Abstract Details

Title Real-World Use of Alpha-Synuclein Seeding Amplification Assay in a Behavioral Neurology Clinic

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P10 - Poster Session 10 (5:00 PM-6:00 PM)

Poster/Presentation
Number 3-018

Objective To characterize use and impact on clinical decision-making of the alpha-synuclein seeding amplification assay (SAA) in a tertiary behavioral neurology clinic.

Background The cerebrospinal fluid (CSF) SAA is a new marker with high specificity for Lewy body disease (LBD) in well-defined research cohorts, but real-world use data are sparse.

Design/Methods This is a retrospective cohort of all cases who had the SAA test (SynTap, Amprion) performed at our behavioral neurology clinic. Medical records were reviewed for diagnosis, clinical syndrome/affected cognitive domain(s), cognitive tests, presence of core LBD features and other symptoms, MRI, PET and SPECT imaging, Alzheimer’s disease biofluid markers, and clinical decisions made following the SAA result.

Results In our first year of use, the SAA was performed for 21 patients. Most were men (76%). Patients at time of testing were between 53-86 years old (mean 74). Mild cognitive impairment was the most common diagnosis (71%) followed by dementia (19%) and subjective cognitive impairment or normal (9.5%). The SAA was abnormal in 9 patients (43%). The p(181)-tau/amyloid-beta(42) ratio was abnormal in 44% of SAA-positive cases and in 45% of SAA-negative cases. In SAA-positive cases, 5 met the core features from McKeith et al. for probable and 2 for possible LBD; in SAA-negative cases, none were probable and 7 were possible LBD. Of the cohort, 17 had questionable or mild motor parkinsonism. Clinical syndromes varied and included amnestic, multidomain (2/6 positive), non-amnestic, dysexecutive and behavioral (0/5), logopenic primary progressive aphasia (1/1), corticobasal syndrome (1/1), behavioral variant frontotemporal dementia (0/1), multiple system atrophy (0/1), and Parkinson’s disease (0/1); there were no purely amnestic patients tested. Subsequent clinical decisions included additional diagnostic tests and medication changes (lecanemab included).

Conclusions The SAA adds diagnostic information in early-stage, heterogeneous clinical presentations and may alter clinical decisions.

Authors/Disclosures
Luke Fischer, MD, PhD (UCSF, Memory and Aging Center) PRESENTER	The institution of Dr. Fischer has received research support from Alzheimer's Association. The institution of Dr. Fischer has received research support from Lewy Body Dementia Association. The institution of Dr. Fischer has received research support from NINDS. Dr. Fischer has received personal compensation in the range of $0-$499 for serving as a Author with MedLink, LLC.
Tara N. Ellingson	Miss Ellingson has nothing to disclose.
Bruce L. Miller, MD, FAAN (University of California, San Francisco)	Dr. Miller has nothing to disclose.
Lawren VandeVrede, MD, PhD (UCSF)	Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving as a Consultant for CND Life Sciences. Dr. VandeVrede has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Siemens. Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Peerview CME. Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Haymarket. Dr. VandeVrede has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Peter Lacques, LLC. Dr. VandeVrede has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for Cunningham Bounds. The institution of Dr. VandeVrede has received research support from Alzheimer's Association. The institution of Dr. VandeVrede has received research support from NIH.

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