Related Experiment Video
Updated: Feb 8, 2026
06:37
Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke
Published on: July 14, 2023
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Disrupted functional network integrity and flexibility after stroke: Relation to motor impairments
Sara Larivière1, Nick S Ward2, Marie-Hélène Boudrias3
1McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montréal, Qc, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, Qc, Canada.
Neuroimage. Clinical
|June 28, 2018
Summary
Stroke patients show altered brain network connectivity during hand movements, with reduced motor network activation and impaired switching between motor and default-mode networks. Improving motor control may enhance network flexibility and recovery.
Area of Science:
- Neuroscience
- Neurorehabilitation
- Motor Control
Background:
- Previous research focused on primary motor cortex (M1) activation after stroke.
- Limited understanding of large-scale network integration for motor, sensory, and cognitive control post-stroke.
- Need to investigate dynamic functional connectivity in whole-brain networks during motor tasks.
Purpose of the Study:
- To assess non-static functional connectivity within whole-brain networks during isometric hand grips in stroke survivors.
- To identify differences in network activity and coordination between stroke patients and healthy controls.
- To explore the relationship between network alterations and motor impairment severity.
Main Methods:
- Functional MRI (fMRI) was used in 17 stroke patients and 24 healthy controls.
- Participants performed visually-paced isometric hand grips.
- Task-based multivariate functional connectivity analysis was applied to assess spatial and temporal network dynamics and group differences.
Main Results:
- Stroke patients exhibited reduced task-related activation in the motor network (including M1) compared to controls.
- Patients showed less deactivation in the default-mode network (DMN) during the task.
- Decreased ipsilesional sensorimotor cortex activity in patients correlated with better motor function; impaired DMN deactivation suggests difficulty switching networks.
Conclusions:
- Stroke impacts large-scale brain network organization during motor tasks, affecting both motor and default-mode networks.
- Impaired network switching may hinder motor recovery.
- Modulating ipsilesional sensorimotor activity could improve motor network integrity, performance, and network flexibility for enhanced stroke recovery.
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