Mammillary body volume abnormalities in anorexia nervosa

Abstract

Objective Several case reports of Wernicke’s Encephalopathy in AN due to thiamine deficiency have described mammillary body (MB) injury, but systematic studies are lacking. Here we evaluated whether underweight and weight-restored individuals with AN demonstrate evidence of abnormal MB morphology, via retrospective examination of a previously collected data set. Method Using standard-resolution T1-weighted magnetic resonance imaging at 3 Tesla, we measured MB volume and fornix area in a cross-sectional study of 12 underweight AN, 20 weight-restored AN, and 30 age- and sex-matched healthy comparisons. Due to the small size of these structures, a manual tracing approach was necessary to obtain accurate measurements. A blinded expert rater manually traced MB and fornix structures in each participant. Results We observed significantly smaller MB volumes in the underweight AN group. However, the weight-restored AN group exhibited significantly larger MB volumes. The right fornix was smaller in the weight-restored AN group only. Discussion These findings suggest the possibility that MB volume and fornix area could represent potential biomarkers of acute weight loss and restoration, respectively. Verification of this finding through prospective studies evaluating MB morphology, cognition, and thiamine levels longitudinally across individual illness trajectories might be warranted.

Preventing Wernicke's encephalopathy in anorexia nervosa: A systematic review

“…Thiamine deficiency occurs in 38% of individuals with AN, and is often unrecognized . Recently, selective brain volume alterations of the mammillary bodies have been linked to acute weight changes, reflecting a specific sensitivity to vitamin B1 deficiency of this brain area. Because of the high oxidative metabolism, it has earlier been suggested that the thalamic region, including the mammillary bodies, is particularly sensitive to thiamine deficiency A possible side‐effect of prolonged vitamin B1 deficiency is Wernicke's encephalopathy (WE).…”

Multimodal neuroimaging in anorexia nervosa

“…This tract is central for body distortion, a key feature in this disorder. There were no differences in the fornix in AN acute phase, but restored patients showed a significant difference only for the right fornix in the study by KhalsaKumar, Patel, Strober, and Feusner (2016) which, instead, found disparities in mammillary body volume of underweight AN patients, whereas it was increased in weight‐restored AN. Microstructural changes in the fornix of AN patients might have been biased by partial volume effects, as demonstrated by Kaufmann et al.…”

The Mammillary Bodies: A Review of Causes of Injury in Infants and Children

“…31,33 In addition to signal changes, MB volume loss has also been reported in patients with anorexia nervosa as well as recovery of MB volume in individuals who regained weight. 30 Recovery of MB volume has also been reported in patients with acute liver failure following treatment with thiamine. 35 Furthermore, MB volume was found to correlate with blood thiamine levels.…”

“…Wernicke encephalopathy in children typically arises from nutritional deficiency, which can occur due to vomiting (eg, due to anorexia nervosa, hyperemesis, gastrointestinal obstruction), [30][31][32] chronic gastrointestinal disease, 33 and following bariatric surgery. 34 Wernicke encephalopathy has also been reported following acute liver failure 35 and pancreatitis.…”