Altered corticomuscular coherence elicited by paced isotonic contractions in individuals with cerebral palsy: a case-control study

The neuromechanical of Beta-band corticomuscular coupling within the human motor system

Beta-band activity in the sensorimotor cortex is considered a potential biomarker for evaluating motor functions. The intricate connection between the brain and muscle (corticomuscular coherence), especially in beta band, was found to be modulated by multiple motor demands. This coherence also showed abnormality in motion-related disorders. However, although there has been a substantial accumulation of experimental evidence, the neural mechanisms underlie corticomuscular coupling in beta band are not yet fully clear, and some are still a matter of controversy. In this review, we summarized the findings on the impact of Beta-band corticomuscular coherence to multiple conditions (sports, exercise training, injury recovery, human functional restoration, neurodegenerative diseases, age-related changes, cognitive functions, pain and fatigue, and clinical applications), and pointed out several future directions for the scientific questions currently unsolved. In conclusion, an in-depth study of Beta-band corticomuscular coupling not only elucidates the neural mechanisms of motor control but also offers new insights and methodologies for the diagnosis and treatment of motor rehabilitation and related disorders. Understanding these mechanisms can lead to personalized neuromodulation strategies and real-time neurofeedback systems, optimizing interventions based on individual neurophysiological profiles. This personalized approach has the potential to significantly improve therapeutic outcomes and athletic performance by addressing the unique needs of each individual.

Corticomuscular Coherence in Children with Unilateral Cerebral Palsy: A Feasibility and Preliminary Protocol Study

Objective This study assessed the feasibility of corticomuscular coherence measurement during a goal-directed task in children with unilateral cerebral palsy while establishing optimal experimental parameters. Methods Participants (Manual Ability Classification System levels I-III) completed a submaximal isometric goal-directed grip task during simultaneous electroencephalography and electromyography (EMG) acquisition. Results All participants (n = 11, 6 females, mean age 11.3 ±2.4 years) completed corticomuscular coherence procedures. Of the 40 trials obtained per extremity, an average of 29 (n = 9) and 27 (n = 10) trials were retained from the more- and less-affected extremities, respectively. Obtaining measurement stability required an average of 28 trials per extremity. Conclusion Findings from this work support the feasibility of corticomuscular coherence measurement in children with unilateral cerebral palsy. Acquiring 28 to 40 corticomuscular coherence trials per extremity is ideal. The experimental parameters established in this work will inform future corticomuscular coherence application in pediatric unilateral cerebral palsy.

Disrupted cortico-peripheral interactions in motor disorders

Motor disorders may arise from neurological damage or diseases at different levels of the hierarchical motor control system and side-loops. Altered cortico-peripheral interactions might be essential characteristics indicating motor dysfunctions. By integrating cortical and peripheral responses, top-down and bottom-up cortico-peripheral coupling measures could provide new insights into the motor control and recovery process. This review first discusses the neural bases of cortico-peripheral interactions, and corticomuscular coupling and corticokinematic coupling measures are addressed. Subsequently, methodological efforts are summarized to enhance the modeling reliability of neural coupling measures, both linear and nonlinear approaches are introduced. The latest progress, limitations, and future directions are discussed. Finally, we emphasize clinical applications of cortico-peripheral interactions in different motor disorders, including stroke, neurodegenerative diseases, tremor, and other motor-related disorders. The modified interaction patterns and potential changes following rehabilitation interventions are illustrated. Altered coupling strength, modified coupling directionality, and reorganized cortico-peripheral activation patterns are pivotal attributes after motor dysfunction. More robust coupling estimation methodologies and combination with other neurophysiological modalities might more efficiently shed light on motor control and recovery mechanisms. Future studies with large sample sizes might be necessary to determine the reliabilities of cortico-peripheral interaction measures in clinical practice.

Community-Based Upper Extremity Power Training for Youth with Cerebral Palsy: A Pilot Study

Aim: To examine the effects of an upper-extremity, community-based, and power-training intervention.Methods: Twelve participants with cerebral palsy (CP) [8 males, 4 females; mean age 14 years 6 months (SD 5 years 4 months), range 7-24] were randomly assigned to a rest-training (RT; n = 6) or training-rest (n = 6) group in this randomized, cross-over design. Training took place in participants' home or school, three times per week for 6 weeks. We examined changes in upper extremity average power output (Pavg) in watts (W) and changes in function via the Pediatric Outcomes Data Collection Instrument (PODCI).Results: Each participant completed at least 15 of the 18 total training sessions (91.2% adherence). Pavg increased 92.2% on average among participants (p < .05). There was a significant three-way interaction among treatment, sequence, and period with the data stratified by (Bimanual Fine Motor Function [BFMF]) level on the pain subscale of the PODCI (p = 0.0118). All participants decreased pain after training with the exception of individuals with lower functioning (BFMF II-V) in the RT group.Conclusion: A community-based upper extremity power-training intervention was feasible and effective at improving power among young people with CP and has the potential to improve pain.

Corticomuscular Coherence and Its Applications: A Review

Corticomuscular coherence (CMC) is an index utilized to indicate coherence between brain motor cortex and associated body muscles, conventionally. As an index of functional connections between the cortex and muscles, CMC research is the focus of neurophysiology in recent years. Although CMC has been extensively studied in healthy subjects and sports disorders, the purpose of its applications is still ambiguous, and the magnitude of CMC varies among individuals. Here, we aim to investigate factors that modulate the variation of CMC amplitude and compare significant CMC between these factors to find a well-developed research prospect. In the present review, we discuss the mechanism of CMC and propose a general definition of CMC. Factors affecting CMC are also summarized as follows: experimental design, band frequencies and force levels, age correlation, and difference between healthy controls and patients. In addition, we provide a detailed overview of the current CMC applications for various motor disorders. Further recognition of the factors affecting CMC amplitude can clarify the physiological mechanism and is beneficial to the implementation of CMC clinical methods.

Dynamic cortical participation during bilateral, cyclical ankle movements: Effects of Parkinson's disease

Parkinson’s disease (PD) is known to increase asymmetry and variability of bilateral movements. However, the mechanisms of such abnormalities are not fully understood. Here, we aimed to investigate whether kinematic abnormalities are related to cortical participation during bilateral, cyclical ankle movements, which required i) maintenance of a specific frequency and ii) bilateral coordination of the lower limbs in an anti-phasic manner. We analyzed electroencephalographic and electromyographic signals from nine men with PD and nine aged-matched healthy men while they sat and cyclically dorsi- and plantarflexed their feet. This movement was performed at a similar cadence to normal walking under two conditions: i) self-paced and ii) externally paced by a metronome. Participants with PD exhibited reduced range of motion and more variable bilateral coordination. However, participants with and without PD did not differ in the magnitude of corticomuscular coherence between the midline cortical areas and tibialis anterior and medial gastrocnemius muscles. This finding suggests that either the kinematic abnormalities were related to processes outside linear corticomuscular communication or PD-related changes in neural correlates maintained corticomuscular communication but not motor performance.

Exergaming with a pediatric exoskeleton: Facilitating rehabilitation and research in children with cerebral palsy

Effective rehabilitation of children with cerebral palsy (CP) requires intensive task-specific exercise but many in this population lack the motor capabilities to complete the desired training tasks. Providing robotic assistance is a potential solution yet the effects of this assistance are unclear. We combined a novel exoskeleton and exercise video game (exergame) to create a new rehabilitation paradigm for children with CP. We incorporated high density electroencephalography (EEG) to assess cortical activity. Movement to targets in the game was controlled by knee extension while standing. The distance between targets was the same with and without the exoskeleton to isolate the effect of robotic assistance. Our results show that children with CP maintain or increase knee extensor muscle activity during knee extension in the presence of synergistic robotic assistance. Our EEG findings also demonstrate that participants remained engaged in the exercise with robotic assistance. Interestingly we observed a developmental trajectory of sensorimotor mu rhythm in children with CP similar, though delayed, to those reported in typically developing children. While not the goal here, the exoskeleton significantly increased knee extension in 3/6 participants during use. Future work will focus on utilizing the exoskeleton to enhance volitional knee extension capability and in combination with EMG and EEG to study sensorimotor cortex response to progressive exercise in children with CP.

Avaliação dos ligamentos longitudinais da coluna de ratos Wistar em modelo experimental da terapia Suit

RESUMO Ligamentos adaptam-se de acordo com a intensidade da atividade física e carga mecânica a que são submetidos. Na última década, na área da fisioterapia neurofuncional infantil, têm surgido métodos e protocolos que possuem em comum o termo suit para caracterizar a existência de vestimentas com bandas elásticas ajustáveis e a possibilidade da aplicação de carga sobre o esqueleto humano. Visto que a carga mecânica pode produzir alterações fibrocartilaginosas sobre os ligamentos e que não foram encontrados estudos avaliando o efeito da terapia suit sobre os ligamentos da coluna, justificam-se pesquisas com métodos experimentais de carga. O objetivo deste trabalho foi analisar as espessuras e morfologia dos ligamentos longitudinais da coluna de ratos Wistar quando submetidos à carga mecânica por compressão vertebral. Trinta animais foram separados em cinco grupos (G1 - controle; G2 - simulação do uso de suit; G3, G4 e G5 - manutenção da vestimenta). Ao modelo experimental do suit, em G4 e G5, foram adaptados pesos ou elásticos dispostos em "X" para sobrecarga vertebral de 50% do peso do animal, que permaneceram com a vestimenta por 40 horas ao longo de 4 semanas de experimento, 5 dias por semana. Não houve diferenças significativas para a espessura, assim como não foram observadas mudanças morfológicas nos ligamentos longitudinais. Conclui-se que não houve alterações nos ligamentos longitudinais da coluna em animais submetidos ao modelo experimental de suit terapia.