Medial prefrontal transcranial alternating current stimulation for apathy in Huntington's disease

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

doi:10.1016/j.pnpbp.2023.110776

Medial prefrontal transcranial alternating current stimulation for apathy in Huntington's disease

Prog Neuropsychopharmacol Biol Psychiatry. 2023 Aug 30:126:110776. doi: 10.1016/j.pnpbp.2023.110776. Epub 2023 Apr 27.

Authors

Marie-Claire Davis¹, Aron T Hill², Paul B Fitzgerald³, Neil W Bailey⁴, Caley Sullivan⁵, Julie C Stout⁶, Kate E Hoy⁷

Affiliations

¹ 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.
² Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; Cognitive Neuroscience Unit, School of Psychology, Deakin University, Melbourne, Australia.
³ Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; School of Medicine and Psychology, Australian National University, Canberra, ACT, Australia.
⁴ 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.
⁵ Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia.
⁶ School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, Victoria, Australia.
⁷ Central Clinical School, Department of Psychiatry, Monash University, Victoria, Australia; The Bionics Institute of Australia, 384-388 Albert St, East Melbourne, VIC 3002, Australia.

PMID: 37120005
DOI: 10.1016/j.pnpbp.2023.110776

Abstract

We investigated the effects of transcranial alternating current stimulation (tACS) targeted to the bilateral medial prefrontal cortex (mPFC) and administered at either delta or alpha frequencies, on brain activity and apathy in people with Huntington's disease (HD) (n = 17). Given the novelty of the protocol, neurotypical controls (n = 20) were also recruited. All participants underwent three 20-min sessions of tACS; one session at alpha frequency (Individualised Alpha Frequency (IAF), or 10 Hz when an IAF was not detected); one session at delta frequency (2 Hz); and a session of sham tACS. Participants completed the Monetary Incentive Delay (MID) task with simultaneous recording of EEG immediately before and after each tACS condition. The MID task presents participants with cues signalling potential monetary gains or losses that increase activity in key regions of the cortico-basal ganglia-thalamocortical networks, with dysfunction of the latter network being implicated in the pathophysiology of apathy. We used the P300 and Contingent Negative Variation (CNV) event-related potentials elicited during the MID task as markers of mPFC engagement. HD participants' CNV amplitude significantly increased in response to alpha-tACS, but not delta-tACS or sham. Neurotypical controls' P300 and CNV were not modulated by any of the tACS conditions, but they did demonstrate a significant decrease in post-target response times following alpha-tACS. We present this as preliminary evidence of the ability of alpha-tACS to modulate brain activity associated with apathy in HD.

Keywords: Contingent negative variation (CNV); Electroencephalography (EEG); Huntington's disease; Monetary incentive delay (MID) task; P300; Transcranial alternating current stimulation.

MeSH terms

Apathy*
Electroencephalography
Evoked Potentials / physiology
Humans
Huntington Disease* / therapy
Transcranial Direct Current Stimulation* / methods