Alteration in Cortical Activity and Perceived Sensation Following Modulated TENS

Abstract

Over the last decades, conventional transcutaneous electrical nerve stimulation (TENS) has been utilized as an efficient rehabilitation intervention for alleviation of chronic pain, including phantom limb pain (PLP). However, recently the literature has increasingly focused on alternative temporal stimulation patterns such as pulse width modulation (PWM). While the effect of non-modulated high frequency (NMHF) TENS on somatosensory (SI) cortex activity and sensory perception has been studied, the possible alteration following PWM TENS at the SI has not yet been explored. Therefore, we investigated the cortical modulation by PWM TENS for the first time and conducted a comparative analysis with the conventional TENS pattern. We recorded sensory evoked potentials (SEP) from 14 healthy subjects before, immediately, and 60 min after TENS interventions (PWM and NMHF). The results revealed suppression of SEP components, theta, and alpha band power simultaneously associated with the perceived intensity reduction when the single sensory pulses applied ipsilaterally to the TENS side. The reduction of N1 amplitude, theta, and alpha band activity occurred immediately after both patterns remained at least 60 min. However, the P2 wave was suppressed right after PWM TENS, while NMHF could not induce significant reduction immediately after the intervention phase. As such, since PLP relief has been shown to be correlated with inhibition at somatosensory cortex, we, therefore, believe that the result of this study provides further evidence that PWM TENS may also be potential therapeutic intervention for PLP reduction. Future studies on PLP patients with PWM TENS sessions is needed to validate our result.

Comparative Analysis of High-Frequency and Low-Frequency Transcutaneous Electrical Stimulation of the Right Median Nerve in the Regression of Clinical and Neurophysiological Manifestations of Generalized Anxiety Disorder

“…The anxiolytic effect results from activation of the prefrontal cortex, insula, temporal gyrus, anterior cingulate cortex, temporal pole, dorsolateral prefrontal cortex, and inferior frontal cortex, which are closely associated with cognition, spirit, and emotion in the brain [ 86 ]. Contemporary studies have shown a significant effect of TENS intervention on cortical activity with suppression of sensory evoked potentials and increase in PSD of theta and alpha rhythms [ 87 ] and in the improvement of functional brain connectivity at both regions and network levels [ 41 , 88 ]. In other studies after TENS intervention, a significant improvement in corticospinal and motor cortex excitability was noted, as well as an increase in the volume of the motor cortical map [ 89 ].…”

From pulse width modulated TENS to cortical modulation: based on EEG functional connectivity analysis

“…Secondly, as we found the effect of PWM TENS for at least an hour following the intervention, in order to enlighten the lasting effect duration for clinical application, later follow-up phases following TENS intervention could be investigated in future studies. Finally, the effect of PWM TENS intervention has been previously studied on corticospinal excitability ( Faghani Jadidi et al, 2022 ) and cortical activity ( Jadidi et al, 2023 ) associated with simultaneous changes on sensory profile and the evidence for the possible underlying mechanism of this pattern on pain modulation has been provided. As a follow-up, here, we investigated the induced alteration by PWM TENS on a higher order level (brain network functional connectivity) in the sensory/pain related brain areas among healthy subjects.…”

“…Each subject received both stimulation patterns in a random order consisting of bipolar rectangular pulses with the characteristics as follows; (1) HF: Conventional high-frequency TENS (100 Hz) with a constant pulse width of 500 μs as control group and (2) PWM: High-frequency TENS (100 Hz) with a dynamic pulse width (modulating sinusoidal wave of 1 Hz) that varied between 0 to 500 μs ( Faghani Jadidi et al, 2022 ; Jadidi et al, 2023 ). Each pattern was delivered for 30 min (20 s on, 10 s off ( Mang et al, 2010 ; Ishibashi et al, 2021 ) with an intensity set individually at 80% of the discomfort threshold (with no visual movement) ( Zarei et al, 2021 , 2022 ; Faghani Jadidi et al, 2022 ).…”

“…These alterations are considered as desired effects on the central nervous system that may lead to chronic pain alleviation. Moreover, suppression of sensory evoked potentials (SEPs) at S1 following PWM TENS was accompanied by a significant reduction of perceived sensation intensity ( Jadidi et al, 2023 ). However, the PWM TENS mechanism on the cortical network level needs further investigation.…”

A Review on the Application of Internet of Medical Things in Wearable Personal Health Monitoring: A Cloud-Edge Artificial Intelligence Approach

“…They integrate advanced technologies into various wearable personal health monitoring systems, offering continuous monitoring, early diagnosis, and remote therapy. Notable among these sensing devices are Implanted Cardioverter Defibrillators (ICDs) [20] and Wearable Cardioverter Defibrillators (WCDs) [21]. These provide lifesaving interventions for individuals with heart rhythm abnormalities.…”