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Cognitive decline

About: Cognitive decline is a research topic. Over the lifetime, 29308 publications have been published within this topic receiving 1174689 citations.


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Journal ArticleDOI
TL;DR: It is suggested that subcortical brain regions exhibit greater vulnerability to the effects of aging than cortical regions, and neurotrophin gene transfer may be an effective means of preventing neuronal atrophy or degeneration in age-related neurodegenerative disorders.
Abstract: The effects of normal aging on the primate brain are incompletely understood. Although both human and nonhuman primates demonstrate clear functional declines in selective attention, “executive” functions, and some components of declarative memory with aging, most studies have failed to demonstrate extensive neuronal atrophy or loss as a substrate for these degenerative changes in primates. In particular, extensive age-related neuronal loss in memory-related brain regions such as the hippocampus and entorhinal cortex has not been found. However, it is possible that neuronal loss or atrophy might occur in subcortical nuclei that modulate the activity of neocortical regions, thereby accounting for altered cognitive function with aging. In the present study, we describe, to our knowledge for the first time, a significant and extensive decline in the number and size of immunolabeled neurons in subcortical cholinergic basal forebrain regions of aged rhesus monkeys, the best animal model of human aging, by using stereological methods. Notably, the loss of subcortical cholinergic neuronal markers in aged monkeys was nearly completely reversed by human nerve growth factor gene delivery. These findings (i) identify reversible cellular atrophy as a potential mechanism contributing to age-related cognitive decline in primates, (ii) suggest, when considered with other studies, that subcortical brain regions exhibit greater vulnerability to the effects of aging than cortical regions, and (iii) indicate that neurotrophin gene transfer may be an effective means of preventing neuronal atrophy or degeneration in age-related neurodegenerative disorders.

233 citations

Journal ArticleDOI
TL;DR: Investigation of differences in the relationship between executive function and gait variability and stability during single task and dual task walking in persons with and without dementia indicates that decreased executive function plays an important role in increased gact variability in dementia patients.

233 citations

Journal Article
TL;DR: The revised Hasegawa's dementia scale (HDS-R), consisting of 9 simple questions with a maximum score of 30, was examined in its usefulness for screening age-associated dementia in a total of 157 subijects and proved to be valid in terms of compatability with the established dementia screening test.
Abstract: Revised Hasegawa's dementia scale (HDS-R), consisting of 9 simple questions with a maximum score of 30, was examined in its usefulness for screening age-associated dementia in a total of 157 subijects: 95 demented patients and 62 non-demented persons. The two groups were age-matched. Cronbach's coefficient alpha was as high as 0.90 in HDS-R. In addition, the coefficient of correlation of each question's score to the total score of other questions in the IHDS-R was significantly high, ranging between 0.79 and 0.40. These findings proved that the HDS-R could satisfy the fundamental prerequisite for dementia screening tests: reliability in terms of internal consistency. Clinical applicability of the HDS-R was confirmed by the following two findings. (a) significant differences were noted between the demented and non-demented groups in each question's score, total mean score and mean score by DS-based severity. (b) Dementia could be most exactly discriminated from non-dementia with sensitivity of 0.90 and specificity of 0.82 at a cutoff point of 20/21 . The coefficient of correlation of the HDS-R to the MMSE was as high as 0.94, proving the HDS-R to be valid in terms of compatability with the established dementia screening test. In conclusion, the HDS-R can screen dementia at the highest conceivable accuracy and efficiency. It may also serve to assess the severity of dementia changing with time and the effect of pharmacotherapy and rehabilitation. Keywords: dementia, screening test, HDS-R, sensitivity, specificity INTRODUCTION Since the primary symptoms of dementia are cognitive decline, various intelligence tests such as the WAIS (Weschesler Adult Intelligence Scale) have f used for its assesment. However the WAIS is not generally able for screening for dementia since it takes too long to administer, and has not been adequately standardize for elderly subject with cognitive changes associated with normal aging. For the purpose of screening for dementia, questions dimild be eat answered key normal elderly persons, but individuals with dementa should find them difficult. Ideally, these should ba a standardized, simple and quick test of cognitive function for routine use by the physcian Many simple scales for assessment of dementia have been deVeloped and are currently in use. Of these, the Mini-Mental State Examination (MMSE) of Folstein et al. (1975) and the Dementia RAM Scale of Blessed et al. (1968) are perhaps the most widely used brief instruments for assessing severity. Hasegawa et al. (1974) developed and standardized a brief dementia screening scale, called the Hasegawa's Dementia Stale (HDS) which comprises 11 questions (Hasegawa 1983). The HDS have been the most widely accepted not only for clinical we in hospitals and elderly nursing home, but also epiderrdolcgxcal surveys in Japan (Hasegawa and hnad, 1989). However, a recent review of the HDS required us to reconsider some questions and study a feasibility for worldwide use. In consequence, we decided to delete the following five questions because they were judged to be obsolete or lacking universality: 1. The place of the subject's birth (since it is impossible to confirm without the presence of the subject's family). 2. The year of the termination of World War II in Japan (since it is not appropriate for international use and not even applicable to Japanese population). 3. The number of days in opte years (since it is very easily answered even by patients with dementia). 4. The name of the present prime minister in Japan (since it is not appropriate for intercultural use). 5. How long have you been here (since it needs advance information from person around the subject or lacks uniformity in answers among among individuals). Instead immediate recall of 3 words, delay recall of 3 words, and list-ratirg fluency were added. The HDS was recontructed in this manner and named the revised HDS (HDS-R). …

233 citations

Journal ArticleDOI
TL;DR: Cognitive outcomes from the randomized placebo-controlled PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) are presented and it is concluded that Employing statin therapy in the elderly in an attempt to prevent cognitive decline seems to be futile.
Abstract: Observational studies have given conflicting results about the effect of statins in preventing dementia and cognitive decline. Moreover, observational studies are subject to prescription bias, making it hard to draw definite conclusions from them. Randomized controlled trials are therefore the preferred study design to investigate the association between statins and cognition. Here we present detailed cognitive outcomes from the randomized placebo-controlled PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Cognitive function was assessed repeatedly in all 5,804 PROSPER participants at six different time points during the study using four neuropsychological performance tests. After a mean follow-up period of 42 months, no difference in cognitive decline at any of the cognitive domains was found in subjects treated with pravastatin compared to placebo (all p > 0.05). Pravastatin treatment in old age did not affect cognitive decline during a 3 year follow-up period. Employing statin therapy in the elderly in an attempt to prevent cognitive decline therefore seems to be futile.

233 citations

Journal ArticleDOI
TL;DR: This work discussed state-of-the-art in wireless and wearable EEG solutions and a number of aspects where such solutions require improvements when handling electrical activity of the brain, including personal traits and sensory inputs, brain signal generation and acquisition, brain sign analysis, and feedback generation.
Abstract: Monitoring human brain activity has great potential in helping us understand the functioning of our brain, as well as in preventing mental disorders and cognitive decline and improve our quality of life. Noninvasive surface EEG is the dominant modality for studying brain dynamics and performance in real-life interaction of humans with their environment. To take full advantage of surface EEG recordings, EEG technology has to be advanced to a level that it can be used in daily life activities. Furthermore, users have to see it as an unobtrusive option to monitor and improve their health. To achieve this, EEG systems have to be transformed from stationary, wired, and cumbersome systems used mostly in clinical practice today, to intelligent wearable, wireless, convenient, and comfortable lifestyle solutions that provide high signal quality. Here, we discuss state-of-the-art in wireless and wearable EEG solutions and a number of aspects where such solutions require improvements when handling electrical activity of the brain. We address personal traits and sensory inputs, brain signal generation and acquisition, brain signal analysis, and feedback generation. We provide guidelines on how these aspects can be advanced further such that we can develop intelligent wearable, wireless, lifestyle EEG solutions. We recognized the following aspects as the ones that need rapid research progress: application driven design, end-user driven development, standardization and sharing of EEG data, and development of sophisticated approaches to handle EEG artifacts.

232 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023914
20221,895
20213,389
20202,982
20192,551
20182,022