Subtle white matter alterations in schizophrenia identified with a new measure of fiber density

Article Article scientifique Article Subtle white matter alterations in schizophrenia identified with a new measure of fiber density eng 2019 author Stämpfli Philipp author Sommer Stefan author Manoliu Andrei author Burrer Achim author Schmidt Andréas Georg 64140 author Herdener Marcus author Seifritz Erich author Kaiser Stefan 0000-0002-3013-2034 868946 author Kirschner Matthias 4636 10.1038/s41598-019-40070-2 30874571 2045-2322 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6420505/ Altered cerebral connectivity is one of the core pathophysiological mechanism underlying the development and progression of information-processing deficits in schizophrenia. To date, most diffusion tensor imaging (DTI) studies used fractional anisotropy (FA) to investigate disrupted white matter connections. However, a quantitative interpretation of FA changes is often impeded by the inherent limitations of the underlying tensor model. A more fine-grained measure of white matter alterations could be achieved by measuring fiber density (FD) - a novel non-tensor-derived diffusion marker. This study investigates, for the first time, FD alterations in schizophrenia patients. FD and FA maps were derived from diffusion data of 25 healthy controls (HC) and 21 patients with schizophrenia (SZ). Using tract-based spatial statistics (TBSS), group differences in FD and FA were investigated across the entire white matter. Furthermore, we performed a region of interest (ROI) analysis of frontal fasciculi to detect potential correlations between FD and positive symptoms. As a result, whole brain TBSS analysis revealed reduced FD in SZ patients compared to HC in several white matter tracts including the left and right thalamic radiation (TR), superior longitudinal fasciculus (SLF), corpus callosum (CC), and corticospinal tract (CST). In contrast, there were no significant FA differences between groups. Further, FD values in the TR were negatively correlated with the severity of positive symptoms and medication dose in SZ patients. In summary, a novel diffusion-weighted data analysis approach enabled us to identify widespread FD changes in SZ patients with most prominent white matter alterations in the frontal and subcortical regions. Our findings suggest that the new FD measure may be more sensitive to subtle changes in the white matter microstructure compared to FA, particularly in the given population. Therefore, investigating FD may be a promising approach to detect subtle changes in the white matter microstructure of altered connectivity in schizophrenia. Dewey 616.89 Swiss National Science Foundation Did you unlearn to experience pleasure? Towards a multimodal computational biomarker for the anhedonia dimension in depression 178107 CH Careers 60 Département de psychiatrie 225 false 1236 Psychopathologie clinique et expérimentale 987 Scientific Reports 9 1 70e46634-95e7-40ce-9b44-ecd36cbcc3a9 Article (Published version) Public 41598_2019_Article_40070.pdf 2004957 application/pdf CC BY openAccess Faculté de médecine / Section de médecine clinique / Département de psychiatrie

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Subtle white matter alterations in schizophrenia identified with a new measure of fiber density	Scientific Reports			2019	399	246

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Schmidt, Andréas Georg