Objective: The neurobiological mechanisms of structural brain abnormalities in patients with anorexia nervosa (AN) remain poorly understood. In particular, little is known about the changes in and the recovery of gray matter (GM) volumes after weight gain and the relation to hormonal normalization in adolescent patients with AN.
Methods: Nineteen female patients aged 12 to 17 years were assessed using magnetic resonance imaging at the time of admission to the hospital (T1) and after weight recovery (T2). Patients were compared with typically developing girls matched for age and intelligence quotient. Structural brain images were analyzed using a voxel-based morphometric approach. Circulating levels of cortisol and gonadotropins were assessed in blood samples.
Results: Compared with controls, patients with AN showed reduced GM in several brain regions along the cortical midline, reaching from the occipital cortex to the medial frontal areas. These GM reductions were mostly reversible at T1. Patients showed a GM increase from T1 to T2 along the cortical midline and in the occipital, temporal, parietal, and frontal lobes. GM increases at T2 correlated inversely with cortisol levels at T1 and positively with weight gain at T2. The strongest associations between regional GM increase and weight gain were found in the cerebellum. In addition, increases in GM volumes at T2 in the thalamus, hippocampus, and amygdala were associated with increases in follicle-stimulating hormone.
Conclusions: Our data suggest that brain alterations in adolescents with acute AN are mostly reversible at T1 and that GM recovery in specific brain regions is associated with weight and hormonal normalization.