Neuropsychological Markers of Progression From Mild Cognitive Impairment to Alzheimer’s Disease (original) (raw)

Mild cognitive impairment: a risk indicator of later dementia, or a preclinical phase of the disease?

International Journal of Geriatric Psychiatry, 2008

Objectives The proposals for classifying the transitional range between normal, ageing-associated cognitive dysfunctions and those suggestive of evolution towards dementia do not clarify whether the profiles are risk indicators of later cognitive impairment or represent preclinical phases of dementia. Methods Retrospective study of the baseline neuropsychological performance of ten subjects with subjective complaints of memory loss which evolved to dementia within 2 years and who meet clinical and neurological diagnosis for Probable Alzheimer's Disease (Progression group). They were compared with 34 normal subjects (Normative group), 33 patients with subjective complaints of memory who in 2 year did not evolve towards dementia and presented a stable profile (Stable group), and 47 Alzheimer's patients (Alzheimer group). A broad neuropsychological battery was administered to assess a range of cognitive functions. Results The Progression group presented a globally poor baseline neuropsychological performance, except in Working Memory, with clear deficits in Episodic Memory and Visual Memory. In the logistic regression analysis, Delayed Verbal Memory was significant as prognostic value for 80 Á 5% of cases. Conclusion Deficit on Episodic and Visual Memory at least 1.5 SD below T ¼ 50 are preclinical manifestations of dementia in subjects with complain of memory loss. The use of broad neuropsychological batteries and the quantitative assessment of deficits is essential to identify and predict the risk of dementia.

Neuropsychological Prediction of Conversion to Alzheimer Disease in Patients With Mild Cognitive Impairment

Archives of General Psychiatry, 2006

Background: Verbal memory impairment, one of the earliest signs of Alzheimer's disease (AD), may help identify people with cognitive impairment, insufficient for a diagnosis of dementia (questionable dementia: QD), at risk of developing AD. Other cognitive parameters have been found that may indicate which people with QD will go on to develop dementia. Nevertheless, some researchers have reported only partial success in differentiating between mild AD and age related cognitive impairment. Objectives: To discover if there are early, pre-clinical cognitive markers that could help identify patients attending our memory clinic who were at risk of developing dementia. Methods: Multidisciplinary assessment of a consecutive sample of 195 patients with QD seen in a National Health Service hospital outpatient clinic; 135 seen for a mean follow up of 24.5 months. Results: Conversion rate to dementia was 27.4% (37 of 135). A diagnosis of probable or possible AD was made in 15.6% (21 of 135) of cases. Despite statistically significant differences in some cognitive tasks between those who did and those who did not go on to dement, Cox regression analyses failed to improve prediction rates markedly above base rates and were unstable. Conclusion: A large number of studies claim good prediction of conversion to dementia using cognitive test scores. Although this study produced similarly good sensitivity and specificity values, proper consideration of the statistical analyses and their clinical significance suggested that these prediction methods are currently too imprecise for clinical use. Use of cognitive indicators combined with neuroradiological, neuropathological, and genetic factors for predicting conversion to dementia might prove more reliable but may be beyond the scope of many geriatric services.

Mild Cognitive Impairment and its Diagnosis to Progression to Dementia with Several Screening Measures

The Open Psychology Journal, 2018

Background:Mild Cognitive Impairment (MCI) is the stage of an individual’s life in which there can be traced a slight amount of decline in cognitive functioning that comprised of memory and thinking skills. This decay in cognitive functioning does not affect the daily functioning of a patient’s life as it happens in the case of dementia.Objective:To review various forms of screening test measures to assess mild cognitive impairment and its extension towards the gradual onset towards the severe cognitive dysfunctioning such as dementia.Method:There are certain functional impairments that are identical to each other. As far as memory and thinking abilities are concerned, its range may vary from minimal to mild that remains quite unnoticed by the person.Results:Presently, the impact of medication is not so effective for MCI. Regular practices of exercises, mind activity and social involvement may help in decreasing risk of further cognitive function decline. Patients with MCI may carry...

Neuropsychological predictors of conversion to probable Alzheimer disease in elderly with mild cognitive impairment

Journal of Neuropsychology, 2015

In the field of neuropsychology, it is essential to determine which neuropsychological tests predict Alzheimer's disease (AD) in people with mild cognitive impairment (MCI) and which cut-off points should be used to identify people at greater risk for converting to dementia. The aim of the present study was to analyse the predictive value of the cognitive tests included in a neuropsychological battery for conversion to AD among MCI participants and to analyse the influence of some sociodemographic variables - sex, age, schooling - and others, such as follow-up time and emotional state. A total of 105 participants were assessed with a neuropsychological battery at baseline and during a 3-year follow-up period. For the present study, the data were analysed at baseline. During the follow-up period, 24 participants (22.85%) converted to dementia (2.79 ± 1.14 years) and 81 (77.14%) remained as MCI. The logistic regression analysis determined that the long delay cued recall and the performance time of the Rey figure test were the best predictive tests of conversion to dementia after an MCI diagnosis. Concerning the sociodemographic factors, sex had the highest predictive power. The results reveal the relevance of the neuropsychological data obtained in the first assessment. Specifically, the data obtained in the episodic verbal memory tests and tests that assess visuospatial and executive components may help to identify people with MCI who may develop AD in an interval not longer than 4 years, with the masculine gender being an added risk factor.

Mild Cognitive Impairment Represents Early-Stage Alzheimer Disease

Archives of Neurology, 2001

Background: Mild cognitive impairment (MCI) is considered to be a transitional stage between aging and Alzheimer disease (AD). Objective: To determine whether MCI represents earlystage AD by examining its natural history and neuropathologic basis. Design: A prospective clinical and psychometric study of community-living elderly volunteers, both nondemented and minimally cognitively impaired, followed up for up to 9.5 years. Neuropathologic examinations were performed on participants who had undergone autopsy. Setting: An AD research center. Participants: All participants enrolled between July 1990 and June 1997 with Clinical Dementia Rating (CDR) scores of 0 (cognitively healthy; n = 177; mean age, 78.9 years) or 0.5 (equivalent to MCI; n=277; mean age, 76.9 years). Based on the degree of clinical confidence that MCI represented dementia of the Alzheimer type (DAT), 3 subgroups of individuals with CDR scores of 0.5 were identified: CDR 0.5/DAT, CDR 0.5/incipient DAT, and CDR 0.5/uncertain dementia. Main Outcome Measure: Progression to the stage of CDR 1, which characterizes mild definite DAT. Results: Survival analysis showed that 100% of CDR 0.5/ DAT participants progressed to greater dementia severity over a 9.5-year period. At 5 years, rates of progression to a score of CDR 1 (or greater) for DAT were 60.5% (95% confidence interval [CI], 50.2%-70.8%) for the CDR 0.5/DAT group, 35.7% (95% CI, 21.0%-50.3%) for the CDR 0.5/incipient DAT group, 19.9% (95% CI, 8.0%-31.8%) for the CDR 0.5/uncertain dementia group, and 6.8% (95% CI, 2.2%-11.3%) for CDR 0/controls. Progression to greater dementia severity correlated with degree of cognitive impairment at baseline. Twenty-four of the 25 participants with scores of CDR 0.5 had a neuropathologic dementing disorder, which was AD in 21 (84%). Conclusions: Individuals currently characterized as having MCI progress steadily to greater stages of dementia severity at rates dependent on the level of cognitive impairment at entry and they almost always have the neuropathologic features of AD. We conclude that MCI generally represents early-stage AD.

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.

Neuropsychological Predictors of Conversion from Mild Cognitive Impairment to Alzheimer's Disease

Journal of Alzheimer's disease: JAD

The construct of mild cognitive impairment (MCI) has been proposed to identify patients at risk of developing Alzheimer's disease (AD) in the pre-clinical stage. Although subjects with MCI have an increased risk of progressing to dementia, most remain stable or return to normality. The new criteria for diagnosing prodromal AD assume that, to increase the predictive value of the MCI, in addition to a defect of delayed recall there must also be the presence of abnormal biomarkers, investigating structural and molecular neuroimaging and cerebrospinal fluid (CSF) analysis of amyloid-β or tau proteins. Although acknowledging that the use of CSF degeneration biomarkers is advisable not only for research, but also for clinical purposes, the present review is centered upon the neuropsychological markers of conversion to AD, which are equally clinically important. In particular, results of this review suggest the following: (a) measures of delayed recall are the best neuropsychological p...

[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.

[Differentiation between mild cognitive impairment and healthy elderly population using neuropsychological tests]

Neuropsychopharmacologia Hungarica : a Magyar Pszichofarmakológiai Egyesület lapja = official journal of the Hungarian Association of Psychopharmacology, 2013

Paired Associates Learning (PAL) test assesses brain functions in those brain regions affected earliest by Alzheimer's dementia. The aim of the present study was to assess the usability of our implementation of the PAL test for screening mild cognitive impairment. Based on Petersen criteria, 14 out of the 63 subjects were diagnosed with mild cognitive impairment. Visuospatial learning was assessed by our implementation of PAL test. The ability of the PAL test to differentiate between study groups was compared to the Addenbrook Cognitive Examination (ACE) and to the Mini Mental State Examination (MMSE). Linear logistic regression was used for statistical analysis, and the results are presented as Receiver Operating Characteristics (ROC) curves. All analyses were performed by SAS 9.2. All the results of neuropsychological tests differed significantly between the study groups. However, considerable difference could be detected between the tests regarding specificity and sensitivity...