Altered Fronto-Temporal Functional Connectivity in Individuals at Ultra-High-Risk of Developing Psychosis

Abstract

BackgroundThe superior temporal gyrus (STG) is one of the key regions implicated in psychosis, given that abnormalities in this region are associated with an increased risk of conversion from an at-risk mental state to psychosis. However, inconsistent results regarding the functional connectivity strength of the STG have been reported, and the regional heterogeneous characteristics of the STG should be considered.MethodsTo investigate the distinctive functional connection of each subregion in the STG, we parcellated the STG of each hemisphere into three regions: the planum temporale, Heschl’s gyrus, and planum polare. Resting-state functional magnetic resonance imaging was obtained from 22 first-episode psychosis (FEP) patients, 41 individuals at ultra-high-risk for psychosis (UHR), and 47 demographically matched healthy controls.ResultsSignificant group differences (in seed-based connectivity) were demonstrated in the left planum temporale and from both the right and left Heschl’s gyrus seeds. From the left planum temporale seed, the FEP and UHR groups exhibited increased connectivity to the bilateral dorsolateral prefrontal cortex. In contrast, the FEP and UHR groups demonstrated decreased connectivity from the bilateral Heschl’s gyrus seeds to the dorsal anterior cingulate cortex. The enhanced connectivity between the left planum temporale and right dorsolateral prefrontal cortex was positively correlated with positive symptom severity in individuals at UHR (r = .34, p = .03).ConclusionsThese findings corroborate the fronto-temporal connectivity disruption hypothesis in schizophrenia by providing evidence supporting the altered fronto-temporal intrinsic functional connection at earlier stages of psychosis. Our data indicate that subregion-specific aberrant fronto-temporal interactions exist in the STG at the early stage of psychosis, thus suggesting that these aberrancies are the neural underpinning of proneness to psychosis.

Aberrant Temporal Connectivity in Persons at Clinical High Risk for Psychosis

“…Findings from a large number of studies converge on the superior and middle temporal cortex as critical loci of anatomical and functional pathology in schizophrenia (51) and, to a lesser extent, in the CHR period (52). Volumetric reductions of the STG(53) and morphological abnormalities of the planum temporale(54) have long been observed in different phases of the illness, and these same temporal regions have been implicated in the genesis of psychotic symptoms(55).…”

Identifying functional network changing patterns in individuals at clinical high-risk for psychosis and patients with early illness schizophrenia: A group ICA study

“…Among model-based approaches, the most widely used is the region of interest (ROI)-based method ( Biswal et al, 1995 ), which measures functional connectivity (correlation or coherence) among different ROIs or between a specified “seed” ROI and all other voxels in brain. Most previous IN studies of CHR individuals employed an ROI-based method seeded by thalamus ( Anticevic et al, 2015 ), superior temporal gyrus ( Yoon et al, 2015 ), posterior cingulate cortex ( Shim et al, 2010 ), medial prefrontal cortex and anterior insula ( Wotruba et al, 2014 ), Broca's area ( Jung et al, 2012 ), or cerebellum ( Wang et al, 2016 ). These studies computed correlations between the mean time series in a specific ROI and the time series of other voxels in brain.…”

“…These studies computed correlations between the mean time series in a specific ROI and the time series of other voxels in brain. The identified IN abnormalities of CHR individuals were primarily located in the frontal lobes ( Anticevic et al, 2015 , Jung et al, 2012 , Wang et al, 2016 , Wotruba et al, 2014 , Yoon et al, 2015 ), temporal lobes ( Yoon et al, 2015 ), thalamus ( Anticevic et al, 2015 ), sensory motor cortex ( Anticevic et al, 2015 ) and Heschl's gyrus ( Anticevic et al, 2015 ), some of which also showed an intermediate degree of abnormality in the CHR syndrome compared to first episode psychosis ( Jung et al, 2012 , Yoon et al, 2015 ). One limitation of such studies is that results depend on a somewhat arbitrary definition of a specific ROI, including delineation of its shape, extent, and precise location ( Du et al, 2012 , Liu, 2011 ).…”

Aberrant intra and inter network resting state functional connectivity in thyrotoxicosis

“…In total, 14 components (Figure ) were identified as RSNs from group melodic output that included DMN; anterior DMN (ADMN); posterior DMN (PDMN); right fronto‐parietal network (RFPN); left fronto‐parietal network (LFPN); sensorimotor network (SMN); medial visual network (MVN); lateral visual network (LVN); task positive network (TPN); salience network (SN); auditory network (AN); fronto‐temporal network (FTN); basal ganglia network (BGN); and emotion network (EN) …”