Pathway-specific modulatory effects of neuromuscular electrical stimulation during pedaling in chronic stroke survivors

Abstract

BackgroundNeuromuscular electrical stimulation (NMES) is extensively used in stroke motor rehabilitation. How it promotes motor recovery remains only partially understood. NMES could change muscular properties, produce altered sensory inputs, and modulate fluctuations of cortical activities; but the potential contribution from cortico-muscular couplings during NMES synchronized with dynamic movement has rarely been discussed.MethodWe investigated cortico-muscular interactions during passive, active, and NMES rhythmic pedaling in healthy subjects and chronic stroke survivors. EEG (128 channels), EMG (4 unilateral lower limb muscles) and movement parameters were measured during 3 sessions of constant-speed pedaling. Sensory-level NMES (20 mA) was applied to the muscles, and cyclic stimulation patterns were synchronized with the EMG during pedaling cycles. Adaptive mixture independent component analysis was utilized to determine the movement-related electro-cortical sources and the source dipole clusters. A directed cortico-muscular coupling analysis was conducted between representative source clusters and the EMGs using generalized partial directed coherence (GPDC). The bidirectional GPDC was compared across muscles and pedaling sessions for post-stroke and healthy subjects.ResultsDirected cortico-muscular coupling of NMES cycling was more similar to that of active pedaling than to that of passive pedaling for the tested muscles. For healthy subjects, sensory-level NMES could modulate GPDC of both ascending and descending pathways. Whereas for stroke survivors, NMES could modulate GPDC of only the ascending pathways.ConclusionsBy clarifying how NMES influences neuromuscular control during pedaling in healthy and post-stroke subjects, our results indicate the potential limitation of sensory-level NMES in promoting sensorimotor recovery in chronic stroke survivors.

Flexible Recruitments of Fundamental Muscle Synergies in the Trunk and Lower Limbs for Highly Variable Movements and Postures

“…Furthermore, if this is the case, it may provide a rationale for designing interventions targeting each fundamental muscle synergy with simple tasks before practicing complex tasks at the beginning of rehabilitation. Potential interventions include muscle synergy-based approaches using functional electrical stimulations to optimize the structure of fundamental synergies and temporal recruitments to improve motor performance in stroke [55][56][57][58]. Lastly, we found that different tasks with various biomechanical demands and constraints may largely share the same muscle synergies with different combinations of synergies to be merged.…”

Combined Use of EMG and EEG Techniques for Neuromotor Assessment in Rehabilitative Applications: A Systematic Review

“…The distribution of papers in the categories is shown in a pie chart in Figure 4. Study of the cortico-muscular coupling (1) during motor tasks [37][38][39][40][41] and (2) with electrical stimulation [42][43][44][45][46] Investigation of the effects of exoskeleton on functional connectivity [47][48][49] Investigation of the effects of visual feedback [50,51] Detection of movement intention [52,53] Study of the interhemispheric interaction with TMS [54] Study of a neurophysiological marker of stress [55] Study of slow cortical potentials in stroke [56] Study of correlation between lower back pain and altered postural stabilization [57] Test new rehabilitation paradigm [34,[58][59][60][61][62] Investigation of the efficacy of BMI [63] and EEG feedback [64] Table 1. Type of study and aim.…”

“…An aim commonly found in these works was the assessment of the cortico-muscular coupling during movements [37][38][39][40][41] as a method to better understand motor control mechanisms for improving the rehabilitation design. Cortico-muscular coherence was also tested as a tool for investigating the effects of functional electrical stimulation [42][43][44][45][46]. Some studies analyzed the effects of treatments based on exoskeletons on neuromotor outcomes [47][48][49].…”

“…[40], 49.9 ± 10.9 [79], 56 [68], n.a. [70], 46-60 [71], 51.4 ± 11.1 [56]; Subacute stroke: 32-79 [50]; Subacute and chronic stroke: 52-64 [69], 42-92 [82] Parkinson disease: 40-80 [76]; Cerebral palsy: 5-19 [34]; Spinal cord injury: 32.5 ± 6.2 [38] [43], 30 [47,48], 23 [59], 12 + 30 [82], 19 + 14 [54], 30 [83], 14 + 14 [79], 28 + 7 [85], 32 [88], 14 + 14 [55] Proximal Lower Limb Knee: [34,42,[47][48][49]80]; Hip and knee: [63] Other Torso: [57]; Face: [74]; Neck: [68] 3.3.1. Cohorts of Subjects…”

Rewiring the Lesioned Brain: Electrical Stimulation for Post-Stroke Motor Restoration

“…100 Moreover, interaction of NMES in dynamic movements could facilitate understanding of post-stroke motor rehabilitation mechanisms in the physical world, and foster to its wide applications in stroke survivors. 118 Previous studies primarily used standardized stimulation settings. It is necessary to investigate more optimized NMES paradigms considering muscle/cortical responses in different motor tasks and subjects.…”