155 research outputs found
Is the incidence of dementia declining?
No full textAction on preventative health could lower the risk of dementia for future generations, argues this report.
Executive summary
The world-wide projections of the prevalence of dementia in the coming decades have been a source of great concern to health systems and societies around the world. The World Alzheimer Report 2010 estimated that there were 36 million people with dementia in 2010, with an expected doubling every 20 years to nearly 115 million in 2050. These sobering figures are based on assumptions that the age-adjusted prevalence of dementia would remain constant and the population would continue to age at the current rate.
The assumption that the incidence of dementia will remain stable is now being put into question. There is emerging evidence to suggest that the incidence of dementia in older individuals may be declining. It appears that this change may be recent and has possibly occurred only in the last one to two decades. It may also be restricted so far to high income countries, although data from low and middle income countries are lacking.
The reasons for this change are not understood, but education, more stimulating environments and better control of vascular risk factors may have contributed. The data are still preliminary and more studies are needed to establish the extent of this change and understand its causes. It should be noted that the decline is not large enough to offset the increase in prevalence of dementia due to the ageing of the population and therefore investment and efforts to develop better treatments and care for people with dementia need to continue.
The fact that dementia rates are malleable is an encouraging finding but the reduction cannot be taken for granted as gains in population health can easily be lost if societies do not remain vigilant and continually proactive. These preliminary findings provide a strong argument for large scale Government investment in dementia-prevention strategies, which should start from early life
sj-docx-1-wso-10.1177_17474930221137019 – Supplemental material for The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis
No full textSupplemental material, sj-docx-1-wso-10.1177_17474930221137019 for The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis by Bonnie Yin Ka Lam, Yuan Cai, Rufus Akinyemi, Geert Jan Biessels, Hilde van den Brink, Christopher Chen, Chin Wai Cheung, King Ngai Chow, Henry Kwun Hang Chung, Marco Duering, Siu Ting Fu, Deborah Gustafson, Saima Hilal, Vincent Ming Ho Hui, Rajesh Kalaria, SangYun Kim, Maggie Li Man Lam, Frank Erik de Leeuw, Ami Sin Man Li, Hugh Stephen Markus, Anna Marseglia, Huijing Zheng, John O’Brien, Leonardo Pantoni, Perminder Singh Sachdev, Eric E Smith, Joanna Wardlaw and Vincent Chung Tong Mok in International Journal of Stroke</p
Mediation of cognitive function improvements by strength gains after resistance training in older adults with mild cognitive impairment: outcomes of the study of mental and resistance training
No full textObjectives: To determine whether improvements in aerobic capacity (VO₂peak) and strength after progressive resistance training (PRT) mediate improvements in cognitive function. Design: Randomized, double-blind, double-sham, controlled trial. Setting: University research facility. Participants: Community-dwelling older adults (aged ≥55) with mild cognitive impairment (MCI) (N = 100). Intervention: PRT and cognitive training (CT), 2 to 3 days per week for 6 months. Measurements Alzheimer's Disease Assessment Scale–cognitive subscale (ADAS-Cog); global, executive, and memory domains; peak strength (1 repetition maximum); and VO₂peak. Results: PRT increased upper (standardized mean difference (SMD) = 0.69, 95% confidence interval = 0.47, 0.91), lower (SMD = 0.94, 95% CI = 0.69–1.20) and whole-body (SMD = 0.84, 95% CI = 0.62–1.05) strength and percentage change in VO₂peak (8.0%, 95% CI = 2.2–13.8) significantly more than sham exercise. Higher strength scores, but not greater VO2peak, were significantly associated with improvements in cognition (P < .05). Greater lower body strength significantly mediated the effect of PRT on ADAS-Cog improvements (indirect effect: β = −0.64, 95% CI = −1.38 to −0.004; direct effect: β = −0.37, 95% CI = −1.51–0.78) and global domain (indirect effect: β = 0.12, 95% CI = 0.02–0.22; direct effect: β = −0.003, 95% CI = −0.17–0.16) but not for executive domain (indirect effect: β = 0.11, 95% CI = −0.04–0.26; direct effect: β = 0.03, 95% CI = −0.17–0.23). Conclusion: High-intensity PRT results in significant improvements in cognitive function, muscle strength, and aerobic capacity in older adults with MCI. Strength gains, but not aerobic capacity changes, mediate the cognitive benefits of PRT. Future investigations are warranted to determine the physiological mechanisms linking strength gains and cognitive benefits.Yorgi Mavros, Nicola Gates, Guy C. Wilson, Nidhi Jain, Jacinda Meiklejohn, Henry Brodaty, Wei Wen, Nalin Singh, Bernhard T. Baune, Chao Suo, Michael K. Baker, Nasim Foroughi, Yi Wang, Perminder S. Sachdev, Michael Valenzuela and Maria A. Fiatarone Sing
Geriatric psychiatry: is the jury still out on the cognitive effects of homocysteine and one-carbon metabolism?
No full textPurpose of review: This review considers the evidence for the contribution of hyperhomocysteinemia to cognitive impairment, the dementias and Parkinson's disease, focusing on published literature from April 2002 to April 2003. Recent findings: Homocysteine is a sulphur-containing amino acid that is involved in cycles related to one-carbon metabolism within the body, and elevations in its level can result from multiple aspects of these cycles. Elevated homocysteine impairs methylation, crucial to DNA synthesis and repair, is toxic to the vascular system, is cytotoxic and is directly neurotoxic. These effects interact with ageing-related pathology and toxins to augment neurodegenerative processes. Controversies remain in the ascertainment of homocysteine levels and in the salience of its contribution to cognitive impairment, the dementias and Parkinson's disease. However, cross-sectional studies generally agree homocysteine levels greater than 14 μmol/l are associated with increased risk of cognitive impairment. Hyperhomocysteinemia is associated with an increased risk of cognitive impairment after stroke, and is a contributory factor to the cognitive deficits of vascular dementia and AD. Elevated homocysteine levels have been demonstrated in L-dopa treated Parkinson's disease patients in associated with vascular risk. Hyperhomocysteinemia is also associated with increased brain atrophy in healthy elderly. Summary: There is an increasingly solid case for the association between hyperhomocysteinemia, as a marker of disturbed one-carbon metabolism, and cognitive impairment. The findings from preliminary investigations of vitamin supplementation to lower homocysteine in candidate conditions such as stroke and dementia are encouraging, but evidence is needed from large randomized controlled trials before supplementation can be advocated
Akathisia and second-generation antipsychotic drugs
No full textPURPOSE OF REVIEW: Akathisa is one of the most common and distressing neuroleptic-induced extrapyramidal side effects. Although it is well recognized in the context of conventional antipsychotic medications, there have been recent concerns raised by clinicians and researchers that this syndrome is overlooked in relation to second-generation or atypical antipsychotics. This review examines the recent literature relevant to second-generation antipsychotic (SGA)-induced akathisia. RECENT FINDINGS: Recent studies using large databases clearly indicate that extrapyramidal side effects, in particular akathisia, do occur with the SGAs, although the frequency is not as high as with the conventional antipsychotics. Risk factors include use of high doses, high potency SGAs, or combinations of SGAs with other psychotropic drugs, bipolar depression, palliative care settings, and comorbid substance abuse in psychosis. The dopamine hypothesis remains plausible for understanding the pathophysiology of akathisia. There is emerging evidence that mirtazapine may be useful in the treatment of acute akathisia. SUMMARY: Even though akathisia is less prevalent with SGAs than with the first-generation drugs, it remains clinically important and all clinicians should be conversant with its recognition and management
Diastolic Blood Pressure Variability in Later Life May Be a Key Risk Marker for Cognitive Decline
No full textBACKGROUND: There is an increasing awareness of the need to understand the interaction between long-term blood pressure patterns and their impact on the brain and cognition. METHODS: Our aim was to investigate the relationship between repeated blood pressure measures and change in cognitive performance over 12 years and imaging data at 12 years using a longitudinal population study. The data consisted of 2 cohorts, one midlife and one later life. Using linear regression, we examined the relationship between blood pressure (systolic, diastolic, change in blood pressure between visits, and visit-to-visit variability), change in cognitive performance and imaging at 12 years. RESULTS: Data on cognitive change were available in 1054 at midlife, baseline age 42.7 (SD 1.5) and 1233 in later life, 62.5 (1.5) years. Imaging data were available in 168 and 233, respectively. After adjustment for multiple comparisons greater diastolic blood pressure variability in later life was associated with a −1.95 point decline (95% CI, −2.89 to −1.01) on an attention-based task and a −0.42 point (95% CI, −0.68 to −0.15) decline in performance on a psychomotor task. A higher SD in diastolic pressure across follow-up was associated with greater white matter hyperintensity volume (%increase per 10 mm Hg increase in the SD [1.50 (95% CI, 1.16–1.94]). CONCLUSIONS: In a largely normotensive/mildly hypertensive population, our analyses reported no relationships between blood pressure and cognition in midlife but a potential role for diastolic blood pressure variability in later life as a risk marker for cognitive decline. This may indicate an at-risk period or a means to identify an at-risk population at the age where diastolic pressure is starting to decline.Ruth Peters, Ying Xu, Ranmalee Eramudugolla, Perminder S. Sachdev, Nicolas Cherbuin, Phillip J. Tully, Moyra E. Mortby, Kaarin J. Anste
Psychological well-being in individuals with mild cognitive impairment
No full textNicola Gates,1–3 Michael Valenzuela,3 Perminder S Sachdev,1,2,4 Maria A Fiatarone Singh5,61School of Psychiatry, 2Centre for Healthy Brain Ageing (CheBA), University of New South Wales, Sydney, NSW, Australia; 3Regenerative Neuroscience Group, Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia; 4Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia; 5Exercise Health and Performance Faculty Research Group, Sydney Medical School, The University of Sydney, Lidcombe, NSW, Australia; 6Hebrew SeniorLife, Boston, MA, and Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USAObjectives: Cognitive impairments associated with aging and dementia are major sources of burden, deterioration in life quality, and reduced psychological well-being (PWB). Preventative measures to both reduce incident disease and improve PWB in those afflicted are increasingly targeting individuals with mild cognitive impairment (MCI) at early disease stage. However, there is very limited information regarding the relationships between early cognitive changes and memory concern, and life quality and PWB in adults with MCI; furthermore, PWB outcomes are too commonly overlooked in intervention trials. The purpose of this study was therefore to empirically test a theoretical model of PWB in MCI in order to inform clinical intervention.Methods: Baseline data from a convenience sample of 100 community-dwelling adults diagnosed with MCI enrolled in the Study of Mental Activity and Regular Training (SMART) trial were collected. A series of regression analyses were performed to develop a reduced model, then hierarchical regression with the Baron Kenny test of mediation derived the final three-tiered model of PWB.Results: Significant predictors of PWB were subjective memory concern, cognitive function, evaluations of quality of life, and negative affect, with a final model explaining 61% of the variance of PWB in MCI.Discussion: Our empirical findings support a theoretical tiered model of PWB in MCI and contribute to an understanding of the way in which early subtle cognitive deficits impact upon PWB. Multiple targets and entry points for clinical intervention were identified. These include improving the cognitive difficulties associated with MCI. Additionally, these highlight the importance of reducing memory concern, addressing low mood, and suggest that improving a person's quality of life may attenuate the negative effects of depression and anxiety on PWB in this cohort.Keywords: positive aging, quality of life, memory concer
Neuropsychological predictors of transition from healthy cognitive aging to mild cognitive impairment: The PATH through life study
No full textObjective: To identify neuropsychological predictors of transition from healthy cognitive aging to mild cognitive impairment (MCI) or any mild cognitive disorder (any-MCD) in a community-based longitudinal study of aging. Design: Longitudinal Participants: Two thousand eighty-two individuals, aged 60-64 years and participating in a prospective epidemiologic study of mental health, and aging were assessed at two time points 4 years apart for MCI using the International Consensus Criteria, the clinical dementia rating scale (CDR, 0.5), or any of a suite of criteria sets for MCDs (any-MCD). Measurements: Logistic regression was used to assess the neuropsychological predictors of conversion to diagnosis including the Mini-Mental State Examination, immediate and delayed recall (IR and DR), Digit Backward, Spot-the-Word (STW), Symbol Digits Modalities Test (SDMT), simple and choice reaction time, and reaction time variability. Results: Of the 2,082 Participants with no cognitive impairment in the first wave of data collection, 18 Participants were diagnosed with MCI, 32 with CDR 0.5, and 64 Participants presented with any-MCD 4 years later. The main neuropsychological predictors of conversion identified in multivariate analyses were measures of IR/DR, STW, Symbol Digit Modalities Task, and reaction time variability. Conclusions: Although most measures were significant predictors of conversion to MCI or any-MCD when assessed independently, four tests (IR/DR, STW, SDMT, and simple reaction time variability) accounted for the explained variance in diagnosis when all tests were assessed together. When predictive value, stability across clinical categories, and psychometric characteristics were considered together, the reaction time variability measure was the best predictor of future cognitive disorder
APOE genotype and entorhinal cortex volume in non-demented community-dwelling adults in midlife and early old age
No full textCopyright © 2012 IOS PressThis article has been made available through the Brunel Open Access Publishing Fund.The apolipoprotein E (APOE) ε4 allele is a risk factor for the neuropathological decline accompanying Alzheimer's disease (AD) while, conversely, the ε2 allele offers protection. One of the brain structures exhibiting the earliest changes associated with the disease is the entorhinal cortex. We therefore investigated the volumes of the entorhinal cortex and other structures in the medial temporal lobe including the parahippocampal gyrus, temporal pole, and inferior, middle, and superior temporal cortices, in relation to APOE genotype. Our main objectives were to determine if (a) volumes systematically varied according to allele in a stepwise fashion, ε2 > ε3 > ε4, and (b) associations varied according to age. We investigate this association in 627 non-demented community-dwelling adults in middle age (44 to 48 years; n = 314) and older age (64 to 68 years; n = 313) who underwent structural MRI scans. We found no evidence of APOE-related variation in brain volumes in the age groups examined. We conclude that if a ε2 > ε3 > ε4 pattern in brain volumes does emerge in non-demented adults living in the community in old age, it is not until after the age of 68 years.This study was funded by the UK Leverhulme
Trust, the British Academy, the NHMRC
Research Fellowship No. 471501, the NHMRC Research Fellowship No.#1002560, the National Health and Medical Research Council of Australia Unit Grant No. 973302, Program Grant No. 179805, Project grant No. 157125; Program grant no. 350833, and the National Computational Infrastructure. This article is made available through the Brunel Open Access Publishing Fund
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