Risk Factors for Transitions from Mild Cognitive Impairment to Dementia: Evidence from Cognitive Reserve

RICARDO ALLEGRI, FERNANDO E. TARAGANO, HUGO KRUPITZKI, BUENOA AIRES, ARGENTINA, CECILIA M. SERRANO, LEANDRO N. LOÑ, DIEGO SARASOLA, CAROL DILLON

Chicago

Congreso; Meeting American Academy of Neurology 2008; 2008

American Academy of Neurology

OBJECTIVE: To identify risk factors associated with progression from mild cognitive impairment to degenerative dementia. BACKGROUND: Mild Cognitive Impairment (MCI) is a transitional stage between normal ageing and dementia, but rates of conversion and risk factors remains controversial. DESIGN/METHODS: A cohort of 239 subjects (age: 72.2±8.1 years, 58% women, education: 12 years) consecutively recruited who met the operational criteria for MCI was assessed and followed for five years (2000 to 2006). They underwent multidimensional assessment and a neuropsychological battery at baseline. Subjects converted to Alzheimer´s disease (AD) over time were classified as Demented; subjects that remained unchanged, or became cognitively normal during follow-up, were defined as Stable. RESULTS: Demented MCI (N = 75; 31.3%) were older (mean age 75.0 +/- 7.0 vs. 70.8 +/- 7.9; p <.001) when compared to Stable (N = 164; 68.7) and their global cognitive performances, at baseline, were more compromised when assessed by global Intelligence Quotient (IQ) (median score 93.5 vs 105; p < .0001), and by MMSE (median score 26 vs. 28; p < .001). Demented had more behavioural symptoms. In the first year 13% converted towards dementia and 40% within three years (the majority transformed towards AD). Logistic regression analysis revealed that education less than 12 years, MMSE less than 27, Boston naming test less than 51, IQ less than 111, age more than 75 years, without leisure activity, and presence of intrusions in memory recall were significantly associated to the conversion to AD (69.2% of the variability of conversion by factorial analysis). CONCLUSIONS/RELEVANCE: MCI is a “population in risk for degenerative dementia”. To plan the care of patients with MCI, it is important to predict as accurately as the rol of the risk factors and the cognitive reserve modulating the conversion to AD.