What does the research say about CSF alpha-synuclein seed amplification assay positivity?

CSF alpha-synuclein seed amplification assay positivity

There are 2 papers on CSF alpha-synuclein seed amplification assay positivity in aging research: 2 observational studies in people. The newest story, Oct 28, 2026: “Combined sleep and smell signs linked to Parkinson’s marker”.

Biomarker

2 papers study it3 findings

1 new paper in 30 daysSee all 2

“hyposmia strongly correlated with a positive CSF α-synuclein SAA-test.”

Persistent Hyposmia as Surrogate for α-Synuclein-Linked Brain PathologymedRxiv2023doi:10.1101/2023.12.19.23300164

Humans2

Associations

Dream enactment behavior

upin humans1

1 study

Dream enactment behavior is associated with CSF alpha-synuclein seed amplification assay positivity in humans (hyposmia with versus without self-reported dream enactment behavior) (85% versus 55%).
“RBD+Hyposmia and Hyposmia+DEB were more likely CSFaSynSAA+ (94% and 85%) vs RBD-Hyposmia (40%) and Hyposmia-DEB (55%).”
Humanshyposmia with versus without self-reported dream enactment behaviorcerebrospinal fluid
Combined sleep and smell signs linked to Parkinson’s marker
medRxivOct 28, 2026Preprint

Hyposmia

upin humans1

1 study

Hyposmia is associated with CSF alpha-synuclein seed amplification assay positivity in humans (RBD with hyposmia compared with RBD without hyposmia) (94% versus 40%).
“RBD+Hyposmia and Hyposmia+DEB were more likely CSFaSynSAA+ (94% and 85%) vs RBD-Hyposmia (40%) and Hyposmia-DEB (55%).”
HumansRBD with hyposmia compared with RBD without hyposmiacerebrospinal fluid
Combined sleep and smell signs linked to Parkinson’s marker
medRxivOct 28, 2026Preprint

Latest

1 paper in 12 months

medRxivOct 28

Combined sleep and smell signs linked to Parkinson’s marker

A spinal-fluid test was positive in 94% with a confirmed dream-enactment sleep disorder and reduced smell, versus 40% with the disorder but no reduced smell.A spinal-fluid test was positive in 94% with a confirmed dream-enactment sleep disorder and reduced smell, versus 40% with the disorder but no reduced smell.

Preprint: cohort studyParkinson's disease

Paper

medRxivDec 19

Persistent Hyposmia as Surrogate for α-Synuclein-Linked Brain Pathology

Preprint: cohort study of 312 peopleBiomarkers