Occipital atrophy signature in prodromal Lewy bodies disease

Abstract

Introduction: Dementia with Lewy bodies (DLB) is typically characterized by parietal, temporal, and occipital atrophy, but less is known about the newly defined prodromal phases. The objective of this study was to evaluate structural brain alterations in prodromal DLB (p-DLB) as compared to healthy controls (HC) and full-blown dementia (DLB-DEM).

Methods: The study included 42 DLB patients (n = 20 p-DLB; n = 22 DLB-DEM) and 27 HC with a standardized neurological assessment and 3-tesla magnetic resonance imaging. Voxel-wise analyses on gray-matter and cortical thickness were implemented to evaluate differences between p-DLB, DLB-DEM, and HC.

Results: p-DLB and DLB-DEM exhibited reduced occipital and posterior parieto-temporal volume and thickness, extending from prodromal to dementia stages. Occipital atrophy was more sensitive than insular atrophy in differentiating p-DLB and HC. Occipital atrophy correlated to frontotemporal structural damage increasing from p-DLB to DLB-DEM.

Discussion: Occipital and posterior-temporal structural alterations are an early signature of the DLB continuum and correlate with a long-distance pattern of atrophy.

Keywords: MRI; cortical thickness; occipital atrophy; prodromal DLB; voxel‐based morphometry.

FIGURE 1

(A) Grey matter atrophy in patients with p‐DLB and DLB compared to HC. Results are p < .05 FDR‐corrected. (B) Patterns of cortical thickness in patients with p‐DLB and DLB compared to HC. Images are p < .001 uncorrected for multiple comparisons. (C) Patterns of gray matter structural covariance between bilateral lingual gyrus and other brain regions in HC (left), p‐DLB (middle), and DLB‐DEM (right). Results are p < .05 FDR‐corrected. Color bar represents t values. HC, healthy controls; p‐DLB, prodromal dementia with Lewy bodies; DLB‐DEM, dementia with Lewy bodies.