Background And Purpose: Functional connection between the motor cortex and muscle can be measured by electroencephalogram-electromyogram (EEG-EMG) coherence. To evaluate the functional connection to muscle between contralateral and ipsilateral motor cortices after pyramidal tract lesions, we investigated 6 patients with chronic subcortical stroke.
Methods: High-resolution EEG and EMG of the hand, forearm, and biceps muscles were recorded during 3 tonic contraction tasks: (1) elbow flexion, (2) wrist extension, and (3) power grip. To evaluate the cortical control of EMG, EEG-EMG coherence was computed.
Results: EEG-EMG coherence was localized over the contralateral sensorimotor area in all circumstances, and there was no significant coherence at the ipsilateral side. EEG-EMG coherence was significantly smaller on the affected side for the hand and forearm muscles but not for the biceps muscle.
Conclusions: All direct functional connections to muscle after recovered subcortical stroke come from the contralateral motor cortex. The different effects of the lesion on the proximal and distal muscles appear to be associated with the strength of the corticospinal pathway.
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http://dx.doi.org/10.1161/hs1101.098764 | DOI Listing |
Neuroimage
January 2025
School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, Shandong, China. Electronic address:
The monosynaptic cortico-motoneuronal connections suggest the possibility of individual motor units (MUs) receiving independent commands from motor cortex. However, previous studies that used corticomuscular coherence (CMC) between electroencephalogram (EEG) signals and electromyogram (EMG) signals have not directly explored the corticospinal functionality at the single motoneuron level. The objective of this study is to find out whether synchronous activities exist between the motor cortex and individual MUs.
View Article and Find Full Text PDFBiomed Signal Process Control
November 2024
University of Illinois Urbana-Champaign, Department of Bioengineering, Grainger College of Engineering, Urbana, Illinois, United States.
Following a stroke, compensation for the loss of ipsilesional corticospinal and corticobulbar projections, results in increased reliance on contralesional motor pathways during paretic arm movement. Better understanding outcomes of post-stroke contralesional cortical adaptation outcomes may benefit more targeted post-stroke motor rehabilitation interventions. This proof-of-concept study involves eight healthy controls and ten post-stroke participants.
View Article and Find Full Text PDFFront Neurosci
October 2024
School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
Introduction: Sensorimotor synchronization (SMS) is the human ability to align body movement rhythms with external rhythmic stimuli. While the effects of rhythmic stimuli containing only temporal information on SMS have been extensively studied, less is known about how spatial information affects SMS performance. This study investigates the neural mechanisms underlying SMS with rhythmic stimuli that include both temporal and spatial information, providing insights into the influence of these factors across different sensory modalities.
View Article and Find Full Text PDFJ Neural Eng
November 2024
Department of Computer, Control, and Management Engineering, Sapienza University of Rome, Rome, Italy.
Brain-Computer Interfaces targeting post-stroke recovery of the upper limb employ mainly electroencephalography to decode movement-related brain activation. Recently hybrid systems including muscular activity were introduced. We compared the motor task discrimination abilities of three different features, namely event-related desynchronization/synchronization (ERD/ERS) and movement-related cortical potential (MRCP) as brain-derived features and cortico-muscular coherence (CMC) as a hybrid brain-muscle derived feature, elicited in 13 healthy subjects and 13 stroke patients during the execution/attempt of two simple hand motor tasks (finger extension and grasping) commonly employed in upper limb rehabilitation protocols.
View Article and Find Full Text PDFNeuroimage
September 2024
Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK. Electronic address:
How cortical oscillations are involved in the coordination of functionally coupled muscles and how this is modulated by different movement contexts (static vs dynamic) remains unclear. Here, this is investigated by recording high-density electroencephalography (EEG) and electromyography (EMG) from different forearm muscles while healthy participants (n = 20) performed movement tasks (static and dynamic posture holding, and reaching) with their dominant hand. When dynamic perturbation was applied, beta band (15-35 Hz) activities in the motor cortex contralateral to the performing hand reduced during the holding phase, comparative to when there was no perturbation.
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