Cortical Morphometry in the Psychosis Risk Period: A Comprehensive Perspective of Surface Features

Abstract

Background-Gyrification features reflect brain development in the early prenatal environment. Clarifying the nature of these features in psychosis can help shed light on the role of early developmental insult. However, the literature is currently widely discrepant, which may reflect confounds related to formally psychotic patient populations or overreliance on a single cortical surface morphometry(CSM) feature. Methods-The present study compares CSM features of gyrification in clinical high-risk (CHR, n=43) youth during the prodromal risk period to typically developing controls over two time points across three metrics; local gyrification index(lGI), mean curvature index(MCI), and sulcal depth (improving resolution and examination of change over 1-year). Results-Gyrification was stable over time, supporting that gyrification reflects early insult rather than abnormal development/reorganization associated with the disease state. Each of the indices highlighted unique, aberrant features in the CHR group with respect to controls. Specifically, lGI reflected hypogyrification in lateral orbitofrontal, superior bank of the superior temporal sulcus, anterior isthmus of the cingulate, and temporal poles; MCI indicated sharper gyral and flatter/wider sulcal peaks in the cingulate, post-central, and lingual gyrus; sulcal depth identified shallow features in parietal, superior temporal sulcus, and cingulate regions. Further, both MCI and sulcal depth converged on abnormal features in the parietal cortex. Conclusions-Gyrification metrics suggest early developmental insult and provides support for neurodevelopmental hypotheses. Observations of stable CSM features across time provide context for interpreting extant studies and speak to CSM as a promising stable marker/endophenotype. Collectively, findings support the importance of considering multiple CSM features.

Cortical Complexity in People at Ultra-High-Risk for Psychosis Moderated by Childhood Trauma

“…We also found that ultra-high risk individuals showed reduced cortical complexity in the superior temporal gyrus (STG) and insula in the left hemisphere, corresponding with previous studies that found differences of gyrification in UHR (23). STG and insula are essential for auditory perception, cognitive functions, thought and language processing.…”

“…These studies have shown subtle cortical folding abnormalities in neocortical areas overlapping with those seen in VBM studies of schizophrenia ( 20 – 22 ). More recently, abnormalities of cortical surface features have also been shown in clinical high-risk youth with a prodromal syndrome ( 23 ). However, it remains unclear whether early environmental stressors like childhood trauma might interact with other (e.g., genetic) factors resulting in abnormal surface morphology.…”

Heschl’s Gyrus Duplication Pattern in Individuals at Risk of Developing Psychosis and Patients With Schizophrenia

“…A few MRI studies on cortical surface features in clinical high-risk individuals also showed similar gross morphological characteristics, such as altered sulcogyral patterns (Sasabayashi et al, 2017;Nakamura et al, 2019) and sulcaldepth abnormalities (Takahashi et al, 2019b), with patients with established Sz. In contrast to the evidence of active gray matter reductions in the superior temporal plane (e.g., HG and planum temporale) during the early illness stages of psychosis (Takahashi and Suzuki, 2018), a recent longitudinal study demonstrated the stability of gyrification features during the clinical high-risk period as a marker of early neurodevelopmental insults (Damme et al, 2019). Nevertheless, high-risk individuals with the later onset of psychosis may exhibit greater gyrification abnormalities before illness onset (Sasabayashi et al, 2017;Das et al, 2018) because greater and/or more prolonged neurodevelopmental deviations during gestation and consequent anomalous postpubertal brain changes may lead to overt and sustained psychosis (Pantelis et al, 2005).…”

Increased brain gyrification in the schizophrenia spectrum

“…Second, this cross‐sectional study could not directly elucidate the trajectories of the gyrification pattern. The cortical folding pattern is assumed to be genetically mediated and remains rather stable across adolescent neuromaturational processes in both HC and high‐risk individuals . However, a progressive LGI reduction was also demonstrated in schizophrenia patients, which may be due to gray matter volumetric reduction overtime .…”