Common increased hippocampal volume but specific changes in functional connectivity in schizophrenia patients in remission and non-remission following electroconvulsive therapy: A preliminary study

Jiang, Yuchao; Xu, Li-Hua; Li, Xiangkui; Tang, Yingying; Wang, Pingfu; Li, Chunbo; Yao, Dezhong; Wang, Jijun; Chen, Luo

doi:10.1016/j.nicl.2019.102081

Cited by 18 publications

(58 citation statements)

References 56 publications

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“…Interestingly, we observed a significant increased pHippocampus–ICC connectivity during retrieval condition and this was found to be strongly associated with memory accuracy in schizophrenia. It is worth mentioning that connectivity alterations between hippocampal subregions and ICC have also been observed by other authors 31 , 54 . The ICC, including the primary visual cortex, is known to send projections to posterior parietal regions through the dorsal visual processing stream 74 – 76 .…”

Section: Discussionsupporting

confidence: 76%

“…In resting-state connectivity, the investigations performed thus far have shown deficits in functional connectivity mainly between the anterior hippocampus (aHippocampus) and DMN regions, such as the medial prefrontal cortex and the PCC 31 , 35 , 52 , 53 , as well as between the posterior hippocampus (pHippocampus) and the anterior cingulate cortex 31 , 35 , 52 , 53 . Alterations of connectivity between the aHippocampus and temporal regions 35 , 53 , 54 , as well as between the pHippocampus and the dorsolateral prefrontal cortex 54 , have also been observed, though less consistently. To our knowledge, only one task-based functional connectivity study has been published on hippocampal subregions in schizophrenia showing reduced connectivity from the posterior hippocampus to the inferior frontal gyrus during a complex working memory task 39 .…”

Section: Introductionmentioning

confidence: 99%

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Functional connectivity abnormalities of the long-axis hippocampal subregions in schizophrenia during episodic memory

et al. 2021

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Past evidence suggests that hippocampal subregions, namely the anterior and posterior parts, may be engaged in distinct networks underlying the memory functions which may be altered in patients with schizophrenia. However, of the very few studies that have investigated the hippocampal longitudinal axis subdivisions functional connectivity in patients with schizophrenia, the majority was based on resting-state data, and yet, none aimed to examine these during an episodic memory task. A total of 41 patients with schizophrenia and 45 healthy controls were recruited for a magnetic resonance imaging protocol in which they performed an explicit memory task. Seed-based functional connectivity analysis was employed to assess connectivity abnormalities between hippocampal subregions and voxel-wise connectivity targets in patients with schizophrenia. We observed a significantly reduced connectivity between the posterior hippocampus and regions from the default mode network, but increased connectivity with the primary visual cortex, in patients with schizophrenia compared to healthy subjects. Increased connectivity between the anterior hippocampus and anterior temporal regions also characterized patients with schizophrenia. In the current study, we provided evidence and support for studying hippocampal subdivisions along the longitudinal axis in schizophrenia. Our results suggest that the abnormalities in hippocampal subregions functional connectivity reflect deficits in episodic memory that may be implicated in the pathophysiology of schizophrenia.

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Section: Discussionsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Functional connectivity abnormalities of the long-axis hippocampal subregions in schizophrenia during episodic memory

et al. 2021

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“…Another group examined the effects of ECT on patients with schizophrenia (i.e., ECT+antipsychotic medication; n=21) compared with schizophrenia patients who did not receive ECT and underwent antipsychotic treatment only (n=21). [44][45][46] Whole-brain analyses showed increased GMVs in the bilateral parahippocampal gyri/hippocampi, right temporal pole/right superior temporal gyrus (STG), and right insula after ECT compared to baseline and the antipsychotics only group. 44 Additional ROI analyses of the insula and hippocampus indicated increased GMVs in the bilateral dorsal anterior insula and posterior insula 46 and bilaterally increased hippocampal volumes.…”

Section: Effect Of Ect On Brain Structuresmentioning

confidence: 99%

“…44 Additional ROI analyses of the insula and hippocampus indicated increased GMVs in the bilateral dorsal anterior insula and posterior insula 46 and bilaterally increased hippocampal volumes. 45 An analysis stratified according to response status to ECT further showed that higher baseline volumes in the left hippocampus-amygdala transition area (HATA) were observed in responders. 45 A separate study group reported that baseline GMVs in the temporal region, including the right insula, left middle temporal gyrus (MTG), and the right STG, along with the left inferior frontal gyrus (IFG), predicted ECT response.…”

Section: Effect Of Ect On Brain Structuresmentioning

confidence: 99%

Systematic Review of the Neural Effect of Electroconvulsive Therapy in Patients with Schizophrenia: Hippocampus and Insula as the Key Regions of Modulation

Moon

Kim

Lho

et al. 2021

Psychiatry Investig

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Objective Electroconvulsive therapy (ECT) has been the most potent treatment option for treatment-resistant schizophrenia (TRS). However, the underlying neural mechanisms of ECT in schizophrenia remain largely unclear. This paper examines studies that investigated structural and functional changes after ECT in patients with schizophrenia. Methods We carried out a systematic review with following terms: ‘ECT’, ‘schizophrenia’, and the terms of various neuroimaging modalities. Results Among the 325 records available from the initial search in May 2020, 17 studies were included. Cerebral blood flow in the frontal, temporal, and striatal structures was shown to be modulated (n=3), although the results were divergent. Magnetic resonance spectroscopy (MRS) studies suggested that the ratio of N-acetyl-aspartate/creatinine was increased in the left prefrontal cortex (PFC; n=2) and left thalamus (n=1). The hippocampus and insula (n=6, respectively) were the most common regions of structural/functional modulation, which also showed symptom associations. Functional connectivity of the default mode network (DMN; n=5), PFC (n=4), and thalamostriatal system (n=2) were also commonly modulated. Conclusion Despite proven effectiveness, there has been a dearth of studies investigating the neurobiological mechanisms underlying ECT. There is preliminary evidence of structural and functional modulation of the hippocampus and insula, functional changes in the DMN, PFC, and thalamostriatal system after ECT in patients with schizophrenia. We discuss the rationale and implications of these findings and the potential mechanism of action of ECT. More studies evaluating the mechanisms of ECT are needed, which could provide a unique window into what leads to treatment response in the otherwise refractory TRS population.

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“…Schizophrenia (Zheng et al, 2019), first episode and chronic disease (Kawano et al, 2015;McHugo et al, 2018), symptom correlates (Kühn et al, 2012;Han et al, 2016), first episode psychosis (Buchy et al, 2016;Baglivo et al, 2018;Li et al, 2018), response to electroconvulsive therapy (Jiang et al, 2019b), conversion of high risk patients (Provenzano et al, 2020), young relatives at risk (Francis et al, 2013;Ho et al, 2017a), progression patterns (Ho et al, 2017b), genetic and cognitive correlates of schizophrenia (Nakahara et al, 2019) Metacognition and insight deficits (Hýža et al, 2016;Orfei et al, 2017;Alkan et al, 2019),…”

Section: Schizophreniamentioning

confidence: 99%

FreeSurfer based segmentation of hippocampal subfields: a review of methods and applications, with a novel quality control procedure for ENIGMA studies and other collaborative efforts

Sämann¹,

Iglesias²,

Gutman³

et al. 2020

Preprint

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Structural hippocampal abnormalities are common in many neurological and psychiatric disorders, and even variation within the normal range is related to cognitive performance and other complex phenotypes such as stress sensitivity. Hippocampal subregions are increasingly studied, as automated algorithms have become available for mapping and volume quantification. In the context of the ENIGMA Consortium, several Disease Working Groups are using the FreeSurfer software to analyze hippocampal subregion (subfield) volumes in patients with major depressive disorder, bipolar disorders, posttraumatic stress disorder, and other conditions, along with data from matched controls. In this overview, we explain the algorithm’s principle, summarize measurement reliability studies, and demonstrate two additional aspects (subfield autocorrelation and volume/reliability correlation) with illustrative data. We then explain the rationale for a standardized hippocampal subfield segmentation quality control (QC) procedure for improved pipeline harmonization. To guide researchers to make optimal use of the algorithm, we discuss how global size and age effects can be modelled, how QC steps can be incorporated and how subfields may be aggregated into composite volumes. This discussion is based on a synopsis of 162 published neuroimaging studies (01/2013–12/2019) that applied the FreeSurfer hippocampal subfield segmentation in a broad range of domains including cognition and healthy aging, brain development and neurodegeneration, affective disorders, schizophrenia, childhood trauma and posttraumatic stress disorder, inflammatory and systemic disease, alcoholism, stress regulation, neurotoxicity, as well as assessments of heritability, effects of candidate genes, genome-wide association studies and epigenetic effects. Lastly, we highlight points where FreeSurfer-based hippocampal subfield studies may be optimized.

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Common increased hippocampal volume but specific changes in functional connectivity in schizophrenia patients in remission and non-remission following electroconvulsive therapy: A preliminary study

Cited by 18 publications

References 56 publications

Functional connectivity abnormalities of the long-axis hippocampal subregions in schizophrenia during episodic memory

Functional connectivity abnormalities of the long-axis hippocampal subregions in schizophrenia during episodic memory

Systematic Review of the Neural Effect of Electroconvulsive Therapy in Patients with Schizophrenia: Hippocampus and Insula as the Key Regions of Modulation

FreeSurfer based segmentation of hippocampal subfields: a review of methods and applications, with a novel quality control procedure for ENIGMA studies and other collaborative efforts

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