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MONITORING THE PROGRESSION OF DEMENTIA USING FDG-PET BRAIN IMAGING AND NETWORK ANALYSIS: ROLE OF THE ALZHEIMER’S DISEASE-RELATED PATTERN

      Background

      Alzheimer’s dementia (AD) and dementia with Lewy bodies (DLB) are most common dementias in elderly and share some pathological characteristics. Clinical differentiation between them is often challenging in early stages. Characteristic patterns of brain glucose metabolism may help differentiating between neurodegenerative dementias (Marcus C, 2014) and provide a tool to follow up disease progression. A characteristic metabolic brain pattern of AD has been identified using FDG-PET brain imaging and specific network analysis - the so called Alzheimer’s disease related pattern (ADRP, Figure 1). It has been shown to be a reproducible and stable biomarker of AD (Mattis PJ, 2016). The aim of this pilot study was to analyse the expression of ADRP in AD and DLB patients at baseline and after the follow up period of two years.

      Methods

      Seven demented patients (three AD and four DLB, Table 1) and 14 age-matched healthy controls (HC) underwent FDG-PET scan, patients were scanned twice in two years. Four patients underwent CSF amyloid analysis. NEUROSTAT/3D-SSP was performed to confirm the clinical diagnosis of AD and DLB and observe progression. ADRP expression was calculated in these 14 images of demented patients and in HC scans using ScanVP software (www.feinsteinneuroscience.org).

      Results

      Mean age of DLB and AD patients was 80.2 and 72.2 years, respectively (p=0.12). Time between two scans was 2.1±0.7 years. We confirmed the diagnosis and disease progression using NEUROSTAT/3D-SSP analysis in all patients. ADRP expression was higher in patients compared to HC at baseline (AD vs. HC p=0.057, DLB vs. HC p=0.015, Figure 2). Expression values significantly increased in all individual AD and DLB patients between baseline and two years (p=0.0149, paired t-test; Figure 3), reaching relatively higher levels in AD than DLB patients at two years (p=0.015). Additionally, more pronounced progression was observed in AD patients compared to DLB patients over two years of follow up.

      Conclusions

      ADRP is a specific metabolic brain pattern characteristic for AD. It may be used as an imaging biomarker of disease progression for demented patients with AD. ADRP expression may also be useful to help differentiate demented patients from HC as well as AD from DLB patients.
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      Tabled 1
      Age (years)GenderClinical diagnosisDiagnosis based on NEUROSTAT analysisDisease duration at first scan (years)Time between the scans (months)CSF ß-amiloid (pg/ml)
      DLB pt. No.176FDLBDLB438492
      DLB pt. No.274MDLBDLB444819
      DLB pt. No.385FDLBDLB112/
      DLB pt. No.486FDLBDLB244401
      AD pt. No.175FADAD135/
      AD pt. No.274MADAD165470
      AD pt. No.367MADAD133/