White Matter Abnormalities in Anorexia Nervosa: Psychoradiologic Evidence From Meta-Analysis of Diffusion Tensor Imaging Studies Using Tract Based Spatial Statistics

Abstract

Background: Anorexia nervosa (AN) is a debilitating illness whose neural basis remains unclear. Studies using tract-based spatial statistics (TBSS) with diffusion tensor imaging (DTI) have demonstrated differences in white matter (WM) microarchitecture in AN, but the findings are inconclusive and controversial. Objectives: To identify the most consistent WM abnormalities among previous TBSS studies of differences in WM microarchitecture in AN. Methods: By systematically searching online databases, a total of 11 datasets were identified, including 245 patients with AN and 246 healthy controls (HC). We used Seed-based d Mapping to analyze fractional anisotropy (FA) differences between AN patients and HC, and performed meta-regression analysis to explore the effects of clinical characteristics on WM abnormalities in AN. Results: The pooled results of all AN patients showed robustly lower FA in the corpus callosum (CC) and the cingulum compared to HC. These two regions preserved significance in the sensitivity analysis as well as in all subgroup analyses. Fiber tracking showed that the WM tracts primarily involved were the body of the CC and the cingulum bundle. Meta-regression analysis revealed that the body mass index and mean age were not linearly correlated with the lower FA. Conclusions: The most consistent WM microstructural differences in AN were in the interhemispheric connections and limbic association fibers. These common "targets" advance our understanding of the complex neural mechanisms underlying the puzzling symptoms of AN, and may help in developing early treatment approaches.

Neuroimaging Findings in Adolescents and Young Adults with Anorexia Nervosa: A Systematic Review

“…The corpus callosum is the principal WM fiber bundle of the brain, involved in motor, perceptual and cognitive functions. Alterations in WM could be related to reduced quantity and speed of information between these areas [ 33 ]. Furthermore, corpus callosum atrophy has been correlated with cognitive flexibility, another core feature of the disease [ 107 ].…”

“…In the second one, Meneguzzo et al identified two clusters of decreased FA, in the left corona radiata and in the left thalamus [ 32 ]. Finally, more recently, Zhang et al analyzed DTI studies using tractbased spatial statistics (TBSS) and reported lower FA in the corpus callosum and the cingulum [ 33 ].…”

Reduced structural connectivity in the corpus callosum in patients with anorexia nervosa

“…Several studies suggested a reduction of white matter integrity in the corpus callosum in AN (Frank et al, 2013;Gaudio et al, 2017;Nickel, Tebartz van Elst, et al, 2019;Olivo et al, 2017;Phillipou et al, 2018;Travis et al, 2015;von Schwanenflug et al, 2019). Two recent meta-analyses confirmed these findings (Barona et al, 2019;Zhang et al, 2020).…”

“…The meta-analysis of Barona et al (2019) on 13 whole brain DTI studies in AN showed the largest cluster of reduced FA in the corpus callosum, followed by subcortical areas (Barona et al, 2019). Zhang et al (2020), who included 11 tract-based spatial statistics studies, showed reduced FA in the corpus callosum and cingulum in AN patients compared to healthy controls (HC). There was no significant correlation between body mass index (BMI) and reduced FA (Zhang et al, 2020).…”

“…Zhang et al (2020), who included 11 tract-based spatial statistics studies, showed reduced FA in the corpus callosum and cingulum in AN patients compared to healthy controls (HC). There was no significant correlation between body mass index (BMI) and reduced FA (Zhang et al, 2020). Investigations focusing on MD in the corpus callosum are heterogeneous and reported both increased (Griffiths et al, 2020;Miles et al, 2020) and decreased (Nagahara et al, 2014) MD in patients compared to HC.…”