White matter integrity is reduced in bulimia nervosa

Abstract

Objective To investigate brain white matter (WM) functionality in bulimia nervosa (BN) in relation to anxiety. Method Twenty-one control (CW, mean age 27±7 years) and 20 BN women (mean age 25±5 years) underwent brain diffusion tensor imaging (DTI) to measure fractional anisotropy (FA; an indication of WM axon integrity) and the apparent diffusion coefficient (ADC; reflecting WM cell damage). Results FA was decreased in BN in the bilateral corona radiata extending into the posterior limb of the internal capsule, the corpus callosum, the right sub-insular white matter and right fornix. In CW but not BN trait anxiety correlated negatively with fornix, corpus callosum and left corona radiata FA. ADC was increased in BN compared to CW in the bilateral corona radiata, corpus callosum, inferior fronto-occipital and uncinate fasciculus. Alterations in BN WM functionality were not due to structural brain alterations. Discussion WM integrity is disturbed in BN, especially in the corona radiate, which has been associated with taste and brain reward processing. Whether this is a premorbid condition or an effect from the illness is yet uncertain. The relationships between WM FA and trait anxiety in CW but not BN may suggest that altered WM functionality contributes to high anxious traits in BN.

The Inverse Relationship between the Microstructural Variability of Amygdala-Prefrontal Pathways and Trait Anxiety Is Moderated by Sex

“…Our data complement and expand previous findings from other groups that utilized dMRI to show an inverse relationship between frontotemporal white matter strength and trait anxiety/anxiety-related constructs (e.g., harm avoidance, neuroticism) in nonclinical populations (Kazlouski et al, 2011; Motzkin et al, 2011; Westlye et al, 2011; Taddei et al, 2012; Bjørnebekk et al, 2013; Mettler et al, 2013; Eden et al, 2015; Greening and Mitchell, 2015). Collectively, these findings support the notion that stronger connectivity between the amygdala and the vPFC reflects the capacity for efficient crosstalk between these brain regions that ultimately leads to beneficial outcomes in terms of anxiety (Kim et al, 2011b).…”

“…The current data are consistent with a recent finding that highlights a female-specific inverse relationship between amygdala-vPFC resting state functional connectivity and self-reported anxiety symptoms (Burghy et al, 2012). Further, a number of previous studies showing an inverse relationship between the structural integrity of an amygdala-vPFC pathway and trait anxiety consisted of dMRI data derived entirely from females (Kazlouski et al, 2011; Mettler et al, 2013; Eden et al, 2015). Finally, an additional study showed a female-specific positive correlation between the structural integrity of the uncinate fasciculus and self-reported use of reappraisal strategy during emotion regulation (Zuurbier et al, 2013).…”

Disruption of brain white matter microstructure in women with anorexia nervosa

“…62 These mixed results might reflect the effects of overlapping pathophysiological mechanisms in the fornix. It is also interesting to note that these mechanisms might be nonspecific to patients with anorexia nervosa, restricting subtype, since a similar pattern of microstructural alterations in the fornix has been found in patients with bulimia nervosa 63 and in overweight and obese individuals. 64 Even if some of these conditions have opposite behavioural consequences, some shared biological effects are suggested, 65 and it is likely that extreme weight conditions might have similar structural effects in this energy balance system.…”

An interoceptive model of bulimia nervosa: A neurobiological systematic review

“…When measured with structural MRI, BN participants were characterized by increased gray matter volumes within the ventral anterior insula (Frank et al, 2013) and when measured by DTI, BN participants displayed disturbed white matter integrity within the right sub-insula (Mettler et al, 2013). …”