遗忘型轻度认知障碍和轻度阿尔茨海默病的认知损害特征研究

目的明确遗忘型轻度认知障碍（amnesia-mild cognitive impairment,a-MCI）患者和轻度阿尔茨海默病（alzheimer＇s disease,AD）患者的认知损害特征。方法对13例a-MCI患者、22例轻度AD患者和37例正常对照进行全面的认知测查,除简易精神状态检查（mini-mental state examination,MMSE）外,测验可覆盖4个认知域：记忆力、信息处理速度、执行功能、视空间结构能力,进行组间比较。结果 3组患者在年龄、受教育程度及性别组成上匹配。轻度AD组的所有认知测验成绩都差于正常对照组,而且多数测验较a-MCI组也有减退。a-MCI组的MMSE、记忆相关测验以及多个执行功能相关测验结果都差于正常对照组,信息处理速度和视空间结构能力相关测验与对照组间无统计学差异。结论轻度AD患者表现为全面的认知功能减退。a-MCI患者除存在显著的记忆障碍外,还存在执行功能的异常,信息处理速度和视空间结构能力尚正常。     

Differential effects of age and executive functions on the resolution of the contingent negative variation: a reexamination of the frontal aging theory

The “frontal aging theory” assumes the deterioration of executive/inhibitory functions as causal factors for the cognitive decline in human aging. The contingent negative variation resolution (CNV-R) is an electroencephalographic potential elicited after the second (informative) stimulus in warned Go/NoGo tasks requiring a response to one type of stimulus (Go) but not to the other (NoGo). Whereas the CNV-R across conditions is a measure of executive functions, the augmented potential in the NoGo condition is a specific measure of inhibitory processes. The aim was to examine the presumed linkage between executive processes and the CNV-R with special regard to inhibition in the NoGo condition, and to test whether any effects of age on this potential can be explained by a failure of (inhibitory) executive functions. Nineteen young and 15 elderly non-demented healthy volunteers were examined in a Go/NoGo CNV-R paradigm and on a test of executive functions focussed on set shifting (Trail Making test). Results showed: (1) Better executive functions are associated with higher amplitudes of the CNV-R across conditions. (2) The CNV-R is higher for elderly than younger subjects; this increment is much stronger in the NoGo condition. In conclusion, the CNV-R across conditions reflects executive processes such as the shift of motor set. A higher CNV-R for elderly subjects (particularly of the inhibition-related NoGo CNV-R) indicates that this group is not impaired in the available amount of executive control but may exert such control for task demands where young subjects do not require it.     

Characteristics of neuropsychological functions in inpatients with poorly‐controlled type 2 diabetes mellitus

Aims/Introduction: It has been suggested that type 2 diabetes is associated with cognitive impairment. We investigated the neuropsychological profile of inpatients with poorly controlled type 2 diabetes and assessed the effects of clinical factors on neuropsychological functions. Materials and Methods: Forty‐two patients with type 2 diabetes and 32 non diabetic control subjects were matched for age, sex ratio, and level of education. Attention & working memory, processing speed, verbal memory, visuospatial memory, visuoconstruction, and executive function were tested. Information about physical function, alcohol use, hypertension, dyslipidemia, and myocardial infarction was retrieved from personal interviews and medical records. Results: Diabetic patients demonstrated mild cognitive deterioration in attention & working memory, processing speed, verbal memory, and executive function. In particular, neuropsychological decline became prominent when tasks related with speed and verbal stimuli became unstructured and complex. Age was significantly associated with the majority of neuropsychological tests, whereas tasks dealing with working memory and executive function were associated with age only in the diabetic group. Duration of diabetes was associated with Backward Digit Span. Conclusions: Accelerated aging had a major influence on cognitive decline in the diabetic group, whereas diminished performance in working memory and executive function might have been more related to diabetes‐related cognitive impairment. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00170.x, 2011)     

Impairment of executive function in elderly patients with major unipolar depression: influence of psychomotor retardation

The results from several studies assessing the executive function in depressed patients compared to control subjects varied from significant impairment to normal performance. To assess the executive impairment in elderly patients with major unipolar depression and to evaluate the influence of psychomotor retardation and severity of depression in the executive deficits, the performance of 15 elderly patients with unipolar depression was compared to that of 15 elderly control subjects on executive tasks. The severity of depression was evaluated by the Montgomery and Asberg depressive scale and that of psychomotor retardation by the Widl?cher's scale. In depressed patients, deficits were found on tasks assessing cognitive flexibility (Modified card sorting test (MCST) and Trail making test B), planification and elaboration of strategies (cognitive estimates), motor initiation (graphic sequences), categorisation and hypothesis making (MCST) and interference resistance (Stroop test). However, depressed patients performed normally on the Hayling test assessing the inhibition processes. Intensity of psychomotor retardation was not correlated to the performance of executive tasks. Conversely, severity of depression was related to the scores of MCST (number of errors and perseverations), Stroop and Hayling tests (time taken to complete the end of the sentence). Unipolar depressed patients showed deficits in most tasks assessing executive function. However, inhibition processes appeared to be intact in depressed patients although their implementation was difficult. The severity of depression but not that of psychomotor retardation was associated with executive deficits.     

Cognitive function and information processing in type 2 diabetes.

AIMS: To determine whether uncomplicated Type 2 diabetes is associated with impairment of cognitive function and information processing ability. METHODS: Thirty-eight participants with uncomplicated Type 2 diabetes and 38 non-diabetic controls were studied. The two groups were comparable for age and premorbid intellectual ability, and did not have other medical disorders likely to affect cognitive function. An extensive battery of tests was administered which assessed different levels and domains of cognitive functions including verbal and visual memory, executive function, general mental ability and efficiency of information processing. RESULTS: No significant differences were found between the diabetic and control groups on any measure of cognitive function or information processing. The performance on these tests was not associated with recent glycaemic control (assessed by HbA1c). Duration of diabetes, however, correlated significantly with poorer performance on several measures of verbal memory. CONCLUSIONS: The results of the present study suggest that some aspect of Type 2 diabetes (as indexed by the estimated duration of the disorder) does relate significantly to cognitive function within the group with diabetes. However, other diabetes-related factors, such as macrovascular disease, hypertension and depression, may contribute more to previously observed cognitive decrements in Type 2 diabetes.     

2型糖尿病患者胰升糖素受体基因的PCR-DGGE扫查

目的　探讨胰升糖素受体 (GCG- R)基因在中国人 2型糖尿病遗传背景中的地位。方法　运用聚合酶链反应-变性梯度凝胶电泳 (PCR- DGGE)技术对 2 0 0例无亲缘关系之中国云南昆明地区汉族人 (2型糖尿病患者 12 0例 ,健康对照者 80例 )的 GCG- R基因编码区进行了分子扫查。结果　仅发现 2例 2型糖尿病患者及 1例健康对照者的 GCG- R基因第 7外显子存在多态变异带型 ,这一杂合子多态变异基因型在 2型糖尿病组和对照组中的发生频率分别为 0 .0 17和0 .0 13,两者之间无显著性差异。此外 ,研究对象 GCG- R基因其它编码区的 PCR- DGGE扫查均未发现异常泳动片段。结论　 GCG- R基因可能不是中国昆明地区汉族人 2型糖尿病的主要致病基因。     

Executive functioning in children with heavy prenatal alcohol exposure

BACKGROUND: Children with heavy prenatal alcohol exposure have well documented deficits in overall cognitive ability. Recently, attention has turned to the executive function (EF) domain in this population. Until recently, comprehensive measures of EF have not been available within one test battery. This study used a battery of tests to assess four domains of EF in alcohol-exposed children. METHODS: The Delis-Kaplan Executive Function Scale was used to evaluate EF in 18 children with heavy prenatal alcohol exposure, with and without a diagnosis of fetal alcohol syndrome (FAS), and 10 nonexposed controls. Children ranged in age from 8 to 15 years. Measures from four domains of executive functioning were analyzed: planning ability, cognitive flexibility, selective inhibition, and concept formation and reasoning. Tasks consisted of primary EF measures as well as measures of secondary component skills. RESULTS: Alcohol-exposed children were deficient on EF measures compared with nonexposed controls. Furthermore, in most cases, children with and without the FAS diagnosis did not differ from one another. These deficits were not entirely explainable by concomitant deficits on component skills. Specific impairments were identified within the domains of planning and response inhibition, with additional deficits in abstract thinking and flexibility. CONCLUSIONS: Deficits in executive functioning were observed in alcohol-exposed children with or without the diagnosis of FAS and in the absence of mental retardation. Performance on these EF tasks provides insight into the cognitive processes driving overall performance and has implications for adaptive and daily functions. These results are consistent with anecdotal and empirical reports of deficits in behavioral control and with neuroanatomical evidence of volumetric reductions in structures within the frontal-subcortical system in children with heavy prenatal alcohol exposure.     

Comparing executive functions between patients with chronic asthma and healthy subjects

Objective: Allergic diseases have different levels of prevalence all over the world. Among them, asthma is the most common chronic disease. Up to now, little attention has been paid to the impact of this chronic disease on people's executive functions. The present study aimed at comparing the executive functions in patients with chronic asthma and healthy subjects. Methods: The study population was patients with chronic asthma who were referred to Al-Zahra hospital in Isfahan Province and their visitors who were assigned as the control group. Thirty patients with chronic asthma and 30 patient visitors were enrolled in this study, and three software programs (Wisconsin, Stroop, and Continuous Performance Tests) were used. Results: The results of multivariate variance analysis showed that there is a significant difference between patients with chronic asthma and healthy subjects in terms of set shifting, inhibition, and attention performance. Conclusions: This study revealed that the executive functions of patients with chronic asthma have significant defects.     

Effect of blood pressure and diabetes mellitus on cognitive and physical functions in older adults: a longitudinal analysis of the advanced cognitive training for independent and vital elderly cohort

OBJECTIVES: To evaluate the effect of blood pressure (BP) and diabetes mellitus (DM) on cognitive and physical performance in older, independent-living adults. DESIGN: Longitudinal study with secondary data analysis from the Advanced Cognitive Training for Independent and Vital Elderly randomized intervention trial. SETTING: Six field sites in the United States. PARTICIPANTS: Two thousand eight hundred two independent-living subjects aged 65 to 94. MEASUREMENTS: Cognitive functions in different domains and physical functions measured using activities of daily living, instrumental activities of daily living (IADLs), and the physical function subscale from the Medical Outcomes Study Short Form-36 (SF-36) Health Survey. RESULTS: After the first annual examination, hypertension was associated with a faster decline in performance on logical reasoning tasks (ability to solve problems following a serial pattern), whereas DM was associated with accelerated decline on the Digit Symbol Substitution Test (speed of processing). The reasoning and Digit Symbol Substitution test are executive function tasks thought to be related to frontal-lobe function. Hypertension and DM were associated with a significantly faster pace of decline on the SF-36 physical function component score. Individuals with DM had a faster pace of decline in IADL functioning than nondiabetic subjects. There was no evidence for an interaction between BP and DM on cognitive or physical function decline. CONCLUSION: Hypertension and DM are associated with accelerated decline in executive measures and physical function in independent-living elderly subjects. Further research is needed to determine whether cardiovascular risk modification ameliorates cognitive and functional decline in elderly people.     

Associations between apolipoprotein E phenotype, glucose metabolism and cognitive function in men. An explorative study in a population sample.

AIMS: To investigate the associations of the apolipoprotein E phenotype (apoE) and disturbed glucose metabolism with cognitive function in a random population sample. METHODS: A cross-sectional study was conducted, in which 528 men aged 54 or 60 years were recruited randomly from a larger population-based sample of 1516 men. A subject was defined as having abnormal glucose tolerance (AGT), if he had a clinical diagnosis of diabetes, with either dietary or oral antidiabetic treatment or showed impaired glucose tolerance in an oral glucose tolerance test. The subjects were divided into three groups according to apolipoprotein E phenotypes: (a) E2/4, E3/4 or E4/4 (apoE E4); (b) E 3/3 (apoE E3); and (c) E2/2 or E2/3 (apoE E2). Memory function was examined using a word-list learning with Buschke's selective reminding method and test. Executive functions were assessed with the Trail Making Test A and B. RESULTS: Those subjects with apoE E2 and abnormal glucose metabolism demonstrated the worst cognitive executive control compared to other groups. Simple cognitive speed did not differ between the groups. CONCLUSIONS: The exploratory analyses revealed that subjects with apoE E2 allele and AGT had worse glycaemic control and cognitive executive control compared to other groups. Different apolipoprotein phenotypes together with impaired glucose tolerance may have different cumulative adverse effects on age-related cognitive performance. Some subgroups of subjects may be especially vulnerable to cognitive impairment.     

Arginine impairs endothelial and executive function in older subjects with cardiovascular risk

Neurovascular coupling, the relationship between cerebral blood flow and neuronal activity, is attenuated in patients with impaired executive function. We tested the hypothesis that peripheral vascular function may associate with executive function in older subjects with cardiovascular risk factors and that treatment with the antioxidant L-arginine would improve both vascular and executive function. Nineteen subjects with type 2 diabetes mellitus and/or controlled hypertension were enrolled. Subjects were treated with L-arginine or placebo for 4 days in a randomized, double-blinded, cross-over study. Brachial artery vascular function, peripheral artery tonometry, and Trail Making Test Part B testing were performed on day 1 and day 4 during each condition. L-arginine significantly reduced the digital reactive hyperemia index, and the comparison of changes against placebo was significant (P = .01). With executive function testing, we observed a significant interaction between treatment and order. Restricting the analysis to the first treatment period, subjects treated with placebo decreased their Trail Making Test Part B times by 57.3 ± 52.5 seconds from day 1 to day 4 (P = .01) while those treated with arginine had no significant change (6.4 ± 18.4 seconds worse, P = .37). In addition, L-arginine was associated with increased mean arterial pressure from 88 ± 9 mm Hg to 92 ± 11 mm Hg, which trended toward significance. L-arginine treatment worsened digital microvascular and executive function in older subjects with cardiovascular risk factors. These data further support a link between vascular and executive function.     

Hippocampal damage and memory impairments as possible early brain complications of type 2 diabetes

Aims/hypothesis There is evidence that type 2 diabetes mellitus is associated with cognitive impairment. Most studies investigating this association have evaluated elderly individuals, after many years of diabetes, who generally have poor glycaemic control and significant vascular disease. The aim of the current study was to investigate the early cognitive consequences and associated brain correlates of type 2 diabetes. Materials and methods With regard to cognition and brain measures, we compared 23 age-, sex- and education-matched control subjects with 23 mostly middle-aged individuals with relatively well-controlled diabetes of less than 10 years from the time of diagnosis. Results We found deficits in hippocampal-based memory performance and preservation of other cognitive domains. Relative to control subjects, individuals with diabetes had reductions in brain volumes that were restricted to the hippocampus. There was an inverse relationship between glycaemic control and hippocampal volume; in multivariate regression analysis, HbA_1c was the only significant predictor of hippocampal volume, accounting for 33% of the observed variance. Other variables commonly associated with type 2 diabetes, such as elevated BMI, hypertension or dyslipidaemia, did not independently contribute to the variance in hippocampal volume. Conclusions/interpretation These results suggest that the medial temporal lobe may be the first brain site affected by type 2 diabetes and that individuals in poorer metabolic control may be affected to a greater extent. S. M. Gold and I. Dziobek contributed equally to this work     

皮层下单灶卒中后患者执行功能损害的研究

目的:研究皮层下单灶卒中后的执行功能损害特点,探讨蒙特利尔认知评估(MoCA)量表(北京版)评估该类患者执行功能的合理性。方法:选择具有单一的丘脑、基底节、侧脑室旁白质卒中病灶的脑损害者31例与健康对照者20名作为研究对象,采用连线测验(TMT)、Stroop色词测验(CWT)、语义相似性测验(ST)评估其执行功能。结果:①皮层下单灶卒中组与健康对照组比较在信息处理速度和准确性、抑制干扰能力、推理转换能力上具有显著差异。②左侧卒中组主要表现为抑制干扰能力损害和信息处理速度减慢;右侧卒中组只表现为信息处理速度减慢。③丘脑组表现为信息处理速度减慢和抑制干扰能力受损;基底节区组表现为信息处理速度减慢和推理转换能力受损;侧脑室旁组基本表现为信息处理速度减慢。结论:①皮层下单灶卒中后的执行功能损害较广泛,且损害模式一致表现为执行速度减慢。②MoCA量表评估皮层下单灶卒中后执行功能损害有一定局限性,建议限时检测或评估耗时指标。     

White Matter Hyperintensities Predict Functional Decline in Voiding,Mobility, and Cognition in Older Adults

OBJECTIVES: To compare magnetic resonance imaging data with functional assessments of mobility, urinary control, and cognition to determine common or distinctive features in the distribution of brain white matter hyperintensities (WMHs) associated with functional decline and impairment. DESIGN: Baseline data from subjects aged 75 to 89 enrolled in a longitudinal study. Assessors and subjects were blinded to group assignment. SETTING: Healthy community‐dwelling volunteers. PARTICIPANTS: Ninety‐nine subjects were enrolled using a balanced 3 × 3 matrix stratified according to age and mobility performance. Exclusion criteria were medication, systemic conditions, and neurological diseases that can compromise mobility. MEASUREMENTS: WMHs were identified using a semi‐automated segmentation method, and regional burdens were assessed using a white matter parcellation atlas. Quantitative measures of mobility, urinary incontinence (UI) severity, and executive function and processing speed were obtained. RESULTS: WMHs occur predictably in predominantly periventricular areas. There were powerful correlations between total (tWMH) and regional (rWMH) WMH, with correlation coefficients of 0.5 to 0.9 for eight of 10 structures analyzed. tWMH predicted functional measures of UI, mobility, executive function, and processing speed nearly as well as the best regional measures. The total volume of WMHs independently explains 5% to 11% of the variability for mobility, UI severity, executive function, and processing speed and is a sensitive (0.7–0.8) predictor of functional decline. The odds of decline in each of the three functional domains was 1.5 to 2.4 times greater with each 1% increase in tWMH. CONCLUSION: This work establishes the importance of brain WMH burden in three major geriatric syndromes. The findings support the inclusion of total WMH burden as a risk factor in the predictive and diagnostic criteria.     

皮质下缺血性脑血管病执行功能损害与脑白质结构的相关性研究

目的 探讨皮质下缺血性脑血管病(SIVD)执行功能损害、MRI脑白质病变和DTI脑白质的微结构变化及其临床相关因素.方法 应用Stroop色词测验(CWT)、连线测验(TMT) 和积木测试(BDT)评价24例SIVD患者和14例认知正常老年人的执行功能,其中SIVD患者分为痴呆(VD)组12例,认知障碍无痴呆(VCIND)组12例;依据年龄相关白质改变的评分方法(ARWMCrs) 测量常规MRI上白质病变程度,同时应用DTI分别测定额、颞、顶、枕叶及胼胝体压部白质正常区的各向异性分数(FA)和平均扩散率(MD)值,分析各影像学测量指标与执行功能的相关性.结果 (1)与健康对照组比较,VD组执行功能三项测验均显著减退,VCIND组BDJ评分降低,TMT时间延长,差异有统计学意义(P<0.05);(2)与对照组相比较,VD、VCIND组白质病变评分增高,分别为12.820±3.573、10.500±2.953(P＜0.05);胼胝体压部MD值均升高,具有统计学差异(P＜0.05);VD患者双额叶、右颞叶、右枕叶、双顶叶及胼胝体压部FA值下降(P＜0.05);VCIND组左额叶、双顶叶白质FA值下降(P＜0.05);(3)与SIVD患者执行功能相关的影像学指标有:左额叶、双颞叶、右顶叶白质正常区FA值、胼胝体压部MD值(P＜0.05).结论 (1)SIVD患者存在执行功能障碍,与其脑白质病变程度可能有关;(2)DTI可以显示SIVD患者常规MRI无法显示的脑白质选择性微结构损害;(3)SIVD患者的多个脑白质区FA及MD与CWT、TMT和BDT存在相关性,提示白质微结构的损害可能反映执行功能的下降.     

Changes in the Episodic Memory and Executive Functions of Abstinent and Relapsed Alcoholics Over a 6-Month Period

Background: It is still unclear whether episodic memory and executive functions capacities can return to normal in abstinent patients over a 6‐month period. Furthermore, the role of interim drinking in cognitive recovery is still not well known. Finally, further research is required to specify the predictive value of cognitive abilities at initial testing in the treatment outcome (abstinence or relapse) . The aims of the present study were therefore to measure changes in episodic memory and executive functions over a 6‐month period in abstinent and relapsed alcoholics and to ascertain whether neuropsychological results at treatment entry can predict treatment outcome at follow‐up. Methods: Fifty‐four alcoholic patients and 54 matched control subjects performed baseline neuropsychological tasks assessing episodic memory, executive functions, the slave systems of working memory and attentional abilities. At the follow‐up session (i.e., 6 months later), episodic memory and 3 executive functions (inhibition, flexibility, and updating) were re‐examined in the alcoholic patients. Results: Results showed that over the 6‐month interval, the abstainers’ episodic memory and executive performances had returned to normal, whereas the relapsers performed lower than before in the flexibility task. Episodic memory and executive functions recovery was correlated, in abstainers, with drinking history and age respectively. Finally, there was no significant difference regarding neuropsychological scores at baseline between abstainers and relapsers. Discussion: Over the 6‐month interval, abstainers normalized episodic memory and executive performances whereas relapsers obtained executive results which were more severely impaired, emphasizing the influence of interim drinking on cognitive changes. Episodic memory, executive functions, the slave systems of working memory and attentional abilities did not appear to be reliable predictors of treatment outcome over a 6‐month interval.     

Genuine episodic memory deficits and executive dysfunctions in alcoholic subjects early in abstinence

BACKGROUND: Chronic alcoholism is known to impair episodic memory function, but the specific nature of this impairment is still unclear. Moreover, it has never been established whether episodic memory deficit in alcoholism is an intrinsic memory deficit or whether it has an executive origin. Thus, the objectives are to specify which episodic memory processes are impaired early in abstinence from alcohol and to determine whether they should be regarded as genuine memory deficits or rather as the indirect consequences of executive impairments. METHODS: Forty recently detoxified alcoholic inpatients at alcohol entry treatment and 55 group-matched controls underwent a neuropsychological assessment of episodic memory and executive functions. The episodic memory evaluation consisted of 3 tasks complementing each other designed to measure the different episodic memory components (learning, storage, encoding and retrieval, contextual memory, and autonoetic consciousness) and 5 executive tasks testing capacities of organization, inhibition, flexibility, updating, and integration. RESULTS: Compared with control subjects, alcoholic patients presented impaired learning abilities, encoding processes, retrieval processes, contextual memory and autonoetic consciousness. However, there was no difference between the 2 groups regarding the storage capacities assessed by the rate of forgetting. Concerning executive functions, alcoholic subjects displayed deficits in each executive task used. Nevertheless, stepwise regression analyses showed that only performances on fluency tasks were significantly predictive of some of the episodic memory disorders (learning abilities for 40%, encoding processes for 20%, temporal memory for 21%, and state of consciousness associated with memories for 26%) in the alcoholic group. DISCUSSION: At alcohol treatment entry, alcoholic patients present genuine episodic memory deficits that cannot be regarded solely as the consequences of executive dysfunctions. These results are in accordance with neuroimaging findings showing hippocampal atrophy. Moreover, given the involvement of episodic memory and executive functions in alcohol treatment, these data could have clinical implications.     

Evidence of dysexecutive syndrome in patients with acromegaly

Purpose

This study aimed to explore different aspects of executive function in patients with acromegaly and investigate the cause of dysexecutive syndrome in these patients.

Methods

We conducted five typical executive function tests (Stroop test, verbal fluency [VF] test, Hayling Sentence Completion Test [HSCT], N-back test, and Sustained Attention to Response Task [SART]) on 42 acromegalic patients and 42 strictly matched healthy controls. Comparative analyses were conducted for five major executive function domains. The Dysexecutive Questionnaire (DEX) was used to assess patients’ subjective feelings about their executive function. All patients underwent a magnetic resonance imaging (MRI) examination and a blood test to determine their pituitary hormone levels before the tests were performed.

Results

The patients exhibited worse results on the Stroop test, VF test, HSCT and N-back test compared to the healthy control group. Moreover, part B of the HSCT and the N-back test performance were negatively correlated with IGF-1 concentrations, and the duration of the disease was significantly associated with the Stroop color task results.

Conclusions

Acromegalic patients were severely impaired in semantic inhibition, executive processing, working memory and executive inhibition, and they have realized a portion of these deficits. A high level of IGF-1, disease duration may contribute to the impairment of specific aspects of executive function.

     

Relationship between dual‐task performance and neurocognitive measures in older adults with mild cognitive impairment

Aim: The aim of this study was to examine the relationship between dual‐task performance and neurocognitive measures in community‐dwelling older people with mild cognitive impairment (MCI). Methods: A total of 98 subjects (mean age 74.8 years, 52.0% female) participated in the study. We compared 36 participants with amnestic MCI (aMCI) with 62 participants with non‐amnestic MCI (non‐aMCI) on dual‐task performance as measured by reaction time responses. The relationships between dual‐task performance and multiple domains of neurocognitive functions, including general cognitive function, visual memory, working memory, executive function and processing speed, were examined. Results: Although there were no statistically significant group differences in simple reaction times (P = 0.734), the aMCI group showed significantly slower dual‐task reaction times than the non‐aMCI group (P = 0.012). Using multiple regression analysis, we found that there was a significant relationship between executive function and dual‐task reaction times (β = 0.298, P = 0.006). Conclusion: These results showed that aMCI subjects showed a specific deficit in dual‐task performance compared with non‐aMCI subjects, and poor dual‐task performance was associated with declines in executive function in older people with MCI. Future longitudinal and interventional studies should investigate the use of dual‐task testing with varying levels of cognitive demand in older adults at risk of dementia. Geriatr Gerontol Int 2013; 13: 314–321 .     

Epithelial and mesothelial basement membranes in diabetic patients and dogs

Summary The influence of diabetes on the thickness of basement membrane of the ciliary epithelium, lens epithelium, and corneal mesothelium (endothelium) was investigated post mortem in eyes from 27 human subjects and 30 dogs. Ten of the human subjects were diabetic, 10 were non-diabetic matched for age and sex, and seven were non-diabetic subjects who had been diagnosed as hypertensive 2–8 years before death. The dogs comprised three prospectively identified groups: 10 were alloxan diabetic for 5 years and kept in poor glucose control, 10 were alloxan diabetic for 5 years and kept in good glucose control, and 10 were non-diabetic animals. Basement membranes at the three sites measured appeared to be normal in the seven non-diabetic hypertensive subjects. Basement membrane of the ciliary epithelium was found to be significantly thicker than normal both in diabetic human subjects and in poorly controlled diabetic dogs. The thickness of the anterior lens capsule was significantly greater in poorly controlled diabetic dogs than in non-diabetic dogs, and showed a significant positive correlation with duration of diabetes in human subjects. Better glucose control in diabetic dogs resulted in significant inhibition of the epithelial basement membrane thickening. The basement membrane of the corneal mesothelium failed to thicken with diabetes both in human subjects and in animals.