A longitudinal study of cognitive function in elderly persons with subjective memory complaints

Are subjective language complaints in memory clinic patients informative?

To diagnose mild cognitive impairment, it is crucial to understand whether subjective cognitive complaints reflect objective cognitive deficits. This question has mostly been investigated in the memory domain, with mixed results. Our study was one of the first to address it for language. Participants were 55-to-93-year-old memory clinic patients (n = 163). They filled in a questionnaire about subjective language and memory complaints and performed two language tasks (naming-by-definition and sentence comprehension). Greater language complaints were associated with two language measures, thus showing a moderate value in predicting language performance. Greater relative severity of language versus memory complaints was a better predictor, associated with three language performance measures. Surprisingly, greater memory complaints were associated with better naming, probably due to anosognosia in further disease progression or personality-related factors. Our findings highlight the importance of relative complaint severity across domains and, clinically, call for developing self-assessment questionnaires asking specific questions about multiple cognitive functions.

Paradoxical relationship between subjective and objective cognition: the role of sleep

STUDY OBJECTIVES

Subjective memory complaints and objective cognitive dysfunction are common in aging populations, however research investigating the associations between them is inconclusive. Given the high prevalence of sleep complaints in middle-aged/older adults, this research tested whether objective cognition interacted with sleep parameters in its associations with subjective cognition.

METHODS

Cognitively healthy adults aged 50+ completed the Pittsburgh Sleep Quality Index, Cognitive Failures Questionnaire (CFQ) and cognitive tasks: Stroop, Sternberg, and Posner cueing. Multiple regression and simple slope analyses examined whether objective cognition interacted with sleep parameters in its associations with subjective memory.

RESULTS

Stroop performance and sleep (efficiency and disturbances) had interactive associations with CFQ-memory. Specifically, better Stroop performance (faster reaction time, RT-control trials) was associated with more memory complaints at worst and average, but not best sleep efficiency. Additionally, faster RT was associated with more memory complaints only for worst sleep disturbance. Similarly, Sternberg performance and sleep (efficiency and disturbances) had interactive associations with CFQ-memory. Specifically, higher proportion correct was associated with more memory complaints only at worst sleep efficiency and sleep disturbance. Finally, Posner performance and sleep disturbance had an interactive association with CFQ-memory. Faster exogenous orienting was associated with more memory complaints only for worst sleep disturbance.

CONCLUSIONS

Objective cognition interacts with sleep efficiency and sleep disturbances in its associations with subjective memory in mid-to-late life. Findings suggest sleep fragmentation plays a role in the discrepant relationship between objective and subjective cognition. Future studies should investigate this relationship in aging populations with sleep disorders and/or cognitive impairments.

Dementia-Free Older Adults with Subjective Cognitive Impairment Show Lower Mood and No Deficits of Spontaneous Memory Retrieval

The aim of the present study was to investigate whether spontaneous retrieval deficits could be found in individuals with Subjective Cognitive Impairment (SCI). The sample consisted of 52 participants over 65 years of age (mean age = 76.00; SD = 7.48) with 11 males. We asked 26 individuals with SCI and 26 individuals without SCI to perform a prospective memory (PM) task that had previously demonstrated spontaneous retrieval deficits in individuals with Mild Cognitive Impairment. The results did not demonstrate the expected differences in a PM task based on spontaneous retrieval [t(50) = -.05; p = .964, d = .01]. However, participants' mood did predict their subjective memory complaints (β = -.51; p < .001) and their subjective assessment of their future memory performance (r = -.38; p < .01). The findings are in line with numerous studies which have shown that SCI is more related to mood disturbance than to objective cognitive functioning.

Adaptation and Validation of the Memory Alteration Test (M@T) in Greek Middle-Aged, Older, and Older-Old Population with Subjective Cognitive Decline and Mild Cognitive Impairment

BACKGROUND

The Memory Alteration Test (M@T) is a verbal episodic and semantic memory screening test able to detect subjective cognitive decline (SCD) and Mild Cognitive Impairment (MCI).

OBJECTIVE

To adapt M@T, creating a Greek version of the Memory Alteration Test (M@T-GR), and to validate M@T-GR compared to the Mini-Mental State Examination (MMSE), and Subjective Cognitive Decline- Questionnaire (SCD-Q) MyCog and TheirCog.

METHODS

232 people over 55 years old participated in the study and they were classified as healthy controls (HC, n = 65), SCD (n = 78), or MCI (n = 89).

RESULTS

The ANCOVA showed that the M@T-GR's total score was significantly different in HC and SCD (I-J = 2.26, p = 0.032), HC and MCI (I-J = 6.16, p < 0.0001), and SCD compared to MCI (I-J = 3.90, p < 0.0001). In particular, a cut-off score of 46.50 points had an 81%sensitivity and 61%specificity for discriminating HC from SCD (AUC = 0.76, p < 0.0001), while a cut-off score of 45.50 had a sensitivity of 92%and a specificity of 73%for discriminating MCI (AUC = 0.88, p < 0.0001), and a cut-off score of 45.50 points had a sensitivity of 63%and a specificity of 73%for discriminating SCD from those with MCI (AUC = 0.69, p < 0.0021). Exploratory factor analysis indicated that there was one factor explaining 38.46%of the total variance. Internal consistency was adequate (α= 0.75), while convergent validity was found between M@T-GR and MMSE (r = 0.37, p < 0.0001) and SCD-Q TheirCog (r = -0.32, p < 0.0001).

CONCLUSION

The M@T-GR is a good to fair screening tool with adequate discriminant validity for administration in people with SCD and MCI in Greece.

Functional cognitive disorders: a systematic review

Cognitive symptoms are common, and yet many who seek help for cognitive symptoms neither have, nor go on to develop, dementia. A proportion of these people are likely to have functional cognitive disorders, a subtype of functional neurological disorders, in which cognitive symptoms are present, associated with distress or disability, but caused by functional alterations rather than degenerative brain disease or another structural lesion. In this Review, we have systematically examined the prevalence and clinical associations of functional cognitive disorders, and related phenotypes, within the wider cognitive disorder literature. Around a quarter of patients presenting to memory clinics received diagnoses that might indicate the presence of functional cognitive disorders, which were associated with affective symptoms, negative self-evaluation, negative illness perceptions, non-progressive symptom trajectories, and linguistic and behavioural differences during clinical interactions. Those with functional cognitive disorder phenotypes are at risk of iatrogenic harm because of misdiagnosis or inaccurate prediction of future decline. Further research is imperative to improve diagnosis and identify effective treatments for functional cognitive disorders, and better understanding these phenotypes will also improve the specificity of diagnoses of prodromal degenerative brain disease.

Is brain connectome research the future frontier for subjective cognitive decline? A systematic review

OBJECTIVE

We performed a systematic literature review on Subjective Cognitive Decline (SCD) in order to examine whether the resemblance of brain connectome and functional connectivity (FC) alterations in SCD with respect to MCI, AD and HC can help us draw conclusions on the progression of SCD to more advanced stages of dementia.

METHODS

We searched for studies that used any neuroimaging tool to investigate potential differences/similarities of brain connectome in SCD with respect to HC, MCI, and AD.

RESULTS

Sixteen studies were finally included in the review. Apparent FC connections and disruptions were observed in the white matter, default mode and gray matter networks in SCD with regards to HC, MCI, and AD. Interestingly, more apparent connections in SCD were located over the posterior regions, while an increase of FC over anterior regions was observed as the disease progressed.

CONCLUSIONS

Elders with SCD display a significant disruption of the brain network, which in most of the cases is worse than HC across multiple network parameters.

SIGNIFICANCE

The present review provides comprehensive and balanced coverage of a timely target research activity around SCD with the intention to identify similarities/differences across patient groups on the basis of brain connectome properties.

Neurocognitive Disorders: Importance of Early/Timely Detection in Daily Clinical Practice

Neurocognitive disorders create important challenges for patients, their families, and clinicians who provide their health care. Early/timely detection in daily clinical practice allows for diagnosis and adequate treatment, psychosocial support, education, and engagement in shared decision-making related to health care, life planning, involvement in research, and financial matters. However, neurocognitive disorders, when present, are not detected or not diagnosed and not documented, in more than half of patients seen by primary care physicians. The aim of this paper is to highlight the strategies and the perspectives to improve the early/timely detection of neurocognitive disorders in daily clinical practice.

Memory and Confusion Complaints in Visually Impaired Older Adults: An Understudied Aspect of Well-Being

Objective: To determine the prevalence of cognitive (memory or confusion) complaints in older adults with visual impairment (VI). Method: We assessed the relationship between VI (corrected visual acuity [VA] < 20/40) and self-reported confusion or problems with memory among participants aged 60 years to 85 years in the 1999-2006 cycles of National Health and Nutrition Examination Survey (n = 5,795). Prevalence estimates of cognitive complaints were calculated using Current Population Surveys. Results: Memory/confusion complaints were reported in 22% of the VI group and 11% of the no VI group (p < .001). In individuals aged ≥ 80 years, 30% of those with VI reported cognitive complaints, as compared with 19% with no VI (p = .003). In fully adjusted models, individuals with VI were more likely (OR = 1.3, p = .049) to report cognitive complaints as compared with those without VI. Conclusion: Subjective reports of memory or confusion are highly prevalent in older individuals with VI.

What are subjective cognitive difficulties and do they matter?

Background

subjective cognitive difficulties (SCD) have been associated with a higher risk of developing dementia. However, there is large variation in the way SCD are assessed and in their associations with cognitive functioning.

Objective

to compare the agreement of different SCD measures in identifying people with SCD and to investigate whether SCD are more strongly associated with cognitive functioning, mood, subjective age or background variables.

Methods

this cross-sectional study included 206 community-dwelling people aged ≥65. SCD were assessed with individual domain specific questions and a multiple-item scaled measure. Performance on tests of memory, attention, and executive function, and ratings of mood, subjective age and demographic information were recorded.

Results

there was some classification overlap between the five measures of SCD, however of the 64 people identified as having SCD, only one person appeared in all five measures of SCD and 34 people were classified by one measure only. There were limited associations between SCD and objective cognition, with more consistent associations with mood and subjective age.

Conclusions

the conflicting evidence regarding whether SCD are related to objective cognition and future risk of dementia may be due to different measures of SCD being employed. Careful consideration and standardisation is recommended regarding the cognitive domains and the reference groups for comparison, the response structure and the classification criteria. Longitudinal studies of SCD that include these considerations are needed to clarify the conceptual utility of SCD.

Self-Reported Memory Function and Psychological Well-Being Among Elderly African American Persons

This study examinedthe impact of self-reported memory deficits on psychological well-being among a sample of 998 elderly African American persons. Using multiple regression and employing other related variables (that previously have been identified as common predictors of psychological well-being), the findings of this study suggest that the risk of having a lower level of psychological well-being was greater for persons with more memory problems, even after demographic characteristics, functional limitations, health status, and cognition were included in regression equations. Self-reported memory deficits werefound to be the strongest predictor of psychological well-being. The strength of relationship between self-reported memory deficits and psychological well-being was stronger among women than men.

Informants' Perception of Subjective Cognitive Decline Helps to Discriminate Preclinical Alzheimer's Disease from Normal Aging

BACKGROUND

Self-reported and informant-reported subjective cognitive decline (SCD) may be useful in the detection of preclinical Alzheimer's disease (Pre-AD) and cognitive impairment related to abnormal amyloid-β (Aβ 42) levels.

OBJECTIVES

a) To compare the Subjective Cognitive Decline Questionnaire (SCD-Q) ratings between Pre-AD subjects and cognitively healthy controls, b) to study the association of SCD-Q scores with levels of AD biomarkers in cognitively healthy and cognitively impaired subjects, and c) to compare SCD-Q ratings in cognitively impaired subjects with or without abnormal Aβ 42.

METHODS

Two hundred and seventeen participants (111 subjects; 106 informants) answered the SCD-Q. All subjects underwent a lumbar puncture to determine levels of Aβ 42 and tau, and an extensive neuropsychological battery. Healthy subjects were classified as Controls (CTR) or Pre-AD according to the absence or the presence of abnormal Aβ 42, and those with cognitive impairment (CI) into Non-amyloid (NonAB-CI) or Amyloid (AB-CI) impairment.

RESULTS

Informants' SCD-Q scores were significantly higher in the Pre-AD group than in the CTR group (F = 6.75; p = 0.01). No significant differences were found in self-ratings. In the cognitively impaired groups, there were no significant differences in the SCD-Q ratings. In the whole sample, informants' ratings of SCD-Q correlated with Aβ 42 (r = -0.21; p = 0.02) and tau levels (r = 0.28; p = 0.00).

CONCLUSIONS

Higher informants' ratings of SCD-Q differentiated Pre-AD subjects from CTR. Informants' ratings of SCD-Q correlated weakly with cerebrospinal fluid AD biomarkers.

Pulse Pressure Magnifies the Effect of COMT Val(158)Met on 15 Years Episodic Memory Trajectories

We investigated whether a physiological marker of cardiovascular health, pulse pressure (PP), and age magnified the effect of the functional COMT Val(158)Met (rs4680) polymorphism on 15-years cognitive trajectories [episodic memory (EM), visuospatial ability, and semantic memory] using data from 1585 non-demented adults from the Betula study. A multiple-group latent growth curve model was specified to gauge individual differences in change, and average trends therein. The allelic variants showed negligible differences across the cognitive markers in average trends. The older portion of the sample selectively age-magnified the effects of Val(158)Met on EM changes, resulting in greater decline in Val compared to homozygote Met carriers. This effect was attenuated by statistical control for PP. Further, PP moderated the effects of COMT on 15-years EM trajectories, resulting in greater decline in Val carriers, even after accounting for the confounding effects of sex, education, cardiovascular diseases (diabetes, stroke, and hypertension), and chronological age, controlled for practice gains. The effect was still present after excluding individuals with a history of cardiovascular diseases. The effects of cognitive change were not moderated by any other covariates. This report underscores the importance of addressing synergistic effects in normal cognitive aging, as the addition thereof may place healthy individuals at greater risk for memory decline.

Regional brain shrinkage and change in cognitive performance over two years: The bidirectional influences of the brain and cognitive reserve factors

We examined relationships between regional brain shrinkage and changes in cognitive performance, while taking into account the influence of chronological age, vascular risk, Apolipoprotein E variant and socioeconomic status. Regional brain volumes and cognitive performance were assessed in 167 healthy adults (age 19-79 at baseline), 90 of whom returned for the follow-up after two years. Brain volumes were measured in six regions of interest (ROIs): lateral prefrontal cortex (LPFC), prefrontal white matter (PFw), hippocampus (Hc), parahippocampal gyrus (PhG), cerebellar hemispheres (CbH), and primary visual cortex (VC), and cognitive performance was evaluated in three domains: episodic memory (EM), fluid intelligence (Gf), and vocabulary (V). Average volume loss was observed in Hc, PhG and CbH, but reliable individual differences were noted in all examined ROIs. Average positive change was observed in EM and V performance but not in Gf scores, yet only the last evidenced individual differences in change. We observed reciprocal influences among neuroanatomical and cognitive variables. Larger brain volumes at baseline predicted greater individual gains in Gf, but differences in LPFC volume change were in part explained by baseline level of cognitive performance. In one region (PFw), individual change in volume was coupled with change in Gf. Larger initial brain volumes did not predict slower shrinkage. The results underscore the complex role of brain maintenance and cognitive reserve in adult development.

Subjective memory complaints, cortical thinning, and cognitive dysfunction in middle-aged adults at risk for AD

Background

Subjective memory complaints (SMCs) represent an individual's perception of subtle changes in memory in the absence of objective impairment in memory. However, it is not fully known whether persons with SMCs harbor brain alterations related to Alzheimer's disease (AD) or whether they indeed demonstrate poorer cognitive performance.

Methods

The participants were 261 middle-age adults (mean age 54.30 years) enrolled in the Wisconsin Registry for Alzheimer's Prevention, a registry of cognitively normal adults at risk of AD. They answered a question pertaining to subjective memory, completed a comprehensive neuropsychological examination, and subsequently underwent a volumetric magnetic resonance imaging scan. Cortical thickness measurements were derived from 10 a priori regions of interest involved in AD. Analyses of covariance were conducted to investigate the group differences in cortical thickness and neuropsychological measures.

Results

Compared with individuals without SMCs, those with SMCs had significant cortical thinning in the entorhinal, fusiform, posterior cingulate, and inferior parietal cortices and significantly reduced amygdala volume. Similarly, those with SMCs had significantly lower test scores on measures of Immediate Memory, Verbal Learning & Memory, and Verbal Ability. Additional adjustment for depressive symptoms (which differed between the groups) attenuated only the findings for the entorhinal cortex (P = .061) and Verbal Ability (P = .076).

Conclusion

At-risk, cognitively healthy individuals with SMCs exhibit cortical thinning in brain regions affected by AD and poorer performance on objective memory tests. These findings suggest that, in some individuals, SMCs might represent the earliest stages of AD.

Risk of dementia and mild cognitive impairment in older people with subjective memory complaints: meta-analysis

OBJECTIVE

To investigate whether people with subjective memory complaints (SMC) but no objective deficits are at increased risk of developing mild cognitive impairment (MCI) and dementia.

METHOD

Major electronic databases were searched till 03/2014, and a meta-analysis was conducted using inception cohort studies.

RESULTS

Across 28 studies, there were 29,723 unique individuals (14,714 with SMC and 15,009 without SMC) (mean 71.6 years) followed on average for 4.8 years through to dementia. The annual conversion rate (ACR) of SMC to dementia was 2.33% (95% CI = 1.93%-2.78%) a relative risk (RR) of 2.07 (95% CI = 1.76-2.44) compared with those without SMC (n = 15,009). From 11 studies the ACR of developing MCI was 6.67% (95% CI = 4.70-8.95%). In long-term studies over 4 years, 14.1% (9.67-19.1%) of people with SMC developed dementia and 26.6% (95% CI = 5.3-39.7) went on to develop MCI. The ACR from SMC to dementia and MCI were comparable in community and non-community settings.

CONCLUSION

Older people with SMC but no objective complaints are twice as likely to develop dementia as individuals without SMC. Approximately 2.3% and 6.6% of older people with SMC will progress to dementia and MCI per year.

Demographic, clinical, and lifestyle correlates of subjective memory complaints in the Australian population

OBJECTIVES

To provide estimates of the prevalence and correlates of subjective memory complaints in older individuals by using population-based Australian data.

DESIGN

2007 National Survey of Mental Health and Well-Being.

SETTING

Australia.

PARTICIPANTS

1,905 community-dwelling participants aged 65-85 years.

MEASUREMENTS

Subjective memory complaints were assessed by using two questions reflecting: (1) poorer memory compared with others of the same age ("worse memory"); and (2) a decline in memory performance over the previous 5 years ("declining memory"). Twelve-month and lifetime diagnoses were derived from structured diagnostic interviews. Other correlates investigated included chronic physical conditions, lifestyle factors, and service use. Analyses adjusted for scores on the Mini-Mental State Examination.

RESULTS

Subjective memory complaints were reported by one-third (33.5%) of respondents. Those who reported either complaint were more likely to report psychological distress, poor functioning, service use, and negative self-assessed mental and physical health. "Declining memory" over the past 5 years was also related to an increase in the rates of psychiatric disorders. After adjusting for other variables of interest, associations were established between subjective memory complaints and psychological distress, poor functioning, negative self-assessed mental health, and alcohol use disorders. Except for the association between "declining memory" and anxiety and depression, these associations remained significant after excluding those with scores <27 on the Mini-Mental State Examination.

CONCLUSIONS

Subjective memory complaints were associated with several negative clinical characteristics that should be considered when interpreting these complaints. Subjective memory complaints may be valid indicators of psychopathology and the need for clinical assessment.

Age and sex related changes in episodic memory function in middle aged and older adults

Age-related change in episodic memory function is commonly reported in older adults. When detected on neuropsychological tests, it may still be difficult to distinguish normal from pathological changes. The present study investigates age-and sex-related changes in a group of healthy middle-aged and older adults, participating in a three-wave study on cognitive aging. The California Verbal Learning test (CVLT-II) was used to assess their episodic memory function. A cross-sectional analysis of results from the first wave showed higher performance in females than males, with a steeper age-related decline in males. This was confirmed in a longitudinal analysis using a mixed effects regression model, but with a lower age-related change and smaller difference between the sexes. Information about learning strategies and errors in the third wave turned out to contribute significantly to explain change in episodic memory function across the three waves. We argue that the results from the longitudinal analyses are generalizable to the population of healthy middle-aged and older individuals, and that they could be useful in guiding clinicians when evaluating individuals with respect to cognitive change.

Choosing Alzheimer's disease prevention clinical trial populations

To assist investigators in making design choices, we modeled Alzheimer's disease prevention clinical trials. We used longitudinal Clinical Dementia Rating Scale Sum of Boxes data, retention rates, and the proportions of trial-eligible cognitively normal participants age 65 and older in the National Alzheimer's Coordinating Center Uniform Data Set to model trial sample sizes, the numbers needed to enroll to account for drop out, and the numbers needed to screen to successfully complete enrollment. We examined how enrichment strategies affected each component of the model. Relative to trials enrolling 65-year-old individuals, trials enriching for older (minimum 70 or 75) age required reduced sample sizes, numbers needed to enroll, and numbers needed to screen. Enriching for subjective memory complaints reduced sample sizes and numbers needed to enroll more than age enrichment, but increased the number needed to screen. We conclude that Alzheimer's disease prevention trials can enroll elderly participants with minimal effect on trial retention and that enriching for older individuals with memory complaints might afford efficient trial designs.

Association of perceived health and depression with older adults' subjective memory complaints: contrasting a specific questionnaire with general complaints questions

The objectives of this paper were to evaluate the association of subjective memory complaints (SMC) with perceived state of health, mood and episodic memory (associative and everyday memory). We studied these areas using two different complaint assessment methods (three general questions and a validated scale). The study included 269 older adults (aged 65-87) with age-related memory changes, but without cognitive impairment. They were evaluated with Mini-cognitive Exam, Rivermead Behavioural Memory Test (a test of everyday memory), Paired Associates Learning Test, Memory Failures of Everyday Questionnaire, three memory complaints questions, Nottingham Health Profile and Geriatric Depression Scale. The results indicated that memory for everyday performance, mood and perceived health were independent predictors of SMC, with mood and perceived health being stronger predictors than actual memory performance. Age was not associated with subjective memory and, with regard to level of education, only the illiterate level was associated with SMC. A specific questionnaire on subjective memory was found to be preferable to an aggregate of complaints questions on self-reported memory; only health profile was found to predict the outcomes on memory complaints questions. Our conclusion is that a group of underlying factors other than everyday memory were playing a role in SMC; these SMC of subjects with age-related memory changes were mainly associated with subjective evaluations of their health.

Subjective cognitive complaints and amyloid burden in cognitively normal older individuals

Accumulating evidence suggests that subjective cognitive complaints (SCC) may indicate subtle cognitive decline characteristic of individuals with preclinical Alzheimer's disease (AD). In this study, we sought to build upon previous studies by associating SCC and amyloid-β deposition using positron emission tomography with Pittsburgh Compound B (PiB-PET) in cognitively normal older individuals. One-hundred thirty one subjects (mean age 73.5±6) were administered three subjective cognitive questionnaires and a brief neuropsychological battery. A relationship between a subjective memory complaints composite score and cortical PiB binding was found to be significant, even after controlling for depressive symptoms. By contrast, there were no significant relationships between objective cognitive measures of memory and executive functions and cortical PiB binding. Our study suggests that SCC may be an early indicator of AD pathology detectable prior to significant objective impairment.

Where Did I Leave My Keys? A Twin Study of Self-Reported Memory Ratings Using the Multifactorial Memory Questionnaire

Behavior genetics has convincingly shown the importance of genetic factors in objective tests of memory function. However, self-report memory tests have received little attention. This study used items from the Multifactorial Memory Questionnaire (MMQ) to estimate the heritability of self-reported memory contentment and ability in 909 monozygotic (MZ) and 1034 dizygotic (DZ) twin pairs aged between 20 and 84 years from the St Thomas' Adult UK Twin Register. Heritability estimates ranged between 37% and 64% for contentment (e.g., reporting to worry about one's memory) and approximately 45% for ability (e.g., reporting a tendency to forget keys). Shared family environmental influences (between 32% and 33%) were found for some abilities (e.g., learning to use a new gadget). Given their clinical significance and ease of administration, these tests could prove to be useful in examining memory functioning in large-scale population studies.

White Matter Changes in Bipolar Disorder, Alzheimer Disease, and Mild Cognitive Impairment: New Insights from DTI

Neuropathological and neuroimaging studies have reported significant changes in white matter in psychiatric and neurodegenerative diseases. Diffusion tensor imaging (DTI), a recently developed technique, enables the detection of microstructural changes in white matter. It is a noninvasive in vivo technique that assesses water molecules' diffusion in brain tissues. The most commonly used parameters are axial and radial diffusivity reflecting diffusion along and perpendicular to the axons, as well as mean diffusivity and fractional anisotropy representing global diffusion. Although the combination of these parameters provides valuable information about the integrity of brain circuits, their physiological meaning still remains controversial. After reviewing the basic principles of DTI, we report on recent contributions that used this technique to explore subtle structural changes in white matter occurring in elderly patients with bipolar disorder and Alzheimer disease.

What Do Cognitive Complaints in a Sample of Memory Clinic Outpatients Reflect?

Conflicting evidence exists concerning the value of cognitive complaints in the course of assessing cognitive performance in individuals. The present study examines whether cognitive complaints are differentially related to cognitive functioning in groups with different diagnoses. 169 older outpatients (76 years on average) were divided into three groups and diagnosed with subjective cognitive complaints, mild cognitive impairment, or dementia. They were then administered a self-rating questionnaire on cognitive complaints, with semantic fluency and global cognitive functioning being assessed as cognitive measures. Multiple regression analyses revealed that, after controlling for depression, age, sex, and education, global cognitive functioning was not related to cognitive complaints. Semantic fluency was related to cognitive complaints depending on the group. Results suggest that cognitive complaints reflect, in part, actual cognitive performance.

Frequency and predictors of proxy-confirmed post-stroke cognitive complaints in lacunar stroke patients without major depression

OBJECTIVE

Many lacunar stroke patients complained of cognitive decline after stroke. This study aims to investigate the factors underlying post-stroke cognitive complaints in these patients.

METHODS

Seventy-five consecutive lacunar stroke patients without major depression were recruited for the study. Stroke severity was measured using NIHSS score and MRI was performed during the acute admission period. At 3 months, objective psychometric performance and depressive symptoms were assessed. Post-stroke cognitive complaints were corroborated by a proxy. Using logistic regression we examined the contribution of demographic features, stroke severity, objective psychometric scores, depressive symptoms, and imaging features (white matter lesion volume and infarct measures) to post-stroke cognitive complaints.

RESULTS

Thirty-two (42.7%) patients had post-stroke cognitive complaints. Patients with post-stroke cognitive complaints had more depressive symptoms and worse psychometric performance than those without. In the multivariate logistic regression model, only the severity of depressive symptoms was independently associated with post-stroke cognitive complaints.

CONCLUSIONS

This study suggests that post-stroke cognitive complaints are frequent among lacunar stroke patients without major depression and are prominently determined by the subclinical depressive symptomatology.

Impaired digit span can predict further cognitive decline in older people with subjective memory complaint: a preliminary result

Subjective memory complaint (SMC) is common among elderly people, and is thought to be part of mild cognitive impairment (MCI). We evaluated whether impaired digit span (IDS) in older people with SMC can predict wider impairment in future neuropsychological tests that correspond to MCI. After a mean of 6.6 years from the initial assessment, we reevaluated 16 subjects with SMC and normal digit span (NDS) scores (mean age 57.6 ± 8.1 years) and 28 subjects with SMC and IDS scores (mean age 59.7 ± 9.9 years). The IDS group showed wider cognitive decline in tests of short-term verbal memory and category verbal fluency compared to the NDS group. IDS scores indicate an earlier step for conversion of SMC to MCI.

Subjective memory complaints in the elderly may be related to factors other than cognitive deficit

Prevalence of subjective memory complaints (SMC) in elderly community dwellers (ECD) ranges from 25 to 50%. Some controversy exists over the association between SMC and cognitive status.

Glucose metabolism and PIB binding in carriers of a His163Tyr presenilin 1 mutation

Six young related pre-symptomatic carriers of a His163Tyr mutation in the presenilin 1 gene who will develop early onset familial Alzheimer's disease (eoFAD), and a control group of 23 non-carriers underwent (18)F-fluorodeoxyglucose positron emission tomography (FDG PET). The mutation carriers were followed-up after 2 years. Multivariate analysis showed clear separation of carriers from non-carriers on both occasions, with the right thalamus being the region contributing most to group differentiation. Statistical parametric mapping (SPM) revealed in the carriers non-significantly lower thalamic cerebral glucose metabolism (CMRglc) at baseline and significantly decreased CMRglc in the right thalamus at follow-up. One mutation carrier was followed-up with FDG PET 10 years after baseline and showed reductions in cognition and CMRglc in the posterior cingulate and the frontal cortex. This subject was diagnosed with AD 1 year later and assessed with an additional FDG as well as an (11)C-PIB PET scan 12 years after baseline. Global cortical CMRglc and cognition were distinctly decreased. PIB binding was comparable with sporadic AD patterns but showing slightly higher striatal levels.

Validation of two inventories for the diagnosis and monitoring of functional memory disorder

OBJECTIVE

Functional memory disorder (FMD) is an acquired nonorganic condition characterized by significant deficits of memory and concentration that occur in daily living and are thought to be caused by psychosocial burden and distress. FMD is an important differential diagnosis to organic mild cognitive impairment. Although frequent, FMD is under-researched and mostly diagnosed by exclusion rather than by positive diagnostic criteria. Diagnosis can be difficult in patients with borderline cognitive test results.

METHODS

To aid in the clinical diagnosis and monitoring of FMD, a short 10-item FMD questionnaire and a 22-item FMD rating scale were developed. They asses a range of memory complaints thought to be indicative of FMD. Each of the two inventories was applied and evaluated in a separate study involving FMD patients and control groups. In one study, the natural course of FMD was observed. In the other study, the effect of a therapeutic intervention was assessed. Here, we present the full text of the two FMD inventories and data on test quality characteristics.

RESULTS

Internal consistency and split-half-reliability indices were excellent throughout. At suitable cutoffs, both versions discriminated FMD patients from control subjects with high accuracy. Both also demonstrated discriminant construct validity. Moreover, the long version demonstrated high test-retest reliability and convergent construct validity and proved to be sensitive to change.

CONCLUSION

The short version of the FMD inventory is a helpful tool in the clinical diagnosis of FMD. The longer version is suitable for monitoring of FMD severity in the context of therapeutic interventions and observational studies. To determine whether the inventories can discriminate FMD from organic mild cognitive impairment, further studies are required.

Subjective memory impairment in a rural population with low education in the Amazon rainforest: an exploratory study

BACKGROUND

The high prevalence of subjective memory impairment (SMI) in the elderly living in developed countries may be partly dependent on greater demand placed on them by new technologies. As part of a comprehensive study on cognitive impairment in a population living in the Amazon rainforest, we evaluated the prevalence of SMI and investigated the features associated with it.

METHODS

We evaluated 163 subjects (82 females) with a mean age of 62.3 years (50-94 years), 110 of whom were illiterate, using the answer to a single question "Do you have memory problems?" to classify them into groups with or without SMI. The assessment involved application of the Mini-mental State Examination (MMSE), delayed recall from the Brief Cognitive Battery designed for the evaluation of low educated and illiterate individuals, the Patient Questionnaire (PQ) of the Primary Care Evaluation of Mental Disorders (PRIME-MD), and the Happiness Analogical Scale.

RESULTS

A very high prevalence of SMI (70%) was observed, exceeding rates reported by similar studies conducted in developed countries. SMI was more frequent in women, whereas age and education did not impact on prevalence. Subjects with SMI had significantly more somatic and psychiatric symptoms on the PQ, as well as lower means on the MMSE, but not on the delayed recall test. Multiple logistic regressions showed that the most important factor associated with the presence of SMI was a high score on the PQ (OR: 3.84, p = 0.011).

CONCLUSION

Psychological and somatic symptoms may be the principal cause of SMI in this population.

Subjective memory complaints and concurrent memory performance in older patients of primary care providers

Subjective memory complaints (SMCs) are known to be inconsistently related to current memory impairment in older adults but this association has not been well investigated in primary care provider (PCP) settings. To characterize the complexity of the relationship between SMCs and objective memory in older outpatients of PCPs, we collected neuropsychological, subjective memory, depression and medical chart data from outpatients aged 65 and older, without documented dementia diagnoses, in eleven PCP offices in and around the Pittsburgh metropolitan area. Results indicated that self-estimates of current memory ability were most strongly associated with objective memory performance; in contrast, perception of worsening memory over the past year showed no association; and specific memory-related activities were only weakly associated. Women were more likely than men to show inconsistency between SMCs and objective memory performance. Only two of the 11 most significantly memory-impaired participants endorsed SMCs and only four had PCP chart documentation of memory problems. Eliciting SMCs in non-demented older adults can be of clinical value in a PCP setting, but significant limitations of patient self-report in more memory-impaired patients underscore the need to develop brief, objective indicators of memory impairment for PCP office use when there is suspicion of decline.

A randomized, two-year study of the efficacy of cognitive intervention on elderly people: the Donostia Longitudinal Study

BACKGROUND

Research on non-pharmacological therapies (cognitive rehabilitation) in old age has been very limited, and most has not considered the effect of interventions of this type over extended periods of time.

OBJECTIVE

To investigate a new cognitive therapy in a randomized study with elderly people who did not suffer cognitive impairment.

METHODS

The efficacy of this therapy was evaluated by means of post-hoc analysis of 238 people using biomedical, cognitive, behavioural, quality of life (QoL), subjective memory, and affective assessments.

RESULTS

Scores for learning potential and different types of memory (working memory, immediate memory, logic memory) for the treatment group improved significantly relative to the untreated controls.

CONCLUSIONS

The most significant finding in this study was that learning potential continued at enhanced levels in trained subjects over an intervention period lasting two years, thereby increasing rehabilitation potential and contributing to successful ageing.

Subjective memory complaints: presence, severity and future outcome in normal older subjects

BACKGROUND/AIMS

Subjective memory complaint (SMC) in normal individuals may predict future cognitive decline. The goal of this study was to examine whether the probability of decline increases with growing intensity of complaint.

METHODS

Normal subjects over the age of 50 years were included in a longitudinal retrospective study (mean follow-up time = 8 years). All subjects (n = 230) underwent cognitive and medical examination at baseline. The presence of SMC was determined based on Global Deterioration Scale staging. A subgroup of 83 participants also received baseline assessment for the intensity of SMC. Logistic regression was used to predict outcome from baseline variables. Three outcome groups were established at the final visit: nondeclining, declining and diagnostically unstable (i.e. the diagnosis changed over time: from normal to mild cognitive impairment, then back to normal).

RESULTS

The presence of SMC was a predictor of future decline but also increased the likelihood of the unstable diagnosis. Increasing intensity of SMC did not further raise the risk for decline. High intensity of complaints and more pronounced affective symptoms predicted the unstable clinical diagnosis.

CONCLUSIONS

The presence of SMC contributes to the risk of future decline, however, the increasing intensity of the perceived impairment does not further enhance the risk.

Perceived Threat of Alzheimer Disease (AD)

The fear of developing Alzheimer disease (AD) is highly salient, particularly for biologic family members. The current study evaluated social/cognitive explanations for perceived AD threat beyond genetic relatedness, including personal experience with AD, belief in negative aging stereotypes, and performance on delayed memory tasks. Participants were 97 healthy older adults aged 50 to 85, self-referred for a free community memory screen. Results showed that, as expected, personal AD experience was related to perceived AD threat. Furthermore, consistent with expectations, AD experience moderated the relationship between perceived AD threat and other explanatory variables, including age, belief in negative aging stereotypes, and cognitive performance. In those with AD experience, whether genetic or not, younger age was associated with more perceived AD threat, but an inverse relationship was seen in those without AD experience. Those with genetic AD experience seem particularly vulnerable to the effects of negative age stereotype beliefs on perceived AD threat, and show an inverse relationship between their actual cognitive performance and their perception of personal AD threat. Results highlight the importance of considering personal experience with AD when assessing a person's self-reported concerns about AD or his/her own memory changes.

ADCS Prevention Instrument Project: the Mail-In Cognitive Function Screening Instrument (MCFSI)

In future research on the prevention of Alzheimer Disease (AD), a large simple prevention trial might test a safe intervention (eg, vitamins) in a very large population (eg, 10,000 subjects), powered to detect a modest treatment effect size. In a large, simple design, regular assessments must be very low cost, for example, handled by mail. The Mail-In Cognitive Function Screening Instrument (MCFSI) was developed for the Alzheimer's Disease Cooperative Study Prevention Instrument Project to evaluate whether a brief mail-in screening tool can be used as a specific and sensitive trigger for a diagnostic evaluation in the course of a prevention trial. The MCFSI consists of 2 similar sets of 14 questions mailed separately to the subject and the study partner, who are asked to complete them independently. The questions are derived from a standard clinical assessment of dementia; they ask about decline in function over the last year. We are currently evaluating the utility of the instrument in 640 subjects over the course of the "simulated" AD prevention trial. Analysis of baseline data showed significant differences in mean MCFSI scores between sex and ethnic groups (for subjects), age groups (for partners), and Clinical Dementia Rating global score groups (both subject and partner). In this nondemented population, both subject's and partner's MCFSI responses were related to cognitive performance. There was no significant association between MCFSI score for either subjects or partners and apolipoprotein E genotype. The MCFSI captures information related to cognitive and functional status in nondemented elderly individuals; the Alzheimer's Disease Cooperative Study Prevention Instrument Project will determine whether this brief, mail-in questionnaire is useful as a trigger for diagnostic evaluation in an AD primary prevention trial.

Subjective memory complaints and cognitive impairment in older people

Subjective memory complaints (SMCs) are common in older people and are often thought to indicate cognitive impairment. We reviewed research on the relationship between SMCs and (a) current cognitive function, (b) risk of future cognitive decline, and (c) depression and personality. SMCs were found to be inconsistently related to current cognitive impairment but were more strongly related to risk of future cognitive decline. However, SMCs were consistently related to depression and some personality traits, e.g. neuroticism. In conclusion, the determinants of SMCs are complex. The utility of SMCs in the diagnosis of pre-dementia states (e.g. mild cognitive impairment) is uncertain and requires further evaluation.

Identifying patients at high and low risk of cognitive decline using Rey Auditory Verbal Learning Test among middle-aged memory clinic outpatients

OBJECTIVES

To investigate whether application of cutoff levels in an episodic memory test (Rey Auditory Verbal Learning Test, RAVLT) is a useful method for identifying patients at high and low risk of cognitive decline and subsequent dementia.

METHODS

224 patients with memory complaints (mean age = 60.7 years, mean MMSE = 28.2) followed-up at a memory clinic over approximately 3 years were assigned retrospectively to one of three memory groups from their baseline results in RAVLT [severe (SIM), moderate (MIM) or no impairment (NIM)]. These groups were investigated regarding cognitive decline.

RESULTS

Patients assigned to SIM showed significant cognitive decline and progressed to dementia at a high rate, while a normal performance in RAVLT at baseline (NIM) predicted normal cognition after 3 years. Patients with MIM constituted a heterogeneous group; some patients deteriorated cognitively, while the majority remained stable or improved.

CONCLUSIONS

The application of cutoff levels in RAVLT at baseline showed that patients with severely impaired RAVLT performance were at a high risk of cognitive decline and progression to dementia, while patients with normal RAVLT results did not show cognitive decline during 3 years. Furthermore, the initial degree of memory impairment was decisive in the cognitive prognosis 3 years later.

Older adults with cognitive complaints show brain atrophy similar to that of amnestic MCI

OBJECTIVE

To examine the neural basis of cognitive complaints in healthy older adults in the absence of memory impairment and to determine whether there are medial temporal lobe (MTL) gray matter (GM) changes as reported in Alzheimer disease (AD) and amnestic mild cognitive impairment (MCI).

METHODS

Participants were 40 euthymic individuals with cognitive complaints (CCs) who had normal neuropsychological test performance. The authors compared their structural brain MRI scans to those of 40 patients with amnestic MCI and 40 healthy controls (HCs) using voxel-based morphometry and hippocampal volume analysis.

RESULTS

The CC and MCI groups showed similar patterns of decreased GM relative to the HC group on whole brain analysis, with differences evident in the MTL, frontotemporal, and other neocortical regions. The degree of GM loss was associated with extent of both memory complaints and performance deficits. Manually segmented hippocampal volumes, adjusted for age and intracranial volume, were significantly reduced only in the MCI group, with the CC group showing an intermediate level.

CONCLUSIONS

Cognitive complaints in older adults may indicate underlying neurodegenerative changes even when unaccompanied by deficits on formal testing. The cognitive complaint group may represent a pre-mild cognitive impairment stage and may provide an earlier therapeutic opportunity than mild cognitive impairment. MRI analysis approaches incorporating signal intensity may have greater sensitivity in early preclinical stages than volumetric methods.

A comparison of MicroCog and the Wechsler Memory Scale (3rd ed.) in older adults

In recent years, computerized assessment of cognitive functions such as memory has increased in popularity. Here we contrast the performance of 33 community-dwelling older adults (mean age 71.2 years, SD = 7.62) on the computer-based MicroCog with the conventional Wechsler Memory Scale-3rd Edition (WMS-III). Participants were screened for possible depression using the Geriatric Depression Scale and completed both memory tests in counterbalanced order. WMS-III General Memory correlated moderately with both the MicroCog Memory index and the General Cognitive Functioning index. Correlations between the visual memory measures of the 2 tests were not statistically significant. Agreement between the tests on the classification of participants as lying within the average, below average, or above average ranges was fair at best. We conclude that the correspondence between the 2 measures is not sufficient to substitute 1 for the other for clinical decision making as to the memory functioning of older adults.

Do subjective memory complaints predict cognitive dysfunction over time? A six-year follow-up of the Maastricht Aging Study

BACKGROUND

Middle-aged and older people often worry that their perceived diminishing memory function may indicate incipient dementia.

OBJECTIVES

The present study addresses questions regarding subjective memory complaints as a predictor of lower performance on cognitive tasks. Also, in participants with subjective memory complaints it was investigated, whether trying to keep mentally active improved memory function. Characteristics of the participants who were and were not interested in an intervention to decrease worries and to improve memory in daily life were determined.

METHODS

Data were obtained from a large longitudinal study: the Maastricht Aging Study, involving 557 participants aged 55 to 85 years. Follow-up measurement was performed after 6 years. Outcome variables were simple, complex and general information processing speed and immediate and delayed recall.

RESULTS

At baseline, forgetfulness was associated with a slower general information processing and delayed recall. At the six-year follow-up, being forgetful was not associated with a significant change in cognitive performance. Taking steps to remain cognitively active was not a predictor of better performance on cognitive tasks at baseline or at the six-year follow-up.

CONCLUSION

Being forgetful might be an indicator of slower general information processing speed and delayed recall at baseline but does not predict cognitive change over 6 years in older adults. However, the effects are rather small and cannot directly be generalized to applications in clinical settings. Other factors, such as depression and anxiety might also underlie the cause of the forgetfulness.

Stability, growth, and decline in adult life span development of declarative memory: cross-sectional and longitudinal data from a population-based study

Five-year changes in episodic and semantic memory were examined in a sample of 829 participants (35-80 years). A cohort-matched sample (N=967) was assessed to control for practice effects. For episodic memory, cross-sectional analyses indicated gradual age-related decrements, whereas the longitudinal data revealed no decrements before age 60, even when practice effects were adjusted for. Longitudinally, semantic memory showed minor increments until age 55, with smaller decrements in old age as compared with episodic memory. Cohort differences in educational attainment appear to account for the discrepancies between cross-sectional and longitudinal data. Collectively, the results show that age trajectories for episodic and semantic memory differ and underscore the need to control for cohort and retest effects in cross-sectional and longitudinal studies, respectively.

Alpha rhythms in mild dements during visual delayed choice reaction time tasks: A MEG study

Can simple delayed response tasks affect latency and amplitude of magnetoencephalographic midline alpha rhythms (6-12 Hz) in early dementia? We recruited 15 mild Alzheimer's disease (AD) and 10 vascular dementia (VaD) patients (paired mini mental state exam of 17-24). The control groups comprised 18 young and 22 elderly normal subjects. In the first task, a simple "cue" stimulus (one bit) was memorized along a brief delay period (3.5-5.5s) up to a "go" stimulus triggering (right or left) button press. In the second task, the "cue" stimulus remained available along the delay period. Event-related reduction in power of the alpha rhythms indexed the cortical activation (event-related desynchronization, ERD) for the trials associated with correct behavioral responses. Behavioral performances to both tasks were lower in the AD and VaD patients than in the normal subjects. In particular, just four AD and five VaD patients executed a sufficient amount of correct responses for the alpha ERD analysis, so they were included in a unique group. In both tasks, the alpha ERD peak was later in latency in the demented and normal elderly subjects than in the normal young subjects. Furthermore, the alpha ERD peak was stronger in amplitude in the demented patients than in the normal subjects. These results suggest that simple delayed response tasks during physiological recordings are quite difficult for patients even at an early dementia stage. Such difficulty may induce the abnormal amount of the related cortical activation in dementia as revealed by the alpha ERD.

Memory evaluation with a new cued recall test in patients with mild cognitive impairment and Alzheimer?s disease

Free delayed recall is considered the memory measure with the greatest sensitivity for the early diagnosis of dementia. However, its specificity for dementia could be lower, as deficits other than those of pure memory might account for poor performance in this difficult and effortful task. Cued recall is supposed to allow a better distinction between poor memory due to concurrent factors and impairments related to the neurodegenerative process. The available cued recall tests suffer from a ceiling effect. This is a prospective, longitudinal study aiming to assess the utility of a new memory test based on cued recall that avoids the ceiling effect in the early diagnosis of Alzheimer's disease (AD). Twenty-five patients with mild cognitive impairment (MCI), 22 probable AD patients (NINCDS-ADRDA) at a mild stage, 22 elderly patients with subjective memory complaints (SMC) and 38 normal age-matched controls took part in the study. The patients underwent a thorough cognitive evaluation and the recommended screening procedure for the diagnosis of dementia. All patients were re-examined 12-18 months later. A newly devised delayed cued recall test using semantic cues (The RI48 Test) was compared with three established memory tests: the Ten Word-List Recall from CERAD, the "Doors" and the "Shapes" Tests from "The Doors and People Test Battery". Forty-four % of the MCI patients fulfilled criteria for probable AD at follow-up. The RI48 Test classified correctly 88% of the MCI and SMC participants and was the best predictor of the status of MCI and mild AD as well as the outcome of the MCI patients. Poor visual memory was the second best predictor of those MCI patients who evolved to AD. A cued recall test which avoids the ceiling effect is at least as good as the delayed free recall tests in the early detection of AD.

No association between subjective memory complaints and apolipoprotein E genotype in cognitively intact elderly

OBJECTIVE

This cross-sectional study examined the relationship between subjective memory complaints and the apolipoprotein epsilon 4 allele (epsilon4), a genetic risk factor for Alzheimer's disease (AD), among cognitively normal subjects identified from a community memory screening.

DESIGN

The sample comprised 232 consecutive white non-Hispanic older adults who presented to a free community-based memory-screening program at a University affiliated memory disorders center. Participants were classified as cognitively normal based on scores on the age and educated adjusted Folstein Mini-Mental Status Exam (MMSAdj) and a brief Delayed Verbal Recall Test (DRT). Subjects were assessed for APOE genotype, subjective memory complaints (Memory Questionnaire, MQ), depressive symptoms (Hamilton Depression Rating Scale, HDRS), and history of four major medical conditions that have been associated with memory loss (stroke/transient ischemic attack [TIA], atherosclerotic heart disease, hypertension, and diabetes). A hierarchical regression analysis was performed to examine the association between APOE genotype and memory complaints after controlling for a host of potential confounding factors.

RESULTS

The APOE epsilon4 allele frequency for cognitively normal subjects was 0.13. Subjective memory complaints were predicted by depressive symptoms and a history of stroke/TIA. They were not associated with APOE genotype, MMSAdj score, DRT score, age, education, gender, and reported history of atherosclerotic heart disease, hypertension, or diabetes.

CONCLUSION

The results did not suggest an association between subjective memory complaints and the APOE epsilon4 allele in this sample of cognitively intact subjects. This indicates that memory complaints may confer risk for future dementia through pathways independent of APOE genotype. The results also show that older adults with memory complaints are at increased risk for underlying depression.

Value of CSF beta-amyloid1-42 and tau as predictors of Alzheimer's disease in patients with mild cognitive impairment

Subjects with mild cognitive impairment (MCI) are at a high risk of developing clinical Alzheimer's disease (AD). We asked to what extent the core biomarker candidates cerebro-spinal fluid (CSF) beta-amyloid(1-42) (Abeta(1-42)) and CSF tau protein concentrations predict conversion from MCI to AD. We studied 52 patients with MCI, 93 AD patients, and 10 healthy controls (HC). The MCI group was composed of 29 patients who had converted to AD during follow-up, and of 23 patients who showed no cognitive decline. CSF Abeta(1-42) and tau protein levels were assessed at baseline in all subjects, using enzyme-linked immunosorbent assays. For assessment of sensitivity and specificity, we used independently established reference values for CSF Abeta(1-42) and CSF tau. The levels of CSF tau were increased, whereas levels of Abeta(1-42) were decreased in MCI subjects. Abeta(1-42) predicted AD in converted MCI with a sensitivity of 59% and a specificity of 100% compared to HC. Tau yielded a greater sensitivity of 83% and a specificity of 90%. In a multiple Cox regression analysis within the MCI group, low baseline levels of Abeta(1-42), but not other predictor variables (tau protein, gender, age, apolipoprotein E epsilon4 carrier status, Mini Mental Status Examination score, observation time, antidementia therapy), correlated with conversion status (P<0.05). Our findings support the notion that CSF tau and Abeta(1-42) may be useful biomarkers in the early identification of AD in MCI subjects.