Altered cerebellar and caudate gray-matter volumes and structural covariance networks preceding dual cognitive and mobility impairments in older people

Abstract

Introduction: The neuroanatomical changes driving both cognitive and mobility impairments, an emerging preclinical dementia syndrome, are not fully understood. We examined gray-matter volumes (GMVs) and structural covariance networks (SCNs) abnormalities in community-based older people preceding the conversion to physio-cognitive decline syndrome (PCDS).

Methods: Voxel-wise brain GMV and established SCNs were compared between PCDS and non-PCDS converters.

Results: The study included 343 individuals (60.2 ± 6.9 years, 49.6% men) with intact cognitive and mobility functions. Over an average 5.6-year follow-up, 116 transitioned to PCDS. Identified regions with abnormal GMVs in PCDS converters were over cerebellum and caudate, which served as seeds for SCNs establishment. Significant differences in cerebellum-based (to right frontal pole and left middle frontal gyrus) and caudate-based SCNs (to right caudate putamen, right planum temporale, left precentral gyrus, right postcentral gyrus, and left parietal operculum) between converters and nonconverters were observed.

Discussion: This study reveals early neuroanatomic changes, emphasizing the cerebellum's role, in dual cognitive and mobility impairments.

Highlights: Neuroanatomic precursors of dual cognitive and mobility impairments are identified. Cerebellar GMV reductions and increased right caudate GMV precede the onset of PCDS. Altered cerebellum- and caudate-based SCNs drive PCDS transformation. This research establishes a foundation for understanding PCDS as a specific dementia syndrome.

Keywords: Diagnostic and Statistical Manual of Mental Disorders ‐ III‐ revised version (DSM‐III‐R); caudate; cerebello‐frontal network; cerebellum VIII; cerebellum crus II; dual cognitive and mobility decline; gray‐matter volume; physio‐cognitive decline syndrome; structural covariance; subcortical network.