Mild cognitive impairment subtypes and vascular dementia in community-dwelling elderly people: a 3-year follow-up study.
OBJECTIVE
To investigate whether mild cognitive impairment (MCI) with multiple impaired cognitive domains (mcd-MCI) is a prodromal manifestation of vascular dementia (VaD).


METHODS
Prospective cohort study.


METHODS
Geriatric unit of the Ospedale Maggiore Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy.


METHODS
Four hundred community-dwelling subjects aged 65 and older who came freely to the geriatric unit as part of a comprehensive geriatric assessment program were evaluated for memory impairment or other cognitive disorders. Subjects with MCI were kept under observation for 3 years.


METHODS
Subjects with MCI were studied by applying a standardized clinical evaluation and a conducting a computed tomography brain scan. Cognitive performance was assessed using the Mini-Mental State Examination, the Clock Drawing Test, and a comprehensive battery of neuropsychological tests. Cardiovascular comorbidity was assessed on the basis of medical history and using electrocardiography, echocardiography, and carotid color Doppler ultrasound.


RESULTS
MCI was found in 65 of the 400 community-dwelling subjects; 31 were classified with amnestic MCI (a-MCI) and 34 with mcd-MCI. A dysexecutive syndrome characterized people with mcd-MCI, who had significantly more vascular comorbidity and signs of vascular disease on brain imaging as well as a higher prevalence of extra pyramidal features, mood disorders, and behavioral symptoms than people with a-MCI. Twenty of the 65 subjects with MCI (31%) progressed to dementia within 3 years of follow-up: 11 subjects with Alzheimer's disease (AD) and nine with VaD. All patients who evolved to AD had been classified with a-MCI at baseline, whereas all patients who evolved to subcortical VaD had been classified with mcd-MCI at baseline.


CONCLUSIONS
All subjects who converted to subcortical VaD had been classified with mcd-MCI, suggesting that mcd-MCI might be an early stage of subcortical VaD.
Zanetti
Mariella
M
Department of Internal Medicine, Geriatric Unit, Ospedale Maggiore Istituto di Ricovero e Cura a Carattere Scientifico, University of Milan, Milan, Italy.
Ballabio
Claudia
C
Abbate
Carlo
C
Cutaia
Chiara
C
Vergani
Carlo
C
Bergamaschini
Luigi
L