No abstract

Alzheimer’s Disease (AD) is a complex, multifactorial and comorbid condition. The asymptomatic behavior in early stages of the disease is a paramount obstacle to formulate a preclinical and predictive model of AD. Not surprisingly, the AD drug approval rate is one of the lowest in the industry, an exiguous 0.4%. The identification of risk factors, preferably obtained by the subject herself, is sorely needed given that the incidence of Alzheimer’s disease grows exponentially with age [Ferri et al., 2005], [Ganguli and Rodriguez, 2011].During the last 7 years, researchers at Proyecto Vallecas have collected information about the project’s volunteers, aged 70 or more. The Proyecto Vallecas dataset includes information about a wide range of factors including magnetic resonance imaging, genetic, demographic, socioeconomic, cognitive performance, subjective memory complaints, neuropsychiatric disorders, cardiovascular, sleep, diet, physical exercise and self assessed quality of life. The subjects in each visit were diagnosed as healthy, mild cognitive impairment (MCI) or dementia.In this study we perform Exploratory Data Analysis to summarize the main characteristics of this unique longitudinal dataset. The objective is to characterize the evolution of the collected features over time and most importantly, how their dynamics are related to cognitive decline. We show that the longitudinal dataset of Proyecto Vallecas, if conveniently exploited, holds promise to identifying either factors promoting healthy aging and risk factors related to cognitive decline.

et al. (2008) indicates that there is not. This study investigates the possible role of familiarity deficits in the diagnosis of AD in two samples of participants with a diagnosis of multi-domain mild cognitive impairment with and without amnestic deficit. It is well known that patients with mild cognitive impairment of amnestic type have a considerably greater probability of converting to AD in a short period of time. Methods: Eleven participants with a diagnosis of non-amnestic multi-domain cognitive impairment and 11 amnestic multi-domain amnestic patients were evaluated according to a number of neuropsychological areas, including verbal comprehension and fluency, long-term episodic memory, working memory, symbolic praxis, and visuospatial ability, depression, anxiety, clinical dementia, and basic everyday activities. All of them were tested in a recognition test 6 months later of a previous test in which they were compared with control groups and with patients already diagnosed with AD. In this experimental test, we assess the degree in which participants are able to use perceptual fluency (unconscious repeated presentations of letters) to improve recognition performance. Results: Results indicated that amnestic mild cognitive impaired patients were unable to use familiarity (defined this way) in recognition 6 months after the initial test. Originally, the deficit was specific to the amnestic sample. These patients did show reliably that they were unable to use familiarity, although their cognitive status and the diagnosis remained as mild cognitive impaired, and none of them had converted to AD yet. Conclusions: The deficit in familiarity originally detected in the sample of amnestic mild cognitive patients was present 6 months later at the same level than in the original test. None of them have converted yet to AD. These results are positive and indicate that familiarity may be a dimension that needs to be taken into account in the diagnosis of MCI.Background: A long preclinical phase precedes dementia onset. Mild cognitive impairment (MCI) has been considered a transitional state between cognitive changes in aging and early overt dementia. However, conversion rates to dementia can substantially differ between studies. Objectives: To differentiate grades of severity of MCI and investigate their rate of progression to dementia. Methods: A population of 349 consecutive ambulatory elderly aged 60 years or older with at least one follow-up examination was stratified into four severity stages according to Clinical Dementia Rating scale (CDR): 78 cognitively normal controls (CDR 0), 36 CDR 0.5/ uncertain dementia (CDR 0.5/unc), 126 CDR 0.5/incipient dementia (CDR 0.5/inc), and 109 CDR 0.5/dementia (CDR 0.5/dem). CERAD battery along with other standardized neuropsychological tests were administered to assess different cognitive domains. Diagnosis of dementia was based on DSM-IV criteria. Results: At baseline, mean age, percentage of women, mean education, mean MMSE score, mean percent of dependence on IADL of th...