Abstract
BackgroundRecent studies have shown aberrant gyrification, i.e. folding of the cortical surface, as a marker of disturbed neocortical development in schizophrenia. Unlike more commonly used markers like voxel-based morphometry, these parameters might be more sensitive to early neurodevelopmental pathologies. It is unclear, however, whether such structural changes might be evident across the schizophrenia spectrum, involving at-risk subjects as well as even healthy subjects with subclinical or attenuated psychotic(-like) symptomsMethodsWe analysed high-resolution MRI scans (3 Tesla, T1-weighted MPRAGE, 1x1x1mm resolution) from n=177 healthy subjects with no current or previous psychiatric condition recruited from the local community. Subjects completed the SCL90R, a general symptom checklist (i.e. self-rating of symptoms), which includes subscales for psychoticism (with subclinical psychotic/-like symptoms) and paranoid ideation. We used the CAT12 toolbox to analyse both gyrification using the absolute mean curvature approach (Luders et al., NeuroImage 2006, as well as cortical thickness and voxel-based morphometry (VBM).ResultsCorrecting for effects of age and gender, we found a significant negative correlation between SCL90R psychoticism scores and gyrification in a left prefrontal / frontopolar cluster, but no similar finding for wither cortical thickness analysis nor analyses of the paranoid ideation subscale.DiscussionOur results suggest that prefrontal gyrification might be a marker for psychotic phenotypes spanning a spectrum from subclinical symptom expression to frank psychosis. This association seems linked to gyrification (rather than other markers of brain structure), which would suggest a relative specificity. Hence, this would be consistent with the assumption that gyrification is related to early neurodevelopmental effects, which lead to liabity to experiencing psychotic symptoms later in life, and might thus serve as an imaging phenotype for early risk detection and intervention in high-risk groups.
Highlights
Clozapine is the most effective anti-psychotic for treatment refractory schizophrenia, but causes significant metabolic disturbances including obesity and type 2 diabetes
Administration of exogenous GLP-1 agonists such as exenatide to animals have been shown to counter this effect of clozapine
Exenatide subcutaneous weekly injections may assist obese people on clozapine lose weight. This randomised, controlled, open-label, pilot trial aimed to evaluate the effect of exenatide on weight loss among clozapine-treated obese adults who have schizophrenia, with or without stable diabetes
Summary
Structural neuroimaging studies report distributed grey matter volume (GMV) deficits in drug-naïve first episode psychosis (FEP), though their relevance to symptom burden and cognitive deficits is currently unclear. We report the initial findings from the voxelbased morphometry (VBM) of GMV To our knowledge, this is the first VBM report from drug-naïve FEP subjects obtained using a 7T MRI acquisition. Methods: We used ultra-high field (7 Tesla) MRI in 28 patients with FEP (satisfying criterion A of DSM-5 schizophrenia) and 18 controls, to evaluate differences in the grey matter. We used multiple regression analysis to predict the scores from processing speed measure (modified Symbol Substitution Test) and the severity of Delusions and Unusual Thought Content (P1 and G9), the 2 symptoms for which most subjects sought treatment in the first place
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call