Dementia with Lewy bodies (DLB) is the second most common cause of dementia. The diagnosis of DLB is particularly important because these patients show good response to cholinesterase inhibitors. Clinical and neuroimaging criteria for DLB have not been acceptable for predictive accuracy. We report a case of progressive dementia in which the differentiation of DLB and Alzheimer disease (AD) on the basis of clinical criteria alone was not possible. The patient was admitted to the hospital because he became worse after he had started treatment for severe AD. Both MRI and brain magnetic resonance spectroscopy were normal. The patient underwent myocardial scintigraphy with I-123 MIBG showing marked reduction in cardiac MIBG accumulation. The heart to mediastinum ratio of MIBG uptake was impaired in both early and delayed images. FDG-PET scan before and after activation with a visual attention task showed occipital cortex hypometabolism as compared with AD and a normal control. This case illustrates the value of combining activated brain FDG PET and cardiac MIBG. The association of these 2 techniques could be used as a potential diagnostic tool in a patient with dementia misdiagnosed as AD.

Introduction: In the last decades, there was an expressive increase in the number of elderly patients with chronic kidney disease starting hemodialysis. Thus, our goal was to evaluate the profile of the elderly in chronic hemodialysis and to compare the cognition and quality of life of the younger elderly with those of the very elderly. Methods: Patients on hemodialysis for at least 3 months, who were 65 years of age or older when they started dialysis were invited to participate, and stratified according to age (under or over 80 years). The participants answered a clinical-epidemiological questionnaire and underwent cognitive tests (Mini Mental State Exam [MMSE], clock drawing test [CDT] and verbal fluency test [VFT]) and a quality of life assessment 36- Item Short Form Health Survey). Results: Of the 125 eligible patients, 124 agreed to participate. The mean age was 76 ± 6 years (28% ≥ 80 years), 56% were men and 55% had ≥ 8 years of schooling. Depression was suggested in 38%. The prevalence of cognitive deficit was 38%, 70% and 30%, by MEEM, CDT and VFT, respectively. The prevalence of any deficit was higher among the very elderly (94% vs. 72%, p = 0.007). Quality of life scores were similar between the two age groups, except for the functional capacity domain, worse in the group with ≥ 80 years (p = 0.033). Conclusion: Elderly patients on chronic hemodialysis have a high prevalence of cognitive deficits, especially the very elderly, but this group does not have a worse quality of life, except for functional capacity.

Background: The Clinical Dementia Rating (CDR) scale is commonly used to stage cognitive impairment, despite having educational limitations. In elderly with low education, a previous study has shown that intraindividual variability of reaction time (CV) and commission errors (CE), measured using a culture-free Go/No-Go task, can reliably distinguish early Alzheimer’s disease (AD) from mild cognitive impairment (MCI) and healthy controls. Objective: We aimed to extend the clinical utility of this culture-free Go/No-Go task in a sample with high educational disparity. Methods: One hundred and ten participants with a wide range of years of formal education (0–14 years) were randomly selected from a geriatric unit and divided based on their CDR scores into cognitively unimpaired (CDR = 0), MCI (CDR = 0.5), and early AD (CDR = 1). All underwent a 90-s reaction-time test that measured the variables previously found to predict CDR in low educated elderly. Here we added years of formal education (educational level) to the model. Multivariate analyses compared differences in group means using educational level as confounding factor. A confirmatory discriminant analyses was performed, to assess if CDR scores could be predicted by the two Go/No-Go variables in a sample with high educational disparity. Results: Over all three groups, differences in both CE and CV reached statistical significance (p <  0.05). The discriminant analysis demonstrated that CV and CE discriminated cognitively impaired from cognitively normal elderly. These results remained similar when discriminating MCI from cognitively unimpaired elderly. Conclusion: The Go/No-Go task reliably discriminates elderly with MCI from elderly without cognitive impairment independent of educational disparity.

Background: Scales for cognitive deterioration usually depend on education level. Objective: We aimed to study the clinical utility of a culture-free Go/No-Go task in a multi-ethnic cohort with low education level. Methods: Sixty-four participants with less than 4 years of formal education were included and divided on the basis of their Clinical-Dementia-Rate scores (CDR) into cognitively unimpaired (CDR = 0), mild cognitive impairment (MCI; CDR = 0.5), and early Alzheimer’s disease (AD, CDR = 1). All underwent a 90-s Continuous Visual Attention Test. This test consisted of a 90-s Go/No-go task with 72 (80%) targets and 18 (20%) non-targets. For each participant, reaction times and intraindividual variability of reaction times of all correct target responses, as well as the number of omission and commission errors were evaluated. Coefficient of variability was calculated for each participant by dividing the standard deviation of the reaction times by the mean reaction time. A MANCOVA was performed to examine between-group differences using age and sex as covariates. Discriminate analysis was performed to find the most reliable test-variable to discriminate the three groups. Results: Commission error, intraindividual variability of reaction time, and coefficient of variability progressively worsened with increasing CDR level. Discriminant analysis demonstrated that coefficient of variability was the best discriminant factor, followed by intraindividual variability of reaction time and commission error. Conclusion: The Go/No-Go task was able to discriminate people with MCI or early AD from controls in the setting of illiteracy.