Differences in Resting State EEG Power Spectrum in Patients with Schizophrenia and Healthy Controls

Abstract

Schizophrenia is a psychiatric disorder characterized by a heterogeneous syndrome of disorganized thoughts, delusions, inappropriate affect, and hallucinations. There has been a continuous effort to discover and specify the neural correlates of schizophrenia based on spontaneous EEG records.EEG signals can be classified based on certain characteristics, one of them through the power spectral analysis of several brain waves. Objectiveto investigate EEG changes in chronic medicated schizophrenia patientsby power spectral density analysis during resting state as compared to control subject. Subject and Method The present study is a case-control study extended from February 2019 to July 2019. Forty subjects were enrolled in this study; 20 patients aging (20-50 years) comprising (9) males and (11) females diagnosed with schizophrenia were analyzed and compared to 20 apparently healthy volunteers comprising (9) males and (11) females. Results The results of the current studyshowed a significant difference in total delta power spectrum between patients and controls, with patients having higher spectral power(p<0.001). Moreover, regional delta power spectral activity showed a significant increment in all brain regions in patients than control.Likewise, analysis of theta wave power spectrum revealed significant increment in total theta power spectrum activity as well as in the temporal region(p˂0.001) compared to control.On the other hand, statistical analysis of alpha wave showed a highly significant decrement in the mean total alpha power spectrum as well as the mean alpha power spectrum at the parieto- occipital brain region in patients as compared to controls. conclusionQEEG analysis of power spectrum of various brain waves in schizophrenic patients demonstrates highly significant increment in slow wave activity of delta and theta frequencies and decrement in fast wave activity of alpha frequency, whether totally or at specific brain regions; which most likely point to a lower cognitive status.