Do the mammillary bodies atrophy with aging? A magnetic resonance imaging study.

Abstract

This retrospective study aimed to explore age-related atrophy of the mammillary bodies (MBs) based on their temporal change using magnetic resonance imaging (MRI). The study included 30 adult outpatients who presented to the hospital and were followed for more than 100months with annual MRIs. The bi-ventricular width (BVW), third ventricle width (TVW), and bi-mammillary dimension (BMD) were measured on axial T2-weighted imaging and analyzed. The 30 patients comprised 1 in their 40s, 5 in their 50s, 6 in their 60s, 11 in their 70s, 5 in their 80s, and 2 in their 90s. The MBs were consistently detected with left-to-right symmetry. The mean BVW was 32 ± 2.2mm on the initial (BVW1) and 32 ± 2.4mm on the last (BVW2) MRI. The mean TVW was 7.0 ± 2.3mm on the initial (TVW1) and 7.6 ± 2.7mm on the last (TVW2) MRI. Furthermore, the mean BMD was 9.9 ± 1.3mm on the initial (BMD1) and 10 ± 1.3mm on the last (BMD2) MRI. Statistically, no age ranges had a large dimension for BVW1, BVW2, TVW1, TVW2, BMD1, or BMD2. Changes between TVW1 and TVW2 were significantly different in the patients in their 80s; changes between BMD1 and BMD2 were not different for any age range or between sexes. Aging alone does not seem to promote MB atrophy. In healthy brains, the MBs may be stationary structures throughout life.