Quantitative electroencephalography as a biomarker for proneness toward developing psychosis.

Author: Fuggetta G1, Bennett MA2, Duke PA2, Young AM2.
1School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, United Kingdom. Electronic address: g.fuggetta@le.ac.uk. 2School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, United Kingdom.
Conference/Journal: Schizophr Res.
Date published: 2014 Feb 6
Other: Pages: S0920-9964(14)00044-9. , Special Notes: doi: 10.1016/j.schres.2014.01.021 , Word Count: 260

The fully dimensional approach to the relationship between schizotypal personality traits and schizophrenia describes schizotypy as a continuum throughout the general population ranging from low schizotypy (LoS) and psychological health to high schizotypy (HiS) and psychosis-proneness. However, no biological markers have yet been discovered that reliably quantify an individual's degree of schizotypy and/or psychosis. This study aimed to evaluate quantitative electroencephalographic (qEEG) measures of power spectra as potential biomarkers of the proneness towards the development of psychosis in schizotypal individuals. The resting-state oscillatory brain dynamics under eyes-closed condition from 16 LoS and 16 HiS individuals were analysed for qEEG measures of background rhythm frequency, relative power in δ, θ, low-α, high-α, low-β, high-β and low-γ frequency bands, and the high-temporal cross-correlation of power spectra between low- and high-frequency bands observed by averaging signals from whole-head EEG electrodes. HiS individuals at rest locked the thalamocortical loop in the low-α band at a lower-frequency oscillation and displayed an abnormally high level of neural synchronisation. In addition, the high-α band was found to be positively correlated with both the high-β and low-γ bands unlike LoS individuals, indicating widespread thalamocortical resonance in HiS individuals. The increase of regional alpha oscillations in HiS individuals suggests abnormal high-level attention, whereas the pattern of correlation between frequency bands resembles the thalamocortical dysrhythmia phenomenon which underlies the symptomatology of a variety of neuropsychiatric disorders including schizophrenia. These qEEG biomarkers may aid clinicians in identifying HiS individuals with a high-risk of developing psychosis.
Copyright © 2014 Elsevier B.V. All rights reserved.
Electroencephalography (EEG), Resting-state oscillations, Schizotypy, Spectral analysis, Thalamocortical dysrhythmia (TCD)

PMID: 24508484