Age-Volume Associations in Cerebellar Regions by Sex and Reproductive Stage

Introduction The cerebellum has established associations with motor function and a well- recognized role in cognition. In advanced age, cognitive and motor impairments contribute to reduced quality of life and are more common. Regional cerebellar volume is associated with performance across these domains and sex hormones may influence this volume. Examining sex differences in regional cerebellar volume in conjunction with age, and in the context of reproductive stage stands to improve our understanding of cerebellar aging and pathology. Methods Data from 530 healthy adults (ages 18-88; 49% female) from the Cambridge Centre for Ageing and Neuroscience database were used here. CERES was utilized to assess lobular volume in T1-weighted images. We examined sex differences in adjusted regional cerebellar volume while controlling for age. A subgroup (n = 354, 50% female) was used to assess group differences in female reproductive stages as compared to age-matched males. Results Sex differences in adjusted volume were seen across most anterior and posterior cerebellar lobules. The majority of cerebellar regions had significant linear relationships with age in males and females. However, there were no interactions between sex and reproductive stage groups (i.e., female reproductive stage did not display a relationship with regional cerebellar volume). Discussion We found sex differences in volume across much of the cerebellum, linear associations with age, and did not find an effect of female reproductive stage on regional cerebellar volume. Longitudinal investigation into hormonal influences on cerebellar structure and function is warranted as hormonal changes with menopause may impact structure over time. ### Competing Interest Statement The authors have declared no competing interest.