What is the practical application of alpha-synuclein seed amplification assay CSF testing for the diagnosis and management of Parkinson's disease?

The α-synuclein seed amplification assay (αSyn-SAA) sensitively identifies patients with Parkinson’s disease from cerebrospinal fluid (CSF) samples. A positive αSyn-SAA is proposed to "biologically define" Parkinson’s disease and anchor disease staging. A positive αSyn-SAA identifies aggregated α-sy...

I use skin biopsies which have good reported sensitivity and specificity to diagnose PD/DLB and MSA (Gibbons et al., PMID 38506839), and anecdotally able to distinguish between PD/DLB and MSA (Gibbons et al., PMID 36657992).

In my practice, I use skin biopsies when the differential includes tardive p...