Transcranial pulsed current stimulation or tPCS is has limited amount of studies currently. It does tend to prove out there are frequency specific effects when stimulating the brain with them. Square wave PEMF induces current though probably at lower amplitudes then with the contact electrodes used in tPCS. PEMF provides frequency specific effects however, without the inherent tDCS / tPCS problem of guiding current flow through the target tissue.

tDCS vs PEMF

Given the recent results provided by previous investigations on transcranial pulsed current stimulation (tPCS) demonstrating its modulatory effects on cortical connectivity; we aimed to explore the application of different pulsed frequencies.Forty healthy individuals older than 18 years were eligible to participate. We found that a random pulsed frequency between 6-10 Hz significantly increased the power and coherence in frontal and central areas for the alpha band compared with sham stimulation. Our findings corroborate the hypothesis that a random frequency ranging into the boundaries of 6-10 Hz induces changes in the naturally occurring alpha oscillatory activity, providing additional data for further studies with tPCS. [2]

Transcranial pulsed current stimulation (tPCS) is emerging as an option in the field of neuromodulation; however, little is known about its effects on cognition and behavior and its neurophysiological correlates as indexed by autonomic responses. Our aim was to identify the effects of tPCS on arithmetic processing and risk-taking behavior, and to further categorize physiological autonomic responses by heart rate variability (HRV) and electrodermal activity measurements before, during, and after exposure to task performance and stimulation. Thirty healthy volunteers were randomized to receive a single session of sham or active stimulation with a current intensity of 2 mA and a random frequency between 1 and 5 Hz. Our results showed that tPCS has a modest and specific effect on cognitive performance as indexed by the cognitive tasks chosen in this study. There was a modest effect of active tPCS only on performance facilitation on a complex-level mathematical task as compared to sham stimulation. On autonomic responses, we observed that HRV total power increased while LF/HF ratio decreased in the tPCS active group compared to sham. There were no group differences for adverse effects. Based on our results, we conclude that tPCS, in healthy subjects, has a modest and specific cognitive effect as shown by the facilitation of arithmetical processing on complex mathematical task. These effects are accompanied by modulation of the central autonomic network providing sympathetic-vagal balance during stressful conditions. Although behavioral results were modest, they contribute to the understanding of tPCS effects and cognitive enhancement.[3]

Compared to a-tDCS, a-tPCS is a better technique for enhancement of CSE. There were no sham effects for application of a-tPCS. However, unlike a-tDCS which modifies neuronal excitability by tonic depolarization of the resting membrane potential, a-tPCS modifies neuronal excitability by a combination of tonic and phasic effects.[8]

Stride length in Parkinson’s increased from 102.1 ± 24.4 to 111.2 ± 22.1 cm, and gait velocity increased from 0.90 ± 0.23 to 0.985 ± 0.19 m/s after tPCS.[12]

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