Free water predicts dementia with Lewy bodies in isolated REM sleep behavior disorder.

ABSTRACT:

Introduction

Most individuals with isolated rapid eye movement sleep behavior disorder (iRBD) develop dementia with Lewy bodies (DLB) or Parkinson's disease (PD). Brain biomarkers predicting specific phenoconversion trajectories are lacking.

Methods

In this multicenter diffusion magnetic resonance imaging study (261 iRBD, 177 controls), free water (FW) was measured in the nucleus basalis of Meynert (NBM) and posterior substantia nigra (SN). Among 230 iRBD patients with follow-up, 64 converted (16 DLB, 38 PD). Time-to-event analyses were performed to assess differential phenoconversion.

Results

Phenoconverters had higher FW in the NBM and posterior SN. Only FW in the NBM predicted conversion to DLB over PD. NBM volume predicted DLB conversion, but only FW remained sign

SUBMITTER: Haddad C 

PROVIDER: S-EPMC12447249 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature