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. 2009 Oct 1;66(7):691-4.
doi: 10.1016/j.biopsych.2009.02.028. Epub 2009 Apr 11.

Preliminary evidence of white matter abnormality in the uncinate fasciculus in generalized social anxiety disorder

K Luan Phan  1 , Anton Orlichenko, Erin Boyd, Mike Angstadt, Emil F Coccaro, Israel Liberzon, Konstantinos Arfanakis
Affiliations

Preliminary evidence of white matter abnormality in the uncinate fasciculus in generalized social anxiety disorder

K Luan Phan et al. Biol Psychiatry. .

Abstract

Background: Individuals with generalized social anxiety disorder (GSAD) exhibit exaggerated amygdala reactivity to aversive social stimuli. These findings could be explained by microstructural abnormalities in white matter (WM) tracts that connect the amygdala and prefrontal cortex, which is known to modulate the amygdala's response to threat. The goal of this study was to investigate brain frontal WM abnormalities using diffusion tensor imaging (DTI) in patients with social anxiety disorder.

Methods: A Turboprop DTI sequence was used to acquire diffusion tensor images in 30 patients with GSAD and 30 matched healthy control subjects. Fractional anisotropy, an index of axonal organization, within WM was quantified in individual subjects, and an automated voxel-based, whole-brain method was used to analyze group differences.

Results: Compared with healthy control subjects, patients had significantly lower fractional anisotropy localized to the right uncinate fasciculus WM near the orbitofrontal cortex. There were no areas of higher fractional anisotropy in patients than controls.

Conclusions: These findings point to an abnormality in the uncinate fasciculus, the major WM tract connecting the frontal cortex to the amygdala and other limbic temporal regions, in GSAD, which could underlie the aberrant amygdala-prefrontal interactions resulting in dysfunctional social threat processing in this illness.

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Conflict of interest statement

Financial Disclosures The authors report no biomedical financial interests or potential conflicts of interest.

Figures

Figure 1
Figure 1
Lower Fractional Anistropy in Right Uncinate Fasciculus in Patients with Generalized Social Anxiety Disorder Than in Healthy Controls. A) Significant group difference (HC > GSAD) in FA values localized to the right uncinate fasciculus; cluster as rendered on a coronal and axial slice of the average FA map from all subjects; B) Scatterplot of individual subjects showing the mean fractional anistropy values across all voxels within the UF cluster for Generalized Social Anxiety Disorder (GSAD) and Healthy Control (HC) subjects. Horizontal lines represent group means.
See this image and copyright information in PMC

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