Cortical activation change induced by neuromuscular electrical stimulation during hand movements: a functional NIRS study

Abstract

ObjectivesNeuromuscular electrical stimulation (NMES) has been used in the field of rehabilitation for a long time. Previous studies on NMES have focused on the peripheral effect, in contrast, relatively little is known about the effect on the cerebral cortex. In the current study, we attempted to investigate the change of cortical activation pattern induced by NMES during execution of hand movements in normal subjects, using functional near infrared spectroscopy (fNIRS).MethodsTwelve healthy normal subjects were randomly assigned to the NMES group (six subjects) and the sham group (six subjects). We measured oxy-hemoglobin (HbO) in six regions of interest (ROI) during pre-NMES and post-NMES motor phase; the left dorsolateral and ventrolateral prefrontal cortex, premotor cortex, primary sensory-motor cortex (SM1), hand somatotopic area of SM1, and posterior parietal cortex. Between the pre-NMES and the post-NMES motor phases, real or sham NMES was applied on finger and wrist extensors of all subjects during a period of 5 minutes.ResultsIn all groups, during the pre-NMES motor phase, the HbO value in the hand somatotopic area of the left SM1 was higher than those of other ROIs. In the NMES group, during the post-NMES motor phase, HbO value variation in the hand somatotopic area of the left SM1 showed a significant decrease, compared with that of sham group (p < 0.05). However, in the sham group, similar aspect of results in HbO values of all ROIs was observed between pre-NMES and post-NMES motor phases (p > 0.05).ConclusionsResults of this study showed that NMES induced a decrease of cortical activation during execution of hand movements. This finding appears to indicate that application of NMES can increase the efficiency of the cerebral cortex during execution of motor tasks.

Current Change Rate Influences Sensorimotor Cortical Excitability During Neuromuscular Electrical Stimulation

“…The results of EEG time-frequency analysis at the C3 electrode are presented in Figure 2. When the NMES current exceeded the motor threshold the EEG oscillations in the alpha band were clearly depressed (Figure 2D), consistent with numerous previous studies (Blickenstorfer et al, 2009; Jang et al, 2014). However, even with a stimulation current intensity lower than the motor threshold, the alpha band EEG oscillation was also depressed during NMES (Figures 2A–C).…”

Exploring Hemodynamic Responses Using Mirror Visual Feedback With Electromyogram-Triggered Stimulation and Functional Near-Infrared Spectroscopy

“…However, we found that the oxy-Hb concentration of the left SMA, right PrG, PoG, and SMA in ESC tasks significantly decreased compared with those without ESC. Jang et al (2014) have demonstrated that cortical activation of the sensorimotor cortex was decreased by neuromuscular ES. They suggested that the results were related to the motor learning effect.…”

Functional Spectroscopy Mapping of Pain Processing Cortical Areas During Non-painful Peripheral Electrical Stimulation of the Accessory Spinal Nerve

“…The main disadvantage is that it does not evaluate infracortical layers, because light has a optimal penetration-scattering rate of 2 cm deep, suffering influence of the extracerebral superficial layers (Hoshi, 2016; Nguyen et al, 2016). Some authors postulate that fNIRS is a preferable tool to evaluate cortical activation induced by any type of electrical stimulation because it is less sensitive to electrical interference when compared to other neuroimaging techniques (Jang et al, 2014). fNIRS evaluating SSC can also be used to discriminate different stimulations, like handshake and cold temperature, as it presents different patterns of hemodynamic responses (Hong et al, 2017).…”