EEG alpha activity increased in response to transcutaneous electrical nervous stimulation in young healthy subjects but not in the healthy elderly

Abstract

Transcutaneous Electrical Nerve Stimulation (TENS) is used not only in the treatment of pain but also in the examination of sensory functions. With aging, there is decreased sensitivity to somatosensory stimuli. It is essential to examine the effect of TENS application on the sensory functions in the brain by recording the spontaneous electroencephalogram (EEG) activity and the effect of aging on the sensory functions of the brain during the application. The present study aimed to investigate the effect of the application of TENS on the brain's electrical activity and the effect of aging on the sensory functions of the brain during application of TENS. A total of 15 young (24.2 ± 3.59) and 14 elderly (65.64 ± 4.92) subjects were included in the study. Spontaneous EEG was recorded from 32 channels during TENS application. Power spectrum analysis was performed by Fast Fourier Transform in the alpha frequency band (8-13 Hz) for all subjects. Repeated measures of analysis of variance was used for statistical analysis (p < 0.05). Young subjects had increased alpha power during the TENS application and had gradually increased alpha power by increasing the current intensity of TENS (p = 0.035). Young subjects had higher alpha power than elderly subjects in the occipital and parietal locations (p = 0.073). We can, therefore, conclude that TENS indicated increased alpha activity in young subjects. Young subjects had higher alpha activity than elderly subjects in the occipital and somatosensory areas. To our knowledge, the present study is one of the first studies examining the effect of TENS on spontaneous EEG in healthy subjects. Based on the results of the present study, TENS may be used as an objective method for the examination of sensory impairments, and in the evaluative efficiency of the treatment of pain conditions. How to cite this article Yıldırım E, Güntekin B, Hanoğlu L, Algun C. 2020. EEG alpha activity increased in response to transcutaneous electrical nervous stimulation in young healthy subjects but not in the healthy elderly. PeerJ 8:e8330

Distinct spatio-temporal and spectral brain patterns for different thermal stimuli perception

“… 18 , where subjects participated in an ice-cube cold pressor experiment. It should be noted, however, that in some previous studies noxious stimulations were instead associated with an increase in alpha activities 44 . This discrepancy is likely to be explained by the chosen stimulation type or subject’s age difference, as reported in the study 44 , where transcutaneous electrical nerve stimulation (TENS) was used to elicit unpleasant sensations and was tested for both young and elderly people.…”

“…It should be noted, however, that in some previous studies noxious stimulations were instead associated with an increase in alpha activities 44 . This discrepancy is likely to be explained by the chosen stimulation type or subject’s age difference, as reported in the study 44 , where transcutaneous electrical nerve stimulation (TENS) was used to elicit unpleasant sensations and was tested for both young and elderly people. When analyzing the other EEG frequency bands, we also observed power decrease (as in alpha power) in the theta and beta frequency bands, as was also reported in previous related studies, whereas an overall increase in the power of gamma-band was observed 5 , 45 – 47 .…”

Enhancing Touch Sensibility with Sensory Electrical Stimulation and Sensory Retraining

“…Due to its excellent temporal resolution, EEG has been widely used to study brain functions. Literature in EEG suggests that the alpha frequency band (8 -13 Hz) activity is associated with sensory processing [48] and several studies have examined the dynamics of alpha oscillations following SES. For example, in a study by Yıldırım et al, the authors investigated the modulatory effects of TENS on alpha power as neural markers of sensory decline in healthy young and elderly participants [48].…”

Changes in Electroencephalography by Modulation of Interferential Current Stimulation

“…The effects of electrical stimulation on electroencephalography (EEG) have previously been reported [16,17]. In healthy volunteers, high-frequency transcutaneous electrical nerve stimulation (TENS) reduces enhanced gamma-band activity following tonic pain induction, which can serve as a functional brain biomarker for pain treatment, specifically for EEG-based neurofeedback approaches [16].…”

“…TENS increases alpha activity in young subjects, who had higher alpha activity than elderly subjects, in occipital and somatosensory areas. Thus, TENS may be used as an objective method to examine sensory impairments and evaluate pain treatment [17].…”