CERAD test performances in amnestic mild cognitive impairment and Alzheimer's disease

Utility of learning ratio scores from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Memory Test in distinguishing patterns of cognitive decline in veterans referred for neuropsychological evaluation

Background: The Learning Ratio (LR) is a novel learning score that has shown improved utility over other learning metrics in detecting Alzheimer's disease (AD) across multiple memory tasks. However, its utility on the Consortium to Establish a Registry for Alzheimer's Disease Word List Memory Test (CERAD WLMT), a widely used list learning measure sensitive to decline in neurodegenerative disease, is unknown. The goal of the current study was to determine the utility of LR on the CERAD WLMT in differentiating between diagnostic (MiNCD vs MaNCD) and etiologic groups (VaD vs AD) in a veteran sample. Methods: Raw learning slope (RLS) and LR scores were examined in 168 veterans diagnosed with major neurocognitive disorder (MaNCD), mild neurocognitive disorder (MiNCD), or normal aging following neuropsychological evaluation. Patients with MaNCD were further classified by suspected etiology (i.e. microvascular disease vs AD). Results: Whereas RLS scores were not significantly different between MiNCD and MaNCD, LR scores were significantly different between all diagnostic groups (p's < .05). Those with AD had lower LR scores and RLS scores compared to those with VaD (p's < .05). LR classification accuracy was acceptable for MiNCD (AUC = .76), excellent for MaNCD (AUC = .86) and VaD (AUC = .81), and outstanding for AD (AUC = .91). Optimal cutoff scores for WLMT LR were derived from Youden's index. Conclusion: Results support the use of LR scores over RLS when interpreting the CERAD WLMT and highlight the clinical utility of LR in differentiating between diagnostic groups and identifying suspected etiology.

Modulation of associations between education years and cortical volume in Alzheimer's disease vulnerable brain regions by Aβ deposition and APOE ε4 carrier status in cognitively normal older adults

Background

Education years, as a measure of cognitive reserve, have been shown to affect the progression of Alzheimer's disease (AD), both pathologically and clinically. However, inconsistent results have been reported regarding the association between years of education and intermediate structural changes in AD-vulnerable brain regions, particularly when AD risk factors were not considered during the preclinical phase.

Objective

This study aimed to examine how Aβ deposition and APOE ε4 carrier status moderate the relationship between years of education and cortical volume in AD-vulnerable regions among cognitively normal older adults.

Methods

A total of 121 participants underwent structural MRI, [18F] flutemetamol PET-CT imaging, and neuropsychological battery assessment. Multiple regression analysis was conducted to examine the interaction between years of education and the effects of potential modifiers on cortical volume. The associations between cortical volume and neuropsychological performance were further explored in subgroups categorized based on AD risk factors.

Results

The cortical volume of the left lateral occipital cortex and bilateral fusiform gyrus demonstrated a significant differential association with years of education, depending on the presence of Aβ deposition and APOE ε4 carrier status. Furthermore, a significant relationship between the cortical volume of the bilateral fusiform gyrus and AD-nonspecific cognitive function was predominantly observed in individuals without AD risk factors.

Conclusion

AD risk factors exerted varying influences on the association between years of education and cortical volume during the preclinical phase. Further investigations into the long-term implications of these findings would enhance our understanding of cognitive reserves in the preclinical stages of AD.

CERAD (Consortium to Establish a Registry for Alzheimer's Disease) Neuropsychology Assessment Battery: 35 Years and Counting

BACKGROUND

In 1986, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) was mandated to develop a brief neuropsychological assessment battery (CERAD-NAB) for AD, for uniform neuropsychological assessment, and information aggregation. Initially used across the National Institutes of Aging-funded Alzheimer's Disease Research Centers, it has become widely adopted wherever information is desired on cognitive status and change therein, particularly in older populations.

OBJECTIVE

Our purpose is to provide information on the multiple uses of the CERAD-NAB since its inception, and possible further developments.

METHODS

Since searching on "CERAD neuropsychological assessment battery" or similar terms missed important information, "CERAD" alone was entered into PubMed and SCOPUS, and CERAD-NAB use identified from the resulting studies. Use was sorted into major categories, e.g., psychometric information, norms, dementia/differential dementia diagnosis, epidemiology, intervention evaluation, genetics, etc., also translations, country of use, and alternative data gathering approaches.

RESULTS

CERAD-NAB is available in ∼20 languages. In addition to its initial purpose assessing AD severity, CERAD-NAB can identify mild cognitive impairment, facilitate differential dementia diagnosis, determine cognitive effects of naturally occurring and experimental interventions (e.g., air pollution, selenium in soil, exercise), has helped to clarify cognition/brain physiology-neuroanatomy, and assess cognitive status in dementia-risk conditions. Surveys of primary and tertiary care patients, and of population-based samples in multiple countries have provided information on prevalent and incident dementia, and cross-sectional and longitudinal norms for ages 35-100 years.

CONCLUSION

CERAD-NAB has fulfilled its original mandate, while its uses have expanded, keeping up with advances in the area of dementia.

The CERAD Word List Memory Test: Normative Data Based on a Norwegian Population-Based Sample of Healthy Older Adults 70 Years and Above. The HUNT Study

BACKGROUND

The CERAD Word List Memory Test (WLMT) is widely used in the assessment of older adults with suspected dementia. Although normative data of the WLMT exist in many different regions of the world, normative data based on large population-based cohorts from the Scandinavian countries are lacking.

OBJECTIVE

To develop normative data for the WLMT based on a large population-based Norwegian sample of healthy older adults aged 70 years and above, stratified by age, gender, and education.

METHODS

A total of 6,356 older adults from two population-based studies in Norway, HUNT4 70 + and HUNT4 Trondheim 70+, were administered the WLMT. Only persons with normal cognitive function were included. We excluded persons with a diagnosis of mild cognitive impairment (MCI) and dementia, and persons with a history of stroke and/or depression. This resulted in 3,951 persons aged between 70 and 90 years, of whom 56.2% were females. Regression-based normative data were developed for this sample.

RESULTS

Age, gender, and education were significant predictors of performance on the WLMT list-learning subtests and the delayed recall subtest, i.e., participants of younger age, female sex, and higher education level attained higher scores compared to participants of older age, male sex, and lower level of education.

CONCLUSION

Regression-based normative data from the WMLT, stratified by age, gender, and education from a large population-based Norwegian sample of cognitively healthy older adults aged 70 to 90 years are presented. An online norm calculator is available to facilitate scoring of the subtests (in percentiles and z-scores).

The Use of Verbal and Nonverbal Memory Tests for Alzheimer's Disease Screening in Taiwan Chinese

Patients with Alzheimer's disease typically have initial deficits in memory. Memory testing can be categorized as verbal or nonverbal by the modality of the stimuli used. We compared the discriminative validity of selected verbal and nonverbal memory tests between non-dementia and Alzheimer's disease in Taiwan. Ninety-eight patients with mild Alzheimer's disease and 269 non-dementia individuals underwent story recall test (immediate and delayed recall), and constructional praxis test (copy and delayed recall). The receiver-operating characteristic curve and area under the curve were evaluated to compare between tests. Patients with Alzheimer's disease performed poorly across all memory tests, and the receiver-operating characteristic curve analysis indicated that story recall immediate and relayed recall, and constructional praxis delayed recall had good classification accuracy with area under the curve of .90, .87 and .87 respectively. These results provide support that both verbal and nonverbal memory tests are reliable measure for screening patients with Alzheimer's disease.

Does the virtual shopping training improve executive function and instrumental activities of daily living of patients with mild cognitive impairment?

To date, ecological validity of virtual shopping training for patients with mild cognitive impairment (MCI) has not been confirmed yet. Main objective of this study was to investigate effects of virtual shopping training on executive function and instrumental activities of daily living (IADL) in patients with MCI. 32 patients with MCI were randomly assigned to the experimental group that received virtual shopping training or the waitlist control group for a total of 16 sessions. To examine effects of virtual shopping training on executive function and IADL, Korean version of the Executive Function Performance Test (EFPT-K) and Korean Instrumental Activities of Daily living (K-IADL) were conducted. After the 16 sessions, the experimental group showed greater improvement in the EFPT-K (p < 0.001) and the K-IADL (p < 0.001) compared to the control group. These results suggest that virtual shopping training might be clinically beneficial to enhance executive function and IADL in patients with MCI.

Initial Adaptation of the General Cognitive Assessment Battery by Cognifit™ for Bulgarian Older Adults

BACKGROUND

Online neuropsychological assessment batteries may facilitate the screening of cognitive functions in older adults and could be useful for early diagnosis and detection of cognitive impairments.

OBJECTIVE

The primary aim of this study was to assess the psychometric qualities of an online multi-domain cognitive assessment battery (General Cognitive Assessment Battery (GCAB) by Cognifit™) applied for the first time in Bulgaria.

METHODS

A total of 20 healthy older adults (6 male and 14 female, aged 60-82) completed the GCAB as well as the Mini-Mental State Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery. Descriptive statistics were used to describe the demographic characteristics of the sample and the scores on the GCAB and the CERAD battery. The internal consistency of the GCAB was evaluated using item analysis and measured with Cronbach's alpha. The concurrent validity of the GCAB was assessed with respect to the CERAD using Spearman's r after verifying the linear relationship between the GCAB and CERAD scores.

RESULTS

The GCAB showed good concurrent validity when compared with the corresponding CERAD tests. The correlation coefficients ranged from 0.67 for working memory to 0.47 for short-term auditory memory. We found very good reliability of the GCAB, with the inter-class correlation coefficient higher than 0.8 for all cognitive domains. There were no significant correlations between MMSE and GCAB scores.

CONCLUSION

The GCAB was found to be valid for the cognitive screening of Bulgarian healthy older adults and may provide an adequate assessment of their cognitive status. The GCAB showed good concurrent validity when compared with the CERAD battery, measuring similar cognitive constructs. Further work is necessary to explore its validity and reliability.

Association of Plasma Oligomerized Beta Amyloid with Neurocognitive Battery Using Korean Version of Consortium to Establish a Registry for Alzheimer's Disease in Health Screening Population

The increasing prevalence of Alzheimer’s disease (AD) has become a global phenomenon presenting serious social and health challenges. For detecting early molecular changes in the disease, several techniques to measure varied species of amyloid beta in the peripheral blood have been recently developed, but the efforts to associate them with cognitive assessments have yet to produce sufficient data. We prospectively collected participants from the consecutive population who visited our center for brain health screening. In total, 97 participants (F:M = 58:39) aged 69.4 ± 7.52 were assessed. Participants performed the Korean version of the Consortium to Establish a Registry for Alzheimer’s disease (CERAD-K), the clinical dementia rating (CDR), plasma oligomeric amyloid-β (OAβ) level tests, routine blood tests, ApoE genotype, and brain MRI. Among total population, 55.7% had a CDR of 0, and 40.2% had a CDR of 0.5. The results showed that word memory and word recall, and the total scores of the CERAD-K were negatively correlated with the plasma OAβ level. With a cut-off value of 0.78 ng/mL for the OAβ level and a −1.5 standard deviation of age/sex/education adjusted norms for the CERAD-K; naming, word memory, word recall, word recognition, and total score were significantly correlated with the OAβ level. No correlation between the OAβ level and mini-mental status examination was found. Our results demonstrate that the level of plasma OAβ was well correlated with the measure of cognitive function through the CERAD-K in the field data collected from consecutive populations. Studies on longitudinal comparisons with large cohorts will further validate the diagnostic value of plasma OAβ as a useful biomarker for screening AD and predicting progression.

Machine-Learning Algorithms Based on Screening Tests for Mild Cognitive Impairment

BACKGROUND

The mobile screening test system for mild cognitive impairment (mSTS-MCI) was developed and validated to address the low sensitivity and specificity of the Montreal Cognitive Assessment (MoCA) widely used clinically.

OBJECTIVE

This study was to evaluate the efficacy machine learning algorithms based on the mSTS-MCI and Korean version of MoCA.

METHOD

In total, 103 healthy individuals and 74 patients with MCI were randomly divided into training and test data sets, respectively. The algorithm using TensorFlow was trained based on the training data set, and then its accuracy was calculated based on the test data set. The cost was calculated via logistic regression in this case.

RESULT

Predictive power of the algorithms was higher than those of the original tests. In particular, the algorithm based on the mSTS-MCI showed the highest positive-predictive value.

CONCLUSION

The machine learning algorithms predicting MCI showed the comparable findings with the conventional screening tools.

The effects of repetitive transcranial magnetic stimulation in older adults with mild cognitive impairment: a protocol for a randomized, controlled three-arm trial

BACKGROUND

Mild Cognitive Impairment (MCI) carries a high risk of progression to Alzheimer's disease (AD) dementia. Previous clinical trials testing whether cholinesterase inhibitors can slow the rate of progression from MCI to AD dementia have yielded disappointing results. However, recent studies of the effects of repetitive transcranial magnetic stimulation (rTMS) in AD have demonstrated improvements in cognitive function. Because few rTMS trials have been conducted in MCI, we designed a trial to test the short-term efficacy of rTMS in MCI. Yet, in both MCI and AD, we know little about what site of stimulation would be ideal for improving cognitive function. Therefore, two cortical sites will be investigated in this trial: (1) the dorsolateral prefrontal cortex (DLPFC), which has been well studied for treatment of major depressive disorder; and (2) the lateral parietal cortex (LPC), a novel site with connectivity to AD-relevant limbic regions.

METHODS/DESIGN

In this single-site trial, we plan to enroll 99 participants with single or multi-domain amnestic MCI. We will randomize participants to one of three groups: (1) Active DLPFC rTMS; (2) Active LPC rTMS; and (3) Sham rTMS (evenly split between DLPFC and LPC locations). After completing 20 bilateral rTMS treatment sessions, participants will be followed for 6 months to test short-term efficacy and track durability of effects. The primary efficacy measure is the California Verbal Learning Test-II (CVLT-II), assessed 1 week after intervention. Secondary analyses will examine effects of rTMS on other cognitive measures, symptoms of depression, and brain function with respect to the site of stimulation. Finally, selected biomarkers will be analyzed to explore predictors of response and mechanisms of action.

DISCUSSION

The primary aim of this trial is to test the short-term efficacy of rTMS in MCI. Additionally, the project will provide information on the durability of cognitive effects and potentially distinct effects of stimulating DLPFC versus LPC regions. Future efforts would be directed toward better understanding therapeutic mechanisms and optimizing rTMS for treatment of MCI. Ultimately, if rTMS can be utilized to slow the rate of progression to AD dementia, this will be a significant advancement in the field.

TRIAL REGISTRATION

Clinical Trials NCT03331796. Registered 6 November 2017, https://clinicaltrials.gov/ct2/show/NCT03331796. All items from the World Health Organization Trial Registration Data Set are listed in Appendix A.

PROTOCOL VERSION

This report is based on version 1, approved by the DSMB on 30 November, 2017 and amended on 14 August, 2018 and 19 September, 2019.

Food Insecurity Is Associated with Lower Cognitive Functioning in a National Sample of Older Adults

BACKGROUND

Food insecurity, a social and economic condition of inadequate food resources, is known to affect cognitive development in children. However, research is sparse among adult populations, particularly older adults who may be more susceptible to accelerated cognitive decline.

OBJECTIVE

The aim of this study was to examine the associations between food insecurity and cognitive functioning among older adults.

METHODS

Data came from 1823 older adults (≥60 y) with incomes ≤300% of the federal poverty level (FPL) from the 2011-2014 NHANES. Food security was measured using the 10-item Adult Food Security Survey Module. Cognitive function was measured using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) word learning subtest and delayed word recall, the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST). The cognitive assessments were then standardized and an overall cognitive function z score was created by averaging across all cognitive assessments. Associations with food insecurity were examined using multivariate linear regression models, adjusting for sociodemographic and health characteristics.

RESULTS

In the analytic population, the prevalence of food insecurity was 23.7%. Across all cognitive assessments, the mean scores among food-insecure adults was significantly lower than the mean scores among food-secure adults. After adjusting for sociodemographic and health characteristics, food insecurity was associated with lower scores on the CERAD word learning subtest (β = -0.14, 95% CI: -0.26, -0.01), the AFT (β = -0.13, 95% CI: -0.25, -0.002), and the DSST (β = -0.24, 95% CI: -0.33, -0.15). Food insecurity was also associated with a lower score on the overall cognitive function z score (β = -0.15, 95% CI: -0.26, -0.05).

CONCLUSIONS

In this national sample of 1823 adults aged ≥60 y, food insecurity was inversely associated with cognitive function, which may translate into higher risk of cognitive impairment over time.

Validation of the Thai version of the short Boston Naming Test (T-BNT) in patients with Alzheimer's dementia and mild cognitive impairment: clinical and biomarker correlates

OBJECTIVES

Impairments in the Boston Naming Test (BNT), which measures confrontational word retrieval, frequently accompanies Alzheimer's dementia (AD) and may predict a more rapid progression of illness. This study aims to validate the Thai version of the 15-item BNT (T-BNT) in participants with AD and amnestic mild cognitive impairment (aMCI) and to externally validate the T-BNT using clinical and biomarker measurements.

METHODS

This cross-sectional study recruited patients with AD, diagnosed according to NINCDS-ADRDA criteria (n = 60), aMCI, diagnosed using the Petersen criteria (n = 60), and healthy controls (n = 62). We examined the internal consistency, concurrent and discriminant reliability of the T-BNT. We also assessed the Mini Mental State Examination (MMSE), the Verbal Fluency Test (VFT) and the Word List Memory (WLM) tests and measured apolipoprotein E polymorphism and serum levels of folic acid, high-density lipoprotein cholesterol (HDL) and triglycerides.

RESULTS

This study validated a 10-item T-BNT (10T-BNT), which yielded good internal consistency (0.92), a one-factor unidimensional structure, and adequate concurrent and discriminant validity. Lower scores on the 10T-BNT highly significantly predict AD, but not aMCI, and are positively associated with VFT and WLM test scores. Furthermore, lowered 10T-BNT scores are significantly associated with the ApoE4 allele, lower folate levels and an increased triglyceride/HDL-cholesterol ratio.

CONCLUSIONS

This study validated the 10T-BNT and the total score on this scale is strongly associated with AD, impairments in semantic and episodic memory and biomarkers, which are known to modify memory via different mechanisms.

Validation of a European Cross-Cultural Neuropsychological Test Battery (CNTB) for evaluation of dementia

BACKGROUND

The aims of this study were to establish the diagnostic accuracy of the European Cross-Cultural Neuropsychological Test Battery (CNTB) for dementia in different ethnic populations in Western Europe, to examine its ability to differentiate cognitive impairment profiles for dementia subtypes, and to assess the impact of demographic variables on diagnostic properties.

METHODS

The study was a Western European cross-sectional multi-center study. A total of 66 patients with dementia and 118 cognitively intact participants were included across six memory clinics; 93 had ethnic minority background and 91 had ethnic majority background. Tests in the CNTB cover global cognitive function, memory, language, executive functions, and visuospatial functions.

RESULTS

Significant differences with moderate to large effect sizes were present between patients with dementia and control participants on all CNTB measures. Area under the curves (AUC) ranged from .62 to .99 with a mean AUC across all measures of .83. Comparison of ethnic minority and majority groups generally revealed higher sensitivity in the minority group but no significant difference in the mean AUC's across all measures (.84 vs78, P = .42). Comparison of impairment profiles for patients with Alzheimer's disease (AD) and non-AD dementia revealed that AD patients were significantly more impaired on the memory domain, whereas patients with non-AD dementia were more impaired on the executive functions domain.

CONCLUSIONS

The CNTB was found to have promising cross-cultural diagnostic properties for evaluation of dementia in the targeted minority and majority populations and could represent a valid cross-cultural alternative to other well-established neuropsychological test batteries when assessing patients from these populations.

Characteristics of Mild Cognitive Impairment Using the Thai Version of the Consortium to Establish a Registry for Alzheimer's Disease Tests: A Multivariate and Machine Learning Study

BACKGROUND

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) developed a neuropsychological battery (CERAD-NP) to screen patients with Alzheimer's dementia. Mild cognitive impairment (MCI) has received attention as a pre-dementia stage.

OBJECTIVES

To delineate the CERAD-NP features of MCI and their clinical utility to externally validate MCI diagnosis.

METHODS

The study included 60 patients with MCI, diagnosed using the Clinical Dementia Rating, and 63 normal controls. Data were analysed employing receiver operating characteristic analysis, Linear Support Vector Machine, Random Forest, Adaptive Boosting, Neural Network models, and t-distributed stochastic neighbour embedding (t-SNE).

RESULTS

MCI patients were best discriminated from normal controls using a combination of Wordlist Recall, Wordlist Memory, and Verbal Fluency Test. Machine learning showed that the CERAD features learned from MCI patients and controls were not strongly predictive of the diagnosis (maximal cross-validation 77.2%), whilst t-SNE showed that there is a considerable overlap between MCI and controls.

CONCLUSIONS

The most important features of the CERAD-NP differentiating MCI from normal controls indicate impairments in episodic and semantic memory and recall. While these features significantly discriminate MCI patients from normal controls, the tests are not predictive of MCI.

Episodic memory and delayed recall are significantly more impaired in younger patients with deficit schizophrenia than in elderly patients with amnestic mild cognitive impairment

BACKGROUND

Both amnestic mild cognitive impairment (aMCI) and schizophrenia, in particular deficit schizophrenia, are accompanied by cognitive impairments. The aim of the present study was to examine the cognitive differences between aMCI and (non)deficit schizophrenia.

METHODS

Towards this end we recruited 60 participants with aMCI, 40 with deficit and 40 with nondeficit schizophrenia and 103 normal volunteers. Cognitive measures were assessed with the Consortium to Establish a Registry for Alzheimer's disease (CERAD) using the Verbal Fluency Test (VFT), Boston Naming Test (BNT), Mini-Mental State Examination (MMSE), Word list memory (WLM), Word list recall (WLRecall) and Word list recognition (WLRecognition). Data were analyzed using multivariate analyses and machine learning techniques.

RESULTS

BNT scores were significantly lower in aMCI as compared with nondeficit schizophrenia. Patients with deficit schizophrenia had significantly lower MMSE, WLM, WL True Recall and WL Recognition than aMCI patients, while WL False Recall was significantly higher in deficit schizophrenia than in aMCI. Neural network importance charts show that deficit and nondeficit schizophrenia are best separated from aMCI using total BNT score, while WLM and WL false Recall follow at a distance.

CONCLUSIONS

Patients with schizophrenia and aMCI have a significantly different neurocognitive profile. Memory impairments, especially in episodic memory, are significantly worse in younger patients with deficit schizophrenia as compared with elderly patients with aMCI, while the latter show more dysnomia than patients with schizophrenia.

CERAD Neuropsychological Battery-Arabic Version: Regression-Based and Stratified Normative Data and Effects of Demographic Variables on Cognitive Performance in Older Omanis

BACKGROUND AND OBJECTIVES

Normative data on cognitive performance for the Omani population are scarce. In this study, we tested a sample of older (≥50 years) community-dwelling Omanis on the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery-Arabic version (CERAD-ArNB). We analyzed the participants' cognitive performance and how it was affected by their sex, age, and level of education.

METHODS

We enrolled 150 older Arabic-speaking Omanis from March 2014 to June 2015. Most of the participants were visitors to patients admitted to a tertiary referral center in the Sultanate of Oman. All participants underwent screening to ensure normal cognitive function before taking the CERAD-ArNB. We used multiple regression analysis and stratification according to demographic variables to illustrate the normative data.

RESULTS

A total of 125 participants, 65 men (52%) and 60 women (48%), met the inclusion criteria and completed the testing. Multiple regression and univariate analyses showed that although sex and age significantly affected cognitive performance on some CERAD-ArNB subtests, education level had by far the greatest effect.

CONCLUSIONS

Lower education level was associated with poorer CERAD-ArNB performance in a sample of cognitively normal Omanis aged 50 years and older. The normative data obtained from this study will help clinicians correctly interpret cognitive performance in the Omani elderly population, and probably in other, culturally similar Arabic-speaking communities.

The Default Mode Network Supports Episodic Memory in Cognitively Unimpaired Elderly Individuals: Different Contributions to Immediate Recall and Delayed Recall

While the neural correlates of age-related decline in episodic memory have been the subject of much interest, the spontaneous functional architecture of the brain for various memory processes in elderly adults, such as immediate recall (IR) and delayed recall (DR), remains unclear. The present study thus examined the neural correlates of age-related decline of various memory processes. A total of 66 cognitively normal older adults (aged 60–80 years) participated in this study. Memory processes were measured using the Auditory Verbal Learning Test as well as resting-state brain images, which were analyzed using both regional homogeneity (ReHo) and correlation-based functional connectivity (FC) approaches. We found that both IR and DR were significantly correlated with the ReHo of these critical regions, all within the default mode network (DMN), including the parahippocampal gyrus, posterior cingulate cortex/precuneus, inferior parietal lobule, and medial prefrontal cortex. In addition, DR was also related to the FC between these DMN regions. These results suggest that the DMN plays different roles in memory retrieval across different retention intervals, and connections between the DMN regions contribute to memory consolidation of past events in healthy older people.

Efficacy of a repeat testing protocol for cognitive fatigue assessment: a preliminary study in postconcussive syndrome participants

Aim:

A small but notable number of individuals who suffer a concussion report ongoing cognitive difficulties. This preliminary study investigated the efficacy of repetitive test application to discern cognitive impairment in those with ongoing symptoms.

Methods:

Participants (n = 17) with continuing self-reported symptoms following a concussion (∼9 months postinjury) were compared with 17 age group matched controls for working memory and word-list learning.

Results:

Both groups performed similarly after the first trial for both assessments. However, in subsequent trials, the postconcussion group performed significantly worse than controls.

Discussion:

While further studies to understand the mechanisms are warranted, data from this preliminary study suggest that a repetitive test application may be useful to discern cognitive fatigue in individuals who report ongoing concerns following a concussion.

Diagnostic Accuracy of Memory Measures in Alzheimer's Dementia and Mild Cognitive Impairment: a Systematic Review and Meta-Analysis

With an increasing focus on biomarkers in dementia research, illustrating the role of neuropsychological assessment in detecting mild cognitive impairment (MCI) and Alzheimer's dementia (AD) is important. This systematic review and meta-analysis, conducted in accordance with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) standards, summarizes the sensitivity and specificity of memory measures in individuals with MCI and AD. Both meta-analytic and qualitative examination of AD versus healthy control (HC) studies (n = 47) revealed generally high sensitivity and specificity (≥ 80% for AD comparisons) for measures of immediate (sensitivity = 87%, specificity = 88%) and delayed memory (sensitivity = 89%, specificity = 89%), especially those involving word-list recall. Examination of MCI versus HC studies (n = 38) revealed generally lower diagnostic accuracy for both immediate (sensitivity = 72%, specificity = 81%) and delayed memory (sensitivity = 75%, specificity = 81%). Measures that differentiated AD from other conditions (n = 10 studies) yielded mixed results, with generally high sensitivity in the context of low or variable specificity. Results confirm that memory measures have high diagnostic accuracy for identification of AD, are promising but require further refinement for identification of MCI, and provide support for ongoing investigation of neuropsychological assessment as a cognitive biomarker of preclinical AD. Emphasizing diagnostic test accuracy statistics over null hypothesis testing in future studies will promote the ongoing use of neuropsychological tests as Alzheimer's disease research and clinical criteria increasingly rely upon cerebrospinal fluid (CSF) and neuroimaging biomarkers.

A systematic review of the diagnostic test accuracy of brief cognitive tests to detect amnestic mild cognitive impairment

OBJECTIVE

People with amnestic mild cognitive impairment (aMCI) are at an increased risk of developing dementia. Efficient ways of identifying this 'at risk' population are required for larger-scale research studies. This systematic review describes the diagnostic accuracy of brief cognitive tests for detecting aMCI.

METHODS

Fifteen databases were searched from 1999 to July 2013 to identify papers for inclusion. Prospective studies assessing the diagnostic test accuracy of simple and brief cognitive tests for identifying people with aMCI against a reference standard (Petersen criteria) were included. Sensitivity, specificity, positive and negative predictive values and likelihood ratios were calculated. Predictive validity and test-retest reliability were also extracted, when provided. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

Thirty-nine studies assessing 42 index tests were included. The Montreal Cognitive Assessment was the most comprehensively assessed test with evidence of high sensitivity for aMCI and good test-retest reliability, but low specificity was reported by the only study judged to be at low risk of bias. Other brief cognitive tests that include an assessment of word recall and multi-task tests that assess several cognitive domains were also found to exhibit high sensitivities and reasonable specificities. However, the confidence of the findings was affected by overall low quality of the contributing studies.

CONCLUSION

Several brief cognitive tests have shown promising diagnostic test accuracy results for identifying aMCI. However, concerns over the quality of the constituent studies and lack of evidence on the predictive validity of these tests mean that new validation studies are warranted. Copyright © 2016 John Wiley & Sons, Ltd.

Practice Effects on Story Memory and List Learning Tests in the Neuropsychological Assessment of Older Adults

Two of the most commonly used methods to assess memory functioning in studies of cognitive aging and dementia are story memory and list learning tests. We hypothesized that the most commonly used story memory test, Wechsler's Logical Memory, would generate more pronounced practice effects than a well validated but less common list learning test, the Neuropsychological Assessment Battery (NAB) List Learning test. Two hundred eighty-seven older adults, ages 51 to 100 at baseline, completed both tests as part of a larger neuropsychological test battery on an annual basis. Up to five years of recall scores from participants who were diagnosed as cognitively normal (n = 96) or with mild cognitive impairment (MCI; n = 72) or Alzheimer's disease (AD; n = 121) at their most recent visit were analyzed with linear mixed effects regression to examine the interaction between the type of test and the number of times exposed to the test. Other variables, including age at baseline, sex, education, race, time (years) since baseline, and clinical diagnosis were also entered as fixed effects predictor variables. The results indicated that both tests produced significant practice effects in controls and MCI participants; in contrast, participants with AD declined or remained stable. However, for the delayed—but not the immediate—recall condition, Logical Memory generated more pronounced practice effects than NAB List Learning (b = 0.16, p < .01 for controls). These differential practice effects were moderated by clinical diagnosis, such that controls and MCI participants—but not participants with AD—improved more on Logical Memory delayed recall than on delayed NAB List Learning delayed recall over five annual assessments. Because the Logical Memory test is ubiquitous in cognitive aging and neurodegenerative disease research, its tendency to produce marked practice effects—especially on the delayed recall condition—suggests a threat to its validity as a measure of new learning, an essential construct for dementia diagnosis.

Alzheimer's Disease: Prototype of Cognitive Deterioration, Valuable Lessons to Understand Human Cognition

It is important for neurologists to become more familiar with neuropsychological evaluation for Alzheimer disease. The growth of this method in research, as an available, inexpensive, and noninvasive diagnostic approach, which can be administered even by non-specialist-trained examiners, makes this knowledge more necessary than ever. Such knowledge has a basic role in planning national programs in primary health care systems for prevention and early detection of Alzheimer disease. This is more crucial in developing countries, which have higher rates of dementia prevalence along with cardiovascular risk factors, lack of public knowledge about dementia, and limited social support. In addition compared to the neurological hard signs which are tangible and measurable, the concept of cognition seems to be more difficult for the neurologists to evaluate and for the students to understand. Dementia in general and Alzheimer's disease as the prototype of cognitive disorders specifically, play an important role to explore all domains of human cognition through its symptomatology and neuropsychological deficits.

The 12 Years Preceding Mild Cognitive Impairment Due to Alzheimer's Disease: The Temporal Emergence of Cognitive Decline

Background: The identification of the type and sequence of cognitive decline in preclinical mild cognitive impairment (MCI) prior to Alzheimer’s disease (AD) is crucial for understanding AD pathogenesis and implementing therapeutic interventions.

Objective: To model the longitudinal courses of different neuropsychological functions in MCI due to AD.

Methods: We investigated the prodromal phase of MCI over a 12-year period in 27 initially healthy participants with subsequent MCI preceding AD (NC-MCI) and 60 demographically matched healthy individuals (NC-NC). The longitudinal courses of cognitive performance (verbal and visual episodic memory, semantic memory, executive functioning, constructional praxis, psychomotor speed, language, and informant-based reports) were analyzed with linear mixed effects models.

Results: The sequence with which different cognitive functions declined in the NC-MCI relative to the NC-NC group began with verbal memory and savings performance approximately eight years, and verbal episodic learning, visual memory, and semantic memory (animal fluency) circa four years prior to the MCI diagnosis. Executive functioning, psychomotor speed, and informant-based reports of the NC-MCI group declined approximately two years preceding the MCI diagnosis.

Conclusions: Measurable neuropsychological deterioration occurs up to approximately eight years preceding MCI due to AD.

Differences in and correlations between cognitive abilities and brain volumes in healthy control, mild cognitive impairment, and Alzheimer disease groups

The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis-cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)-were acquired. Of the CERAD-K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups. GM and WM volumes differed significantly among the three groups. There was a significant positive correlation between Boston Naming Test scores and GM and WM volumes. In conclusion, the Boston Naming Test and GM and WM brain volumes differentiated the three tested groups accurately, and there were strong correlations between Boston Naming Test scores and GM and WM volumes. These results will help to establish a test method that differentiates the three groups accurately and is economically feasible.

Frequency of dementia syndromes with a potentially treatable cause in geriatric in-patients: analysis of a 1-year interval

In addition to neurodegenerative and vascular causes of dementia, in the differential diagnosis potentially reversible conditions of dementia also must be assessed. Routine laboratory parameters and neuroimaging, which are recommended for the differential diagnosis of suspected dementia by the German S3 Guideline "Dementia", were retrospectively studied in 166 geriatric patients with suspected dementia. Delirium was diagnosed in six patients (3.6%). These six patients were excluded from the study. Of the 160 remaining patients, there were 99 (59.6%) with an already known dementia. In this subgroup of patients, we found a potentially treatable cause of dementia in 18.2%. In the remaining 61 patients (36.8%), the newly diagnosed dementia syndrome was established according to ICD-10 criteria. Potentially reversible causes of the dementia syndrome were found in 19 of these patients (31.1%). The most common cause was depressive pseudodementia in eight patients followed by vitamin B12 deficiency in six patients. A significant amount of our patients showed laboratory or imaging changes suggestive of potentially reversible causes of the dementia syndrome upon admission. The results of our study indicate the importance of careful differential diagnosis of dementia based on the recommendations of guidelines. Although therapy of these potential causes is not always accompanied by a full recovery, the identification and therapy of treatable causes of cognitive deficits are possible even for general practitioners, who often are the primary contact persons of affected individuals.

Attention and CERAD test performances in cognitively impaired elderly subjects

OBJECTIVES

Attention plays a fundamental role in cognitive performance and is closely interrelated with all major cognitive domains. In this retrospective study, we correlated different measures of attention with standard cognitive parameters in 85 cognitively impaired elderly individuals presenting with cognitive complaints to a memory clinic.

MATERIALS AND METHODS

Z-scores of all relevant cognitive parameters of a extended Consortium to Establish a Registry for Alzheimer's disease (CERAD-Plus) neuropsychological battery were correlated with tonic and phasic alertness, inhibition, and divided attention, assessed by a computerized test battery of attention. The pooled sample consisted of 36 patients with the diagnosis of mild AD, 30 patients with mild cognitive impairment, and 19 patients with major depressive disorder.

RESULTS

Subjects of all diagnostic groups exhibited normal results in all subtests of attention. Reaction times of neither the tonic nor the phasic alertness task were correlated with any parameter of memory and global cognition. However, significant correlations were obtained between reaction times in the alertness tasks and the trail-making tests. Omissions in the divided attention task yielded the strongest correlations with deficits in cognitive performance, particularly in the verbal learning tasks, the Boston naming test, and the trail-making tests.

CONCLUSIONS

Our data demonstrate the relative independency of the CERAD-Plus on the variability of attention and particularly alertness suggesting its robustness in psychiatric memory clinic settings. Moreover, CERAD-Plus subtests correlated considerably with failure rates in divided attention, suggesting that impairment in divided attention tasks may be early markers of cognitive impairment.

Education-corrected CERAD identifies MCI and dementia in Parkinson's disease

OBJECTIVES

This study examined whether controlling for educational background in the CERAD cognitive screening battery would affect the likelihood of patients with Parkinson's disease to fulfill criteria for mild cognitive impairment (PD-MCI) and dementia (PDD).

MATERIALS & METHODS

One-hundred seventeen patients with PD were studied. Cognitive impairment was determined as two subtest scores falling below either the standard cutoff scores or education-corrected cutoff scores. The presence of dementia was determined by clinical interview or Clinical Dementia Rating. Patients were then classified as PD-MCI and PDD according to cognitive test performance and presence/absence of dementia.

RESULTS

The number of cognitively impaired patients (PD-MCI or PDD) was significantly higher when education-controlled cutoff scores were used (62.5% vs 38%). Correspondingly, the number of false negatives (demented PD patients performing normally in CERAD) was significantly lower when education-corrected cutoff scores were used (4% vs 10%).

CONCLUSIONS

Controlling for education increases the sensitivity of the CERAD for PD-MCI and PDD.

A Summary Score for the Framingham Heart Study Neuropsychological Battery

OBJECTIVE

To calculate three summary scores of the Framingham Heart Study neuropsychological battery and determine which score best differentiates between subjects classified as having normal cognition, test-based impaired learning and memory, test-based multidomain impairment, and dementia.

METHOD

The final sample included 2,503 participants. Three summary scores were assessed: (a) composite score that provided equal weight to each subtest, (b) composite score that provided equal weight to each cognitive domain assessed by the neuropsychological battery, and (c) abbreviated score comprised of subtests for learning and memory. Receiver operating characteristic analysis was used to determine which summary score best differentiated between the four cognitive states.

RESULTS

The summary score that provided equal weight to each subtest best differentiated between the four cognitive states.

DISCUSSION

A summary score that provides equal weight to each subtest is an efficient way to utilize all of the cognitive data collected by a neuropsychological battery.

Disrupted Intrinsic Networks Link Amyloid-β Pathology and Impaired Cognition in Prodromal Alzheimer's Disease

Amyloid-β pathology (Aβ) and impaired cognition characterize Alzheimer's disease (AD); however, neural mechanisms that link Aβ-pathology with impaired cognition are incompletely understood. Large-scale intrinsic connectivity networks (ICNs) are potential candidates for this link: Aβ-pathology affects specific networks in early AD, these networks show disrupted connectivity, and they process specific cognitive functions impaired in AD, like memory or attention. We hypothesized that, in AD, regional changes of ICNs, which persist across rest- and cognitive task-states, might link Aβ-pathology with impaired cognition via impaired intrinsic connectivity. Pittsburgh compound B (PiB)-positron emission tomography reflecting in vivo Aβ-pathology, resting-state fMRI, task-fMRI, and cognitive testing were used in patients with prodromal AD and healthy controls. In patients, default mode network's (DMN) functional connectivity (FC) was reduced in the medial parietal cortex during rest relative to healthy controls, relatively increased in the same region during an attention-demanding task, and associated with patients' cognitive impairment. Local PiB-uptake correlated negatively with DMN connectivity. Importantly, corresponding results were found for the right lateral parietal region of an attentional network. Finally, structural equation modeling confirmed a direct influence of DMN resting-state FC on the association between Aβ-pathology and cognitive impairment. Data provide evidence that disrupted intrinsic network connectivity links Aβ-pathology with cognitive impairment in early AD.

Effects of combined cognitive and exercise interventions on cognition in older adults with and without cognitive impairment: a systematic review

Global concern on the potential impact of dementia is mounting. There are emerging calls for studies in older populations to investigate the potential benefits of combining cognitive and exercise interventions for cognitive functions. The purpose of this systematic review is to examine the efficacy of combined cognitive and exercise training in older adults with or without cognitive impairment and evaluate the methodological quality of the intervention studies. A systematic search of Cinahl, Medline, PsycINFO, ProQuest, EMBASE databases and the Cochrane Library was conducted. Manual searches of the reference list from the included papers and additional internet searches were also done. Eight studies were identified in this review, five of which included a cognitively impaired population and three studies included a cognitively healthy population. The results showed that combined cognitive and exercise training can be effective for improving the cognitive functions and functional status of older adults with and without cognitive impairment. However, limited evidence can be found in populations with cognitive impairment when the evaluation included an active control group comparison. Further well-designed studies are still needed to explore the potential benefits of this new intervention paradigm.

The effect of a pre- and postoperative orthogeriatric service on cognitive function in patients with hip fracture: randomized controlled trial (Oslo Orthogeriatric Trial)

BACKGROUND

Delirium is a common complication in patients with hip fractures and is associated with an increased risk of subsequent dementia. The aim of this trial was to evaluate the effect of a pre- and postoperative orthogeriatric service on the prevention of delirium and longer-term cognitive decline.

METHODS

This was a single-center, prospective, randomized controlled trial in which patients with hip fracture were randomized to treatment in an acute geriatric ward or standard orthopedic ward. Inclusion and randomization took place in the Emergency Department at Oslo University hospital. The key intervention in the acute geriatric ward was Comprehensive Geriatric Assessment including daily interdisciplinary meetings. Primary outcome was cognitive function four months after surgery measured using a composite outcome incorporating the Clinical Dementia Rating Scale (CDR) and the 10 words learning and recalls tasks from the Consortium to Establish a Registry for Alzheimer's Disease battery (CERAD). Secondary outcomes were pre- and postoperative delirium, delirium severity and duration, mortality and mobility (measured by the Short Physical Performance Battery (SPPB)). Patients were assessed four and twelve months after surgery by evaluators blind to allocation.

RESULTS

A total of 329 patients were included. There was no significant difference in cognitive function four months after surgery between patients treated in the acute geriatric and the orthopedic wards (mean 54.7 versus 52.9, 95% confidence interval for the difference -5.9 to 9.5; P = 0.65). There was also no significant difference in delirium rates (49% versus 53%, P = 0.51) or four month mortality (17% versus 15%, P = 0.50) between the intervention and the control group. In a pre-planned sub-group analysis, participants living in their own home at baseline who were randomized to orthogeriatric care had better mobility four months after surgery compared with patients randomized to the orthopedic ward, measured with SPPB (median 6 versus 4, 95% confidence interval for the median difference 0 to 2; P = 0.04).

CONCLUSIONS

Pre- and postoperative orthogeriatric care given in an acute geriatric ward was not effective in reducing delirium or long-term cognitive impairment in patients with hip fracture. The intervention had, however, a positive effect on mobility in patients not admitted from nursing homes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01009268 Registered November 5, 2009.

CERAD test performance and cognitive impairment in Parkinson's disease

OBJECTIVES

Many patients with Parkinson's disease (PD) develop mild cognitive impairment (PD-MCI) and dementia (PDD). The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neurocognitive test battery was originally developed to identify early Alzheimer's disease, but it has become a widely used screening instrument also for other types of dementia. The aim of the study was to examine differences in CERAD test performances between cognitively intact and impaired PD patients.

MATERIALS AND METHODS

Eighty-eight PD patients participating in a rehabilitation course were studied. The Clinical Dementia Rating (CDR) was used to assess cognitive impairment. Sixty-six patients were cognitively intact and 22 had cognitive impairment (≥1 in two or more domains or a sum of boxes score of ≥3). The Finnish CERAD test battery was used to measure cognitive functions in seven different domains (language functions, verbal learning, visuospatial functions, delayed recall, memory consolidation, recognition memory, and executive functions).

RESULTS

There were significant differences between the cognitively intact and impaired patients in six CERAD subtests (wordlist learning sum, wordlist delayed recall, constructional praxis recall, clock drawing, verbal fluency and constructional praxis copy) when controlling for covariates (disease duration, motor symptoms, age, and education). No differences were observed in memory consolidation scores.

CONCLUSIONS

The results indicate that mild cognitive impairment in PD is related to deficits in memory, executive functions, and visuospatial functions. The memory deficit is non-amnestic and does not entail accelerated forgetting. CERAD shows promise in identifying PD patients with cognitive impairment and increased risk of dementia.

Higher anticholinergic drug scale (ADS) scores are associated with peripheral but not cognitive markers of cholinergic blockade. Cross sectional data from 21 Norwegian nursing homes

AIM

This study evaluated a presumed gradual decline in cognitive function in nursing home residents when the anticholinergic drug scale (ADS) score increased above 3.

METHOD

The study population was recruited from 21 nursing homes in Norway. Criteria for inclusion were ADS score ≥ 3 and no severe dementia, defined as Clinical Dementia Rating (CDR) score < 3. Primary cognitive end points were CERAD 10-word lists for recall and Mini Mental State Examination (MMSE). Secondary end points were activity of daily living (ADL), mouth dryness and serum anticholinergic activity (SAA). The patients were stratified into subgroups according to ADS score, i.e. a reference group with score 3 and test groups with scores 4, 5 or ≥6. End points were compared by analyses of covariance (ancova).

RESULTS

Overall, 230 of the 1101 screened nursing home residents (21%) had an ADS score ≥3. After exclusion 101 residents were recruited and among these, 87 managed to participate in the study. No significant differences were detected in cognitive function or ADL when ADS increased above 3 (P > 0.10), but in vivo (mouth dryness) and in vitro (SAA) measures of peripheral anticholinergic activity were significantly higher in patients with an ADS score ≥6 (P < 0.01).

CONCLUSION

The present study does not support a progressive decline in cognitive function with ADS score above 3. This might indicate that the ADS score model has limited potential to predict the clinical risk of central anticholinergic side effects in frail elderly patients receiving multiple anticholinergic drugs.

Differences in learning rates for item and associative memories between amnestic mild cognitive impairment and healthy controls

BACKGROUND

It has been established that the overall performance of associative memory was disproportionately impaired in contrast to item memory in aMCI (Amnestic mild cognitive impairment) patients, but little is known about the specific aspects of the memory process that show differences between aMCI and healthy controls. By comparing an item-item associative learning test with an individual item learning test, the present study investigated whether the rate of learning was slower in associative memory than in item memory in aMCI. Furthermore, we examined whether deficits in intertrial acquisition and consolidation contributed to the potential disproportionate impairments in the learning rate of associative memory for aMCI patients. In addition, we further explored whether the aMCI-discriminative power of the associative memory test increases more than that of the item memory test when the number of learning-test trials increases.

METHODS

A group of 40 aMCI patients and 40 matched control participants were administered a standardized item memory test (Auditory Verbal Learning Test, AVLT) and a standardized associative memory test (Paired Associative Learning Test, PALT), as well as other neuropsychological tests and clinical assessments.

RESULTS

The results indicated that the learning rate deficits in aMCI patients were more obvious for associative memory than for item memory and that the deficits resulted from impairments in both intertrial acquisition and consolidation. In addition, the receiver operating characteristic curve and logistical regression analysis revealed that the discriminative power of the associative memory test for aMCI was larger than that of the item memory test, especially with more than one learning-test trials.

CONCLUSIONS

Due to more deficits in learning rate of associative memory than that of item memory, the discriminative power for aMCI tended to be larger in associative memory than in item memory when the number of learning-test trials increased. It is suggested that associative memory tests with multiple trials may be particularly useful for early detection of aMCI.

Applicability of the CANTAB-PAL computerized memory test in identifying amnestic mild cognitive impairment and Alzheimer's disease

AIM

To compare the diagnostic accuracy of a computerized test, the CANTAB paired associate learning (PAL) to that of an established and validated noncomputerized test, the CERAD Wordlist Learning task in differentiating between normal aging, aMCI and AD in a cross-sectional design.

METHODS

58 participants were assessed (19 with mild probable AD, 17 aMCI, 22 healthy controls).

RESULTS

The variables found to best discriminate between the three groups were the CANTAB PAL total errors adjusted (p < 0.0001, 81.0% of the cases correctly classified), and CERAD Wordlist Learning Delayed Recall (p < 0.0001, 77.6% of the cases correctly classified). Using both PAL total errors adjusted and Wordlist Learning Delayed Recall, 84.5% of the cases were correctly classified.

DISCUSSION

The results suggest that the CANTAB could be used for screening of AD-typical memory impairment.

Neural correlates of true and false memory in mild cognitive impairment

The goal of this research was to investigate the changes in neural processing in mild cognitive impairment. We measured phase synchrony, amplitudes, and event-related potentials in veridical and false memory to determine whether these differed in participants with mild cognitive impairment compared with typical, age-matched controls. Empirical mode decomposition phase locking analysis was used to assess synchrony, which is the first time this analysis technique has been applied in a complex cognitive task such as memory processing. The technique allowed assessment of changes in frontal and parietal cortex connectivity over time during a memory task, without a priori selection of frequency ranges, which has been shown previously to influence synchrony detection. Phase synchrony differed significantly in its timing and degree between participant groups in the theta and alpha frequency ranges. Timing differences suggested greater dependence on gist memory in the presence of mild cognitive impairment. The group with mild cognitive impairment had significantly more frontal theta phase locking than the controls in the absence of a significant behavioural difference in the task, providing new evidence for compensatory processing in the former group. Both groups showed greater frontal phase locking during false than true memory, suggesting increased searching when no actual memory trace was found. Significant inter-group differences in frontal alpha phase locking provided support for a role for lower and upper alpha oscillations in memory processing. Finally, fronto-parietal interaction was significantly reduced in the group with mild cognitive impairment, supporting the notion that mild cognitive impairment could represent an early stage in Alzheimer's disease, which has been described as a 'disconnection syndrome'.

Cognitive effects of reducing anticholinergic drug burden in a frail elderly population: a randomized controlled trial

BACKGROUND

Observational studies report a relationship between anticholinergic drug scale (ADS) score and cognitive function. This study investigated whether a reduced ADS score improved cognitive function in a frail elderly population.

METHODS

This randomized, controlled, single-blinded trial, recruited long-term residents with an ADS score of greater than or equal to 3 from 22 nursing homes in Norway. The participants were randomly allocated (1:1) to intervention or control. The intervention was a pharmacist-initiated reduction of ADS score after multidisciplinary drug reviews. Primary end point was Consortium to Establish a Registry for Alzheimer's Disease 10-wordlist test for immediate recall. Secondary end points were Mini-Mental Sate Examination, delayed recall and recognition of words, saliva flow, and serum anticholinergic activity (SAA).The participants were retested after 4 and 8 weeks, and the study groups were compared after adjusting for baseline differences.

RESULTS

Eighty-seven patients were included. The median ADS score was reduced by 2 units (p < .0001) in the intervention group and remained unchanged in the control group. After 8 weeks, the adjusted mean difference in immediate recall was 0.54 words between the intervention and control group (95% confidence interval [CI]: -0.91, 2.05; p = .48). The study groups did not differ significantly in any of the other cognitive end points, salvia flow, or SAA at either follow-up (p > .18).

CONCLUSION

Pharmacist-initiated drug changes significantly reduced ADS score but did not improve cognitive function in nursing home residents. Moreover, the drug changes did not reduce SAA or mouth dryness significantly, which might indicate limited applicability of the ADS score to prevent prescription risks in this population.

Changes in cognition

The clinical hallmark of Alzheimer's disease (AD) is a gradual decline in cognitive function. For the majority of patients the initial symptom is an impairment in episodic memory, i.e., the ability to learn and retain new information. This is followed by impairments in other cognitive domains (e.g., executive function, language, spatial ability). This impairment in episodic memory is evident among individuals with mild cognitive impairment (MCI) and can be used to predict likelihood of progression to dementia, particularly in association with AD biomarkers. Additionally, cognitively normal individuals who are likely to progress to mild impairment tend to perform more poorly on tests of episodic memory than do those who remain stable. This cognitive presentation is consistent with the pathology of AD, showing neuronal loss in medial temporal lobe structures essential for normal memory. Similarly, there are correlations between magnetic resonance imaging (MRI) measures of medial temporal lobe structures and memory performance among individuals with mild cognitive impairment. There are recent reports that amyloid accumulation may also be associated with memory performance in cognitively normal individuals.

Comparison between the story recall test and the word-list learning test in Korean patients with mild cognitive impairment and early stage of Alzheimer's disease

Among verbal memory tests, two that are commonly used to measure the ability of verbal memory function in cognitive impairment are story recall tests and word-list learning tests. However, research is limited regarding which test might be more sensitive in discriminating between normal cognitive aging and patients with Alzheimer's disease (AD) in the Korean population. The purpose of the current study was to compare the word-list learning test (Seoul Verbal Learning Test; SVLT) and the story recall test (Korean Story Recall Test; KSRT) to determine which test is more sensitive in discriminating between individuals with normal cognitive aging and patients with mild cognitive impairment (MCI) and early stage of AD in Korea. A total of 53 healthy adults, 127 patients with MCI, and 72 patients with early stage of AD participated in this study. The receiver-operating characteristic (ROC) curve and area under the curve (AUC) were evaluated to compare these two tests. The results showed that the AUC of the SVLT was significantly larger than the AUC of the KSRT in all three groups (healthy adults vs. MCI and early stage of AD; healthy adults vs. MCI; healthy adults vs. early stage of AD). However, in comparison of patients with MCI and early stage of AD, the AUC of SVLT and the AUC of KSRT were not significant. The word-list learning test is a more useful tool for examining verbal memory function for older adults in Korea than the story recall test.

CERAD-neuropsychological battery in screening mild Alzheimer's disease

OBJECTIVES

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery (nb) is used as an evaluation tool for dementia. In Finland, CERAD-nb was introduced in 1999 and has been proposed to be used in primary health care. However, some of its parts need reassessment and focusing. The goal of this study was to examine the sensitivity and specificity of the subtests and their cut-off points most appropriate for identifying mild Alzheimer's disease (AD).

MATERIALS AND METHODS

The study population consisted of 171 patients with mild AD and 315 cognitively normal elderly. Both groups underwent CERAD-nb investigation as a part of a wider examination procedure.

RESULTS

The most efficient subtests to discriminate patients with mild AD from the normal elderly were Wordlist delayed recall and savings, Wordlist learning and Wordlist recognition and a new variable of Total recall. Optimal cut-off points for each subtest are suggested. The sensitivities of the verbal memory subtests varied between 0.75 and 0.94, the specificities between 0.80 and 0.93 and the areas under the receiver operating characteristics curve between 0.89 and 0.96.

CONCLUSIONS

The CERAD-nb is capable of differentiating cases with mild AD from normal elderly individuals particularly with its verbal memory subtests. New cut-off scores for CERAD's subtests validated in the study further enhance the differentiating power, and with these clarifications, CERAD-nb is considered appropriate to be used as a screening tool for AD even in primary health care.

Evaluation of a summary score of cognitive performance for use in trials in perioperative and critical care

BACKGROUND/AIMS

Cognitive dysfunction after medical treatment is increasingly being recognized. Studies on this topic require repeated cognitive testing within a short time. However, with repeated testing, practice effects must be expected. We quantified practice effects in a demographically corrected summary score of a neuropsychological test battery repeatedly administered to healthy elderly volunteers.

METHODS

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Neuropsychological Assessment Battery (for which a demographically corrected summary score was developed), phonemic fluency tests, and trail-making tests were administered in healthy volunteers aged 65 years or older on days 0, 7, and 90. This battery allows calculation of a demographically adjusted continuous summary score.

RESULTS

Significant practice effects were observed in the CERAD total score and in the word list (learning and recall) subtest. Based on these volunteer data, we developed a threshold for diagnosis of postoperative cognitive dysfunction (POCD) with the CERAD total score.

CONCLUSION

Practice effects with repeated administration of neuropsychological tests must be accounted for in the interpretation of such tests. Ignoring practice effects may lead to an underestimation of POCD. The usefulness of the proposed demographically adjusted continuous score for cognitive function will have to be tested prospectively in patients.

Norms for CERAD constructional praxis recall

Recall of the four-item constructional praxis measure was a later addition to the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery. Norms for this measure, based on cognitively intact African Americans age ≥70 (Indianapolis-Ibadan Dementia Project, N=372), European American participants age ≥66 (Cache County Study of Memory, Health and Aging, N=507), and European American CERAD clinic controls age ≥50 (N = 182), are presented here. Performance varied by site; by sex, education, and age (African Americans in Indianapolis); education and age (Cache County European Americans); and only age (CERAD European American controls). Performance declined with increased age, within age with less education, and was poorer for women. Means, standard deviations, and percentiles are presented separately for each sample.

The 10-word learning task in the differential diagnosis of early Alzheimer's disease and elderly depression: A cross-sectional pilot study

OBJECTIVES

Identification of early Alzheimer's disease (AD) has become very important. Episodic memory tasks appear to have predictive power for indicating early AD. Deficits in encoding and storage processes that are characteristic of AD, however, must be distinguished from non-AD deficits that can also affect memory, including difficulties that may be present in depression. This pilot study was set up to ascertain whether a 10-word-list-learning task (delayed recognition and rate of forgetting) may be useful in making the differentiation between mild AD and depression.

METHOD

A Dutch version of Rey's auditory verbal learning test was administered to 36 mild AD patients, 41 depressed patients, and 47 healthy controls. Data were analyzed in a cross-sectional manner.

RESULTS

Receiver operating characteristic analyses showed that for differentiating mild AD and depression, both delayed recognition and percentage of forgetting have sufficient diagnostic accuracy.

CONCLUSION

Percentage of forgetting had the highest diagnostic accuracy for differentiating mild AD and depressed patients and may be useful in the early detection of AD.

Self-administered Gerocognitive Examination (SAGE): a brief cognitive assessment Instrument for mild cognitive impairment (MCI) and early dementia

OBJECTIVES

To develop a self-administered cognitive assessment instrument to facilitate the screening of mild cognitive impairment (MCI) and early dementia and determine its association with gold standard clinical assessments including neuropsychologic evaluation.

METHODS

Adults aged above 59 years with sufficient vision and English literacy were recruited from geriatric and memory disorder clinics, educational talks, independent living facilities, senior centers, and memory screens. After Self-administered Gerocognitive Examination (SAGE) screening, subjects were randomly selected to complete a clinical evaluation, neurologic examination, neuropsychologic battery, functional assessment, and mini-mental state examination (MMSE). Subjects were identified as dementia, MCI, or normal based on standard clinical criteria and neuropsychologic testing.

RESULTS

Two hundred fifty-four participants took the SAGE screen and 63 subjects completed the extensive evaluation (21 normal, 21 MCI, and 21 dementia subjects). Spearman rank correlation between SAGE and neuropsychologic battery was 0.84 (0.76 for MMSE). SAGE receiver operating characteristics on the basis of clinical diagnosis showed 95% specificity (90% for MMSE) and 79% sensitivity (71% for MMSE) in detecting those with cognitive impairment from normal subjects.

CONCLUSIONS

This study suggests that SAGE is a reliable instrument for detecting cognitive impairment and compares favorably with the MMSE. The self-administered feature may promote cognitive testing by busy clinicians prompting earlier diagnosis and treatment.

FDG-PET mapping the brain substrates of visuo-constructive processing in Alzheimer's disease

The anatomical basis of visuo-constructive impairment in AD is widely unexplored. FDG-PET can be used to determine functional neuronal networks underlying specific cognitive performance in the human brain. In the present study, we determined the pattern of cortical metabolism that was associated with visuo-constructive performance in AD. We employed two widely used visuo-constructive tests that differ in their demand on visual perception and processing capacity. Resting state FDG-PET scans were obtained in 29 probable AD patients, and cognitive tests were administered. We made a voxel-based regression analysis of FDG uptake to scores in visual test performance, using the SPM5 software. Performance in the CERAD Drawing test correlated with FDG uptake in the bilateral inferior temporal gyri, bilateral precuneus, right cuneus, right supramarginal gyrus and right middle temporal gyrus covering areas of dorsal and ventral visual streams. In contrast, performance in the more complex RBANS Figure Copy test correlated with FDG uptake in the bilateral fusiform gyri, right inferior temporal gyrus, left anterior cingulate gyrus, left parahippocampal gyrus, right middle temporal gyrus and right insula, encompassing the ventral visual stream and areas of higher-level visual processing. The study revealed neuronal networks underlying impaired visual test performance in AD. The extent of involvement of visual and higher order association cortex increased with greater test complexity. From a clinical point of view, both of these widely used visual tests evaluate the integrity of complementary cortical networks and may contribute complementary information on the integrity of visual processing in AD.

ERP generator anomalies in presymptomatic carriers of the Alzheimer's disease E280A PS-1 mutation

Although subtle anatomical anomalies long precede the onset of clinical symptoms in Alzheimer's disease, their impact on the reorganization of brain networks underlying cognitive functions has not been fully explored. A unique window into this reorganization is provided by presymptomatic cases of familial Alzheimer's disease (FAD). Here we studied neural circuitry related to semantic processing in presymptomatic FAD cases by estimating the intracranial sources of the N400 event-related potential (ERP). ERPs were obtained during a semantic-matching task from 24 presymptomatic carriers and 25 symptomatic carriers of the E280A presenilin-1 (PS-1) mutation, as well as 27 noncarriers (from the same families). As expected, the symptomatic-carrier group performed worse in the matching task and had lower N400 amplitudes than both asymptomatic groups, which did not differ from each other on these variables. However, N400 topography differed in mutation carrier groups with respect to the noncarriers. Intracranial source analysis evinced that the presymptomatic-carriers presented a decrease of N400 generator strength in right inferior-temporal and medial cingulate areas and increased generator strength in the left hippocampus and parahippocampus compared to the controls. This represents alterations in neural function without translation into behavioral impairments. Compared to controls, the symptomatic-carriers presented a similar anatomical shift in the distribution of N400 generators to that found in presymptomatic-carriers, albeit with a larger reduction in generator strength. The redistribution of N400 generators in presymptomatic-carriers indicates that early focal degeneration associated with the mutation induces neural reorganization, possibly contributing to a functional compensation that enables normal performance in the semantic task.