Assessment of cognition in mild cognitive impairment: A comparative study (original) (raw)

[O2‐05‐01]: Methods to improve the detection of mild cognitive impairment

Alzheimer's & Dementia, 2005

We examined whether the performance of the National Institute of Aging's Consortium to Establish a Registry for Alzheimer's Disease's 10-word list (CWL), part of the consortium's neuropsychological battery, can be improved for detecting Alzheimer's disease and related disorders early. We focused on mild cognitive impairment (MCI) and mild dementia because these stages often go undetected, and their detection is important for treatment. Using standardized diagnostic criteria combined with history, physical examination, and cognitive, laboratory, and neuroimaging studies, we staged 471 community-dwelling subjects for dementia severity by using the Clinical Dementia Rating Scale. We then used correspondence analysis (CA) to derive a weighted score for each subject from their item responses over the three immediate-and one delayed-recall trials of the CWL. These CA-weighted scores were used with logistic regression to predict each subject's probability of impairment, and receiver operating characteristic analysis was used to measure accuracy. For MCI vs. normal, accuracy was 97% [confidence interval (C.I.) 97-98%], sensitivity was 94% (C.I. 93-95%), and specificity was 89% (C.I. 88-91%). For MCI͞mild dementia vs. normal, accuracy was 98% (C.I. 98-99%), sensitivity was 96% (C.I. 95-97%), and specificity was 91% (C.I. 89-93%). MCI sensitivity was 12% higher (without lowering specificity) than that obtained with the delayed-recall total score (the standard method for CWL interpretation). Optimal positive and negative predictive values were 100% and at least 96.6%. These results show that CA-weighted scores can significantly improve early detection of Alzheimer's disease and related disorders.

Assessing the progression of mild cognitive impairment to Alzheimer's disease: current trends and future directions

2010

clinical diagnosis of probable Alzheimer's disease (AD), fi rst established over 25 years ago, was the requirement of a dementia syndrome. Th e clinician then proceeded to systematically rule out and exclude other neurological and/or medical conditions that might have accounted for the observed cognitive decline. Th is set of criteria as well as the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) criteria for a dementia syndrome and probable AD [1] were designed to be conservative so that a neurodegenerative condition could not be established unless cognitive function was sufficiently compromised to interfere with an individual's social and/or occupational function.

Methods to improve the detection of mild cognitive impairment

Proceedings of The National Academy of Sciences, 2005

We examined whether the performance of the National Institute of Aging's Consortium to Establish a Registry for Alzheimer's Disease's 10-word list (CWL), part of the consortium's neuropsychological battery, can be improved for detecting Alzheimer's disease and related disorders early. We focused on mild cognitive impairment (MCI) and mild dementia because these stages often go undetected, and their detection is important for treatment. Using standardized diagnostic criteria combined with history, physical examination, and cognitive, laboratory, and neuroimaging studies, we staged 471 community-dwelling subjects for dementia severity by using the Clinical Dementia Rating Scale. We then used correspondence analysis (CA) to derive a weighted score for each subject from their item responses over the three immediate-and one delayed-recall trials of the CWL. These CA-weighted scores were used with logistic regression to predict each subject's probability of impairment, and receiver operating characteristic analysis was used to measure accuracy. For MCI vs. normal, accuracy was 97% [confidence interval (C.I.) 97-98%], sensitivity was 94% (C.I. 93-95%), and specificity was 89% (C.I. 88 -91%). For MCI͞mild dementia vs. normal, accuracy was 98% (C.I. 98 -99%), sensitivity was 96% (C.I. 95-97%), and specificity was 91% (C.I. 89 -93%). MCI sensitivity was 12% higher (without lowering specificity) than that obtained with the delayed-recall total score (the standard method for CWL interpretation). Optimal positive and negative predictive values were 100% and at least 96.6%. These results show that CA-weighted scores can significantly improve early detection of Alzheimer's disease and related disorders.

Development of a rapid screening instrument for mild cognitive impairment and undiagnosed dementia

Journal of Alzheimer's disease : JAD, 2008

Mild cognitive impairment (MCI) often presages development of Alzheimer's disease (AD). We recently completed a cross-sectional study to test the hypothesis that a combination of a brief cognitive screening instrument (Mini-Cog) with a functional scale (Functional Activities Questionnaire; FAQ) would accurately identify individuals with MCI and undiagnosed dementia. The Mini-Cog consists of a clock drawing task and 3-item recall, and takes less than 5 minutes to administer. The FAQ is a 30-item questionnaire completed by an informant. In addition to the Mini-Cog and FAQ, a traditional cognitive test battery was administered, and two neurologists and a neuropsychologist determined a consensus diagnosis of Normal, MCI, or Dementia. A classification tree algorithm was used to pick optimal cutpoints, and, using these cutpoints, the combined Mini-Cog and FAQ (MC-FAQ) predicted the consensus diagnosis with an accuracy of 83% and a weighted kappa of 0.81. When the population was divide...

Validation of Brain Health Test-7 for Detecting Patients with Mild Cognitive Impairment and Early Dementia

Taiwanese Journal of Psychiatry

Objectives: We intended to develop a simple dementia screening tool to help primary care physicians identify patients with mild cognitive impairment (MCI) and early dementia. Methods: The brain health test-7 (BHT-7) was developed based on the original BHT study. Study patients aged 50 years and above with normal cognition, MCI, and dementia were recruited. All patients received evaluation with the BHT-7, mini-mental state examination (MMSE), Montreal cognitive assessment (MoCA), and clinical dementia rating (CDR) for cognitive function. The performance of BHT-7 in identifying cognitive impairment was compared with that of MMSE and MoCA. Results: We enrolled 376 study participants. The mean BHT-7, MMSE, and MoCA scores showed significant differences among the three groups. Compared to MMSE and MoCA, the BHT-7 (sensitivity = 86%, specificity = 76%, area under curve = 88%) showed better sensitivity in differentiating MCI from the normal group, with a cutoff value of 17/18. The scores of the three tests were all affected by educational level. Conclusion: The BHT-7 is a simple and easy-to-use cognitive screening tool that may be useful in primary care settings to identify patients with MCI or early dementia.

Neuropsychological Markers of Progression From Mild Cognitive Impairment to Alzheimer’s Disease

American Journal of Alzheimers Disease and Other Dementias, 2006

To find early clinical markers that may predict a likely progression to Alzheimer's disease (AD), the authors performed neuropsychological tests on 82 mild cognitive impairment (MCI) subjects. After 3 years, 38 patients developed AD while 44 retained the diagnosis of MCI. The cognitive differences between the groups were studied. Patients who developed AD showed significantly lower values than did MCI subjects in some neuropsychological scores (P = .02-.001), with sensitivities and specificities higher than 84% and 64%, respectively, for detecting early-onset AD, with a 7.9-fold increased risk of converting to AD (P < .001). Regarding the logistic regression model, the CAMCOG Memory and Perception cognitive screening items were the optimum independent tools to classify the patients who will progress to AD, showing a relative risk of progression of 10.5 (P = .002), 5.5 (P = .008), and 3.9 times (P = .05), respectively, with a sensibility of of 92.1% and a specificity 72.7% .

Predicting outcome in mild cognitive impairment: 4-year follow-up study

The British Journal of Psychiatry, 2010

Background Cognitive impairment precedes the diagnosis of Alzheimer's disease. It is unclear which psychometric measures predict dementia, and what cut-off points should be used. Replicable cognitive measures to provide information about differential diagnosis and prognosis would be clinically useful. Aims In a prospective cohort study we investigated which measures distinguish between individuals with amnestic mild cognitive impairment (aMCI) that converts to dementia and those whose impairment does not, and which combination of measures best predicts the fate of people with aMCI. Method Forty-four participants with aMCI underwent extensive neuropsychological assessment at baseline and annually thereafter for an average of 4 years. Differences in baseline cognitive performance of participants who were converters and non-converters to clinically diagnosed dementia were analysed. Classification accuracy was estimated by sensitivity, specificity, positive and negative predictive v...

The Utility of the Dementia Severity Rating Scale in Differentiating Mild Cognitive Impairment and Alzheimer Disease From Controls

Alzheimer disease and associated disorders, 2014

The current study investigated the utility of the Dementia Severity Rating Scale (DSRS) total score to identify individuals at the earliest stage of impairment (ie, mild cognitive impairment/MCI). In addition, the authors sought to investigate how well the measure correlates with an expanded battery of cognitive tests and other measures of functional abilities. Of the 320 participants included in this study, 85 were normal controls, 96 had single-domain or multiple-domain amnestic MCI, and 139 had possible or probable Alzheimer disease (AD). Each participant underwent a thorough cognitive, neurological, and physical examination. Results from this study indicated that the DSRS total scores differed significantly between the 3 groups (P<0.001) and accurately identified 81% of the control group, 60% of the MCI group, and 78% of the AD group in a post hoc discriminant analysis. When combined with a brief cognitive measure (ie, Consortium to Establish a Registry for Alzheimer's Di...

Diagnostic accuracy of early cognitive indicators in mild cognitive impairment

Dementia & Neuropsychologia

The aging of the population leads to an increase in the prevalence of dementia and mild cognitive impairment (MCI). Alzheimer's disease (AD) is the most common cause of dementia. Recent studies highlight the early non-amnestic deficits in AD and MCI. The European Union report shows the importance of thoroughly assessing cognitive aspects that have been poorly evaluated, such as processing speed (PS), which could represent early indicators of cognitive decline. Objective: To analyze the diagnostic accuracy of PS measures in older adults with MCI, AD, and those who are cognitively-healthy. Methods: A cross-sectional study was conducted by performing an extensive neuropsychological assessment in three samples: 26 control participants, 22 individuals with MCI, and 21 individuals with AD. Analysis of variance (ANOVA) was employed to test the relationship between dependent variables and the clinical group. Post hoc tests (Bonferroni test) were used when a significant ANOVA result was ...