Mismatch negativity correlates with delta and theta EEG power in schizophrenia

The goal of the present study was to investigate the correlation of mismatch negativity (MMN) to other biological and clinical measures in schizophrenic patients using Quantitative electroencepharography (QEEG), computed tomography (CT), and psychopathological ratings. MMN was recorded during an auditory oddball paradigm. QEEG was recorded in the resting condition. Additionally, areas of the lateral ventricles and Sylvian fissure were measured using CT. Although the authors could not obtain a significant difference in MMN amplitudes between controls and the schizophrenic patients, MMN deflection inversely correlated with slow wave QEEG power and dilation of the lateral ventricles. Furthermore, the longer the duration of illness, the lower the MMN amplitudes and the larger the SF-BR in the patients. However there was no significant correlation between illness duration and QEEG. In this view, a correlation between MMN and the delta power in QEEG might usefully suggest a progression in pathology of first manifestation of psychosis. The patients with reduced MMN accompanied by greater slow waves even at their first manifestation might have severely progressing pathological process and poor prognosis of disease outcome.