Diego Onyszko

Estimation of the risk of conversion of mild cognitive impairment of Alzheimer type to Alzheimer's disease in a south Brazilian population-based elderly cohort: the PALA study

BACKGROUND Higher mild cognitive impairment (MCI) prognostic variability has been related to sample characteristics (community-based or specialized clinic) and to diverse operationalization criteria. The aim of the study was to evaluate the trajectory of MCI of Alzheimer type in a population-based elderly cohort in Southern Brazil. We also estimated the risk for the development of probable Alzheimers disease (AD) in comparison with healthy subjects. METHODS Data were derived from a population-based cohort (the PALA study). MCI outcomes were sub-classified into three categories: conversion, stabilization, and reconversion. The risk of progression to dementia was compared between MCI and normal participants. The analysis was based on 21 MCI subjects and 220 cognitively intact participants (N = 241). RESULTS Of the 21 MCI subjects, 38% developed dementia, 24% remained stable and 38% improved. The MCI annual conversion rate to AD was 8.5%. MCI was associated with significantly higher risk of conversion to AD (HR = 49.83, p = 0.004), after adjustment for age, education, sex and Mini-Mental State Examination score. CONCLUSIONS Independent of the heterogeneity of the outcomes, MCI of the Alzheimer type participants showed significantly higher risk of developing probable AD, demonstrating the impact of the use of these MCI criteria that emphasize long-term episodic memory impairment.

Neuropsychiatric symptoms as the main determinant of caregiver burden in Alzheimer's disease

Caregiver burden is common in Alzheimer’s disease (AD), decreasing the quality of life among caregivers and patients. Projections of aging and aging-related diseases such as AD in developing countries justify additional data about this issue because people living in these countries have shown similarly high levels of caregiver strain as in the developed world. Objective The aim of this study was to analyze the association of AD caregivers’ burden with patients’ neuropsychiatric symptoms (NPS), cognitive status, severity of dementia, functional capacity, caregiver sociodemographic characteristics, and the characteristics of care provided by caregivers. Methods A cross-sectional study was conducted in a sample of 39 consecutive AD patients and their primary caregivers. NPS were evaluated using the Neuropsychiatric Inventory (NPI). Severity of dementia was assessed with the Clinical Dementia Rating (CDR) scale. Functional capacity was assessed using the Katz and Lawton scales. The burden level was rated using the Burden Interview (BI). Sociodemographic characteristics of caregivers and the characteristics of care provided by them were evaluated. The Mann-Whitney U-test, Kruskal-Wallis test and Spearman’s rho coefficient were performed. Results The BI had a moderate correlation with NPI intensity (rho=0.563), p<001. Female caregivers reported a greater level of burden (p=0.031) than male caregivers. The other variables were not significantly associated to caregiver burden. Conclusion NPS were the main determinant of burden in primary caregivers of AD patients. This result underscores the need for prevention and treatment of these symptoms. Sex also had an effect on caregiver burden, but the small male sample in this study precludes the generalization of this finding.

Correlation between serum brain-derived neurotrophic factor and verbal fluency

ering “probable AD” alone as well as “probable” plus “ possible” AD. The neuropathological diagnosis of AD was defined using multiple combinations of CERAD neuritic plaque density scores and Braak neurofibrillary tangle stages.Results:The sensitivity of the clinical diagnosis of AD ranged from 65% to 87% while specificity ranged from 64% to 78%. Sensitivity was increased with more permissive clinical criteria and specificity was increased with more restrictive criteria while the opposite was true for neuropathological criteria. The highest combined diagnostic performance (sensitivity of 79% and specificity of 71%) was achieved when the clinical diagnosis was defined as including both probable and possible AD and the neuropathological diagnosis was defined as being inclusive of the following two situations: 1) frequent neuritic plaque density with Braak stage III-VI 2) moderate neuritic plaque density with Braak stage V or VI. Conclusions: Agreement between the clinical and neuropathological definitions of AD, based on data from NIA ADC’s, varies depending on the levels of clinical and neuropathological confidence, with sensitivities and specificities ranging between 64% and 87%. The rate of misdiagnosis is critical for many types of research, including the calculation of sample size for clinical trials.

Were elderly patients, who were escorted by family members for medical appointments, more likely to present cognitive dysfunction?

the strongest associations. The estimated relative risks with 95% confidence intervals were 0.94 (0.89 to 0.99) per 10 year increase in age, 0.33 (0.23 to 0.49) comparing blacks to non-blacks, and 1.61 (1.37 to 1.89) for individuals with a college education or more compared to those with less than college education. These estimates are all adjusted for family and clinical characteristics. Conclusions: Performance of autopsy does not occur randomly, in fact, many factors appear to play a role. This study was among the first attempts to approach the problem using multivariate statistical methods. Our results suggest that autopsy was much more likely to be performed on younger subjects, Caucasians, and subjects with higher education. These results show that neuropathological data are available on a rather select sample, which influences generalizability. We also illustrate how such results can be used to help correct for selective sampling in neuropathology studies.

The role of social network in dementia incidence: Porto Alegre Longitudinal Aging (PALA) study

and to assess the influence of other variables such as gender, age, education, manual activities and reading habits in this sample. Methods: The sample consisted of 520 individuals of both sexes from three different health care institutions (School Hospital, Center for Living and Unit-Family Health). All participants received a questionnaire and the standard Mini Mental State Examination (MMSE), which is an auxiliary method of treatment of possible cognitive deficits in individuals at risk, such as the elderly. The cutoff used was 13 points for illiterates, 18 for primary and secondary education and 26 for high school graduates (Bertolucci, 1994). Results: The mean age was 66.3 years. The mean score of MMSE in the total sample was 24.8 points.19.6% of the total sample had scores suggestive of dementia, with similar distribution between the sexes. Frequency of manual activity and reading are inversely related to the frequency of cognitive impairment. Conclusions: It was observed that the prevalence rates suggesting dementia were lower in the Center for Living, which may be correlated with the frequent practice of physical and social activities, and possibly greater interpersonal contact. Individuals from the primary unit and tertiary care displayed similar prevalence.

Burden interview versus neuropsychiatric inventory: Evaluation of burden in caregivers of Alzheimer's disease patients

This study aims to evaluate patient and caregiver’s characteristics related with neuropsychiatric symptoms. Methods: A cross-sectional study was conducted in a sample of 58 probable Alzheimer’s disease (AD) patients (NINCDS-ADRDA criteria). The neuropsychiatric symptoms were evaluated by the Brazilian version of the Neuropsychiatric Inventory (NPI). The dementia severity was assessed with the Clinical Dementia Rating (CDR), Brazilian version. The analyzed patient’s variables were sex, age, age of onset of AD symptoms and education. The analyzed caregiver’s variables were sex, type of relationship, age, education, time as caregiver, weekly time of care, residing with patient and type of job. Student’s t test and one-way Anova were performed for parametric variables. Spearman’s rho was used for correlations. Results: NPI intensity and distress were similar in both patient’s sex (p 1⁄4 0.742 and p 1⁄4 0.902, respectively) and in the three stages of severity of dementia (F1⁄4 1.951, p1⁄4 0.152; F1⁄4 0.763, p1⁄4 0.471, respectively). Patient’s education was inversely correlated with NPI frequency, intensity and distress (rho1⁄4 -0.283, rho1⁄4 -0.276, rho1⁄4 -0.262, p1⁄4 0.05). NPI intensity and distress were similar in both caregiver’s sex (p1⁄4 0.809 and p1⁄4 0.743, respectively), relationship type (p> 0.5) and caregiver’s type of job (p > 0.5). However, a tendency for statistical difference was observed between caregivers who resided and those who not resided with patients (p 1⁄4 0.05), caregivers who resided with patients showed higher NPI intensity and NPI distress. Caregiver’s education was inversely correlated with NPI frequency, intensity and distress (rho1⁄4 -0.302, rho1⁄4 -0. 272, rho1⁄4 -0. 300, p1⁄4 0.05). Caregiver’s age was inversely correlated with NPI severity (rho 1⁄4 -0.270, p 1⁄4 0.05). Weekly time of care was correlated with NPI frequency (rho 1⁄4 0. 291, p1⁄4 0.05). Conclusions: Some variables may interfere on neuropsychiatric symptoms evaluation by caregivers of AD patients, as age, education, weekly time of care and residing with patients. Some of them can be modified through different approaches improving quality of care.