title: Pre-MCI and MCI: neuropsychological, clinical, and imaging features and progression rates.
abstract: OBJECTIVE
  To compare clinical, imaging, and neuropsychological characteristics and longitudinal course of subjects with pre-mild cognitive impairment (pre-MCI), who exhibit features of MCI on clinical examination but lack impairment on neuropsychological examination, to subjects with no cognitive impairment (NCI), nonamnestic MCI (naMCI), amnestic MCI (aMCI), and mild dementia.
  
  
  METHODS
  For 369 subjects, clinical dementia rating sum of boxes (CDR-SB), ApoE genotyping, cardiovascular risk factors, parkinsonism (UPDRS) scores, structural brain MRIs, and neuropsychological testing were obtained at baseline, whereas 275 of these subjects received an annual follow-up for 2-3 years.
  
  
  RESULTS
  At baseline, pre-MCI subjects showed impairment on tests of executive function and language, higher apathy scores, and lower left hippocampal volumes (HPCV) in comparison to NCI subjects. Pre-MCI subjects showed less impairment on at least one memory measure, CDR-SB and UPDRS scores, in comparison to naMCI, aMCI and mild dementia subjects. Follow-up over 2-3 years showed 28.6% of pre-MCI subjects, but less than 5% of NCI subjects progressed to MCI or dementia. Progression rates to dementia were equivalent between naMCI (22.2%) and aMCI (34.5%) groups, but greater than for the pre-MCI group (2.4%). Progression to dementia was best predicted by the CDR-SB, a list learning and executive function test.
  
  
  CONCLUSIONS
  This study demonstrates that clinically defined pre-MCI has cognitive, functional, motor, behavioral and imaging features that are intermediate between NCI and MCI states at baseline. Pre-MCI subjects showed accelerated rates of progression to MCI as compared to NCI subjects, but slower rates of progression to dementia than MCI subjects.
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Miami Beach, Florida, USA. duara@msmc.com
authors.forename: Ranjan
authors.initials: R
authors.lastname: Duara
authors.forename: David A
authors.initials: DA
authors.lastname: Loewenstein
authors.forename: Maria T
authors.initials: MT
authors.lastname: Greig
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Potter
authors.forename: Warren
authors.initials: W
authors.lastname: Barker
authors.forename: Ashok
authors.initials: A
authors.lastname: Raj
authors.forename: John
authors.initials: J
authors.lastname: Schinka
authors.forename: Amy
authors.initials: A
authors.lastname: Borenstein
authors.forename: Michael
authors.initials: M
authors.lastname: Schoenberg
authors.forename: Yougui
authors.initials: Y
authors.lastname: Wu
authors.forename: Jessica
authors.initials: J
authors.lastname: Banko
authors.forename: Huntington
authors.initials: H
authors.lastname: Potter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001057:Apolipoproteins E / Q000235:genetics; D001284:Atrophy / Q000473:pathology; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000473:pathology* / Q000523:psychology*; D003704:Dementia / Q000150:complications / Q000473:pathology / Q000523:psychology; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000523:psychology; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods / Q000523:psychology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D020734:Parkinsonian Disorders / Q000150:complications / Q000473:pathology / Q000523:psychology; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012307:Risk Factors
chemical_list: D001057:Apolipoproteins E