title: Assessment of dementia risk in aging adults using both FDG-PET and FDDNP-PET imaging.
abstract: BACKGROUND
  In a previous study, positron emission tomography (PET) with 2-(1-{6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile (FDDNP), a molecule that binds to plaques and tangles in vitro, identified three subgroups of non-demented subjects according to FDDNP binding patterns: low global (LG) binding; high frontal, parietal, medial temporal binding (HF/PA); and high medial and lateral temporal and posterior cingulate (HT/PC) binding. In this follow-up investigation, we compared 2-deoxy-2-[F-18]fluoro- d-glucose (FDG)-PET cerebral metabolic patterns in the three FDDNP-PET binding subgroups.
  
  
  METHODS
  Fifty-four subjects with normal aging (N = 28) or amnestic forms of mild cognitive impairment (N = 26) underwent FDDNP-PET and FDG-PET scanning. Subjects in the LG, HF/PA, and HT/PC FDDNP subgroups were compared according to visual ratings, statistical parametric mapping, and automated region of interest analyses of their FDG-PET data.
  
  
  RESULTS
  The FDDNP-PET subgroups demonstrated different glucose metabolic patterns according to visual ratings, region of interest, and statistical parametric mapping analyses of FDG-PET data. The LG FDDNP subgroup showed no areas of significant hypometabolism relative to the other subgroups and had low Alzheimer's disease risk by FDG-PET standards. The HF/PA FDDNP subgroup demonstrated hypometabolism in bilateral inferior parietal/parietotemporal, bilateral posterior cingulate, perisylvian, mid-temporal gyrus, and dorsolateral prefrontal regions, which is a pattern suggestive of high Alzheimer's disease risk. The HT/PC FDDNP subgroup demonstrated heterogeneous FDG-PET patterns with predominant anterior frontal and anterior temporal hypometabolism, suggestive of mixed etiologies, including fronto-temporal dementia risk.
  
  
  CONCLUSIONS
  The FDG-PET data provided independent validation that different patterns of FDDNP-PET binding in non-demented individuals may be associated with differential dementia risk.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences and Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA. HUlercoli@mednet.ucla.edu
authors.forename: L M
authors.initials: LM
authors.lastname: Ercoli
authors.forename: G W
authors.initials: GW
authors.lastname: Small
authors.forename: P
authors.initials: P
authors.lastname: Siddarth
authors.forename: V
authors.initials: V
authors.lastname: Kepe
authors.forename: S-C
authors.initials: SC
authors.lastname: Huang
authors.forename: K J
authors.initials: KJ
authors.lastname: Miller
authors.forename: H
authors.initials: H
authors.lastname: Lavretsky
authors.forename: S Y
authors.initials: SY
authors.lastname: Bookheimer
authors.forename: J R
authors.initials: JR
authors.lastname: Barrio
authors.forename: D H S
authors.initials: DH
authors.lastname: Silverman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002531:Cerebellum / Q000000981:diagnostic imaging* / Q000378:metabolism; D016000:Cluster Analysis; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging* / Q000378:metabolism; D003704:Dementia / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D016874:Neurofibrillary Tangles / Q000000981:diagnostic imaging / Q000378:metabolism; D009570:Nitriles / Q000493:pharmacokinetics; D058225:Plaque, Amyloid / Q000000981:diagnostic imaging / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: C444520:2-(1-(6-((2-fluoroethyl)(methyl)amino)-2-naphthyl)ethylidene)malononitrile; D009570:Nitriles; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18