Abstract Details

Title Brain glucose metabolism in Lewy Body Dementia: implications for diagnostic criteria

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P5 - Poster Session 5 (5:30 PM-6:30 PM)

Poster/Presentation
Number 9-011

Objective This study aims to provide a validation of the [18F]FDG-PET metabolic signatures at the single-subject level in supporting Lewy body dementia (LBD) diagnosis in the early clinical phases, characterized by high diagnostic uncertainty.

Background [18F]FDG-PET represents a valuable tool in the diagnostic work-up, providing hypometabolism patterns indicative of different neurodegenerative conditions, since the earliest disease phase. The role of [18F]FDG-PET in LBD needs further confirmation by considering large samples of LBD patients and with disease comparisons, applying state-of-the-art metrics.

Design/Methods In this retrospective study, we included N=72 patients with heterogeneous Clinical Classification at Entry (Mild Cognitive Impairment, atypical parkinsonisms, possible LBD), all with a diagnosis of probable LBD at follow-up (Diagnostic Reference). We obtained patterns of [18F]FDG-PET hypometabolism in single-cases with a validated voxel-wise analysis (p<0.05, FWE-corrected). The hypometabolism patterns were independently classified by expert raters, blinded to any clinical information. The Diagnostic Reference was compared with [18F]FDG-PET classification alone and with Clinical Classification at Entry. In addition, the diagnostic accuracy of [18F]FDG-PET maps was assessed in the differential diagnosis with Alzheimer’s disease dementia (ADD) (N=60) and Parkinson’s disease (PD) (N=36).

Results

Clinical Classification at Entry produced several misclassifications with only a concordance of 61.1% with the Diagnostic Reference. The single-subject [18F]FDG-PET hypometabolism maps, showing a temporo-parietal and occipital involvement, accurately predicted diagnosis of probable LBD at follow-up (Concordance=88.9%), providing a ≈50% increase of accuracy with respect to the Clinical Classification at Entry. Notably, [18F]FDG-PET hypometabolism maps yielded extremely high discriminative power, distinguishing LBD from ADD and PD conditions with an accuracy >90%.

Conclusions

The present validation paper argues for the inclusion of [18F]FDG-PET as an indicative biomarker in current diagnostic criteria for LBD. The assessment of [18F]FDG-PET hypometabolism pattern at entry may shorten the diagnostic time, producing benefits for treatment options and management of patients.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Andrea Pilotto	Andrea Pilotto has nothing to disclose.
	No disclosure on file
Sandro Iannaccone	No disclosure on file
Giuseppe Magnani	Giuseppe Magnani has nothing to disclose.
Alessandro Padovani, MD	No disclosure on file
Luigi Ferini-Strambi, MD	Dr. Ferini-Strambi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Bioprojet. Dr. Ferini-Strambi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for lundbeck. Dr. Ferini-Strambi has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for idorsia. Dr. Ferini-Strambi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Italfarmaco. Dr. Ferini-Strambi has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi. Dr. Ferini-Strambi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bruno Farmaceutici. Dr. Ferini-Strambi has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier Sleep Medicine.

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