Volume measurement with magnetic resonance imaging of hippocampus-amygdalaformation in patients with anorexia nervosa

The purpose of our work was to evaluate the volume of hippocampus-amygdala formation (HAF) in patients with anorexia nervosa (AN), being this structur e a crucial target for the glucocorticoid action in the adaptative stress-r esponse. AN patients have biochemical hypercortisolism associated to normal ACTH levels, but do not develop the characteristic clinical features of gl ucocorticoid hypersecretion. Furthermore, in these patients cortisol levels usually do not suppress after dexametasone challenge. Twenty AN females (a ged 30.0 +/-5.1) with 10.5 +/-4.2 yr of disease underwent a brain magnetic resonance (MR) examination during the recovery phase; an age-matched contro l group (CG) of 20 healthy female volunteers was also studied. Two interlea ved T1-weighted spin-echo sequences for 46 contiguous 2-mm coronal slices ( pixel 0.98(2) mm) were used. The volumes of both right and left HAFs were c alculated with manual contouring from the third ventricle to the Sylvian aq ueduct. IGF-I, T-3, gonadotropins, 24-h urine free cortisol, and BMI were o btained for both patients (on admission and on present evaluation) and CG. Mann-Whitney, Wilcoxon and Spearman tests were used. AN patients showed a s ignificant (p=0.0001) reduction of total (right plus left) HAF volume (6.6 +/-1.3 cm(3)) when compared with CG (8.9 +/-1.1). No significant difference was found between right and left HAF in both patients and CG. In AN patien ts, no significant correlation was found between the HAF and all the hormon al parameters or BMIs, while a trend towards significance was observed with duration of the disease (r=-0.398; p=0.082). MR imaging demonstrated a sig nificant volume reduction of HAF in AN patients during the recovery phase o f the disease, suggesting a possible causal role in the pathogenesis of the disease. (J. Endocrinol. Invest. 24: 510-514, 2001) (C) 2001, Editrice Kur tis.