title: Brain metabolism and cerebrospinal fluid biomarkers profile of non-amnestic mild cognitive impairment in comparison to amnestic mild cognitive impairment and normal older subjects.
abstract: BACKGROUND
  Mild cognitive impairment (MCI) is classically considered a transitional stage between normal aging and dementia. Non-amnestic MCI (naMCI) patients, however, typically demonstrate cognitive deficits other than memory decline. Furthermore, as a group, naMCI have a lower rate of an eventual dementia diagnosis as compared to amnestic subtypes of MCI (aMCI). Unfortunately, studies investigating biomarker profiles of naMCI are scarce. The study objective was to investigate the regional brain glucose metabolism (rBGM) with [18F]FDG-PET and cerebrospinal fluid (CSF) biomarkers in subjects with naMCI as compared to a control group (CG) and aMCI subjects.
  
  
  METHODS
  Ninety-five patients were included in three different groups: naMCI (N = 32), aMCI (N = 33) and CG (N = 30). Patients underwent brain MRI and [18F]FDG-PET. A subsample (naMCI = 26, aMCI = 28) also had an assessment of amyloid-β, tau, and phosphorylated tau levels in the CSF.
  
  
  RESULTS
  Both MCI groups had lower rBGM in relation to the CG in the precuneus. Subjects with naMCI showed decreased right prefrontal metabolism as well as higher levels of CSF amyloid-β relative to aMCI subjects.
  
  
  CONCLUSIONS
  While amnestic MCI subjects showed a biomarker profile classically related to MCI due to Alzheimer's disease, naMCI patients illustrated a decrease in both prefrontal hypometabolism and higher CSF amyloid-β levels relative to the aMCI group. These biomarker findings indicate that naMCI is probably a heterogeneous group with similar precuneus hypometabolism compared to aMCI, but additional frontal hypometabolism and less amyloid-β deposition in the brain. Clinical follow-up and reappraisal of biomarkers of the naMCI group is needed to determine the outcome and probable etiological diagnosis.
authors.affiliation: Department of Radiology/Nuclear Medicine Center/LIM43, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo,Trav. Ovídio Pires de Campos S/N, prédio do Centro de Medicina Nuclear, 2 andar - LIM43, Cerqueira Cesar, São Paulo, CEP 05403-010, Brazil. artur.coutinho@hc.fm.usp.br.
authors.forename: Artur M N
authors.initials: AM
authors.lastname: Coutinho
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. portofhg@gmail.com.
authors.forename: Fábio H G
authors.initials: FH
authors.lastname: Porto
authors.affiliation: Department of Psychiatry - R. Dr. Ovídio Pires de Campos, São Paulo, 785 CEP 01060-970, Brazil. fabio_duran@hotmail.com.
authors.forename: Fabio L S
authors.initials: FL
authors.lastname: Duran
authors.affiliation: Department of Radiology/Nuclear Medicine Center/LIM43, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo,Trav. Ovídio Pires de Campos S/N, prédio do Centro de Medicina Nuclear, 2 andar - LIM43, Cerqueira Cesar, São Paulo, CEP 05403-010, Brazil. prando@usp.br.
authors.forename: Silvana
authors.initials: S
authors.lastname: Prando
authors.affiliation: Department of Radiology/Nuclear Medicine Center/LIM43, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo,Trav. Ovídio Pires de Campos S/N, prédio do Centro de Medicina Nuclear, 2 andar - LIM43, Cerqueira Cesar, São Paulo, CEP 05403-010, Brazil. crachelo@gmail.com.
authors.forename: Carla R
authors.initials: CR
authors.lastname: Ono
authors.affiliation: Department of Radiology/Nuclear Medicine Center/LIM43, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo,Trav. Ovídio Pires de Campos S/N, prédio do Centro de Medicina Nuclear, 2 andar - LIM43, Cerqueira Cesar, São Paulo, CEP 05403-010, Brazil. estherfalcaofeitosa@gmail.com.
authors.forename: Esther A A F
authors.initials: EA
authors.lastname: Feitosa
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. liviaspindola@gmail.com.
authors.forename: Lívia
authors.initials: L
authors.lastname: Spíndola
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. maira_oliveira@hotmail.com.
authors.forename: Maira O
authors.initials: MO
authors.lastname: de Oliveira
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. patriciafigvale@terra.com.br.
authors.forename: Patrícia H F
authors.initials: PH
authors.lastname: do Vale
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. helio.gomes@hc.fm.usp.br.
authors.forename: Helio R
authors.initials: HR
authors.lastname: Gomes
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. rnitrini@uol.com.br.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Nitrini
authors.affiliation: Department of Neurology...Av. Dr. Enéas de Carvalho Aguiar, São Paulo, 255 CEP 05403-900, Brazil. sbrucki@uol.com.br.
authors.forename: Sonia M D
authors.initials: SM
authors.lastname: Brucki
authors.affiliation: Department of Radiology/Nuclear Medicine Center/LIM43, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo,Trav. Ovídio Pires de Campos S/N, prédio do Centro de Medicina Nuclear, 2 andar - LIM43, Cerqueira Cesar, São Paulo, CEP 05403-010, Brazil. buch@usp.br.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Buchpiguel
mesh_terms: D000368:Aged; D000647:Amnesia / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D001931:Brain Mapping; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010766:Phosphorylation; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D016875:tau Proteins / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; C054369:MAPT protein, human; D019275:Radiopharmaceuticals; D016875:tau Proteins; D019788:Fluorodeoxyglucose F18