title: QEEG indexed frontal connectivity effects of transcranial pulsed current stimulation (tPCS): A sham-controlled mechanistic trial.
abstract: Transcranial pulsed current stimulation (tPCS) is a non-invasive brain stimulation technique that employs weak, pulsed current at different frequency ranges, inducing electrical currents that reach cortical and subcortical structures. Very little is known about its effects on brain oscillations and functional connectivity and whether these effects are dependent on the frequency of stimulation. Our aim was to evaluate the effects of tPCS with different frequency ranges in cortical oscillations indexed by high-resolution qEEG changes for power and interhemispheric coherence. Thirty-eight healthy subjects were enrolled and received a single 20-min session of either sham or active stimulation with 1 Hz, 100 Hz or random frequency (1-5 Hz). We conducted an exploratory analysis to detect changes in mean power for theta, alpha and beta, and interhemispheric coherence for alpha and theta and four different sub-bands cognitive and non-specific adverse effects were recorded. We found that active stimulation with a random frequency ranging between 1 and 5 Hz is able to significantly increase functional connectivity for the theta and low-alpha band as compared to sham and active stimulation with either 1 or 100 Hz. Based on these findings, we discuss the possible effects of tPCS on resting functional connectivity for low-frequency bands in fronto-temporal areas. Future studies should be conducted to investigate the potential benefit of these induced changes in pathologic states.
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Castillo Saavedra
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA; School of Health Sciences, De Montfort University, Leicester, UK.
authors.forename: Leon
authors.initials: L
authors.lastname: Morales-Quezada
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Deniz
authors.initials: D
authors.lastname: Doruk
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Rozinsky
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Livia
authors.initials: L
authors.lastname: Coutinho
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA; School of Technology and Management and Centre for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, Leiria, Portugal.
authors.forename: Paula
authors.initials: P
authors.lastname: Faria
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Iago
authors.initials: I
authors.lastname: Perissinotti
authors.affiliation: Stroke Biological Recovery Laboratory, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA.
authors.forename: Qing-Mei
authors.initials: QM
authors.lastname: Wang
authors.affiliation: Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA. Electronic address: felipe.fregni@ppcr.hms.harvard.edu.
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
mesh_terms: D000328:Adult; D058256:Brain Waves; D004311:Double-Blind Method; D004569:Electroencephalography; D058407:Electroencephalography Phase Synchronization; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D013702:Temporal Lobe / Q000502:physiology; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
keywords: Alpha coherence; Functional connectivity; Theta coherence; Transcranial pulsed current stimulation