Three year longitudinal changes of subcortical volumes in SuperAgers

Background “SuperAgers” refer to older adults whose cognitive abilities were comparable to those in middle age or to those of young adults. Given that the volumes of the subcortical structures are the main structures of the frontal‐subcortical circuits that are associated with frontal function, investigating the changes of subcortical volumes in Superagers could help understand the underpinning neural characteristics in SuperAgers. Therefore, the purpose of this study to examine the longitudinal changes of subcortical structures in Superagers compared to typical agers. Methods We enrolled a total of 100 elderly (60 years old or older) with normal cognitive functions. The normal cognitive function was defined when participants scored above ‐ 1.SD of population norm on the tests of memory and scored above ‐ 1.5 SD on the tests of language, attention, visuospatial and executive functions. We defined the superagers based on their performance compared to middle‐aged adults (45 year old) on the delayed recall scores in both the Seoul Verbal Learning Test and the Rey Rey‐Osterrieth Complex Figure Test. We followed up cognitive function and brain MRI every year for three years. The T1 images of each subject were processed to obtain the anatomical parcellations of subcortical structures by the FreeSurfer software. Mixed effect model was used to analyze the longitudinal changes of subcortical volumes with age, sex and education years as covariates. Result A total of 46 participants were classified as the superagers. At the baseline, SuperAgers demonstrated greater volumes not only in the hippocampus but also in the putamen, thalamus and pallidum. During the three year follow‐up, superagers continued to show greater volumes in the hippocampus, putamen, thalamus and pallidum. Conclusion These results indicate that Superagers might be resilient to age‐related structural volume change not only in the hippocampus but also in other subcortical volumes such as putamen, thalamus and pallidum.