Cognitive Performance in Early Neuronal Synuclein Disease with Hyposmia but without Motor Disability: Association with Dopamine Deficiency and Isolated Rapid Eye Movement Sleep Behavior Disorder.

ABSTRACT:

Objective

To determine the impact of dopamine deficiency and isolated rapid eye movement (REM) sleep behavior disorder (iRBD) on cognitive performance in early neuronal α-synuclein disease (NSD) with hyposmia but without motor disability.

Methods

Using Parkinson's Progression Markers Initiative baseline data, cognitive performance was assessed with a cognitive summary score (CSS) derived from robust healthy control (HC) norms. Performance was examined for participants with hyposmia in early NSD-Integrated Staging System (NSD-ISS), either stage 2A (cerebrospinal fluid α-synuclein seed amplification assay [SAA]+, dopamine transporter scan [DaTscan]-) or 2B (SAA+, DaTscan+).

Results

Participants were stage 2A (n = 101), stage 2B (N = 227), and HCs (n = 158). Although sta

SUBMITTER: Weintraub D 

PROVIDER: S-EPMC12392052 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature