Abstract

Introduction: Functional brain connectivity could be altered in patients with schizophrenia (SQZ), which has been called disconnectome. Methods: To evaluate the functional cortical network by wide band spectral analysis of the EEG from paranoid SQZ patients compared to control subjects, EEG (eyes open) from adult SQZ patients (n=14) and control subjects (n=14) were analyzed by Fourier analysis, imaginary coherence, and the minimum spanning tree to detect backbone connections, thus reducing synchronizations induced by electrical volume conduction. The number of cortical connections was aggregated in a two-dimensional connectivity matrix and differences between groups were evaluated by z-score test. Results: A total of 712 significant connections were found in the Controls but 433 in the SQZ group (-39.2%; p<0.0001). The SQZ group showed less strong cortical connections than the Control group, with significant decrease (-93.4%) of the total strong connected nodes with a mean value of-23.6% (p<0.05), in other (6.6%) an increased connectivity was detected with a mean value of +37.7% (p<0.05). Significant between-group differences were found at C3, O1 and T6 EEG locations. Conclusions: These results suggest that patients with SQZ show differential changes mainly with reduction but also in some areas with increased cortical connectivity without the masking effect of synchronizations induced by electrical volume conduction.