J Korean Neuropsychiatr Assoc.  2019 May;58(2):105-114. 10.4306/jknpa.2019.58.2.105.

Electroencephalography and Schizophrenia

• Lee SH

• KMID: 2449053
• DOI: http://doi.org/10.4306/jknpa.2019.58.2.105

Abstract

Electroencephalography (EEG) and event-related potentials (ERPs) are useful measures of information processing that are believed to reflect the cognitive processing of the brain. Recently, these electrophysiological markers have been studied repeatedly to examine patients with schizophrenia. Among the ERPs components, P50, P300, mismatch negativity, loudness dependence of auditory evoked potentials, and 40 Hz auditory steady state response are meaningful neurophysiological markers of schizophrenia. The employment of novel ERP paradigms designed to carefully characterize the early spectrum of perceptual and cognitive information processing allows investigators to identify the neurophysiological basis of cognitive dysfunction in schizophrenia and examine the associated clinical and functional impairments. Lately, functional neural networks using resting state EEG have been studied extensively in patients with schizophrenia. In this article, qEEG, several ERP components, and functional neural networks that were considered useful neurophysiological markers of schizophrenia are reviewed and their clinical implications are discussed.

Keyword

Schizophrenia; EEG; P50 evoked potentials; Event-related potentials; Functional neural network

MeSH Terms

Automatic Data Processing
Brain
Electroencephalography*
Employment
Evoked Potentials
Evoked Potentials, Auditory
Humans
Research Personnel
Schizophrenia*

Figure

• 

  Fig. 1 The figure on the left shows topography of the beta wave activity of schizophrenia patients with AH, and schizophrenia patients with N-AH (A). The right figure shows activated regions of the brain in AH compared to N-AH by calculating the signal source activity of quantified brainwaves in the LORETA program; increased areas in the beta 1 band (B) and increased areas in the beta 2 band (C). Adapted from Lee et al. Schizophr Res 2006;83:111-119.10) AH : Auditory hallucinations, N-AH : Non-auditory hallucinations, LORETA : Low resolution electromagnetic tomography.

• 

  Fig. 2 While the P50 paradigm waveform of the healthy controls shows a significant decrease in the width of S2 compared to S1, there is no significant difference between S1 and S2 in schizophrenia (A). This is the result of reflecting abnormalities in the auditory gating of patients with schizophrenia. Treatment of schizophrenia can normalize these P50s, with treatments that increase the amplitude of S1 and treatments that reduce the amplitude of S2 (B). Adapted from Smucny et al. Transl Psychiatry 2015;5:e587.21) S1 : First stimulus, S2 : Second stimulus, Sz : Schizophrenia.

• 

  Fig. 3 Mean event-related potentials waveform for patients with schizophrenia and healthy controls (arrow indicates P300). Adapted from Kim et al. Brain Topogr 2014;27:307-317.31)

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  Fig. 4 Topographic maps of MMN of patients with schizophrenia and bipolar disorder patients and healthy controls (A); Comparison of Three Group MMN amplitude at FCz (B). Adapted from Kim et al. Schizophr Bull 2019;45:425-435.53) MMN : Mismatch negativity.

• 

  Fig. 5 Comparison of event-related potentials waveforms by sound loudness between patients with recent-onset, sub-chronic and chronic schizophrenia and healthy controls (A). LDAEP comparison between patients with recent-onset, sub-chronic and chronic schizophrenia and healthy controls (B). LDAEP comparison between all schizophrenia patients and healthy controls (C). Adapted from Park et al. Schizophr Res 2015;168:180-184.69) LDAEP : Loudness dependence of auditory evoked potential.

• 

  Fig. 6 ASSR comparison between patients with SZ and HCs. If the inter-train interval (3050-3500 ms) between each sound stimulation is given longer than the existing study paradigm, patients with SZ report greater ASSR activity than HCs. Adapted from Kim et al. Neuroimage Clin 2019;22:101732.82) SZ : Schizophrenia, HC : Healthy control.

• 

  Fig. 7 The node points where the clustering coefficient is reduced in patients with schizophrenia compared to healthy controls are shown. Adapted from Shim et al. Schizophr Res 2014;156:197-203.98)

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