PhD Scientific Days 2022

Mental Health Sciences I. (Poster discussion will take place in the Aula during the Coffee Break)

Resting-state Delta- and Theta-band EEG Functional Connectivity in Schizophrenia

Text of the abstract

Introduction: Schizophrenia is a serious and complex mental disease, known to be associated with various subtle structural and functional deviations in the brain. Recently, increased attention is given to the analysis of brain-wide, global mechanisms, strongly altering the communication of long-distance brain areas in schizophrenia.
Aims: in this research, we aimed to study EEG functional connectivity and network differences in schizophrenia.
Methods: Altogether, 37 patients with schizophrenia and 33 matched healthy control subjects were enrolled in our study. Two 2 minutes long 64 channel EEG recordings were registered during resting (in eyes open and eyes closed conditions respectively). Average connectivity strength was estimated with Weighted Phase Lag Index (wPLI) for delta (0.5-4 Hz) and theta (4-7 Hz) frequency bands. In order to analyze functional network topology Minimum Spanning Tree (MST) algorithms were applied.
Results: Results show that patients have weaker functional connectivity in both delta (eyes closed condition) and theta (eyes open condition) frequency bands. Concerning network differences, the result of lower diameter, higher leaf number, and also higher maximum degree and maximum betweenness centrality in patients suggest a star-like, more random network topology in patients with schizophrenia.
Conclusion: Our findings of disturbed global functional connectivity in patients are in accordance with some previous findings based on resting state EEG (and fMRI) data, suggesting that MST network structure in schizophrenia is biased towards a less optimal, more centralized organization.
Funding: Hungarian Research Found - OTKA PD 115837; Bolyai Research Fellowship Program of the Hungarian Academy of Sciences; ÚNKP - New National Excellence Program of the Ministry of Human Capacities. Higher Education Institutional Excellence Programme of the Ministry of Human Capacities in Hungary, within the framework of the Neurology thematic programme of Semmelweis University.