Renaissance of quantitative electroencephalography (QEEG) in psychiatry

Abstract

Hundreds of QEEG-related papers brought new information about the temporal dynamics of complex neuronal interactions that underlie impaired processing in many psychiatric diagnoses. Besides this fact, many researchers, clinical psychiatrists and neuroscientists prefer new imaging techniques (Positron Emission Tomography, PET; and functional Magnetic Resonance, fMRI) even if they are based on an indirect index of brain computing as metabolic or hemodynamic measurements which are blind to millisecond phenomena. We present the results of our studies provided with QEEG techniques (Low Resolution Electromagnetic Tomography, LORETA; EEG coherence, EEG cordance) in: 1) more than 60 patients with schizophrenia examined by means of QEEG and PET. We found significantly lower EEG coherence values, mainly from the left frontotemporal derivations in patients group and there was also significant correlation between the decrease of frontotemporal EEG coherence and elevated glucose metabolic uptake in the limbic structures (posterior cingulate and hippocampus). LORETA analysis showed almost the same results as analysis of PET images, not only in basal disease process, but also after successful application of rTMS in the subgroup of patients with treatment-resistant auditory hallucination. 2) in more than 30 patients with resistant depressive disorder we computed the new EEG indicator value (EEG cordance), and we showed, that the decrease in prefrontal EEG cordance in theta frequency band may indicate early changes of prefrontal activity and can become a useful tool in the prediction of response to antidepressants.

The study was supported by MSMTCR project 1M0517.