Cognitive aging in persons with minimal amyloid-β and white matter hyperintensities

Substantial individual differences exist in the magnitude of the cognitive decline associated with normal aging. Potential contributors to this intersubject variability include white matter hyperintensities (WMH) and preclinical Alzheimer′s disease, evident as increased brain amyloid. This study examined whether older individuals with minimal evidence of WMH and/or brain amyloid-beta (seen on positron emission tomography with the Pittsburgh compound B radiotracer—PiB) still showed significant cognitive decrements compared to the young. Older individuals, conservatively screened for normal range performance on an extensive neuropsychological battery, underwent structural magnetic resonance imaging (MRI) and PiB scans and performed tests of information processing speed, working memory and inhibitory function. The elderly were divided into PiB(+) and PiB(−) groups based on radiotracer retention. There were no significant differences in cognitive performance between PiB(+) and PiB(−) elderly. However, both PiB groups performed significantly worse than did the young on cognitive testing. WMH burden in the same individuals was quantified by consensus ratings using a 10 point scale with a median split defining two groups, WMH(+) and WMH(−). There were no differences in cognitive performance between WMH(+) and WMH(−) individuals, but both WMH groups performed significantly worse than did the young. Older participants who were both PiB(−) and WMH(−) also performed significantly worse than did the young in all three cognitive domains. The present results suggest that normal-elderly individuals whose brain scans show minimal evidence of amyloid deposition or WMH, still demonstrate a major decrement in comparison to younger persons on measures of processing resources and inhibitory efficiency.     

A new early cognitive screening measure to detect cognitive side-effects of electroconvulsive therapy?

Cognitive side-effects from electroconvulsive therapy (ECT) can be distressing for patients and early detection may have an important role in guiding treatment decisions over the ECT course. This prospective study examined the utility of an early cognitive screening battery for predicting cognitive side-effects which develop later in the ECT course. The screening battery, together with the Mini Mental Status Examination (MMSE), was administered to 123 patients at baseline and after 3 ECT treatments. A more detailed cognitive battery was administered at baseline, after six treatments (post ECT 6) and after the last ECT treatment (post treatment) to assess cognitive side-effects across several domains: global cognition, anterograde memory, executive function, speed and concentration, and retrograde memory. Multivariate analyses examined the predictive utility of change on items from the screening battery for later cognitive changes at post ECT 6 and post treatment. Results showed that changes on a combination of items from the screening battery were predictive of later cognitive changes at post treatment, particularly for anterograde memory (p < 0.01), after controlling for patient and treatment factors. Change on the MMSE predicted cognitive changes at post ECT 6 but not at post treatment. A scoring method for the new screening battery was tested for discriminative ability in a sub-sample of patients. This study provides preliminary evidence that a simple and easy-to-administer measure may potentially be used to help guide clinical treatment decisions to optimise efficacy and cognitive outcomes. Further development of this measure and validation in a more representative ECT clinical population is required.     

The ApoE4 genotype modifies the relationship of long-term glycemic control with cognitive functioning in elderly with type 2 diabetes

AimTo assess whether the APOE4 genotype affects the relationship of long-term glycemic control with cognitive function in elderly with type 2 diabetes (T2D).MethodsParticipants were cognitively normal and pertained to a Diabetes Registry which provided access to HbA1c levels and other T2D related factors since 1998. Glycemic control was defined as the mean of all HbA1c measurements available (averaging 18 measurements) per subject. Four cognitive domains (episodic memory, semantic categorization, attention/working memory and executive function), based on factor analysis and an overall cognitive score (the sum of the 4 cognitive domains) were the outcome measures.ResultsThe analysis included 808 subjects; 107 (11.9%) subjects had ≥1ApoE4 allele. In ApoE4 carriers, higher mean HbA1c level was significantly associated with lower scores on all cognitive measures except attention/working memory (p-values ranging from 0.047 to 0.003). In ApoE4 non-carriers, higher mean HbA1c level was significantly associated with lower scores on executive function, but not with other cognitive measures—despite the larger sample size. Compared to non-carriers, there were significantly stronger associations in ApoE4 carriers for overall cognition (p=0.02), semantic categorization (p=0.03) and episodic memory (p=0.02), and the difference for executive function approached statistical significance (p=0.06).ConclusionIn this cross-sectional study of cognitively normal T2D subjects, higher mean HbA1c levels were generally associated with lower cognitive performance in ApoE4 carriers, but not in non-carriers, suggesting that ApoE4 affects the relationship between long-term glycemic control and cognition, so APOE4 carriers may be more vulnerable to the insults of poor glycemic control.     

Investigation of nursing students' knowledge of and attitudes about problem-based learning

PurposeTo investigate nursing students' knowledge of and attitudes about problem-based learning (PBL).MethodsA total of 1200 students were surveyed at eight nursing colleges in Hunan Province.ResultsIn all, 1037 valid questionnaires were returned, for an effective return rate of 86.4%. Some 54.4% of the students learned that PBL was a pedagogical method from teachers, and 27.8% of the students had participated in PBL courses. Almost all of students (97.6%) were interested in PBL, and 66.7% of survey participants believed that students who were not good at solving problems would have difficulty in PBL courses.ConclusionNursing educators should guide students to adapt to new learning approaches, and encourage students to participate in the teaching reform to promote students' autonomous learning ability, innovation ability, and comprehensive ability.     

APOE interacts with age to modify rate of decline in cognitive and brain changes in Alzheimer's disease

ObjectiveTo determine (1) whether age-standardized cognitive declines and brain morphometric change differ between Young-Old patients with Alzheimer's disease (YOAD) and Very-Old patients with Alzheimer's disease (VOAD), and (2) whether the apolipoprotein E (APOE) genotype modifies these neuropsychological and morphometric changes.MethodsBaseline and 12-month follow-up neuropsychological and morphometric measures were examined for healthy control subjects and patients with AD. The two AD groups were divided further into subgroups on the basis of the presence of at least one APOE ε4 allele.ResultsThe YOAD group showed more severe deficits and steeper declines in cognition than the VOAD group. Moreover, the presence of an APOE ε4 allele had a more deleterious effect on the YOAD group than the VOAD group on cognition and brain structure both cross-sectionally and longitudinally.ConclusionsResults underscore the importance of integrating an individual's age and genetic susceptibility—and their interaction—when examining neuropsychological and neuroimaging changes in the early stages of Alzheimer's disease.     

Single night video-game use leads to sleep loss and attention deficits in older adolescents

The present study investigated adolescent video-game use prior to bedtime and subsequent sleep, working memory and sustained attention performance. Participants were 21 healthy, good-sleeping adolescents (16 male) aged between 15 and 20 years (M = 17.6 years, SD = 1.8). Time spent video-gaming and subsequent sleep was measured across one night in the sleep laboratory. There were significant correlations between time spent video-gaming and sleep and between video-gaming and sustained attention, but not working memory. Sleep duration, in turn, had a significant negative association with sustained attention performance. Mediation analyses revealed that the relationship between video-gaming and sustained attention was fully mediated by sleep duration. These results indicate that video-gaming affected the ability to sustain attention only in as much as it affected sleep. In order to minimise negative consequences of video-game playing, video-games should be used in moderation, avoiding use close to the sleep period, to obviate detriments to sleep and performance.     

血管性认知功能障碍模型动物的认知功能评价方法

血管性认知功能障碍(vascular cognitive impairment,VCI)是由各种脑血管病导致的从轻度认知障碍到痴呆的一大类综合征.在VCI动物实验中,选择可靠的测试方法对于评价动物认知功能以及提高动物模型的质量尤为重要.     

Retirement and cognitive decline. A longitudinal analysis using SHARE data

We show that a new measure of cognitive decline, that can be computed in longitudinal surveys where respondents perform the same recall memory tests over the years, is highly predictive of the onset of dementia. Using SHARE data, we investigate the way retirement affects cognitive decline over time controlling for age, education and other confounding factors. We find that retirement has a long-term detrimental effect on cognition for individuals who retire at the statutory eligibility age. It plays instead a protective role for those who retire on an early retirement scheme.     

Brain iron deposits are associated with general cognitive ability and cognitive aging

A novel analysis of magnetic resonance imaging (MRI) scans based on multispectral image fusion was used to quantify iron deposits in basal ganglia and microbleeds in 143 nondemented subjects of the generally healthy Lothian Birth Cohort, who were tested for general cognitive ability (intelligence) at mean ages of 11, 70, and 72 years. Possessing more iron deposits at age 72 was significantly associated with lower general cognitive ability at age 11, 70, and 72, explaining 4% to 9% of the variance. The relationships with old age general cognitive ability remained significant after controlling for childhood cognition, suggesting that iron deposits are related to lifetime cognitive decline. Most iron deposits were in the basal ganglia, with few microbleeds. While iron deposits in the general population have so far been dismissed in the literature, our results show substantial associations with cognitive functioning. The pattern of results suggests that iron deposits are not only a biomarker of general cognitive ability in old age and age-related cognitive decline, but that they are also related to the lifelong-stable trait of intelligence.