Open AccessEvidence of frontotemporal structural hypoconnectivity in social anxiety disorder: A quantitative fiber tractography study
Author(s) -
Baur Volker,
Brühl Annette Beatrix,
Herwig Uwe,
Eberle Tanja,
Rufer Michael,
Delsignore Aba,
Jäncke Lutz,
Hänggi Jürgen
Publication year - 2013
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.21447
Subject(s) - uncinate fasciculus , orbitofrontal cortex , fractional anisotropy , fasciculus , white matter , psychology , inferior longitudinal fasciculus , diffusion mri , tractography , neuroscience , social anxiety , anxiety , medicine , magnetic resonance imaging , prefrontal cortex , psychiatry , radiology , cognition
Abstract Investigation of the brain's white matter fiber tracts in social anxiety disorder (SAD) may provide insight into the underlying pathophysiology. Because models of pathological anxiety posit altered frontolimbic interactions, the uncinate fasciculus (UF) connecting (orbito‐) frontal and temporal areas including the amygdala is of particular interest. Microstructural alterations in parts of the UF have been reported previously, whereas examination of the UF as discrete fiber tract with regard to more large‐scale properties is still lacking. Diffusion tensor imaging was applied in 25 patients with generalized SAD and 25 healthy control subjects matched by age and gender. By means of fiber tractography, the UF was reconstructed for each participant. The inferior fronto‐occipital fasciculus (IFOF), originating from the frontal cortex similarly to the UF, was additionally included as control tract. Volume and fractional anisotropy (FA) were compared between the groups for both tracts. Volume of left and right UF was reduced in patients with SAD, reaching statistical significance for the left UF. Bilateral IFOF volume was not different between groups. A similar pattern was observed for FA. Reduced volume of the left UF in SAD fits well into pathophysiological models of anxiety, as it suggests deficient structural connectivity between higher‐level control areas in the orbitofrontal cortex and more basal limbic areas like the amygdala. The results point to a specific role of the left UF with regard to altered white matter volume in SAD. However, results should be replicated and functional correlates of altered UF volume be determined in future studies. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.