Effects of medial prefrontal transcranial alternating current stimulation on neural activity and connectivity in people with Huntington’s disease and neurotypical controls.

May 01, 2023

Experts: Marie-Claire Davis,Paul B Fitzgerald,Neil W Bailey,Caley Sullivan,Julie C Stout,Aron T Hill,Kate E Hoy

We investigated the effects of transcranial alternating current stimulation (tACS) targeted to the medial prefrontal cortex (mPFC) on resting electroencephalographic (EEG) indices of oscillatory power, aperiodic exponent and offset, and functional connectivity in 22 late premanifest and early manifest stage individuals with HD and 20 neurotypical controls. Participants underwent three 20-minute sessions of tACS at least 72 hours apart; one session at alpha frequency (either each participant’s Individualised Alpha Frequency (IAF), or 10Hz when an IAF was not detected); one session at delta frequency (2Hz); and a session of sham tACS. Session order was randomised and counterbalanced across participants. EEG recordings revealed a reduction of the spectral exponent (‘flattening’ of the 1/f slope) of the eyes-open aperiodic signal in participants with HD following alpha-tACS, suggestive of an enhancement in excitatory tone. Contrary to expectation, there were no changes in oscillatory power or functional connectivity in response to any of the tACS conditions in the participants with HD. By contrast, alpha-tACS increased delta power in neurotypical controls, who further demonstrated significant increases in theta power and theta functional connectivity in response to delta-tACS. This study contributes to the rapidly growing literature on the potential experimental and therapeutic applications of tACS by examining neurophysiological outcome measures in people with HD as well as neurotypical controls.
Copyright © 2023. Published by Elsevier B.V.

Author

admin

View all posts

ABOUT THE EXPERTS

Marie-Claire Davis,Paul B Fitzgerald,Neil W Bailey,Caley Sullivan,Julie C Stout,Aron T Hill,Kate E Hoy

Marie-Claire Davis

Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; Statewide Progressive Neurological Disease Service, Calvary Health Care Bethlehem, Victoria Australia. Electronic address: marie-claire.davis@monash.edu.

Paul B Fitzgerald

School of Medicine and Psychology, Australian National University, Canberra, ACT, Australia.

Neil W Bailey

Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; School of Medicine and Psychology, Australian National University, Canberra, ACT, Australia; Monarch Research Institute Monarch Mental Health Group, Sydney, NSW, Australia.

Caley Sullivan

Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia.

Julie C Stout

School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, Victoria, Australia.

Aron T Hill

Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; Cognitive Neuroscience Unit, School of Psychology, Deakin University, Melbourne, Australia.

Kate E Hoy

Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; The Bionics Institute of Australia, 384-388 Albert St, East Melbourne, VIC, 3002, Australia.