REVERSIBILITY OF BRAIN-TISSUE LOSS IN ANOREXIA-NERVOSA ASSESSED WITH A COMPUTERIZED TALAIRACH 3-D PROPORTIONAL GRID

We describe the results of our follow-up magnetic resonance imaging (M RI) study of underweight patients with anorexia nervosa, using rigorou s methodology to control for head position across time. All subjects f irst underwent an initial scan and rescan to verify that our computeri zed three-dimensional co-planar grid method for volume measurement was reliable and accurate, regardless of head positioning. After a period of several months, subjects had a follow-up scan to assess for change s that may have occurred following significant weight gain. Ventricula r and total brain volume measurements from the initial scans were comp ared with the scans from an age- and sex-matched normal control group to determine whether we could replicate previous findings of ventricul ar enlargement compared with controls and whether brain volume is redu ced compared with controls. Anorexic subjects had significantly larger ventricles when compared with normal controls but did not differ sign ificantly in total brain volume. Using a repeated measures analysis of variance, a priori contrasts compared the initial/rescan pair volumes with each other and the initial/rescan pair volumes with the follow-u p volume. These analyses showed that ventricular and total brain volum es derived from the initial/rescan pair were nearly identical, but tha t at follow-up ventricular volume decreased significantly and total br ain volume increased significantly after weight gain.