title: Is mild cognitive impairment prodromal for vascular dementia like Alzheimer's disease?
abstract: OBJECTIVE
  Individuals with mild cognitive impairment (MCI) are at increased risk of Alzheimer's disease (AD) and probably other forms of dementia. Some subtypes of vascular dementia (VaD) may possess minor neuropathological changes of AD that may contribute to cognitive impairments. It was posited that MCI, identified by criteria described here, might present as a prodrome for VaD and AD.
  
  
  METHODS
  Serial Mini-Mental State Examination was administered at 3- to 6-month intervals, and neuroimaging was performed annually. Subtle cognitive dysfunctions were weighted and measured according to MCI criteria defined here. Subjects identified with MCI were then followed up for an additional 3.88+/-3.01 years. Diagnoses of VaD and AD were made according to established criteria.
  
  
  RESULTS
  During 3.72+/-2.94 years of follow-up of the original normative subjects, 73 of 291 (25.1%) developed MCI. Of the 27 subjects who developed VaD, 15 (55.6%) had prodromal MCI. Of these, two thirds were subclassified as having small-vessel dementia. The remaining 12 patients with VaD (44.4%) were diagnosed directly from a cognitively normal status without preceding MCI. These were predominantly multi-infarct or strategic-infarct dementia (66.7%). An additional 35 MCI subjects (47.9%) developed AD. Both VaD and AD diagnosed after MCI prodromes manifested similar spectral domains of cognitive impairments, which included memory, during their MCI stages.
  
  
  CONCLUSIONS
  In some VaD subtypes, particularly those caused by subcortical microvascular disease, dementia may be preceded by MCI, which has similar domains of cognitive impairment and a similar progressive course that may mimic AD.
authors.affiliation: Department of Neurology, Baylor College of Medicine, Veterans Administration Medical Center, Houston, Tex 77030, USA. jmeyer@bcm.tmc.edu
authors.forename: John Stirling
authors.initials: JS
authors.lastname: Meyer
authors.forename: Gelin
authors.initials: G
authors.lastname: Xu
authors.forename: John
authors.initials: J
authors.lastname: Thornby
authors.forename: Munir H
authors.initials: MH
authors.lastname: Chowdhury
authors.forename: Minh
authors.initials: M
authors.lastname: Quach
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D015331:Cohort Studies; D015897:Comorbidity; D015140:Dementia, Vascular / Q000145:classification / Q000453:epidemiology*; D003710:Demography; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D015995:Prevalence; D012306:Risk; D013781:Texas / Q000453:epidemiology