β-Amyloid PET and 123I-FP-CIT SPECT in Mild Cognitive Impairment at Risk for Lewy Body Dementia.

Abstract

OBJECTIVE:

To determine the clinical phenotypes associated with the β-amyloid PET and dopamine transporter imaging (123I-FP-CIT SPECT) findings in mild cognitive impairment (MCI) with the core clinical features of dementia with Lewy bodies (DLB; MCI-LB).

METHODS:

Patients with MCI who had at least 1 core clinical feature of DLB (n = 34) were grouped into β-amyloid A+ or A- and 123I-FP-CIT SPECT D+ or D- groups based on previously established abnormality cut points for A+ with Pittsburgh compound B PET standardized uptake value ratio (PiB SUVR) ≥1.48 and D+ with putamen z score with DaTQUANT <-0.82 on 123I-FP-CIT SPECT. Individual patients with MCI-LB fell into 1 of 4 groups: A+D+, A+D-, A-D+, or A-D-. Log-transformed PiB SUVR and putamen z score were tested for associations with patient characteristics.

RESULTS:

The A-D+ biomarker profile was most common (38.2%), followed by A+D+ (26.5%) and A-D- (26.5%). The least common was the A+D- biomarker profile (8.8%). The A+ group was older, had a higher frequency of APOE ε4 carriers, and had a lower Mini-Mental State Examination score than the A- group. The D+ group was more likely to have probable REM sleep behavior disorder. Lower putamen DaTQUANT z scores and lower PiB SUVRs were independently associated with higher Unified Parkinson's Disease Rating Scale-III scores.

CONCLUSIONS:

A majority of patients with MCI-LB are characterized by low β-amyloid deposition and reduced dopaminergic activity. β-Amyloid PET and 123I-FP-CIT SPECT are complementary in characterizing clinical phenotypes of patients with MCI-LB.

• Authors: Qin Chen, Val J Lowe, Bradley F Boeve, Scott A Przybelski, Toji Miyagawa, Matthew L Senjem, Clifford R Jack Jr, Timothy G Lesnick, Walter K Kremers, Julie A Fields, Hoon-Ki Min, Christopher G Schwarz, Jeffrey L Gunter, Jonathan Graff-Radford, Rodolfo Savica, David S Knopman, David Jones, Tanis J Ferman, Neill R Graff-Radford, Ronald C Petersen, Kejal Kantarci
• Journal: Neurology (Neurology) Vol. 96 Issue 8 Pg. e1180-e1189 (Feb 22 2021) ISSN: 1526-632X [Electronic] United States
• PMID: 33408148 (Publication Type: Journal Article)
• Copyright: Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.