frame: Baseline, six-week, 10-week, and 18-week follow-ups.
Pairwise joint angle-to-angle correlation value
Pairwise joint angle-to-angle correlation is a way to see the joint coupling using kinematic data. It will be calculated using Pearson's correlation coefficient between joint angles during the point-to-point reaching task.
Time frame: Baseline, six- week, 10-week, and 18-week follow-ups.
Active range of motion
The active range of motion will be calculated from full active range tasks for shoulder flexion/extension, internal/external rotation, abduction/adduction, elbow flexion/extension, and wrist pronation/supination. Kinematic joint positions and angles will be used to calculate the same.
Time frame: Baseline, six-week, 10-week, and 18-week follow-ups.
EEG Spectral power ratios
EEG-derived spectral power ratios will be calculated, in resting and task conditions, across different frequency bands (delta, theta, alpha, beta, gamma) and different events (onset, successful match, etc.) across four different directions of target match.
Time frame: Baseline and six-week follow-up.
EEG-derived Brain Symmetry Index
The revised brain symmetry index with EEG signals will be computed in the resting state during eyes open and closed conditions.
Time frame: Baseline and six-week follow-up.
Cortico-muscular connectivity
Functional connectivity using a directed transfer function will be computed to identify the information flow and coherence among EEG and EMG signals in the desired brain region and muscle activation associated with directional 4-target isometric force generation.
Time frame: Baseline and six-week follow-up.
Cortico-cortical connectivity
Functional connectivity using a directed transfer function will be computed to identify the information flow and coherence among EEG signals from different regions of interest (sources, e.g., ipsi and contralesional fronto-parietal regions, primary motor cortex and somatosensory cortices).
Time frame: Baseline and six-week follow-up.
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