Temporoparietal Connectivity Within Default Mode Network Associates With Clinical Improvements in Schizophrenia Following Modified Electroconvulsive Therapy

Abstract

Although modified electroconvulsive therapy (ECT) has been reported to be effective for the treatment of schizophrenia (SCZ), its action mechanism is unclear. To elucidate the underlying ECT mechanisms of SCZ, this study used a longitudinal cohort including 21 SCZ patients receiving only antipsychotics (DSZ group) and 21 SCZ patients receiving a regular course of ECT combining with antipsychotics (MSZ group) for 4 weeks. All patients underwent magnetic resonance imaging (MRI) scans at baseline (t1) and follow-up (t2) time points. A matched healthy control (HC) group included 23 individuals who were only scanned at baseline. Functional connectivity (FC) within the default mode network (DMN) was evaluated before and after ECT. Significant interaction of the group over time was found in FC between angular gyrus (AG) and middle temporal gyrus (MTG). Post-hoc analysis showed a significantly enhanced FC of left AG(AG.L) and right MTG (MTG.R) in the MSZ group relative to the DSZ group. In addition, the right AG (AG.R) showed significantly enhanced FC between MTG.R and left MTG (MTG.L) after ECT in the MSZ group, but no in the DSZ group. In particular, the FCs change in AG.L-MTG.R and AG.R-MTG.R were positively correlated with the Positive and Negative Syndrome Scale (PANSS) negative score reduction. Furthermore, the FC change in AG.L-MTG.R was also positively correlated with the PANSS general psychopathology score reduction. These findings confirmed a potential relationship between ECT inducing hyperconnectivity within DMN and improvements in symptomatology of SCZ, suggesting that ECT controls mental symptoms by regulating the temporoparietal connectivity within DMN.

Resting-state functional MRI in treatment-resistant schizophrenia

“…Blazer et al ( 2022 ) presented the data of three additional participants compared to Sarpal et al ( 2022a ) in their longitudinal CLZ study. The study on ECT by Huang et al ( 2018 ), Jiang et al ( 2019a , b ), Wang et al ( 2020 ), Hu H. et al ( 2022 ), and Hu Q. et al ( 2022 ) reported on exactly the same patient cohort of 21 TRS individuals receiving a regular course of modified ECT combined with antipsychotics (MSZ), 21 SCZ individuals taking only antipsychotics (DSZ), and 23 HC, although one of the mentioned studies (Hu H. et al, 2022 ) listed (likely by mistake) different age characteristics for DSZ.…”

“…During rs-fMRI acquisition, some studies told the participants to keep their eyes open and to look at a fixation cross (White et al, 2016 ; McNabb et al, 2018a , b ; Pillinger et al, 2019 ; Blazer et al, 2022 ; Sarpal et al, 2022a ), while in other studies, they were asked to close their eyes (Alonso-Solís et al, 2015 ; Huang et al, 2018 ; Jiang et al, 2019a , b ; Wang et al, 2020 ; Hu H. et al, 2022 ; Hu Q. et al, 2022 ; Kim et al, 2022 ). Some studies did not report whether the acquisitions were done with open or closed eyes (Ganella et al, 2017 , 2018 ; Gao et al, 2018 ; Yang et al, 2020 ).…”

“…Seven studies (with two patient cohorts) were reviewed to cover this topic. In ECT-eligible TRS individuals, higher functional connectivities were noted between the left angular and the right middle temporal gyri (Hu Q. et al, 2022 ), and between the left superior occipital cortex and the left rostral temporal thalamus seed ROI as well as the right caudal temporal thalamus seed ROI (Wang et al, 2020 ) compared to HC. The same cohort of patients exhibited higher functional connectivities between bilateral caudal hippocampus seed ROIs and bilateral superior temporal gyri compared to DSZ (Jiang et al, 2019b ).…”

“…Increased functional connectivities post-ECT compared to pre-treatment were noted between the right sensory thalamus seed ROI and the right putamen (Wang et al, 2020 ), between the right angular and the left middle temporal gyri (Hu Q. et al, 2022 ), and between several DMN and cerebellar regions (Hu H. et al, 2022 ).…”

Electroconvulsive therapy for obsessive-compulsive disorder: A retrospective study

“…Electroconvulsive therapy (ECT) is a technique used to treat mental illnesses by applying electrical current through the brain. There is ample clinical evidence that ECT is mainly used in major depressive disorder (MDD), bipolar disorder, schizophrenia ( 15 – 18 ). However, Current guidelines do not include ECT as an alternative treatment for refractory OCD ( 6 ).…”