Artikel
Alterations in White Matter-Integrity in Patients with Anorexia Nervosa – A Longitudinal Study
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Veröffentlicht: | 18. Februar 2016 |
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Background: Despite increasing interest in white matter alterations in patients with Anorexia Nervosa (AN), there are only a few and inconsistent studies. Especially, there is a lack of longitudinal study designs.
Methods: We employ Diffusion-Tensor-Imaging (DTI; 36 diffusion sensitizing gradients; b-value 1300 s/mm ² , 2.5 mm^3 isotropic voxel resolution) to search for differences in white matter properties in 44 female patients with acute restrictive AN (acAN) before (time point 1; Tp1; BMI Mean: 14.85, STD: 1.20) and after (time point 2; Tp2; BMI Mean: 18.72, STD: 1.10) inpatient-treatment (Mean: 2.99 month, STD: 1.04) and a minimum BMI increase of 10% (Mean: 26.59, STD: 9.44). At Tp1 the adolescent's age ranged from 12 to 22 (Mean = 15.4, STD = 2.28). DTI images were processed using FSL’s TBSS (University of Oxford Centre for Functional MRI of the Brain). Paired group-comparisons were performed and voxelwise maps were generated for fractional anisotropy (FA). Clusters were then extracted using the recommended threshold-free cluster enhancement method [Smith2009] at p < 0.05, FWE corrected.
Results: BMI and SDS increased significantly between Tp1 and Tp2 (p < 0.001). Compared to Tp2 patients at Tp1 showed significantly higher FA in the right hemisphere mainly including right superior longitudinal fasciculus, anterior, posterior and superior corona radiata, anterior and posterior limb of internal capsule and corticospinal tract. After recovery of weight (Tp2) four main areas with increased FA were identified compared to Tp1: body and genu of corpus callosum, external capsule, fornix and anterior thalamic radiation.
Conclusions: Our findings do not support previous studies that had suggested reduced white-matter integrity in the acute state of AN [Via2014]. Instead, we found that FA decreases in patients with AN during weight recovery, but also increases in several brain regions. However, the areas where microstructural changes occur are consistent with previous findings [Kazlouski2011, Frieling2012], encouraging the presence of illness-related brain changes in specific brain regions. To corroborate our results, ongoing studies examine mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) as well as the impact of age and weight at Tp1 regarding alterations in DTI scalars.