Entorhinal Cortex Volume, Thickness, Surface Area and Curvature Trajectories over the Adult Lifespan

The entorhinal cortex (ERC) acts as a connection between the hippocampus and temporal cortex and plays a key role in memory retrieval and navigation. The morphology of this brain region changes with age. However, there are few quantitative magnetic resonance imaging studies of ERC morphology across the healthy adult lifespan. In this study, we quantified ERC volume, thickness, surface area, and curvature in a large number of subjects spanning seven decades of life. Using structural MRI data from 563 healthy subjects ranging from 19 to 86 years of age, we explored the adult lifespan trajectory of ERC volume, thickness, surface and curvature. ERC volume, thickness, and surface area initially increased with age, reaching a peak at about 32 years, 40 years, and 50 years of age, respectively, after which they decreased with age. ERC volume and surface area were hemispherically leftward asymmetric, whereas ERC thickness was hemispherically rightward asymmetric, with no gender differences. The direction of asymmetry differed across the measures. This informs previous inconsistencies in reports of ERC asymmetry. ERC aging began in mid-adulthood. At this stage of life, it may be important to adopt some strategies to reduce the effects of aging on cognition.