INTRODUCTION

The cognitive and neuroimaging evolution during dementia with Lewy bodies (DLB) from the prodromal phase (Pro-DLB; subjective cognitive impairment [SCI] to mild cognitive impairment [MCI]) according to amyloid beta (Aβ) status is poorly understood.

METHODS

The decline of Lewy-Memento patients with SCI or MCI was compared according to Aβ status across four groups: Pro-DLB, prodromal Alzheimer's disease (Pro-AD), Pro-DLB+AD, and a group without prodromal DLB and AD (no symptoms [NS]). We observed the evolution of cognitive, functional, quality of life measures, brain volumetry, and metabolism on fluorodeoxyglucose positron emission tomography.

RESULTS

In the Pro-DLB and Pro-DLB+AD groups, Aβ+ patients had more cognitive and functional decline than the Aβ- patients. In the Pro-AD and NS groups, Aβ+ patients had more functional decline. Aβ+ Pro-AD showed a greater volume decline of the brain (left insula).

DISCUSSION

The presence of amyloid lesions worsens very prodromal DLB patients over time, both cognitively and functionally, but without increasing atrophy.

HIGHLIGHTS

Patients at a very prodromal stage, subjective cognitive impairment or mild cognitive impairment, had a clinical diagnosis of either prodromal Alzheimer's disease (Pro-AD), prodromal dementia with Lewy bodies (Pro-DLB), Pro-DLB+AD, or no diagnosis.Amyloid beta positive (Aβ+) patients had more functional decline, whatever the group.Aβ+ DLB patients (Pro-DLB and Pro-DLB+AD) had more global cognitive (Mini-Mental State Examination) decline.Aβ+ Pro-AD patients showed a greater volume decline of the left insula.