Abstract Details

Title Longitudinal 123I-FP-CIT SPECT Imaging in Isolated REM Sleep Behavior Disorder

Topic Sleep

Presentation(s) S1 - Sleep: Want to Hear the Latest? (1:36 PM-1:48 PM)

Poster/Presentation
Number 004

Background iRBD patients are known to be at high risk for developing an overt synucleinopathy – particularly Dementia with Lewy Bodies (DLB) and Parkinson’s Disease (PD). Reduced nigrostriatal uptake on 123I-FP-CIT SPECT reflects dopamine deficiency.

Objective To assess how 123I-FP-CIT SPECT findings in isolated REM Sleep Behavior Disorder (iRBD) change longitudinally and whether an abnormal 123I-FP-CIT SPECT scan precedes and predicts future transition to an overt synucleinopathy.

Design/Methods Participants with polysomnography-confirmed iRBD from the Mayo Clinic Alzheimer’s Disease Research Center database ± North American Prodromal Synucleinopathy (NAPS) Consortium who had two or more longitudinal 123I-FP-CIT SPECT scans and have been followed prospectively for >24 months were included (n=34). Striatonigral dopamine transporter uptake was evaluated semi-quantitatively with 123I-FP-CIT SPECT using DaTQUANT 2.0 software (GE Healthcare) to calculate z-scores of putamen uptake.

Results Sixteen participants (47%) developed an overt synucleinopathy (phenoconverters) and 18 participants (53%) remained as iRBD (stable iRBD). Follow-up years did not differ between phenoconverters and stable iRBD (5.4 ± 2.3 vs 5.7 ± 1.8 years). At baseline, phenoconverters were older (69.1 ± 6.1 vs 63.2 ± 6.3 years old), had more negative DaTQUANT putamen z-scores (-2.10 ± 1.57 vs -0.26 ± 1.19), later onset of RBD (62.3 ± 8.1 vs 46.3 ± 15.4 years old), and shorter duration of RBD (6.9 ± 4.2 vs 16.9 ± 12.4 years) than stable iRBD. Putamen z-score declined faster in phenoconverters than in stable iRBD (z-score slope -0.27 ± 0.29 vs -0.05 ± 0.23). Among phenoconverters, eleven participants (69%) had one or more putamen z-scores of <-2.0 prior to phenoconversion, and time from initial putamen z-score of <-2.0 to phenoconversion was 3.1 ± 2.2 years.

Conclusions These findings suggest that iRBD patients with a decline in putamen uptake on 123I-FP-CIT SPECT and later onset/ shorter duration of RBD is associated with progression of iRBD to an overt synucleinopathy.

Authors/Disclosures
Toji Miyagawa, MD, PhD (Mayo Clinic) PRESENTER	Dr. Miyagawa has nothing to disclose.
Scott Przybelski	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Timothy Lesnick	No disclosure on file
Michael Silber, MB, ChB, FAAN (Mayo Clinic)	Dr. Silber has received publishing royalties from a publication relating to health care. Dr. Silber has received personal compensation in the range of $500-$4,999 for serving as a Topic writer with UpToDate.
Stuart McCarter, MD (Mayo Clinic)	Dr. McCarter has received research support from NIH.
Erik K. St. Louis, MD (Mayo Clinic)	Dr. St. Louis has received publishing royalties from a publication relating to health care. Dr. St. Louis has received publishing royalties from a publication relating to health care.
Jonathan Graff-Radford, MD, FAAN	Dr. Graff-Radford has received personal compensation for serving as an employee of Mayo Clinic. Dr. Graff-Radford has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for NINDS/NIH. The institution of Dr. Graff-Radford has received research support from NIH. The institution of Dr. Graff-Radford has received research support from Eisai. The institution of Dr. Graff-Radford has received research support from Cognition therapeutics.
David T. Jones, MD (Mayo Clinic)	Dr. Jones has received intellectual property interests from a discovery or technology relating to health care.
Rodolfo Savica, MD, PhD, FAAN (Mayo Clinic)	The institution of Dr. Savica has received research support from ACADIA Pharmaceuticals, Inc.
David S. Knopman, MD, FAAN (Mayo Clinic)	Dr. Knopman has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for DIAN TU study. The institution of Dr. Knopman has received research support from NIH.
Ronald C. Petersen, MD, PhD, FAAN (Mayo Clinic)	Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genentech. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Nestle. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Eli Lilly and Co.. Dr. Petersen has received personal compensation in the range of $0-$499 for serving as a Consultant for Eisai, Inc.. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novo Nordisk. Dr. Petersen has received publishing royalties from a publication relating to health care. Dr. Petersen has received publishing royalties from a publication relating to health care. Dr. Petersen has received publishing royalties from a publication relating to health care. Dr. Petersen has a non-compensated relationship as a Board of Directors with American Brain Foundation that is relevant to AAN interests or activities.
Walter Kremers	No disclosure on file
Leah K. Forsberg, PhD (Mayo Clinic)	Ms. Forsberg has nothing to disclose.
Julie A. Fields, PhD (Mayo Clinic)	The institution of Dr. Fields has received research support from National Institutes of Health. The institution of Dr. Fields has received research support from Patient-Centered Outcomes Research Institute.
Tanis J. Ferman (Mayo Clinic Jacksonville)	Ms. Ferman has nothing to disclose.
Hugo Botha, MD (Mayo School of Graduate Medical Education, Rochester)	Dr. Botha has received research support from NIH.
Vijay K. Ramanan, MD, PhD (Mayo Clinic)	The institution of Dr. Ramanan has received research support from the National Institutes of Health. The institution of Dr. Ramanan has received research support from the Mangurian Foundation for Lewy Body Disease Research. The institution of Dr. Ramanan has received research support from as part of clinical trials sponsored by the Alzheimer's Association, Eisai, the Alzheimer's Treatment and Research Institute at USC, and Transposon Therapeutics, Inc.. The institution of Dr. Ramanan has received research support from Medscape. Dr. Ramanan has received personal compensation in the range of $500-$4,999 for serving as a Conference Speaker/Organizer (Honoraria) with AANI.
Laura Allen, NP (Mayo Clinic)	Ms. Allen has nothing to disclose.
Kejal Kantarci, MD (Mayo Clinic)	The institution of Dr. Kantarci has received research support from Eli Lilly. The institution of Dr. Kantarci has received research support from NIH. The institution of Dr. Kantarci has received research support from ADDF.
Val J. Lowe, MD (Mayo Clinic)	Dr. Lowe has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for AVID Radiopharmaceutical. Dr. Lowe has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Eisai Inc. The institution of Dr. Lowe has received research support from AVID Radiopharmaceuticals.
Bradley F. Boeve, MD, FAAN (Mayo Clinic)	Dr. Boeve has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for Rainwater Charitable Foundation. The institution of Dr. Boeve has received research support from Alector. The institution of Dr. Boeve has received research support from EIP Pharma. The institution of Dr. Boeve has received research support from Transposon. The institution of Dr. Boeve has received research support from Cognition Therapeutics. Dr. Boeve has received publishing royalties from a publication relating to health care.