title: An investigation of PreMCI: subtypes and longitudinal outcomes.
abstract: OBJECTIVE
  To investigate the clinical features and rates of progression of conditions that are not considered to be normal, but do not fulfill criteria for mild cognitive impairment (MCI).
  
  
  METHODS
  We longitudinally evaluated 269 elderly subjects who did not meet formal criteria for MCI at baseline but had: (1) a clinical history suggesting MCI without neuropsychological deficits (PreMCI-Clinical); or (2) neuropsychological deficits on one or more memory measures in conjunction with a negative clinical examination (amnestic PreMCI-NP) or were normal on both neuropsychological and clinical examination.
  
  
  RESULTS
  The rate of progression to MCI or dementia over an average of 2- to 3 years was 3.7% for no cognitive impairment subjects, whereas it was significantly greater for all PreMCI subtypes (22.0% for PreMCI-Clinical, 38.9% for amnestic PreMCI-NP subjects with two or more memory impairments). Among PreMCI subjects as a whole, lower baseline scores on object memory and category fluency tests were the best predictors of progression to MCI or dementia. Cardiovascular risk factors, Parkinsonian symptoms, and hippocampal atrophy were not associated with progression.
  
  
  CONCLUSIONS
  Distinct PreMCI subtypes defined on the basis of clinical and neuropsychological evaluations were found to have distinct characteristics, but both subtypes demonstrated elevated risk for progression to MCI or dementia. Despite the lack of evidence of clinical impairment, subjects with neuropsychological deficits in two memory domains were particularly at increased risk for progression of their deficits.
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL, USA. dloewenstein@att.net
authors.forename: David A
authors.initials: DA
authors.lastname: Loewenstein
authors.forename: Maria T
authors.initials: MT
authors.lastname: Greig
authors.forename: John A
authors.initials: JA
authors.lastname: Schinka
authors.forename: Warren
authors.initials: W
authors.lastname: Barker
authors.forename: Qian
authors.initials: Q
authors.lastname: Shen
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Potter
authors.forename: Ashok
authors.initials: A
authors.lastname: Raj
authors.forename: Larry
authors.initials: L
authors.lastname: Brooks
authors.forename: Daniel
authors.initials: D
authors.lastname: Varon
authors.forename: Michael
authors.initials: M
authors.lastname: Schoenberg
authors.forename: Jessica
authors.initials: J
authors.lastname: Banko
authors.forename: Huntington
authors.initials: H
authors.lastname: Potter
authors.forename: Ranjan
authors.initials: R
authors.lastname: Duara
mesh_terms: D000368:Aged; D000647:Amnesia / Q000175:diagnosis / Q000209:etiology; D002318:Cardiovascular Diseases; D060825:Cognitive Dysfunction / Q000145:classification* / Q000175:diagnosis* / Q000503:physiopathology; D018450:Disease Progression; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012307:Risk Factors