Targeting reduced neural oscillations in patients with schizophrenia by transcranial alternating current stimulation
Sangtae Ahn, Juliann M Mellin, Sankaraleengam Alagapan, Morgan L Alexander, John H Gilmore, L Fredrik Jarskog, Flavio Fröhlich, Sangtae Ahn, Juliann M Mellin, Sankaraleengam Alagapan, Morgan L Alexander, John H Gilmore, L Fredrik Jarskog, Flavio Fröhlich
Abstract
Transcranial alternating current stimulation (tACS) modulates endogenous neural oscillations in healthy human participants by the application of a low-amplitude electrical current with a periodic stimulation waveform. Yet, it is unclear if tACS can modulate and restore neural oscillations that are reduced in patients with psychiatric illnesses such as schizophrenia. Here, we asked if tACS modulates network oscillations in schizophrenia. We performed a randomized, double-blind, sham-controlled clinical trial to contrast tACS with transcranial direct current stimulation (tDCS) and sham stimulation in 22 schizophrenia patients with auditory hallucinations. We used high-density electroencephalography to investigate if a five-day, twice-daily 10Hz-tACS protocol enhances alpha oscillations and modulates network dynamics that are reduced in schizophrenia. We found that 10Hz-tACS enhanced alpha oscillations and modulated functional connectivity in the alpha frequency band. In addition, 10Hz-tACS enhanced the 40Hz auditory steady-state response (ASSR), which is reduced in patients with schizophrenia. Importantly, clinical improvement of auditory hallucinations correlated with enhancement of alpha oscillations and the 40Hz-ASSR. Together, our findings suggest that tACS has potential as a network-level approach to modulate reduced neural oscillations related to clinical symptoms in patients with schizophrenia.
Keywords: Alpha oscillation; Auditory hallucination; Auditory steady-state response; Electroencephalography; Functional connectivity; Schizophrenia.
Conflict of interest statement
Conflict of Interest
Dr. Fröhlich is the lead inventor of IP filed by UNC. The clinical studies performed in the Frohlich Lab have received a designation as conflict of interest with administrative considerations. Dr. Fröhlich is the founder, CSO and majority owner of Pulvinar Neuro LLC, a company that markets research tDCS and tACS devices. Dr. Fröhlich has received research funding from the National Institute of Health, the Brain Behavior Foundation, the Foundation of Hope, the Human Frontier Science Program, Tal Medical, and individual donations. Dr. Fröhlich is an adjunct professor in Neurology at the Insel Hospital of the University of Bern, Switzerland. Dr. Fröhlich receives royalties for his textbook Network Neuroscience published by Academic Press. Drs. Gilmore and Jarskog have received funding from the National Institute of Health. Dr. Jarskog has received research support from Auspex/Teva, Boehringer Ingelheim, and Otsuka. Dr. Jarskog has consulted to Roche and Clintara/Bracket. Dr. Gilmore has no financial conflicts. Drs. Ahn and Alagapan have no financial conflicts. Juliann M. Mellin and Morgan L. Alexander have no financial conflicts.
Copyright © 2018 Elsevier Inc. All rights reserved.
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Source: PubMed