Épidémiologie de la maladie d’Alzheimer et des syndromes apparentés

La maladie d’Alzheimer et les syndromes apparentés (c’est-à-dire les autres causes de démences, essentiellement) sont devenus un problème majeur de santé publique en France et sont en passe de devenir, enfin, une priorité, en raison du vieillissement de la population. L’épidémiologie de ces affections est un des éléments essentiels pour la décision en santé publique et pour la connaissance de ces maladies et de leurs déterminants. Selon les estimations les plus raisonnables, il y aurait actuellement en France environ 850 000 cas de maladie d’Alzheimer et syndromes apparentés, et environ 220 000 nouveaux cas par an. Les progrès de la prise en charge font que la durée de la maladie augmente, ainsi que le nombre des malades. En dehors du développement d’un traitement curatif bien peu probable à court terme, seule une politique de prévention devrait permettre de contenir l’accroissement de ce nombre dans un proche avenir. Quatre pistes de prévention sont crédibles : les facteurs de risques cardiovasculaire, notamment l’hypertension artérielle ; la nutrition ; les activités stimulantes et physiques ; l’équilibre affectif et social.Alzheimer’s disease and related disorders (dementia) are a major public health problem due to the number of cases in the general population, the projections for the future, and the consequences of these diseases. We can estimate that about 850 000 cases of dementia were present in France in 2005 and this number will increase to 1 200 000 in 2020 and 2 100 000 in 2040 if the incidence and the duration of the disease did not change. The development of prevention is therefore necessary. Four ways of prevention are credible. The most important is the treatment of vascular risk factors and particularly hypertension. Other ways are nutritionnal factors, stimulating leisure activities and depression

Human Daily Activities Indexing in Videos from Wearable Cameras for Monitoring of Patients with Dementia Diseases

Our research focuses on analysing human activities according to a known behaviorist scenario, in case of noisy and high dimensional collected data. The data come from the monitoring of patients with dementia diseases by wearable cameras. We define a structural model of video recordings based on a Hidden Markov Model. New spatio-temporal features, color features and localization features are proposed as observations. First results in recognition of activities are promising

Wearable video monitoring of people with age Dementia : Video indexing at the service of helthcare

International audienceExploration of video surveillance material for healthcare becomes a reality in medical research. In this paper we propose a video monitoring system with wearable cameras for early diagnostics of Dementia. A video acquisition set-up is designed and the methods are developed for indexing the recorded video. The noisiness of audio-visual material and its particularity yield challenging problems for automatic indexing of this content

Lifetime exposure to ambient ultraviolet radiation and the risk for cataract extraction and age-related macular degeneration : the Alienor Study

While exposure to ultraviolet radiation (UVR) is a recognized risk factor for cataract, its association is more controversial with age-related macular degeneration (AMD). We report the associations of lifetime exposure to ambient UVR with cataract extraction and AMD. The Alienor Study is a population-based study of 963 residents of Bordeaux (France), aged 73 years or more. Lifetime exposure to ambient UVR was estimated from residential history and Eurosun satellite-based estimations of ground UVR. It was divided in three groups (lower quartile, intermediate quartiles, upper quartile), using the intermediate quartiles as the reference. Early and late AMD was classified from retinal color photographs. Cataract extraction was defined as absence of the natural lens at slit-lamp. After multivariate adjustment, subjects in the upper quartile of lifetime ambient UVR exposure were at increased risk for cataract extraction (odds ratio [OR] = 1.53; 95% confidence interval [CI], 1.04-2.26; P = 0.03) and for early AMD (OR = 1.59; 95% CI, 1.04-2.44; P = 0.03), by comparison with subjects in the intermediate quartiles. Subjects in the lower quartile of UVR exposure also were at increased risk for early AMD (OR = 1.69; 95% CI, 1.06-2.69; P = 0.03), by comparison with those with medium exposure. Associations of late AMD with UVR exposure was not statistically significant. This study further confirms the increased risk for cataract extraction in subjects exposed to high ambient UVR. Moreover, it suggests that risk for early AMD is increased in subjects exposed to high UVR, but also to low UVR, by comparison with medium exposures

Evolution of dementia diagnosis over time (1988-2013): Evidence from French and English cohorts. Implication for secular trends analyses.

INTRODUCTION: The aims of this study are to examine the evolution of clinical dementia diagnosis over 3 decades and to investigate secular trends of dementia. METHODS: Four cohorts covering a period from 1988 to 2013 were used: the Personnes Agées Quid and Three-City-Bordeaux studies, and the Cognitive Function and Aging Study (CFAS) I and II. Mini-Mental State Examination scores at clinical diagnosis were evaluated over a 24-year follow-up period in French studies. An algorithmic approach was applied to CFAS I and II to provide dementia prevalence and incidence estimates. RESULTS: A significant increase of the Mini-Mental State Examination score at diagnosis was observed until 2000 and a significant decrease after. We reported a prevalence of 8.8% for CFAS I (1990-1993) compared with a prevalence of 6.5% in CFAS II (2008-2011). The 2-year incidence rate was estimated at 31.2/1000 (95% confidence interval = 28.0-34.8) for CFAS I and 15.0/1000 (95% confidence interval = 13.5-16.7) for CFAS II. DISCUSSION: Applying a stable algorithm to different cohorts across time can provide a robust method for time trends estimation.Includes MRC grants

Activity/rest cycle and disturbances of structural backbone of cerebral networks in aging.

OBJECTIVE: Although aging is associated with alterations of both activity/rest cycle and brain structure, few studies have evaluated associations between these processes. The aim of this study was to examine relationship between activity/rest cycle quality and brain structural integrity in aging subjects by exploring both grey and white matter compartments. MATERIAL AND METHODS: Fifty-eight elderly subjects (76±0.5 years; 41% female) without dementia, sleep disorders and medications were included in the analysis. Actigraphy was used to measure parameters of activity/rest cycle (24-h amplitude, 24-h fragmentation and 24-h stability) and sleep (total sleep time and sleep fragmentation) over a minimal period of 5 days. Whole brain linear regression analyses were performed on grey matter volumes maps using voxel based morphometry and on white matter integrity using tract based statistics analyses. RESULTS: A lower 24-h amplitude and a higher sleep fragmentation were independently associated with a reduction of white matter integrity in models including age and gender as covariates. The association between 24-h amplitude and white matter integrity decreased but remained significant in a model accounted for sleep fragmentation, indicating a specific effect of 24-h cycle disturbances. No association with grey matter volumes was observed. CONCLUSION: In elderly, not only sleep but also 24-h cycle disturbances were associated with altered structural connectivity. This alteration of structural backbone networks related to activity/rest cycle disturbances in aging might constitute a cerebral frailty factor for the development of cognitive impairment

Benzodiazepine use and risk of dementia: prospective population based study

Producción CientíficaObjective To evaluate the association between use of benzodiazepines and incident dementia. Design Prospective, population based study. Setting PAQUID study, France. Participants 1063 men and women (mean age 78.2 years) who were free of dementia and did not start taking benzodiazepines until at least the third year of follow-up. Main outcome measures Incident dementia, confirmed by a neurologist. Results During a 15 year follow-up, 253 incident cases of dementia were confirmed. New use of benzodiazepines was associated with an increased risk of dementia (multivariable adjusted hazard ratio 1.60, 95% confidence interval 1.08 to 2.38). Sensitivity analysis considering the existence of depressive symptoms showed a similar association (hazard ratio 1.62, 1.08 to 2.43). A secondary analysis pooled cohorts of participants who started benzodiazepines during follow-up and evaluated the association with incident dementia. The pooled hazard ratio across the five cohorts of new benzodiazepine users was 1.46 (1.10 to 1.94). Results of a complementary nested case-control study showed that ever use of benzodiazepines was associated with an approximately 50% increase in the risk of dementia (adjusted odds ratio 1.55, 1.24 to 1.95) compared with never users. The results were similar in past users (odds ratio 1.56, 1.23 to 1.98) and recent users (1.48, 0.83 to 2.63) but reached significance only for past users. Conclusions In this prospective population based study, new use of benzodiazepines was associated with increased risk of dementia. The result was robust in pooled analyses across cohorts of new users of benzodiazepines throughout the study and in a complementary case-control study. Considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects of this drugclass in the general population, indiscriminate widespread use should be cautioned against