Pre-attentive Visual Processing in Alzheimer's Disease: An Event-related Potential Study.

INTRODUCTION: While identifying Alzheimer's Disease (AD) in its early stages is crucial, traditional neuropsychological tests tend to lack sensitivity and specificity for its diagnosis. Neuropsychological studies have reported visual processing deficits of AD, and event-related potentials (ERPs) are suitable to investigate pre-attentive processing with superior temporal resolution. OBJECTIVE: This study aimed to investigate visual attentional characteristics of adults with AD, from pre-attentive to attentive processing, using a visual oddball task and ERPs. METHODS: Cognitively normal elderly controls (CN) and patients with probable AD (AD) were recruited. Participants performed a three-stimulus visual oddball task and were asked to press a designated button in response to the target stimuli. The amplitudes of 4 ERPs were analyzed. Mismatchnegativity (vMMN) was analyzed around the parieto-occipital and temporo-occipital regions. P3a was analyzed around the fronto-central regions, whereas P3b was analyzed around the centro-parietal regions. RESULTS: Late vMMN amplitudes of the AD group were significantly smaller than those of the CN group, while early vMMN amplitudes were comparable. Compared to the CN group, P3a amplitudes of the AD group were significantly smaller for the infrequent deviant stimuli, but the amplitudes for the standard stimuli were comparable. Lastly, the AD group had significantly smaller P3b amplitudes for the target stimuli compared to the CN group. CONCLUSION: Our findings imply that AD patients exhibit pre-attentive visual processing deficits, known to affect later higher-order brain functions. In a clinical setting, the visual oddball paradigm could be used to provide helpful diagnostic information since pre-attentive ERPs can be induced by passive exposure to infrequent stimuli.

Peripheral cannabinoid 1 receptor blockade mitigates adipose tissue inflammation via NLRP3 inflammasome in mouse models of obesity.

AIM: To analyze the metabolic parameters and adipose tissue inflammation via NLRP3 inflammasome following chronic treatment of mouse models of obesity with AJ5018 as the peripherally restricted cannabinoid 1 receptor (CB1R) antagonist. MATERIALS AND METHODS: The selectivity for CB1R over CB2R, brain/plasma concentration ratio, and centrally mediated neurobehavioural effects of AJ5018, were assessed. The long-term effects of AJ5018 and rimonabant on the metabolic parameters and adipose tissue inflammation were analyzed in diet-induced obese (DIO) mice and diabetic db/db mice. RESULTS: AJ5018 had a higher degree of selectivity for CB1R over CB2R and markedly reduced brain penetrance, as reflected by the lower brain/plasma concentration ratio and the attenuated centrally mediated neurobehavioural effects, compared with its brain-penetrant parent compound rimonabant. In DIO and db/db mice, AJ5018 exhibited comparable effects to rimonabant in improving metabolic abnormalities and suppressing macrophage infiltration into white adipose tissue, activation of the NLRP3 inflammasome, and production of proinflammatory cytokines. CONCLUSIONS: These results suggest that peripheral CB1R blockade improves obesity-induced insulin resistance by suppressing adipose tissue inflammation via the NLRP3 inflammasome.

National study of the nutritional status of Korean older adults with dementia who are living in long-term care settings.

AIM: To evaluate the nutritional status of older adults with dementia who were living in long-term care settings. METHODS: As a secondary analysis, this study used the data from the Nationwide Survey on Dementia Care in Korea that was conducted between December 1, 2010, and August 31, 2011, which surveyed 3472 older adults with dementia, aged ≥60 years (mean age: 81.24 years), who were residing in 248 randomly selected long-term care settings in South Korea. Twenty-three different variables that related to the participants' demographics, diseases, and functional and nutritional characteristics were selected. The nutritional status was assessed by using the Mini Nutritional Assessment (MNA). Descriptive statistics, an ANOVA, and a chi-squared test were used to analyze the data. RESULTS: The mean MNA score of the participants was 17.90. The malnutrition rate was 38.4% (n = 1333), with 54.7% (n = 1900) of the participants at risk for malnutrition. The largest population with malnutrition resided in long-term care hospitals (47.9%), followed by nursing homes (34.1%), and group homes (25.9%). Being older and female, while exhibiting higher cognitive impairment, more neuropsychiatric symptoms, higher functional dependency, and a higher number of disabilities, were associated with poor nutritional status. CONCLUSION: The nutritional status of older adults with dementia who were living in long-term care settings in South Korea was poor and associated with multiple factors. Paying special attention to recognizing, assessing, preventing, and treating malnutrition in this population is necessary.

Association Between Small Decrease in Serum Sodium Concentration within the Normal Range and All-Cause and Cardiovascular Mortality in Elderly Adults over 5 Years.

OBJECTIVES: To determine the importance of a decrease in serum sodium concentration within the normal range in elderly adults. DESIGN: Prospective cohort. SETTING: The Korean Longitudinal Study on Health and Aging. PARTICIPANTS: Randomly selected, community-based elderly population with a corrected serum sodium level between 135.0 and 145.0 mEq/L (N = 949). MEASUREMENTS: Survival status was determined during 63.3 ± 16.6 months of follow-up. RESULTS: Participants were divided into corrected sodium groups as follows: 73 (7.7%) in Group 1 (sodium 135.0-138.0 mEq/L), 635 (66.9%) in Group 2 (sodium 138.1-142.0 mEq/L), and 241 (25.4%) in Group 3 (sodium 142.1.0-145.0 mEq/L). There were 34 (46.6%) deaths in Group 1, 124 (19.5%) in Group 2, and 52 (21.6%) in Group 3 (P < .001). In a Cox proportional hazards analysis, a 2-mEq/L higher sodium level reduced the risk of death by 14.9% (95% confidence interval (CI) = 0.1-27.4%, P = .048). Group 1 had risk of mortality that was 2.7 times as high as that of Group 2 (95% CI = 1.76-4.11, P < .001). Participants with a measured sodium level of 138.0 mEq/L or less and a corrected sodium level greater than 138.0 mEq/L had a better survival rate than those with a measured sodium level of 138.0 mEq/L or less and a corrected sodium level of 138.0 mEq/L or less. CONCLUSION: A slightly lower serum sodium concentration within the normal range was a major risk factor for mortality in elderly adults. Sodium level corrected according to serum glucose concentration was a more meaningful risk factor than measured sodium level.

Combined impact of adiponectin and retinol-binding protein 4 on metabolic syndrome in elderly people: the Korean Longitudinal Study on Health and Aging.

The prevalence of metabolic syndrome (MS) increases with progressing and is potentially associated with changes in adipose-derived cytokines, including adiponectin and retinol-binding protein 4 (RBP4). We aimed to determine the prevalence of MS, and the relationships between these factors and MS in elderly people. A population-based cohort study, the Korean Longitudinal Study on Health and Aging (KLoSHA), was performed on subjects aged > or =65 years by random stratified sampling in 2005-2006 (439 men and 561 women). Anthropometrics, biochemical factors including adiponectin and RBP4 levels, body composition, and abdominal fat by computed tomography (CT) were measured. The prevalence of MS was 61.0% in women and 39.9% in men. After adjustment for age, gender, smoking, alcohol, and exercise status and muscle mass, participants with the lowest quartile of adiponectin had a higher risk for having MS than those with the highest quartile (odds ratio (OR) = 4.12, P < 0.01). Similarly, subjects with the highest quartile of RBP4 showed an increased risk for having MS (OR = 1.73, P < 0.01). When both the lowest adiponectin and the highest RBP4 quartiles were combined, the OR increased to 6.22 compared with the opposite quartiles (i.e., highest adiponectin and lowest RBP4 concentrations). Furthermore, circulating levels of adiponectin and RBP4 were significantly correlated with visceral fat and insulin resistance index. In this study, the increased prevalence of MS in elderly but relatively lean population was associated with low adiponectin and high RBP4 levels. The combination of these factors might predict older subjects at high risk for having MS.

A normative study of the CERAD neuropsychological assessment battery in the Korean elderly.

This study aimed to explore the effects of age, education and gender on the performance of eight tests in the Korean version of the CERAD neuropsychological assessment battery and to provide normative information on the tests in the Korean elderly. The battery was administered to 618 healthy volunteers aged from 60 to 90. People with serious neurological, medical and psychiatric disorders, including dementia, were excluded. Multiple linear regression analyses were performed to assess the relative contribution of the demographic factors on the score of each cognitive test. Age, education, and gender were found to have significant effects on the performance of many tests in the battery. Based on these results, 4 overlapping age normative tables (60 to 74, 65 to 79, 70 to 84, and 75 to 90 years of age) with 3 educational strata (0 to 3 years, 4 to 6 years, and 7 years and more) for both genders are presented. The normative information will be useful for a clinical interpretation of the CERAD neuropsychological battery in Korean elderly as well as for comparing the performance of the battery across countries.

Influence of the apolipoprotein E type 4 allele on cerebral glucose metabolism in Alzheimer's disease patients.

It is still unclear whether apolipoprotein E epsilon 4 (APOE E4) influences the cerebral glucose metabolism abnormalities found in Alzheimer's disease (AD), although APOE E4 is a well-known risk factor for AD. [(18)F]Fluorodeoxyglucose PET was conducted in patients with very mild (n=17), mild (n=27), and moderate-to-severe (n=19) AD. The presence of APOE E4 was associated with greater reduction of glucose metabolism in the left inferior temporal region in very mild AD but neither in mild nor in moderate-to-severe AD. These findings favor the hypothesis that APOE E4 is related mainly to the development of AD, not to its progression.

Development of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K): clinical and neuropsychological assessment batteries.

A Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) was created. The English-American version of CERAD clinical and neuropsychological assessment batteries was translated into Korean, and the psychometrical properties of the cognitive tests in the CERAD-K were established. In the translation, including back-translation, the basic structures of all measures in the original CERAD batteries were maintained. The CERAD-K was administered in a standardized manner to 106 dementia patients (aged 70.4 +/- 8.1 years), including 78 Alzheimer's disease (AD) patients, and 186 controls (aged 68.4 +/- 4.6 years) who were recruited from 3 university hospitals and 2 elderly welfare centers. The cognitive tests in the CERAD-K successfully differentiated controls from the dementia patients and from the AD patients. They also showed substantial interrater reliability and 1-month test-retest reliability. The CERAD-K is an equally reliable and valid equivalent for the English version of the CERAD clinical and neuropsychological assessment batteries.