White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study

Abstract

BackgroundAnorexia nervosa (AN) often begins in adolescence, however, the understanding of the underlying pathophysiology at this developmentally important age is scarce, impeding early interventions. We used diffusion tensor imaging (DTI) to investigate microstructural white matter (WM) brain changes including an experimental longitudinal follow-up.MethodsWe acquired whole brain diffusion-weighted brain scans of 22 adolescent female hospitalized patients with AN at admission and nine patients longitudinally at discharge after weight rehabilitation. Patients (10–18 years) were compared to 21 typically developing controls (TD). Tract-based spatial statistics (TBSS) were applied to compare fractional anisotropy (FA) across groups and time points. Associations between average FA values of the global WM skeleton and weight as well as illness duration parameters were analyzed by multiple linear regression.ResultsWe observed increased FA in bilateral frontal, parietal and temporal areas in AN patients at admission compared to TD. Higher FA of the global WM skeleton at admission was associated with faster weight loss prior to admission. Exploratory longitudinal analysis showed this FA increase to be partially normalized after weight rehabilitation.ConclusionsOur findings reveal a markedly different pattern of WM microstructural changes in adolescent AN compared to most previous results in adult AN. This could signify a different susceptibility and reaction to semi-starvation in the still developing brain of adolescents or a time-dependent pathomechanism differing with extend of chronicity. Higher FA at admission in adolescents with AN could point to WM fibers being packed together more closely.

Toward valid and reliable brain imaging results in eating disorders

“…In one study in adolescents, short‐term dehydration after exercise over 90 min did not show altered brain volume, but greater brain response when compared with a control group in fronto‐parietal cortex while performing an executive function task; task performance was similar between groups (Kempton et al, ). To date, three studies tried to address the question of whether brain abnormalities in underweight anorexia nervosa may be due to dehydration by measuring urine specific gravity immediately prior to neuroimaging, but found no evidence of dehydration related to brain morphology (Bernardoni et al, ; King et al, ; Vogel et al, ). However, this does not exclude the existence and effects of dehydration in eating disorders.…”

Normal white matter microstructure in women long‐term recovered from anorexia nervosa: A diffusion tensor imaging study

“…Findings from such studies are inconsistent. In a longitudinal investigation (Vogel et al, ), increased FA in frontal, temporal, and parietal fibers among adolescent patients were observed to partially normalize following weight‐restoration. In another longitudinal study, Cha et al () observed increased FA in fibers connecting the orbitofrontal cortex and the nucleus accumbens among adolescent and adult patients with AN, which persisted following weight‐restoration with no indication of partial normalization.…”

“…For adult patients, studies point to decreased FA (Frieling et al, ; Hayes et al, ; Kazlouski et al, ; Nagahara et al, ; Via et al, ), which in some instances is accompanied by increased MD (Nagahara et al, ; Via et al, ). For adolescents, the emerging findings are more inconsistent; both reduced (Frank et al, ; Travis et al, ) and increased (Cha et al, ; Travis et al, ; Vogel et al, ) FA have been reported. Also, a recent investigation found no evidence of any WM microstructure alterations in adolescent AN patients (Pfuhl et al, ).…”

“…The mechanisms underlying these alterations in WM microstructure are not known. One study excluded dehydration as the possible culprit (Vogel et al, 2016). It is known that WM microstructure can be affected by a variety of factors, including sleep deprivation (Elvsåshagen et al, 2015) and fasting (Bakan et al, 2015).…”

Preserved white matter microstructure in adolescent patients with atypical anorexia nervosa

“…White matter (WM) integrity and structural connectivity (Frank, Shott, Hagman, & Yang, 2013;Gaudio et al, 2017;Kaufmann et al, 2017;Olivo et al, 2017;Pfuhl et al, 2016;Travis et al, 2015;Vogel et al, 2016;von Schwanenflug et al, 2018) have been explored with somewhat conflicting results ( Figure 1). White matter (WM) integrity and structural connectivity (Frank, Shott, Hagman, & Yang, 2013;Gaudio et al, 2017;Kaufmann et al, 2017;Olivo et al, 2017;Pfuhl et al, 2016;Travis et al, 2015;Vogel et al, 2016;von Schwanenflug et al, 2018) have been explored with somewhat conflicting results ( Figure 1).…”