Disturbed functional connectivity within the left prefrontal cortex and sensorimotor areas predicts impaired cognitive speed in patients with first-episode schizophrenia. (30th May 2018)

• Record Type: Journal Article
• Authors: Krukow, Paweł; Jonak, Kamil; Karakuła-Juchnowicz, Hanna; Podkowiński, Arkadiusz; Jonak, Katarzyna; Borys, Magdalena; Harciarek, Michał
• Is Part Of: Psychiatry research. Volume 275(2018)
• Page Start: 28
• Page End: 35
• Publication Date: 2018-05-30
• Subjects: Phase lag index -- Functional connectivity -- EEG -- Processing speed -- First-episode schizophrenia; Psychiatry -- Periodicals; Brain -- Imaging -- Periodicals; Psychiatry -- Periodicals; Diagnostic Imaging -- Periodicals; Psychiatrie -- Périodiques; Cerveau -- Imagerie pour le diagnostic -- Périodiques; 616.890754
• DOI: 10.1016/j.pscychresns.2018.03.001
• Languages: English
• ISSNs: 0925-4927

Abstract

Abstract: This study aimed at identifying abnormal cortico-cortical functional connectivity patterns that could predict cognitive slowing in patients with schizophrenia. A group of thirty-two patients with the first-episode schizophrenia and comparable healthy controls underwent resting-state qEEG and cognitive assessment. Phase Lag Index (PLI) was applied as a connectivity index and the synchronizations were analyzed in six frequencies. Pairs of electrodes were grouped to separately cover frontal, temporal, central, parietal and occipital regions. PLI was calculated for intra-regional connectivity and between-regions connectivity. Computer version processing speed tests were applied to control for possible fluctuations in cognitive efficiency during the performance of the tasks. In the group of patients, in comparison to healthy controls, significantly higher PLI values were recorded in theta frequency, especially in the posterior areas and decreased PLI in low-alpha frequency within the frontal regions. Mean PLI in gamma frequency was also lower in the patients group. Regression analysis showed that lower intra-regional PLI for left frontal cortex and higher PLI within somatosensory cortex in theta band, together with the duration of untreated psychosis, proved to be significant predictors of impaired processing speed in first-episode patients. Our investigation confirmed that disrupted cortico-cortical synchronization contributes to cognitive slowing in schizophrenia. Highlights: The signal-space functional connectivity was examined in schizophrenia patients. The Phase Lag Index (PLI) was used as a connectivity measure. Connectivity values in theta, low alpha and gamma bands differentiated the groups. The PLI for frontal and sensorimotor cortex predicted cognitive slowing in patients. Cortico-cortical disconnections impede processing speed in schizophrenia.