Simplifying Alzheimer's Disease Monitoring: A Novel Machine-Learning Approach to Estimate the Clinical Dementia Rating Sum of Box Changes Using the Mini-Mental State Examination and Functional Activities Questionnaire

Background

Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice.

Objective

Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing.

Methods

Baseline data from 944 ADNI and 171 J-ADNI amyloid-positive participants were used to build machine-learning models predicting annualized CDRSB changes between visits, based on MMSE and FAQ scores. Prediction performance was evaluated with mean absolute error (MAE) and R2 comparing predicted to actual rmDeltaCDRSB/rmDeltayear. We further assessed whether decline in cognitive function surpassing particular thresholds could be identified using the predicted rmDeltaCDRSB/rmDeltayear.

RESULTS

The models achieved the minimum required prediction errors (MAE <  1.0) and satisfactory prediction accuracy (R2>0.5) for mild cognitive impairment (MCI) patients for changes in CDRSB over periods of 18 months or longer. Predictions of annualized CDRSB progression>0.5, >1.0, or >1.5 demonstrated a consistent performance (i.e., Matthews correlation coefficient>0.5). These results were largely replicated in the J-ADNI case predictions.

CONCLUSIONS

Our method effectively predicted MCI patient deterioration in the CDRSB based solely on MMSE and FAQ scores. It may aid routine practice for disease-modifying therapy drug efficacy evaluation, without necessitating CDR testing at every visit.

Brain Age Is Associated with Cognitive Outcomes of Cholinesterase Inhibitor Treatment in Patients with Mild Cognitive Impairment

Background

The effect of cholinesterase inhibitor (ChEI) on mild cognitive impairment (MCI) is controversial. Brain age has been shown to predict Alzheimer's disease conversion from MCI.

Objective

The study aimed to show that brain age is related to cognitive outcomes of ChEI treatment in MCI.

Methods

Brain MRI, the Clinical Dementia Rating (CDR) and Mini-Mental State Exam (MMSE) scores were retrospectively retrieved from a ChEI treatment database. Patients who presented baseline CDR of 0.5 and received ChEI treatment for at least 2 years were selected. Patients with stationary or improved cognition as verified by the CDR and MMSE were categorized to the ChEI-responsive group, and those with worsened cognition were assigned to the ChEI-unresponsive group. A gray matter brain age model was built with a machine learning algorithm by training T1-weighted MRI data of 362 healthy participants. The model was applied to each patient to compute predicted age difference (PAD), i.e. the difference between brain age and chronological age. The PADs were compared between the two groups.

Results

58 patients were found to fit the ChEI-responsive criteria in the patient data, and 58 matched patients that fit the ChEI-unresponsive criteria were compared. ChEI-unresponsive patients showed significantly larger PAD than ChEI-responsive patients (8.44±8.78 years versus 3.87±9.02 years, p = 0.0067).

Conclusions

Gray matter brain age is associated with cognitive outcomes after 2 years of ChEI treatment in patients with the CDR of 0.5. It might facilitate the clinical trials of novel therapeutics for MCI.

Association between Cerebral Coordination Functions and Clinical Outcomes of Alzheimer's Dementia

Background: Alzheimer’s dementia (AD) is a degenerative disease that impairs cognitive function, initially, and then motor or other function, eventually. Motor coordination function impairment usually accompanies cognition impairment but it is seldom examined whether it can reflect the clinical outcomes of AD. Methods: 113 clinically diagnosed AD patients with a mean age of 78.9 ± 6.9 years underwent an annual neuropsychological assessment using the Mini-Mental State Examination (MMSE), the Cognitive Abilities Screening Instrument (CASI), the Sum of Boxes of Clinical Dementia Rating (CDR-SB), and the CDR. The cerebral coordination function was evaluated through correlations among 15 joints with a kinetic depth sensor annually. An intra-individual comparison of both cognitive and motor coordination functions was performed to examine their correlations. Results: The changes in coordination function in the lower limbs can significantly reflect the clinical outcomes, MMSE (p < 0.001), CASI (p = 0.006), CDR (p < 0.001), and CDR-SB (p < 0.001), but the changes in upper limbs can only reflect the clinical outcome in CDR (p < 0.001). Conclusions: The use of a kinetic depth sensor to determine the coordination between joints, especially in lower limbs, can significantly reflect the global functional and cognitive outcomes in AD. Such evaluations could be another biomarker used to evaluate non-cognitive outcomes in AD for clinical and research purposes.

Associations among sleep-disordered breathing, arousal response, and risk of mild cognitive impairment in a northern Taiwan population

STUDY OBJECTIVES

Dementia is associated with sleep disorders. However, the relationship between dementia and sleep arousal remains unclear. This study explored the associations among sleep parameters, arousal responses, and risk of mild cognitive impairment (MCI).

METHODS

Participants with the chief complaints of memory problems and sleep disorders were screened from the sleep center database of Taipei Medical University Shuang-Ho Hospital, and the parameters related to the Cognitive Abilities Screening Instrument (CASI), Clinical Dementia Rating (CDR), and polysomnography (PSG) were determined. All the examinations were conducted within 6 months and without a particular order. The participants were divided into those without cognitive impairment (CDR = 0) and those with MCI (CDR = 0.5). Mean comparison, linear regression models, and logistic regression models were employed to investigate the associations among obtained variables.

RESULTS

This study included 31 participants without MCI and 37 with MCI (17 with amnestic MCI; 20 with multidomain MCI). Patients with MCI had significantly higher mean values of the spontaneous arousal index (SpArI) and SpArI in the nonrapid eye movement (NREM) stage (SpArI_NREM) than those without MCI. An increased risk of MCI was significantly associated with an increase SpArI and SpArI_NREM with various adjustments. Significant associations between the CASI scores and the oximetry parameters and sleep disorder indexes were observed.

CONCLUSIONS

Repetitive respiratory events with hypoxia were associated with cognitive dysfunction. Spontaneous arousal, especially in NREM sleep, was related to the risk of MCI. However, additional longitudinal studies are required to confirm their causality.

Validation of the Korean Quick Dementia Rating System (K-QDRS)

BACKGROUND

The Quick Dementia Rating System (QDRS) is a brief and rapid dementia staging tool that does not require a trained rater.

OBJECTIVE

The purpose of this study is to demonstrate the validity, reliability, and diagnostic usefulness of the Korean version of the QDRS (K-QDRS).

METHODS

We collected a total of 411 subject-informant dyads including cognitively unimpaired (CU, n = 22), mild cognitive impairment (MCI, n = 198), and dementia (n = 191). The Clinical Dementia Rating (CDR) scale, Korean version of the Mini-Mental State Examination (K-MMSE), Korean version of instrumental activity of daily living (K-IADL), Short Form of the Geriatric Depression Scale, Caregiver-Administered Neuropsychiatric Inventory (CGA-NPI), and detailed neuropsychological tests were administered as gold standards of dementia staging, cognition, function, mood, and behavior.

RESULTS

Internal consistency of the K-QDRS was excellent with Cronbach's alpha of 0.933. Concurrent validity was also satisfactory, with the K-QDRS correlating highly with the CDR Sum of Boxes (Pearson's r = 0.791), K-MMSE (Pearson's r = -0.518), K-IADL (Pearson's r = 0.727), and CGA-NPI (Pearson's r = 0.700). The K-QDRS was highly correlated with the global CDR, K-IADL, and CGA-NPI. We suggested two types of comparisons (for initial diagnosis and for follow-up evaluation). The cutoff scores for follow-up were 1.0 for MCI, 3.5 for very mild dementia, 6.5 for mild dementia, and 11.0 for moderate dementia.

CONCLUSION

The K-QDRS is a valid and reliable dementia rating questionnaire and can be used, briefly and rapidly, in various settings like clinical practices, longitudinal cohort studies, and community primary care.

Vortioxetine improves cognition in mild cognitive impairment

This study investigated the effects of vortioxetine on cognitive function in adults with mild cognitive impairment (MCI). This single-arm, open-label, phase II study enrolled 111 adults with MCI without depressive symptoms to receive 5-10 mg/day vortioxetine for 6 months. Main outcomes assessed: cognitive function [Montreal Cognitive Assessment (MoCA); Digit Symbol Substitution Test (DSST)], disease severity [Clinical Dementia Rating (CDR)], clinician-assessed improvement and safety. Mean MoCA score increased from 24.2 points (baseline) to 29.7 points (month 6), placing most subjects within the cognitively normal range (≥26 points). Compared with baseline, MoCA and DSST scores were significantly improved at months 1, 3 and 6 (P < 0.001 for all). Global CDR scores significantly improved from baseline to month 6 (mean change -0.37 points; P < 0.001), representing an improvement from very mild impairment (0.50 points) to cognitively normal status (0.13 points), mainly in CDR memory scores. At month 6, 89.6% of subjects had improved disease severity. Adverse events and adverse drug reactions were reported in 9.9% (n = 11) and 2.7% (n = 3) of subjects, respectively. Vortioxetine treatment was associated with significant improvement in cognitive function and a favorable safety profile in community-dwelling older adults with MCI. Given the lack of evidence for efficacious pharmacologic interventions for MCI, our results are encouraging and warrant further investigation.

Predicting the Severity of Parkinson's Disease Dementia by Assessing the Neuropsychiatric Symptoms with an SVM Regression Model

In this study, we measured the convergence rate using the mean-squared error (MSE) of the standardized neuropsychological test to determine the severity of Parkinson's disease dementia (PDD), which is based on support vector machine (SVM) regression (SVR) and present baseline data in order to develop a model to predict the severity of PDD. We analyzed 328 individuals with PDD who were 60 years or older. To identify the SVR with the best prediction power, we compared the classification performance (convergence rate) of eight SVR models (Eps-SVR and Nu-SVR with four kernel functions (a radial basis function (RBF), linear algorithm, polynomial algorithm, and sigmoid)). Among the eight models, the MSE of Nu-SVR-RBF was the lowest (0.078), with the highest convergence rate, whereas the MSE of Eps-SVR-sigmoid was 0.110, with the lowest convergence rate. The results of this study imply that this approach could be useful for measuring the severity of dementia by comprehensively examining axial atypical features, the Korean instrumental activities of daily living (K-IADL), changes in rapid eye movement sleep behavior disorder (RBD), etc. for optimal intervention and caring of the elderly living alone or patients with PDD residing in medically vulnerable areas.

Economic Burden of Alzheimer's Disease Dementia in Japan

BACKGROUND

Alzheimer's disease dementia (ADD) is the leading cause of long-term care in Japan.

OBJECTIVE

This study estimates the annual healthcare and long-term care costs in fiscal year 2018 for adults over 65 years of age with ADD in Japan and the informal care costs and productivity loss for their families.

METHODS

Healthcare and long-term care costs for ADD were estimated according to the disease severity classified by the clinical dementia rating (CDR) score, using reports from a literature review. For the costs of time spent on caregiving activities, productivity loss for ADD family caregivers aged 20-69 and informal care costs for all ADD family caregivers were estimated.

RESULTS

The total healthcare cost of ADD was JPY 1,073 billion, of which 86% (JPY 923 billion) was attributed to healthcare costs other than ADD drug costs (JPY 151 billion). The healthcare costs other than ADD drug costs by severity were less than JPY 200 billion for CDR 0.5, CDR 1, and CDR 2, respectively, but increased to JPY 447 billion (48%) for CDR 3. The public long-term care costs were estimated to be JPY 4,783 billion, which increased according to the severity. Total productivity loss for ADD family caregivers aged 20-69 was JPY 1,547 billion and the informal care cost for all ADD family caregivers was JPY 6,772 billion.

CONCLUSION

ADD costs have a significant impact on public-funded healthcare, long-term care systems, and families in Japan. To minimize the economic burden of ADD, prolonging healthy life expectancy is the key factor to address.

Effect of Advanced Glycation End Products on the Progression of Alzheimer's Disease

BACKGROUND

Shared links between type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) have been well-known. A high concentration of advanced glycation end products (AGEs) has been reported to contribute to impaired mobility in patients with AD, but there is limited understanding regarding the longitudinal impact of AGEs on cognitive performance.

OBJECTIVE

This study aims to explore whether the concentrations of AGEs mediate the clinical progression of cognitive performance in patients with AD and T2DM.

METHODS

Twenty-five patients aged 79.0±5.8 years who were diagnosed with probable AD with a Clinical Dementia Rating (CDR) of 0.5 or 1 and T2DM were enrolled in this study. When patients participated in the study, the concentration of plasma AGEs was tested. A series of neuropsychological tests, namely the Mini-Mental Status Examination (MMSE), Cognitive Assessment Screening Instrument (CASI), and CDR, were performed annually during follow-up. The association between the concentration of AGEs and changes in overall cognition and cognition related daily living performance was analyzed.

RESULTS

After the mean 48.6±2.1 months of follow-up, AGEs were found to be significantly associated with a change in CDR. A total of 12 (48%) patients experienced a decline in CDR; they had a significantly higher concentration of AGEs than did those whose CDR did not deteriorate (100.5 ± 14.2 versus 81.5 ± 17.7; p = 0.007). This difference in CDR remained significant after adjustment for age, sex, education level, and apolipoprotein E4 status (adjusted p = 0.023).

CONCLUSION

In conclusion, this study indicates that a high concentration of AGEs may be a predictor of a long-term decline in cognition related daily living performance in patients with AD and T2DM.

Predicting Clinical Dementia Rating Using Blood RNA Levels

The Clinical Dementia Rating (CDR) is commonly used to assess cognitive decline in Alzheimer's disease patients and is included in the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. We divided 741 ADNI participants with blood microarray data into three groups based on their most recent CDR assessment: cognitive normal (CDR = 0), mild cognitive impairment (CDR = 0.5), and probable Alzheimer's disease (CDR ≥ 1.0). We then used machine learning to predict cognitive status using only blood RNA levels. Only one probe for chloride intracellular channel 1 (CLIC1) was significant after correction. However, by combining individually nonsignificant probes with p-values less than 0.1, we averaged 87.87% (s = 1.02) predictive accuracy for classifying the three groups, compared to a 55.46% baseline for this study due to unequal group sizes. The best model had an overall precision of 0.902, recall of 0.895, and a receiver operating characteristic (ROC) curve area of 0.904. Although we identified one significant probe in CLIC1, CLIC1 levels alone were not sufficient to predict dementia status and cannot be used alone in a clinical setting. Additional analyses combining individually suggestive, but nonsignificant, blood RNA levels were significantly predictive and may improve diagnostic accuracy for Alzheimer's disease. Therefore, we propose that patient features that do not individually predict cognitive status might still contribute to overall cognitive decline through interactions that can be elucidated through machine learning.

A comparison of sociobehavioral impact on cognitive preservation in Alzheimer's disease between Taiwan and Korea: A cross-national study

Both Taiwan and Korea are developed countries with different cultures. When encountering the issue of dementia, such sociobehavioral factors have various and different impacts on dementia. We aim to assess the cross-national difference of sociobehavioral impact on cognitive preservation in Alzheimer's disease (AD) between Taiwan and Korea.A uniformed data set was administered regarding AD. We evaluated annual cognitive function using the Mini-Mental State Examination (MMSE), Clinical Dementia Rating sum of box (CDR-SB), and CDR for 2 continuous years. Annual change of scores compared with the baseline indicated cognitive change as preservation or decline. We recorded the sociodemographic variables of interest, including education duration, level of independence, living situation, and marital status. Step-wise regression analyses were performed to determine the independent factors for cognitive preservation.In total, 503 participants in Taiwan and 77 participants in Korea were recruited from 2011 to 2014. The baseline demographic characteristics were different in levels of education, living situation, level of independence, and dementia severity between the 2 countries. With follow-up for 2 years, cognitive preservation was associated with CDR staging at baseline and independence [adjusted odds ratio (OR) = 1.657, 95% confidence interval (95% CI) = 1.109-2.477, P = .014] in the Taiwanese population, whereas cognitive preservation was related to living alone (adjusted OR = 3.316, 95% CI = 1.135-9.687, P = .028) in the Korean population. The levels of education showed inconsistency in cognitive preservation in both countries.Cognitive preservation was associated with independence in the Taiwanese population, whereas cognitive preservation was related to living alone in the Korean population. By practicing relevant socioeconomic support, this might contribute to lessening the negative impact of dementia and preserving cognition in different countries.

Global Clinical Dementia Rating Score of 0.5 May Not Be an Accurate Criterion to Identify Individuals with Mild Cognitive Impairment

Many studies use the global clinical dementia rating (CDR) of 0.5 as a criterion for mild cognitive impairment, but past studies have not fully discussed its validity. The authors developed the ABC Dementia Scale (ABC-DS) to accurately monitor the changes in activities for daily living, behavioral and psychological symptoms of dementia, and cognitive function. When we carried out a cluster analysis of ABC-DS scores of 110 individuals for whom global CDR was 0.5, there were three groups with different levels of activities for daily living and cognitive function. O’Bryant et al. proposed a new guideline to stage dementia using the CDR sum of boxes scores (CDR-SOB). We used their proposal and ABC-DS scores to evaluate the validity of CDR 0.5 as a definition of mild cognitive impairment (MCI). We concluded that the CDR-SOB scores and ABC-DS score are more accurate than global CDR of 0.5 for specifying individuals with MCI.

Analyzing the chance of developing dementia among geriatric people: a cross-sectional pilot study in Bangladesh

AIM

Alzheimer's disease is the most common form of dementia, representing 60-80% of cases, and ageing is the primary risk factor for the development of Alzheimer's disease. The objective of this study was to examine the chance of developing dementia (i.e. mild cognitive impairment (MCI), Alzheimer's disease) among geriatric people in Bangladesh.

METHODS

This study included 390 adult citizens of Bangladesh (age range: 60-70 years). The Takeda Three Colors Combination (TTCC) test was used to detect the prevalence of MCI and mild dementia among the subjects, and then the Clinical Dementia Rating was used to determine the level of dementia.

RESULTS

The subjects who were aged 60-65 years included 154 with MCI, 76 with mild dementia, 1 with moderate dementia, 4 with severe dementia, and 29 without dementia. The subjects who were aged 66-70 years included 75 with MCI, 36 with mild dementia, 0 with moderate dementia, 2 with severe dementia, and 13 without dementia. The sensitivity of the TTCC was 75% and 58% for the mild dementia and MCI groups, respectively, and the specificity was 52%. The odds ratio of incorrect responses to the TTCC was 3.42 (95% confidence interval: 1.63-7.21) for subjects with mild dementia compared those without dementia. However, the TTCC outcomes revealed no significant differences between the MCI and non-dementia groups. The results showed no significant associations between cognitive decline/developing dementia and social status/occupation.

CONCLUSION

The outcomes of this study indicated that most of the subjects had MCI or mild dementia and were farmers aged 60-65 years.

Pattern of cerebral hypoperfusion according to the clinical staging in dementia with Lewy bodies

This study aimed to detect different patterns of cerebral hypoperfusion in DLB according to clinical staging. Thirty-three patients with DLB were recruited by clinical dementia rating (CDR) stage. Compared with control, cerebral hypoperfusion was mainly observed in the lingual gyrus, the cuneus, the occipital gyrus in CDR 0.5 group; the fusiform gyrus, the middle temporal gyrus, and the posterior cingulate in CDR 1; and the lingual gyrus, the cuneus, the hippocampus, the fusiform gyrus, and the inferior frontal gyrus in CDR 2. Our findings suggest that cerebral hypoperfusion spreads to the frontal cortex and temporal lobes as disease progresses.

Unobtrusive Detection of Mild Cognitive Impairment in Older Adults Through Home Monitoring

The early detection of dementias such as Alzheimer's disease can in some cases reverse, stop, or slow cognitive decline and in general greatly reduce the burden of care. This is of increasing significance as demographic studies are warning of an aging population in North America and worldwide. Various smart homes and systems have been developed to detect cognitive decline through continuous monitoring of high risk individuals. However, the majority of these smart homes and systems use a number of predefined heuristics to detect changes in cognition, which has been demonstrated to focus on the idiosyncratic nuances of the individual subjects, and thus, does not generalize. In this paper, we address this problem by building generalized linear models of home activity of older adults monitored using unobtrusive sensing technologies. We use inhomogenous Poisson processes to model the presence of the recruited older adults within different rooms throughout the day. We employ an information theoretic approach to compare the generalized linear models learned, and we observe significant statistical differences between the cognitively intact and impaired older adults. Using a simple thresholding approach, we were able to detect mild cognitive impairment in older adults with an average area under the ROC curve of 0.716 and an average area under the precision-recall curve of 0.706 using activity models estimated over a time window of 12 weeks.

Apathy is more severe in vascular than amnestic mild cognitive impairment in a community: the Kurihara Project

AIM

 The aim of this study was to estimate the prevalence of apathy, and to compare vascular mild cognitive impairment (vMCI), amnestic MCI (amMCI), and other type using Clinical Assessment for Spontaneity (CAS).

METHODS

 Agreement to take part in the study was obtained from 590 community dwellers, aged ≥75 years living in Kurihara, Japan. Of the 590 subjects, 221 had a clinical dementia rating (CDR) of 0 (normal); 295 had CDR 0.5 (mild cognitive impairment; MCI); and 74 had CDR 1+ (dementia). The CDR 0.5 subjects were divided into three groups: 55 with vMCI (Erkinjuntti et al. criteria), 91 with amMCI and 149 with other type. To evaluate the various aspects of apathy, we used the three CAS subscales: clinical interview (CAS1), self-evaluation (CAS2), and caregiver assessment (CAS3). Three analyses were then performed to determine: (i) the validity of CAS; (ii) the prevalence rate of apathy in CDR 0 versus CDR 0.5 versus CDR 1+; and (iii) the prevalence rate of apathy in normal versus vMCI versus amMCI versus other type.

RESULTS

 CAS was validated with the Apathy Evaluation Scale. There were significant differences among the three CDR groups in CAS1, CAS2 and CAS3 (P < 0.001). The prevalence rate of apathy in each CAS in the CDR 1+ group was higher than the CDR 0.5 group, which was higher than the CDR 0 group. There was a significant difference in CAS3 score between the four groups (the normal and the three subgroups; P < 0.001). Apathy in vMCI was more severe than in the other three groups (P < 0.05) on CAS3 score.

CONCLUSIONS

 vMCI subjects have more severe apathy compared with amMCI subjects on caregiver assessment.

Feasibility and validity of dementia assessment by trained community health workers based on Clinical Dementia Rating

OBJECTIVES

To determine the level of agreement between dementia rating by trained community health workers (CHWs) based on the Clinical Dementia Rating (CDR) and the criterion standard: physician diagnosis.

DESIGN

Cross-sectional validation study.

SETTING

Community gathering places such as ethnic churches, senior centers, low-income elderly apartments, and ethnic groceries in the Baltimore-Washington metropolitan area.

PARTICIPANTS

Ninety community-dwelling Korean-American individuals aged 60 and older.

MEASUREMENTS

The CDR is a standardized clinical dementia staging instrument used to assess cognitive and functional performance using a semistructured interview protocol. Six CHWs trained and certified as CDR raters interviewed and rated study participants. A bilingual geriatric psychiatrist evaluated participants independently for dementia status.

RESULTS

CHWs rated 61.1% of the participants as having mild cognitive impairment (MCI; CDR = 0.5) or dementia (CDR≥1), versus 56.7% diagnosed by the clinician. A receiver operating characteristic (ROC) curve analysis demonstrated good predictive ability of CDR rating by trained CHWs (area under the ROC curve = 0.86, 95% confidence interval = 0.78-0.93, sensitivity = 85.5%, specificity = 88.6%) in detecting MCI and dementia.

CONCLUSION

The findings provide preliminary evidence that trained CHWs can effectively identify community-dwelling elderly Korean adults with MCI and dementia for early follow-up assessment and care in a community with scarce bilingual caregivers and programs.

Clock drawing test in elderly individuals with different education levels: correlation with clinical dementia rating

OBJECTIVE

The aim of this study was to describe the performance in Clock Drawing Test (CDT) of the elderly individuals assessed in a geriatric clinic, with at least 1 year of schooling, comparing with other groups with higher education and with Clinical Dementia Rating (CDR) levels. The study also aims to correlate the results of CDT and other used diagnostic tests for dementia by CDR levels, providing additional validity evidence to the CDT.

METHODS

Cross-sectional study with 426 elderly individuals, >60 years old and at least 1 year of education. All participants searched for medical assistance at Geriatric and Gerontology Ambulatory of Jundiaí city, in Brazil. The community-dwelling outpatients previously undergone a detailed clinical examination and neuropsychological evaluation: Cambrigde Cognitive Examination (CAMCOG), Mini-Mental State Examination (MMSE), andCDT. To differentiate data from diagnostic groups based on CDR, it Kruskal-Wallis test was used. Pearson statistics were calculated to compare data from CDT and CDR. The statistical analyses were 2-tailed and were considered significant when P < .05.

RESULTS

Regarding CDT, groups with more years of schooling showed similar means in CDR = 0 and CDR = 0.5 and in CDR = 1 and CDR = 2. Shulman and Sunderland scale were high score in groups with more years of education and above of cutoff points in all CDT score. On the contrary, in Mendez scale we did not observed similar means. Otherwise, in the group with less years of schooling greater means differences in the CDT were observed.

CONCLUSION

The CDT did not show a strong correlation with MMSE and CAMCOG, both important instruments in Brazilian population to investigate dementia. For elderly individuals with high education levels, the CDT did not seem to be a good test to detect cognitive impairment.

Cognitive test performance predicts change in functional status at the population level: the MYHAT Project

In the community at large, many older adults with minimal cognitive and functional impairment remain stable or improve over time, unlike patients in clinical research settings, who typically progress to dementia. Within a prospective population-based study, we identified neuropsychological tests predicting improvement or worsening over 1 year in cognitively driven everyday functioning as measured by Clinical Dementia Rating (CDR). Participants were 1682 adults aged 65+ and dementia-free at baseline. CDR change was modeled as a function of baseline test scores, adjusting for demographics. Among those with baseline CDR = 0.5, 29.8% improved to CDR = 0; they had significantly better baseline scores on most tests. In a stepwise multiple logistic regression model, tests which remained independently associated with subsequent CDR improvement were Category Fluency, a modified Token Test, and the sum of learning trials on Object Memory Evaluation. In contrast, only 7.1% with baseline CDR = 0 worsened to CDR = 0.5. They had significantly lower baseline scores on most tests. In multiple regression analyses, only the Mini-Mental State Examination, delayed memory for visual reproduction, and recall susceptible to proactive interference, were independently associated with CDR worsening. At the population level, changes in both directions are observable in functional status, with different neuropsychological measures predicting the direction of change.

Requiring an amyloid-beta1-42 biomarker for prodromal Alzheimer's disease or mild cognitive impairment does not lead to more efficient clinical trials

BACKGROUND

Low cerebrospinal fluid (CSF) amyloid-beta(1-42) concentration and high total-tau/Abeta(1-42) ratio have been recommended to support the diagnosis of prodromal Alzheimer's disease (AD) in patients with amnestic mild cognitive impairment (aMCI) and also to select patients for clinical trials (Shaw et al, Ann Neurol 2009;65:403-13; Dubois et al, Lancet Neurol 2007;6:734-46).

METHODS

We tested this recommendation with clinical trials simulations using patients from the Alzheimer Disease Neuroimaging Initiative who fulfilled the following entry criteria: (1) aMCI, (2) aMCI with CSF Abeta(1-42) 0.39. For each criterion, we randomly resampled the database obtaining samples for 1000 trials for each trial scenario, planning for 1 or 2 year trials with samples from 50 to 400 patients per treatment or placebo group, with up to 40% dropouts, outcomes after using the AD assessment scale-cognitive subscale and clinical dementia rating scale with effect sizes ranging from 0.15 to 0.75, and calculated statistical power.

FINDINGS

Approximately 70% to 74% of aMCI patients with CSF measures met biomarker criteria. The addition of the low Abeta(1-42) or high tau/Abeta(1-42) requirement resulted in minimal or no increase in the power of the trials compared with enrolling aMCI without requiring the biomarker criteria. Slightly larger mean differences between the placebo and treatment groups fulfilling biomarker criteria were offset by increased outcome variability within the groups.

INTERPRETATIONS

Although patients with aMCI or patients with prodromal AD meeting CSF biomarkers criteria were slightly more cognitively impaired and showed greater decline than patients with aMCI diagnosed without considering the biomarkers, the requirement of biomarker-positive patients would most likely not result in more efficient clinical trials, and trials would take longer because fewer patients would be available. A CSF Abeta(1-42) marker, however, could be useful as an explanatory variable or covariate when warranted by the action of a drug.