A comparative cross-cultural study of the prevalence of late life depression in low and middle income countries.

BACKGROUND: Current estimates of the prevalence of depression in later life mostly arise from studies carried out in Europe, North America and Asia. In this study we aimed to measure the prevalence of depression using a standardised method in a number of low and middle income countries (LMIC). METHODS: A one-phase cross-sectional survey involving over 17,000 participants aged 65 years and over living in urban and rural catchment areas in 13 sites from 9 countries (Cuba, Dominican Republic, Puerto Rico, Mexico, Venezuela, Peru, China, India and Nigeria). Depression was assessed and compared using ICD-10 and EURO-D criteria. RESULTS: Depression prevalence varied across sites according to diagnostic criteria. The lowest prevalence was observed for ICD-10 depressive episode (0.3 to 13.8%). When using the EURO-D depression scale, the prevalence was higher and ranged from 1.0% to 38.6%. The crude prevalence was particularly high in the Dominican Republic and in rural India. ICD-10 depression was also associated with increased age and being female. LIMITATIONS: Generalisability of findings outside of catchment areas is difficult to assess. CONCLUSIONS: Late life depression is burdensome, and common in LMIC. However its prevalence varies from culture to culture; its diagnosis poses a significant challenge and requires proper recognition of its expression.

Stroke incidence and risk factors in Havana and Matanzas, Cuba.

INTRODUCTION: Cerebrovascular disease is the third-leading cause of death and the second-leading cause of disability and dementia. OBJECTIVE: Determine stroke incidence and risk factors in a population of adults aged 65 and over in Cuba (Havana and Matanzas). MATERIAL AND METHODS: This prospective longitudinal study, completed between April 2008 and Abril 2011, re-evaluated 2916 elderly adults with an average follow-up time of 4 years. Cases included 2316 living subjects and 600 verbal autopsies. Study variables were age, sex, educational level, self-reported health, and description of chronic diseases and substance abuse. Laboratory tests included genotyping APOE. Stroke was diagnosed based on the World Health Organization definition. We calculated the global incidence rate for stroke, broken down by sex, age group, and risk factors for incident stroke. RESULTS: Stroke incidence was 786.2 in 100000 persons/year (95% CI: 672.3-906.4). History of alcohol consumption (HR: 3.5; 95% CI: 3.3-3.7), dementia (HR: 3.0; 95% CI, 1.6-5.5) and male sex (HR: 1.8; 95% CI, 1.2-2.8) were shown to be risk factors for incident stroke. CONCLUSIONS: Stroke incidence was similar to rates reported in developed countries and lower than that in low- to middle-income countries. Given that diabetes mellitus, heart disease, arterial hypertension, smoking, APOE4, etc. are associated with higher mortality rates, they will require separate analysis in a study of stroke risk factors.

A brief dementia screener suitable for use by non-specialists in resource poor settings--the cross-cultural derivation and validation of the brief Community Screening Instrument for Dementia.

OBJECTIVE: Brief screening tools for dementia for use by non-specialists in primary care have yet to be validated in non-western settings where cultural factors and limited education may complicate the task. We aimed to derive a brief version of cognitive and informant scales from the Community Screening Instrument for Dementia (CSI-D) and to carry out initial assessments of their likely validity. METHODS: We applied Mokken analysis to CSI-D cognitive and informant scale data from 15 022 participants in representative population-based surveys in Latin America, India and China, to identify a subset of items from each that conformed optimally to item response theory scaling principles. The validity coefficients of the resulting brief scales (area under ROC curve, optimal cutpoint, sensitivity, specificity and Youden's index) were estimated from data collected in a previous cross-cultural validation of the full CSI-D. RESULTS: Seven cognitive items (Loevinger H coefficient 0.64) and six informant items (Loevinger H coefficient 0.69) were selected with excellent hierarchical scaling properties. For the brief cognitive scale, AUROC varied between 0.88 and 0.97, for the brief informant scale between 0.92 and 1.00, and for the combined algorithm between 0.94 and 1.00. Optimal cutpoints did not vary between regions. Youden's index for the combined algorithm varied between 0.78 and 1.00 by region. CONCLUSION: A brief version of the full CSI-D appears to share the favourable culture- and education-fair screening properties of the full assessment, despite considerable abbreviation. The feasibility and validity of the brief version still needs to be established in routine primary care.

The prevalence, correlates and impact of dementia in Cuba. A 10/66 group population-based survey.

BACKGROUND: We aimed to estimate the prevalence, correlates and impact of dementia in Havana and Matanzas, Cuba. METHODS: A 1-phase catchment area survey of all over 65-year-old residents of 7 catchment areas in Havana and 1 in Matanzas was conducted. Dementia diagnosis was established according to DSM-IV and our own, pre-validated 10/66 criteria. The impact of dementia was assessed through associations with needs for care, cutting back on work to care and caregiver psychological morbidity. RESULTS: We interviewed 2,944 older people, a response proportion of 96.4%. The prevalence of DSM-IV dementia was 6.4% and that of 10/66 dementia 10.8%. Both dementia outcomes were associated with older age, less education, a family history of dementia, shorter leg length and smaller skull circumference. Dementia, rather than physical health problems or depression, was the main contributor to needs for care (population-attributable prevalence fraction = 64.6%) and caregiver cutting back on work (population-attributable prevalence fraction = 57.3%). CONCLUSION: The prevalence of dementia in Cuba is similar to Europe. Among health conditions, dementia is the major contributor to dependency and caregiver economic and psychological strain. More attention needs to be given to it and other chronic diseases associated more with disability than premature mortality.

[Spectral analysis of EEG coherence in Alzheimer's disease]. / Analisis espectral de la coherencia cerebral en la enfermedad de Alzheimer.

INTRODUCTION: In analysis of the electrical activity of the brain, coherence is a measure of the degree of synchrony between two or more regions of the brain with regard to their frequency values over a unit of time. AIMS: To explore the functional alterations caused by Alzheimer's disease (AD), by evaluating the behaviour of coherence over the whole spectrum of EEG frequencies. PATIENTS AND METHODS: We studied a group of 42 patients with AD, according to criteria of the NINCDS ADRDA group. Partial coherence (e.g. between two derivations each time) was calculated within and between hemispheres, during a state of mental rest; the Z statistic was also determined by comparing the coherence values with the standard data for age, sex and functional state of the brain. RESULTS: Significantly low coherence values were obtained for the frontal central regions of the left hemisphere (LH) and for the occipital parietal regions of the right hemisphere (RH) in the delta band. The same localisations were carried out for the theta band, in addition to the centrotemporal and temporal regions of the LH. The highest incoherence values were observed for the alpha and beta bands, more specifically in frontal central and occipital parietal derivations of the RH, and temporal derivations of the LH. CONCLUSIONS: Non activated partial coherence acts as an indicator of the degree of functional disconnection between brain regions in AD. Studying activated coherence in these patients could contribute new elements to our knowledge about the functional disorders observed in this disease.

A novel presenilin 1 mutation (L174 M) in a large Cuban family with early onset Alzheimer disease.

We studied a Cuban family with presenile dementia (autosomal dominant) consisting of 281 members within six generations, the proband descended from a Spanish founder. Mean age at onset was 59 years of age. Memory impairment was the main symptom in all patients, additionally, ischemic episodes were described in 4 (n = 18) patients. Neuropathological examination of brain material (1 patient) revealed neuronal loss, amyloid plaques, and neurofibrillary tangles. Thirty DNA samples were genotyped (regions on chromosome 1, 3, 10, 12, 14, 17, 19, 20, and 21). A maximum Lod score of 3.79 at theta = 0 was obtained for marker D14S43, located in a 9-cM interval in which all patients shared the same haplotype. Sequencing of the PSEN1 gene revealed a heterozygous base substitution, C520A (exon 6), which is predicted to cause an amino acid change from leucine to methionine in the TMIII of the presenilin 1 protein. The mutation was found to co-segregate with the disease phenotype and the associated disease haplotype. The C --> A change was not observed in 80 control chromosomes from the Cuban population. Leucine at position 174 is highly conserved among species and is identical in presenilin 1 and presenilin 2 proteins. We propose the L174 M mutation might lead to an abnormal N-terminal and probably C-terminal fragments and malfunction of the protein complex. In conclusion, we found a novel PSEN1 mutation in a large family with clinical and pathological diagnosis of early onset familial Alzheimer disease, which may be relevant for other Hispanic populations.