Association between heavy metal exposure and poor working memory and possible mediation effect of antioxidant defenses during aging

BACKGROUND

Inverse associations have been observed between memory performance and blood concentrations of cadmium (Cd) and lead (Pb). Low antioxidant cell activity has also been linked to decline in memory due to aging. However, it has not yet been established whether the heavy metal-memory relationship is mediated by differences in antioxidant activity.

METHODS

We examined Cd and Pb levels, as well as oxidative stress parameters, in blood samples from 125 older adults (age range 50-82years). The Counting Span Test (CST) was used to evaluate working memory capacity (WMC). The Monte Carlo Method for Assessing Mediation (MCMAM) was used to analyze the mediation role of antioxidant activity in the heavy metals-memory association.

RESULTS

High blood Cd (BCd) concentration alone, and in combination with elevated blood Pb (BPb) concentration, was associated with poor WMC (p≤0.001) and low enzymatic antioxidant defenses (p≥0.006). The variance in WMC accounted for by BCd or by BCd combine with BPb was 20.6% and 18.6%, respectively. The MCMAM revealed that the influence of BCd and BPb concentrations on WMC was mediated by low antioxidant capacity (confidence interval - CI: 0.072 to -0.064 for BCd; CI: -0.062 to -0.045 for BPb).

CONCLUSION

These findings showed Pb and Cd blood concentration in older adults, even at levels below the current recommended threshold, was negatively associated with WMC and that this relationship may be partly mediated by low antioxidant defenses. Knowledge on the environmental factors that negatively influence brain and cognition during aging can help inform public policy strategies to prevent and control the adverse effects of environmental contaminant exposure during aging.

Ischemic cerebrovascular burden evaluated by magnetic resonance imaging in an elderly Brazilian community: The Pietà study

In developing countries, cardiovascular risk factors are poorly controlled, leading to high prevalence of cerebrovascular diseases. The aim of the study was to evaluate the burden of white matter lesions in magnetic resonance through the Fazekas scale in a population aged 75 + years living in the community, and to investigate possible associations between vascular lesions, cardiovascular risk factors and cognitive status. Subjects were selected from a community-based study on brain aging conducted in Caeté (Minas Gerais state), Brazil. Overall, 177 participants (112 cognitively healthy, 36 with cognitive impairment-no dementia and 29 with dementia), being 108 women, aged 79.3 ± 3.8 years, with 3.1 ± 2.9 years of educational level, underwent a 3 Tesla magnetic resonance scanner with fluid attenuated image recovery acquisition. Severity of white matter lesions was assessed through the Fazekas scale. Severe white matter lesions were present in 31.1% of the whole sample and in 25.0% of the cognitively healthy individuals. A significant association was found between severe white matter lesions and cognitive impairment (OR = 2.20, 95% CI 1.17–6.53; p = 0.021), as well as with hypertension (OR = 1.92, 95% CI 1.03–7.39; p = 0.043). In conclusion, a high prevalence of severe white matter lesions was observed in this elderly Brazilian population sample, and white matter lesions were associated with hypertension and cognitive status. Importantly, the prevalence of white matter lesions was also high in cognitively healthy subjects.

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The ischemic cerebrovascular burden assessed by MRI in an elderly Brazilian community is very high.

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MRI white matter lesions were associated with cognitive impairment and hypertension.

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Even in cognitively healthy individuals the prevalence of ischemic cerebrovascular lesions was high.

Which factors are associated with global cognitive impairment in Wilson's disease?

Background

Patients with Wilson's disease (WD) present cognitive impairment, especially in executive functions. Which other factors might be associated with global cognitive decline in these patients remains unclear.

Objective

To assess which factors are associated with worse performance on a global cognitive test in patients with WD.

Methods

Twenty patients with WD underwent cognitive assessment with the following tests: the Mini-Mental State Examination (MMSE), Dementia Rating Scale (DRS), verbal fluency test, brief cognitive battery, clock drawing test, Frontal Assessment Battery, Stroop test, Wisconsin card sorting test, Hopper test, cubes (WAIS) and the Pfeffer questionnaire. MRI changes were quantified. Patients with poor performance on the DRS were compared to patients with normal performance.

Results

Nine patients had a poor performance on the DRS. This group had lower educational level (9.11±3.58× 12.82±3.06) and a greater number of changes on MRI (9.44±2.74× 6.27±2.45). The presence of hyperintensity in the globus pallidus on MRI was more frequent in this group (66.6% vs 9.0%), with OR=5.38 (95% CI 0.85-33.86).

Conclusion

Global cognitive impairment was prevalent in this sample of patients with WD and was associated with low educational level, number of changes on MRI and MRI hyperintensity in the globus pallidus.

Kraepelin’s description of chronic mania: a clinical picture that meets the behavioral variant frontotemporal dementia phenotype

ABSTRACT Chronic mania is an under-investigated condition and few reports have associated this disorder with an organic background. The present work examines Kraepelin’s reliable description of chronic mania from a current behavioral neurology viewpoint. Kraepelin had described a cluster of symptoms that are now recognized as core manifestations of the behavioral variant frontotemporal dementia (bvFTD) clinical phenotype. We also carried out additional reviews of original manuscripts from Kraepelin’s peers, in order to find any case reports that might fulfill the current diagnostic proposal for bvFTD. Even though we failed to find an ideal case, we found some scholars who seemed to agree that chronic mania should be considered a special form of dementia. The present work highlights, through historical data, the possible overlapping features between primary psychiatric disorders and neuropsychiatric symptoms secondary to neurodegenerative conditions.

Cross-country discrepancies on public understanding of stress concepts: evidence for stress-management psychoeducational programs

BACKGROUND

Negative effects of stress have pose one of the major threats to the health and economic well being of individuals independently of age and cultural background. Nevertheless, the term "stress" has been globally used unlinked from scientificevidence-based meaning. The discrepancies between scientific and public stress knowledge are focus of concern and little is know about it. This is relevant since misconceptions about stress may influence the effects of stress-management psychoeducational programs and the development of best practices for interventions. The study aimed to analyze stress knowledge among the Canadian and Brazilian general public and to determine the extent to which scientific and popular views of stress differ between those countries.

METHODS

We evaluated 1156 healthy participants between 18 and 88 years of age recruited from Canada (n = 502) and Brazil (n = 654). To assess stress knowledge, a questionnaire composed of questions regarding stress concepts ("stress is bad" versus "stress-free life is good") and factors capable of triggering the stress response ("novelty, unpredictability, low sense of control and social evaluative threat versus "time pressure,work overload, conflict, unbalance and children") was used.

RESULTS

Both Canadian and Brazilian participants showed misconceptions about stress and the factors capable of triggering a stress response. However, the rate of misconceptions was higher in Brazil than in Canada (p < 0.05).

CONCLUSION

These findings suggest a lack of public understanding of stress science and its variance according to a country's society. Psychoeducational programs and vulnerability of stress-related disorder are discussed.

Neuropsychiatric Symptoms, Caregiver Burden and Distress in Behavioral-Variant Frontotemporal Dementia and Alzheimer's Disease

BACKGROUND/AIMS

We aimed to compare caregiver burden and distress in behavioral-variant frontotemporal dementia (bvFTD) and Alzheimer's disease (AD) and to investigate which factors contribute to caregivers' burden and distress.

METHODS

Fifty patients and their caregivers were invited to participate. Among the patients, 20 had a diagnosis of bvFTD and 30 had AD. Caregivers and patients were statistically equivalent for age, sex, education and dementia severity according to Clinical Dementia Rating. The protocol included the Short Zarit Burden Inventory, the Neuropsychiatric Inventory (NPI), Disability Assessment for Dementia (DAD), the Cornell Scale for Depression in Dementia (CSDD), Addenbrooke's Cognitive Examination-Revised, the Executive Interview with 25 Items, Direct Assessment of Functional Status and the Geriatric Anxiety Inventory (GAI).

RESULTS

In the NPI, caregivers of bvFTD patients reported a higher presence and severity of neuropsychiatric symptoms and caregiver distress compared to caregivers of AD patients. There was no significant difference in the perceived burden. In bvFTD, DAD and GAI scores were significantly correlated with burden, whereas in AD, burden was correlated with CSDD and NPI scores. Psychiatric symptoms were associated with distress in both groups.

CONCLUSIONS

Caregivers of bvFTD patients experienced higher levels of distress than caregivers of AD patients. Patients' functional limitations were associated with burden of caregivers of bvFTD patients, whereas neuropsychiatric symptoms were associated with caregiver strain in both groups.

Effects of Soccer Heading on Brain Structure and Function

Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered as an offensive or defensive move whereby the player's unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of 6-12 incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years, some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the establishment of safety guidelines that could help to minimize the risk of possible adverse effects of soccer on brain structure and function.

Effects of the Staff Training for Assisted Living Residences protocol for caregivers of older adults with dementia: A pilot study in the Brazilian population

AIM

To investigate the effects of the Staff Training for Assisted Living Residences administered to formal caregivers of older adults with behavioral and psychological symptoms of dementia in the institutional environment.

METHODS

The project was developed in two long-term care institutions in Belo Horizonte, Brazil, with 25 formal caregivers and 46 older adults with dementia. The training was carried out over 6 weeks. Evaluations were carried out with the caregivers and the elderly residents, using specific instruments to evaluate different domains (demographic data, etiological diagnoses of dementia, severity of dementia, global cognition, functional performance, quality of life, behavior, burden of caregiver, depression and anxiety). The total time for data collection was 6 months.

RESULTS

A significant improvement in behavioral and psychological symptoms of dementia, as assessed by the Neuropsychiatric Inventory, was observed (P < 0.008), with no changes in the other indexes. No significant changes were observed in parameters related to caregivers.

CONCLUSIONS

The Staff Training for Assisted Living Residences protocol was effective in reducing neuropsychiatric symptoms in dementia patients, and might be a feasible and positive strategy to train formal caregivers in long-term care institutions in Brazil. Geriatr Gerontol Int 2017; 17: 449-455.