Multisensory Flicker Modulates Widespread Brain Networks and Reduces Interictal Epileptiform Discharges in Humans

• Type of Material: Article
• Authors: Jon Willie, Emory University; Robert Gross, Emory University; Annabelle Singer, Emory University; Brian Cabaniss, Emory University; Lou T Blanpain, Emory University; Emily Chen, Emory University; James Park, Emory University; Michael Y Walelign, Georgia Institute of Technology, Atlanta
• Language: English
• Date: 2023-03-17
• Publisher: NIH
• Publication Version: Preprint (Prior to Peer Review)
• Copyright Statement: The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.
• Final Published Version (URL): http://dx.doi.org/10.1101/2023.03.14.23286691
• Title of Journal or Parent Work: medRxiv
• Volume: 2023
• Keywords: Flicker; steady-state evoked potential; human intracranial electrophysiology; brain oscillations; entrainment; resonance

Abstract

Modulating brain oscillations has strong therapeutic potential. However, commonly used non-invasive interventions such as transcranial magnetic or direct current stimulation have limited effects on deeper cortical structures like the medial temporal lobe. Repetitive audio-visual stimulation, or sensory flicker, modulates such structures in mice but little is known about its effects in humans. Using high spatiotemporal resolution, we mapped and quantified the neurophysiological effects of sensory flicker in human subjects undergoing presurgical intracranial seizure monitoring. We found that flicker modulates both local field potential and single neurons in higher cognitive regions, including the medial temporal lobe and prefrontal cortex, and that local field potential modulation is likely mediated via resonance of involved circuits. We then assessed how flicker affects pathological neural activity, specifically interictal epileptiform discharges, a biomarker of epilepsy also implicated in Alzheimer’s and other diseases. In our patient population with focal seizure onsets, sensory flicker decreased the rate interictal epileptiform discharges. Our findings support the use of sensory flicker to modulate deeper cortical structures and mitigate pathological activity in humans.