Memory complaints in a community sample aged 60-64 years: associations with cognitive functioning, psychiatric symptoms, medical conditions, APOE genotype, hippocampus and amygdala volumes, and white-matter hyperintensities

Do employed and not employed 55 to 64-year-olds' memory complaints relate to memory performance? A longitudinal cohort study

BACKGROUND

Whether middle-aged individuals are capable of employment continuation may be limited by poor memory. Subjective memory complaints may be used to identify those at risk of poor memory. Research questions, therefore, were (i) are prevalent memory complaints associated with relevantly poor memory performance and decline in 55 to 64-year-olds; (ii) are incident memory complaints associated with relevant memory decline; and (iii) do these associations differ between employed and not employed individuals?

METHODS

Participants of the Longitudinal Aging Study Amsterdam (LASA) were examined. Data were weighted by sex, age and region. To examine the association of prevalent memory complaints with relevantly poor learning ability (n=903) and delayed recall (n=897; both assessed with the Auditory Verbal Learning Test), subnormal (≤ mean-1 SD) and impaired (≤ mean-1.5 SD) memory performance were defined. To examine the association of prevalent and incident memory complaints with relevant decline after 3 years in learning ability (n=774 and 611, respectively) and delayed recall (n=768 and 603, respectively), above normal (≤ mean-1 SD) and clinically relevant (≤ mean-1.5 SD) memory decline were investigated. Logistic regression analyses were applied.

RESULTS

Adjusted for gender, education and age, individuals with memory complaints more often had impaired delayed recall and clinically relevant decline in learning ability. Incident memory complaints were borderline significantly associated with clinically relevant decline in learning in continuously employed individuals (paid job ≥ 1 h weekly), but not in continuously not employed individuals.

CONCLUSION

Memory complaints may identify 55 to 64-year-olds at risk of memory impairment and decline. Our results provide hypotheses about the association between memory complaints and decline in employed 55 to 64-year-olds.

Subjective cognitive impairment

PURPOSE OF REVIEW

To describe the recent (2011-2012) literature relevant to subjective cognitive impairment (SCI), focusing principally on studies of this symptom in older age groups. This is an issue of growing importance: although the symptom itself is controversial in older people because of variable associations with objective cognitive impairment, it remains one of the few presenting complaints which may identify people experiencing early cognitive decline.

RECENT FINDINGS

Several neuroimaging studies confirm earlier reports of associations between SCI and underlying abnormalities whereas those between subjective and objective cognitive function remain heterogeneous. Several studies now highlight the fact that, regardless of underlying associations, SCI as a symptom is associated with significant concern but is something for which older people rarely seek help.

SUMMARY

Neuroimaging findings suggest that older people may be more aware of underlying brain changes than was previously apparent or than can be detected using conventional neuropsychological assessments. However, not all of these brain changes are necessarily progressive or neurodegenerative. At least some attention should be paid to interventions for what is a common, often distressing, but underreported symptom.

Online memory screening--are older adults interested and can it work?

Subjective memory concerns are common in older adults and may prompt the use of web-based cognitive screening. Websites which purport to provide memory screening are numerous and can influence health behaviours; however there is currently limited evidence regarding their validity. The current research aims to assess potential user's attitudes and motivations regarding online cognitive screening and to evaluate the preliminary evidence for the feasibility and validity of two subjective online cognitive measures. The sample consisted of community-based older adults, 30 with, and 30 without, memory concerns. Participants rated their likelihood of their accessing online cognitive screening and gave rationales. Participants' performance on objective pen and paper measures of cognition was compared to performance on subjective online screening measures. The majority of participants indicated they would access online cognitive screening. A total of 100% of participants were able to use the online tools without assistance. None of the online measures was positively associated with the pen and paper screening measures. Anxiety and depression were significantly associated with subjective memory concerns. This study provided no supporting evidence for the validity of either subjective online screening measure assessed. Anxiety and depression were significantly associated with subjective cognition, indicating that, although they may not predict objective cognition, complaints about memory in older adults should be taken seriously by health professionals.

Can mild cognitive impairment be accurately diagnosed in english speakers from linguistic minorities? Results from the Sydney Memory and Ageing study

OBJECTIVES

: The aim of this article was to examine the prevalence and incidence over 2 years of mild cognitive impairment (MCI) in English speakers from linguistic minorities.

DESIGN

: Cross-sectional and longitudinal with 2-year follow-up.

SETTING

: Eastern suburbs of Sydney, New South Wales, Australia.

PARTICIPANTS

: Eight hundred twenty-seven community-dwelling participants from English-speaking backgrounds (ESB) and 160 participants from non-English-speaking backgrounds (NESB) recruited through the electoral roll.

MEASUREMENTS

: Participants were assessed using 11 neuropsychological tests measuring memory, language, attention/processing speed, and executive function. Questionnaires measuring functional impairment and subjective cognitive complaints were completed by participants or informants.

RESULTS

: We found a two- to threefold higher prevalence of MCI in NESB participants than ESB participants depending on the impairment criterion applied. This difference was because of higher rates of objective cognitive impairment in NESB participants; rates of functional impairment and subjective cognitive complaints did not differ between the groups. This association between MCI prevalence and NESB status was accounted for by the proportion of time the participant spoke English and the proportion of life they had lived in Australia, but not by age, gender, and education. There were no differences between NESB and ESB groups in MCI incidence, dementia incidence, or rates of conversion from MCI to dementia. NESB participants had lower rates of reversion from MCI to normal.

CONCLUSIONS

: It is difficult to accurately diagnose MCI in persons from linguistic minority groups, even when proficient in English as neuropsychological test scores may not be valid for these groups. English language ability and level of acculturation should be considered when assessing older persons from ethnic minority groups.

Subjective well-being in Swedish active seniors or seniors with cognitive complaints and its relation to commonly available biomarkers

Well-being (WB) is a complex variable in its relation to physical health and other personal and social characteristics. The aim was to study subjective well-being (SWB) and its possible associations with traditional biomarkers of cardiovascular risk or dementia, in Swedish seniors. SWB was estimated by the Psychological General Well-Being (PGWB) index in two study groups. The active seniors (AS) group consisted of community-dwelling elderly Swedes leading an active life (n=389). The DGM cohort (n=300) consisted of subjects referred to the Memory Unit at the Department of Geriatrics, the cognitive problems had to be subjective, mild or moderate (MMSE≥10). There were differences in all six subdimensions of SWB or distress, and in the sum of PGWB scores, between the two study groups (p<0.001 for all), and adjustment for differences in biomarkers of somatic health (age, sex, blood pressure, BMI, HDL cholesterol, ApoB/ApoA1 ratio, creatinine, and homocysteine) did not attenuate these differences. In addition, cognition as assessed by the Clock-Drawing Test (CDT) showed independent associations with four of the PGWB subdimensions and with the PGWB sum. Among the subjects in the DGM cohort, SWB was equally low among subjects with an MCI (minor cognitive impairment) diagnosis or without a dementia diagnosis as among subjects diagnosed with dementia disorder. We conclude that the nosological grouping variable (AS vs. DGM cohort) and a cognitive factor were the main independent predictors of SWB in this sample of elderly Swedes, whereas biomarkers of somatic health played a subordinated role.

Differential distribution of subjective and objective cognitive impairment in the population: a nation-wide twin-study

We report the prevalence of subjective cognitive impairment (SCI) and cognitive impairment no dementia (CIND), their socio-demographic profile, and the contribution of genetic background and shared familial environment to SCI and CIND. Subjects were 11,926 dementia-free twin individuals aged ≥65 from the Swedish Twin Registry. SCI was defined as subjective complaint of cognitive change without objective cognitive impairment and CIND was defined according to current criteria. Overall prevalence rates of SCI and CIND were 39% (95% CI 38-39%) and 25% (95% CI 24-25%). In multivariate GEE models, both SCI and CIND were older compared with people without any cognitive impairment. CIND were also less educated, more likely to be unmarried and to have lower socioeconomic status (SES). SCI individuals differed from persons with CIND as they were older, more educated, more likely to be married, and to have higher SES. Co-twin control analysis, which corrects for common genetic and shared environmental background, confirmed the association of low education with CIND. Probandwise concordance for SCI and CIND was 63% and 52% in monozygotic twins, 63% and 50% in dizygotic same-sex twins, and 42% and 29% in dizygotic unlike-sex twins. Tetrachoric correlations showed no significant differences between monozygotic and dizygotic same-sex twins. We conclude that subjective and objective cognitive impairment are both highly prevalent among nondemented elderly yet have distinct sociodemographic profiles. Shared environmental influences rather than genetic background play a role in the occurrence of SCI and CIND.

Subjective memory impairment in older adults: aetiology, salience and help seeking

BACKGROUND

Subjective memory impairment (SMI) is one of the key symptoms with which people with early cognitive impairment may present to health services. However, little research has investigated how older people view the symptom, its salience and how often help is sought. The objectives were to investigate (a) factors associated with SMI, (b) salience of SMI in comparison with other symptoms and (c) help seeking for SMI.

METHOD

A cross-sectional survey was based in two Primary Care services in south London in which registered people aged 65+ were interviewed blind to the study objectives. Measurements included systematic ascertainment of SMI and other common symptoms/disorders. In each of these, concern and interference were quantified, and participants were asked to rank all reported symptoms/disorders in order of importance.

RESULTS

Of 126 participants, any SMI was reported in 66.7%, and 31.0% reported SMI to a significant degree. SMI occupied a middling rank in terms of salience, being ranked as more concerning than angina, asthma, hypertension or a previous heart attack in around half of participants in whom these co-occurred. However, only one participant with SMI had sought help from their GP, making it the least likely symptom to be reported.

CONCLUSION

Subjective memory impairment is common and appears to have functional and/or emotional significance for many older people. However, very few appear to seek medical attention for this symptom, which has implications for wider policy regarding prompt assessment and diagnosis of mild cognitive impairment or dementia.

Subjective cognition and amyloid deposition imaging: a Pittsburgh Compound B positron emission tomography study in normal elderly individuals

OBJECTIVE

To study the relationship between subjective cognition and the neuropathological hallmark of Alzheimer disease (AD), amyloid-β (Aβ) deposition, using carbon 11-labeled Pittsburgh Compound B (PiB) positron emission tomography in normal elderly individuals.

DESIGN

Cross-sectional analysis.

SUBJECTS

Forty-eight cognitively normal elderly subjects (11 with high PiB uptake and 28 with low PiB uptake) were included. All underwent clinical and neuropsychological evaluations, magnetic resonance imaging, and positron emission tomography.

SETTING

Berkeley Aging Cohort Study.

MAIN OUTCOME MEASURE

Relationship between PiB uptake and subjective cognition measures.

RESULTS

Subjects with high PiB uptake showed significantly lower performance than those with low PiB uptake on an episodic memory measure and were less confident about their general memory abilities when required to evaluate themselves relative to other people of the same age. High and low PiB uptake groups did not differ on the accuracy of their cognitive self-reports compared with objective cognitive performance. General memory self-reports from the whole group were significantly correlated with regional PiB uptake in the right medial prefrontal cortex and anterior cingulate cortex and in the right precuneus and posterior cingulate cortex. Reduced confidence about memory abilities was associated with greater PiB uptake in these brain regions. All results were independent of demographic variables and depressive affects.

CONCLUSIONS

A decrease of self-confidence about memory abilities in cognitively normal elderly subjects may be related to the neuropathological hallmark of AD measured with PiB-positron emission tomography. Subjective cognitive impairment may represent a very early clinical manifestation of AD.

Early dysfunction of functional connectivity in healthy elderly with subjective memory complaints

It is still an open question whether subjective memory complaints (SMC) can actually be considered to be clinically relevant predictors for the development of an objective memory impairment and even dementia. There is growing evidence that suggests that SMC are associated with an increased risk of dementia and with the presence of biological correlates of early Alzheimer's disease. In this paper, in order to shed some light on this issue, we try to discern whether subjects with SMC showed a different profile of functional connectivity compared with subjects with mild cognitive impairment (MCI) and healthy elderly subjects. In the present study, we compare the degree of synchronization of brain signals recorded with magnetoencephalography between three groups of subjects (56 in total): 19 with MCI, 12 with SMC and 25 healthy controls during a memory task. Synchronization likelihood, an index based on the theory of nonlinear dynamical systems, was used to measure functional connectivity. Briefly, results show that subjects with SMC have a very similar pattern of connectivity to control group, but on average, they present a lower synchronization value. These results could indicate that SMC are representing an initial stage with a hypo-synchronization (in comparison with the control group) where the brain system is still not compensating for the failing memory networks, but behaving as controls when compared with the MCI subjects.

Subjective memory complaints, vascular risk factors and psychological distress in the middle-aged: a cross-sectional study

BACKGROUND

Subjective memory complaints (SMC) are common but their significance is still unclear. It has been suggested they are a precursor of mild cognitive impairment (MCI) or dementia and an early indicator of cognitive decline. Vascular risk factors have an important role in the development of dementia and possibly MCI. We therefore aimed to test the hypothesis that vascular risk factors were associated with SMC, independent of psychological distress, in a middle-aged community-dwelling population.

METHODS

A cross-sectional analysis of baseline data from the 45 and Up Study was performed. This is a cohort study of people living in New South Wales (Australia), and we explored the sample of 45, 532 participants aged between 45 and 64 years. SMC were defined as 'fair' or 'poor' on a self-reported five-point Likert scale of memory function. Vascular risk factors of obesity, diabetes, hypertension, hypercholesterolemia and smoking were identified by self-report. Psychological distress was measured by the Kessler Psychological Distress Scale. We tested the model generated from a randomly selected exploratory sample (n = 22, 766) with a confirmatory sample of equal size.

RESULTS

5, 479/45, 532 (12%) of respondents reported SMC. Using multivariate logistic regression, only two vascular risk factors: smoking (OR 1.18; 95% CI = 1.03 - 1.35) and hypercholesterolaemia (OR 1.19; 95% CI = 1.04 - 1.36) showed a small independent association with SMC. In contrast psychological distress was strongly associated with SMC. Those with the highest levels of psychological distress were 7.00 (95% CI = 5.41 - 9.07) times more likely to have SMC than the non-distressed. The confirmatory sample also demonstrated the strong association of SMC with psychological distress rather than vascular risk factors.

CONCLUSIONS

In a large sample of middle-aged people without any history of major affective illness or stroke, psychological distress was strongly, and vascular risk factors only weakly, associated with SMC, although we cannot discount psychological distress acting as a mediator in any association between vascular risk factors and SMC. Given this, clinicians should be vigilant regarding the presence of an affective illness when assessing middle-aged patients presenting with memory problems.

Multimorbidity and its relation to subjective memory complaints in a large general population of older adults

BACKGROUND

Multimorbidity has been suggested to be associated with a variety of negative health-related outcomes. The present study was designed to evaluate the association between multimorbidity and subjective memory complaints.

METHODS

This cross-sectional study was based on data obtained from a postal survey designed by the Public Health Service (Gemeentelijke Gezondheids Dienst, GGD) involving 15,188 persons aged 55 years and over living independently in Limburg, the Netherlands. Multivariate logistic regression analyses, adjusted for potentially important covariates, were performed to evaluate the association between self-reported multimorbidity and three outcomes related to subjective memory complaints.

RESULTS

Multimorbidity was indeed related to subjective memory complaints. The association between multimorbidity and subjective memory complaints was positively influenced by age. Moreover, multimorbidity was related to the degree of worrying about memory complaints in people who perceived themselves as forgetful. Multimorbidity was also associated with reporting a larger increase in these subjective memory complaints during the past year. In this latter case, multimorbidity had more prognostic capability in men than in women. Psychological distress was related to all three subjective memory-related outcome measures.

CONCLUSIONS

In our sample, which was representative of the Dutch population, multimorbidity was associated with subjective memory complaints. The relationship between multimorbidity and subjective memory complaints differed between men and women and between age groups.

Discrete neuroanatomical networks are associated with specific cognitive abilities in old age

There have been many attempts at explaining age-related cognitive decline on the basis of regional brain changes, with the usual but inconsistent findings being that smaller gray matter volumes in certain brain regions predict worse cognitive performance in specific domains. Additionally, compromised white matter integrity, as suggested by white matter hyperintensities or decreased regional white matter fractional anisotropy, has an adverse impact on cognitive functions. The human brain is, however, a network and it may be more appropriate to relate cognitive functions to properties of the network rather than specific brain regions. We report on graph theory-based analyses of diffusion tensor imaging tract-derived connectivity in a sample of 342 healthy individuals aged 72-92 years. The cognitive domains included processing speed, memory, language, visuospatial, and executive functions. We examined the association of these cognitive assessments with both the connectivity of the whole brain network and individual cortical regions. We found that the efficiency of the whole brain network of cortical fiber connections had an influence on processing speed and visuospatial and executive functions. Correlations between connectivity of specific regions and cognitive assessments were also observed, e.g., stronger connectivity in regions such as superior frontal gyrus and posterior cingulate cortex were associated with better executive function. Similar to the relationship between regional connectivity efficiency and age, greater processing speed was significantly correlated with better connectivity of nearly all the cortical regions. For the first time, regional anatomical connectivity maps related to processing speed and visuospatial and executive functions in the elderly are identified.

Longitudinal neuroimaging correlates of subjective memory impairment: 4-year prospective community study

BACKGROUND

Complaints about memory are common in older people but their relationship with underlying brain changes is controversial.

AIMS

To investigate the relationship between subjective memory impairment and previous or subsequent changes in white matter lesions and brain volumes.

METHOD

In a community cohort study of 1336 people without dementia, 4-year changes in brain magnetic resonance imaging measures were investigated as correlates of subjective memory impairment at baseline and follow-up.

RESULTS

Subjective memory impairment at baseline was associated with subsequent change in hippocampal volume and at follow-up impairment was associated with previous change in hippocampal, cerebrospinal fluid and grey matter volume and with subcortical white matter lesion increases. All associations with volume changes were U-shaped with significant quadratic terms - associations between least decline and subjective memory impairment were potentially explained by lower baseline hippocampal volumes in the groups with least volume change. Associations between hippocampal volume change and subjective memory impairment at follow-up were independent of cognitive decline and depressive symptoms, they were stronger in participants with the apolipoprotein E (APOE) ε4 allele and in those without baseline subjective memory impairment.

CONCLUSIONS

Complaints of poor memory by older people, particularly when new, may be a realistic subjective appraisal of recent brain changes independent of observed cognitive decline.

Development of the Cognitive Dysfunction Questionnaire (CDQ) in a population based sample

The study reports on the development of a questionnaire for assessment of adult cognitive dysfunction (CDQ). Participants in a population-based sample (65±15 years, N=370) responded to a 90-item pilot version covering multiple aspects of memory/cognition. Based on exploratory principal components analyses and correlations with criterion measures of cognitive functioning (MMSE, Block Design, semantic/episodic memory), 20 items loading on 6 components were selected for the final version of the questionnaire. Cronbach's α for the total score was 0.90. There was evidence of construct validity as judged by correlations between CDQ scores, objective cognitive measures, and a subjective memory measure (PRMQ). Discriminant validity was demonstrated by a low and non-significant correlation with depressive symptoms. Further evidence of construct validity was provided by correlations with age and educational attainment. In conclusion, the CDQ is promising as a self-rating screening tool for cognitive dysfunction, and will be the subject of further development and validation.

The Sydney Memory and Ageing Study (MAS): methodology and baseline medical and neuropsychiatric characteristics of an elderly epidemiological non-demented cohort of Australians aged 70-90 years

BACKGROUND

The Sydney Memory and Ageing Study (Sydney MAS) was initiated in 2005 to examine the clinical characteristics and prevalence of mild cognitive impairment (MCI) and related syndromes, and to determine the rate of change in cognitive function over time.

METHODS

Non-demented community-dwelling individuals (N = 1037) aged 70-90 were recruited from two areas of Sydney, following a random approach to 8914 individuals on the electoral roll. They underwent detailed neuropsychiatric and medical assessments and donated a blood sample for clinical chemistry, proteomics and genomics. A knowledgeable informant was also interviewed. Structural MRI scans were performed on 554 individuals, and subgroups participated in studies of falls and balance, metabolic and inflammatory markers, functional MRI and prospective memory. The cohort is to be followed up with brief telephone reviews annually, and detailed assessments biannually.

RESULTS

This is a generally well-functioning cohort mostly living in private homes and rating their health as being better than average, although vascular risk factors are common. Most (95.5%) participants or their informants identified a cognitive difficulty, and 43.5% had impairment on at least one neuropsychological test. MCI criteria were met by 34.8%; with 19.3% qualifying for amnestic MCI, whereas 15.5% had non-amnestic MCI; 1.6% had impairment on neuropsychological test performance but no subjective complaints; and 5.8% could not be classified. The rate of MCI was 30.9% in the youngest (70-75) and 39.1% in the oldest (85-90) age bands. Rates of depression and anxiety were 7.1% and 6.9% respectively.

CONCLUSIONS

Cognitive complaints are common in the elderly, and nearly one in three meet criteria for MCI. Longitudinal follow-up of this cohort will delineate the progression of complaints and objective cognitive impairment, and the determinants of such change.

Predictive utility of type and duration of symptoms at initial presentation in patients with mild cognitive impairment

BACKGROUND/AIMS

To assess (1) the duration and symptoms present in participants with mild cognitive impairment (MCI) and (2) the impact of these variables on predicting conversion to Alzheimer's disease (AD).

METHODS

Participants with MCI (n = 148) were assessed and followed systematically.

RESULTS

Decline in memory was reported as the first symptom in 118 of the cases. Converters had more symptoms (e.g. language decline, depression), and the combination of decline in memory and in performance of high-order social/cognitive activities as well as disorientation more often than nonconverters (p = 0.036). In an age-stratified Cox model, predictors of conversion to AD were shorter time since onset of memory decline and lower baseline MMSE score.

CONCLUSIONS

Recent onset of memory decline with older age, decreased MMSE score, change in performance and disorientation indicate a greater likelihood of short-term conversion to AD.

The limitations of employment as a tool for social inclusion

Background

One important component of social inclusion is the improvement of well-being through encouraging participation in employment and work life. However, the ways that employment contributes to wellbeing are complex. This study investigates how poor health status might act as a barrier to gaining good quality work, and how good quality work is an important pre-requisite for positive health outcomes.

Methods

This study uses data from the PATH Through Life Project, analysing baseline and follow-up data on employment status, psychosocial job quality, and mental and physical health status from 4261 people in the Canberra and Queanbeyan region of south-eastern Australia. Longitudinal analyses conducted across the two time points investigated patterns of change in employment circumstances and associated changes in physical and mental health status.

Results

Those who were unemployed and those in poor quality jobs (characterised by insecurity, low marketability and job strain) were more likely to remain in these circumstances than to move to better working conditions. Poor quality jobs were associated with poorer physical and mental health status than better quality work, with the health of those in the poorest quality jobs comparable to that of the unemployed. For those who were unemployed at baseline, pre-existing health status predicted employment transition. Those respondents who moved from unemployment into poor quality work experienced an increase in depressive symptoms compared to those who moved into good quality work.

Conclusions

This evidence underlines the difficulty of moving from unemployment into good quality work and highlights the need for social inclusion policies to consider people's pre-existing health conditions and promote job quality.

Risk factors for incident mild cognitive impairment--results from the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe)

OBJECTIVES

To provide age- and gender-specific incidence rates of MCI among elderly general practitioner (GP) patients (75+ years) and to identify risk factors for incident MCI.

METHOD

Data were derived from the longitudinal German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe). Incidence was calculated according to the 'person-years-at-risk' method. Risk factors were analysed using multivariate logistic regression models.

RESULTS

During the 3-year follow-up period, 350 (15.0%) of the 2331 patients whose data were included in the calculation of incidence developed MCI [person-years (PY) = 6198.20]. The overall incidence of MCI was 56.5 (95% confidence interval = 50.7-62.7) per 1000 PY. Older age, vascular diseases, the apoE epsilon4 allele and subjective memory complaints were identified as significant risk factors for future MCI.

CONCLUSION

Mild cognitive impairment is frequent in older GP patients. Subjective memory complaints predict incident MCI. Especially vascular risk factors provide the opportunity of preventive approaches.

Do subjective memory complaints predict senile Alzheimer dementia?

Many elderly complain about their memory and undergo dementia screening by the Mini-Mental State Examination (MMSE). While objective memory impairment always precedes Alzheimer dementia (AD) it is unclear whether subjective memory complaints are predicting AD. We tried to answer this question in a prospective cohort study. The 75-years old non-demented inhabitants of Vienna-Transdanube were investigated for conversion to AD after 30 months. The predictive value of subjective memory complaints was analysed in two groups: subjects with high MMSE-score (28-30) and subjects with low MMSE-score (23-27). Only in subjects with high MMSE univariate analyses showed an association between subjective memory complaints and incident AD. In both groups the verbal memory test was the main predictor of AD in multivariate analyses. We suggest to perform memory testing in subjects complaining about memory irrespective of their performance in a screening procedure like the MMSE.

Subjective cognitive impairment: increased prefrontal cortex activation compared to controls during an encoding task

OBJECTIVE

Subjective cognitive impairment (SCI) has been proposed as a clinical stage which may precede mild cognitive impairment in the clinical continuum of AD, and is characterised by the presence of subjective memory complaints in the absence of objective cognitive deficits. Specific memory-related brain activation differences have been reported in mild cognitive impairment and in cognitively normal individuals at known genetic risk of AD; our objective was to determine whether similar differences are present in people with SCI.

METHODS

We compared brain activation in a memory clinic sample of 10 SCI subjects and 10 controls during a verbal episodic memory encoding task using functional magnetic resonance imaging (fMRI).

RESULTS

There were no differences between groups on measures of encoding success (recognition accuracy) nor was there evidence of altered semantic processing. Both groups activated left prefrontal cortex (PFC) and cerebellum during encoding. The SCI group also demonstrated activation in left medial temporal, occipitoparietal and medial frontal cortex. Group comparisons revealed increased activation in SCI in left PFC, where activation strength correlated with memory task performance.

CONCLUSIONS

The activation differences reported in this study may reflect the employment of compensatory strategies in the face of early AD pathology, although a number of alternative explanations need to be considered. Further studies with larger samples may help to determine whether the observed activation changes are likely to be associated with early neuropathological processes or with other unrelated factors.

Reproductive period and cognitive function in a representative sample of naturally postmenopausal women aged 60–64 years

BACKGROUND

Greater lifetime estrogen exposure has been postulated to result in better cognition in later life, particularly in the area of verbal memory. In women, the highest levels of endogenous estrogen occur during their reproductive period, between menarche and menopause.

OBJECTIVE

To investigate the association between reproductive period and cognition.

METHODS

The sample consisted of 760 naturally postmenopausal women aged 60-64 years (mean age 62.5 +/- 1.5 years) participating in the PATH Through Life Study who were randomly drawn from the population of Canberra, Australia. Participants were administered a verbal learning test (immediate recall and 1-minute delay), the Mini-Mental State Examination (MMSE), digit span backwards, the Symbol-Digit Modalities Test and simple and choice reaction time tests.

RESULTS

There were no significant associations detected between reproductive period and performance on any of the cognitive tests, either before or after controlling for potential confounding variables.

CONCLUSIONS

Reproductive period, a surrogate measure of endogenous estrogen exposure, had no detectable effect on cognitive performance in this sample.

Stability in the clinical characteristics of patients with memory complaints

The objectives of this study were to examine potential clinical and neuropsychological changes over time in non-demented patients with subjective memory complaints (<or=70 years) and to compare the patients with objective memory impairment (OMI) with those who suffer from subjective memory impairment (SMI). OMI and SMI patients did not differ regarding duration of memory problems, age or education. At baseline no differences were revealed between the OMI and SMI patients regarding self-reported cognitive deficits, self-reported worry about deficits, and symptoms of anxiety or depression. None of the patients had converted to dementia at follow-up. Eighty percent of the OMI patients and 61% of the SMI patients reported cognitive deficits to the same degree at follow-up as at baseline. Despite a significant reduction of depressive symptoms in the OMI patients, a considerable portion of both OMI and SMI patients scored above the cut off score on both anxiety and depression subscales at baseline as well as at follow-up. Our study reveals close points of similarity between patients with memory complaints, verified by test, and patients with memory complaints, not verified by test, as well as stability over time regarding important clinical aspects.

Characteristics of help-seeking behaviour in subjects with subjective memory complaints at a memory clinic: a case-control study

OBJECTIVE

Memory complaints in the absence of objective test impairments are common. Only a subset of these subjects seeks medical attention for these complaints. The aim of the present study was to investigate which factors determine why people with subjective memory complaints (SMC) seek medical attention.

METHODS

Thirty-three cases with SMC from a memory clinic were compared to 85 control subjects with SMC from a population-based study who did not seek help for their complaints. We investigated whether cases differed from controls with respect to the following: depressive and anxiety symptoms (SCL-90), extraversion and neuroticism (EPQ), meta-memory (MIA), quality of life (SF-36), changes in memory and daily functioning according to a relative (DECO), life-changing events, and a family history of dementia.

RESULTS

Cases with SMC who seek medical attention, scored lower on memory self-efficacy and quality of life. They were more often worried due to a positive family history of dementia by comparison to the control subjects. Relatives of cases reported more deterioration in daily functioning than relatives of controls. Both the cases and control subjects had similar levels of depressive and anxiety symptoms, as well as levels of extraversion and neuroticism.

CONCLUSION

Lower memory self-efficacy and quality of life, deterioration in daily functioning, and worries due to a positive family history for dementia are factors that determine why subjects with SMC seek medical attention. This information may be useful for the development of interventions for these subjects.

Subjective memory symptoms in surgical and nonsurgical coronary artery patients: 6-year follow-up

BACKGROUND

Self-reported cognitive and memory complaints after coronary artery bypass graft (CABG) operations are common. Several studies have attempted to quantify the incidence of such complaints and to examine the relationship between subjective and objective cognitive functioning, but the etiology and longitudinal course of these self-reports remain unclear.

METHODS

Measures of subjective memory complaints were compared in two groups: 220 CABG patients and 92 nonsurgical cardiac patients at 3 months, and 1, 3, and 6 years. At 6 years, additional measures were used to quantify memory self-assessment. The frequency of subjective complaints at each time point was determined, and associations with objective cognitive performance as well as depression were examined.

RESULTS

At early (3-month or 1-year) follow-up, subjective memory complaints were reported more often by the CABG than the nonsurgical group (45.5% vs 17.0%, p < 0.0001). By 6 years, the frequency of complaints was similar (52%) in both groups. Subjective memory ratings were significantly correlated with performance on several memory tests at 6 years. This relationship was not confounded by depression.

CONCLUSIONS

Subjective memory complaints are more frequent early in follow-up in patients undergoing CABG than in controls, but are similar by 6 years. The increase in subjective complaints over time may be related to progression of underlying cerebrovascular disease. Unlike previous studies, we found that subjective memory assessments were correlated with objective performance on several memory tests. Although subjective memory complaints are more common in patients with depression, they cannot be explained by depression alone.

The nature of cognitive complaints in healthy older adults with and without objective memory decline

Cognitive and memory complaints were assessed in 100 healthy older adults on two occasions over 2.5 years as part of a 6-year study assessing cognition, mood, and general health factors. Diminished memory for names and actions and lapses in concentration were common complaints, regardless of the individuals' actual cognitive status. No change in cognitive complaints occurred over time, even for individuals whose memory had declined over 6 years. Cognitive complaints correlated with anxiety, depression, and general mental health but not with objectively measured memory or cognition, education or age. Complaints did not differ with gender, apolipoprotein E epsilon4 genotype, cardiovascular risk factors, or intake of sedating medications. Thus, cognitive complaints could not differentiate memory-declining older adults from cognitively normal older adults and were more closely associated with mood and general mental health than actual cognitive status, age, or potential risk factors for Alzheimer's disease. Thus, the evaluation of cognitive complaints must be broad and must consider the correspondence of complaints not only to relevant measurable cognitive abilities but also to the affect of the individual.

Cortical sources of resting EEG rhythms in mild cognitive impairment and subjective memory complaint

Are cortical electroencephalographic (EEG) rhythms altered in amnesic and non-amnesic mild cognitive impairment (MCI), subjective memory complaint (SMC), and healthy elderly (Nold) subjects? Eyes-closed resting EEG was recorded in 79 Nold, 53 SMC, 51 non-amnesic MCI, and 92 amnesic MCI subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz) and gamma (30-40 Hz). Cortical EEG sources were estimated by standardized low resolution brain electromagnetic tomography (sLORETA). Results showed that (i) the frontal delta sources were greater in amplitude in the amnesic MCI and SMC subjects than in the Nold subjects (p<0.05-0.01); (ii) the parietal and occipital theta sources were lower in amplitude in the SMC subjects than in the Nold subjects (p<0.046); (iii) the occipital theta sources were greater in amplitude in the amnesic MCI subjects than in the SMC and non-amnesic MCI subjects (p<0.02-0.01); (iv) the parietal and occipital alpha 1 sources were greater in amplitude in the Nold subjects than in the SMC, non-amnesic MCI and amnesic MCI subjects (p<0.00001); (v) the central alpha 1 sources were lower in amplitude in the SMC subjects than in the non-amnesic MCI subjects (p<0.002); (vi) the occipital alpha 1 sources were greater in amplitude in the SMC subjects than in the amnesic MCI subjects (p<0.0003); (vii) the parietal and occipital alpha 2 sources were greater in amplitude in the Nold subjects than in the non-amnesic MCI subjects (p<0.041-0.0004); (viii) the occipital alpha 2 sources were greater in the SMC subjects than in the non-amnesic MCI subjects (p<0.02). These results suggest that amnesic MCI and SMC subjects present some of the typical alterations of brain neural synchronization as revealed by resting cortical EEG rhythms in Alzheimer's disease patients.

Positron emission tomography scans obtained for the evaluation of cognitive dysfunction

The degree of intactness of human cognitive functioning for a given individual spans a wide spectrum, ranging from normal to severely demented. The differential diagnosis for the causes of impairment along that spectrum is also wide, and often difficult to distinguish clinically, which has led to an increasing role for neuroimaging tools in that evaluation. The most frequent causes of dementia are neurodegenerative disorders, Alzheimer's disease being the most prevalent among them, and they produce significant alterations in brain metabolism, with devastating neuropathologic, clinical, social, and economic consequences. These alterations are detectable through positron emission tomography (PET), even in their earliest stages. The most commonly performed PET studies of the brain are performed with (18)F-fluorodeoxyglucose as the imaged radiopharmaceutical. Such scans have demonstrated diagnostic and prognostic utility for clinicians evaluating patients with cognitive impairment and in distinguishing among primary neurodegenerative disorders and other etiologies contributing to cognitive decline. In addition to focusing on the effects on cerebral metabolism examined with (18)F-fluorodeoxyglucose PET, some other changes occurring in the brains of cognitively impaired patients assessable with other radiotracers will be considered. As preventive and disease-modifying treatments are developed, early detection of accurately diagnosed disease processes facilitated by the use of PET has the potential to substantially impact on the enormous human toll exacted by these diseases.

Measure of quality of life for Taiwanese persons with early to moderate dementia and related factors

BACKGROUND

This study validates the Chinese Dementia-Quality of Life instrument (DQoL) in patients with early to moderate stages of Alzheimer's disease (AD) (Clinical Dementia Rating Scale, CDR=0.5, 1, and 2; MMSE >or= 12).

METHODS

A cross-sectional design was used involving 98 participants (27 controls, 35 patients with questionable dementia (QD), and 36 patients with mild to moderate AD) and 51 paired family caregivers (FCs) (20 FCs of QD patients, 31 FCs of AD patients). FCs were recruited to evaluate patients' DQoL using the parallel form. Internal consistency, construct validity and concurrent validity of the DQoL were examined.

RESULTS

The findings indicated that the Chinese DQoL instrument has stable internal consistency but only moderate validity when used in early to moderate AD participants with MMSE greater than, or equal to 12. The DQoL and Self-esteem subscales were significantly different across the three dementia severity groups. The values of internal consistency of the DQoL and its five subscales were high for the ratings of both the patients and the FCs. The interscale correlations for the DQoL were almost all significant for patients' and FCs' ratings. Agreement of the DQoL and its subscales for patients and FCs was significant. However, two inconsistencies were found in the results of the factor analysis and the prior conceptualization of patients' DQoL, the subscales of Self-esteem and Negative Affect. Global cognitive impairment and self-care problems significantly correlated with the patients' DQoL, while the patients' depressive symptoms and self-care problems significantly correlated with the FCs' DQoL.

CONCLUSIONS

The Chinese DQoL reported by early to moderate AD patients has good reliability, but moderate validity because the patients' depressive symptoms did not correlate with their DQoL and the major subscales. Both patients' and FCs' ratings on DQoL are important in research and treatment decision making.

Biomarkers of cerebrovascular disease in dementia

There is increasing recognition that cerebrovascular disease contributes significantly to the development and progression of patients with dementia. The concepts of pure vascular and pure degenerative dementia have been replaced with a recognition that, in many patients, there is a spectrum of neurodegenerative and vascular processes. This is supported by preliminary studies showing response to vascular therapeutics and ventriculo-peritoneal shunting in patients with Alzheimer's disease. This article examines the imaging biomarkers that are available for the characterization of microvascular abnormality in the ageing brain, with particular reference to microvascular angiopathy, cerebral embolic disease, orthostatic hypotension and abnormalities of Monro-Kellie homeostasis.

Memory complaints to the general practitioner: data from the GuidAge study

Memory complaints are relatively common in elderly people, although they are not always reported to the general practitioner (GP). These subjective complaints do not necessarily correlate with objective measures of memory impairment or cognitive performance, but they may be an early indication of impairment at a state that is undetectable by standard testing instruments. Memory complaints may also predict future cognitive decline. The GuidAge study is a secondary prevention trial for Alzheimer's disease involving non-demented individuals aged 70 years or older having spontaneously complained of memory problems to their GP. More than half of participants had a Clinical Dementia Rating score of 0.5 at baseline. The percentage of participants reporting problems on the McNair and Kahn scale varied from 6.2% to 78.6% per item. Certain specific memory complaints may be more related than others to the beginning of the neurodegenerative process, and could predict future cognitive decline. The importance of memory complaints should not be underestimated in clinical practice.

Patterns of subjective memory impairment in the elderly: association with memory performance

BACKGROUND

The association of subjective memory impairment (SMI) with cognitive performance in healthy elderly subjects is poor because of confounds such as depression. However, SMI is also a predictor for future dementia. Thus, there is a need to identify subtypes of SMI that are particularly related to inferior memory performance and may represent at-risk stages for cognitive decline.

METHOD

A total of 2389 unimpaired subjects were recruited from the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe), as part of the German Competence Network on Dementia. Clusters of SMI according to patterns of response to SMI questions were identified. Gender, age, depressive symptoms, apolipoprotein E (apoE) genotype, delayed recall and verbal fluency were included in a Classification and Regression Tree (CART) analysis to identify discriminators between the clusters.

RESULTS

We identified three clusters. Cluster 1 contained subjects without memory complaints. Cluster 2 contained subjects with general memory complaints, but mainly without memory complaints on individual tasks of daily living. Cluster 3 contained subjects with general memory complaints and complaints on individual tasks of daily living. Depressive symptoms, as the first-level discriminator, distinguished between clusters 1 and 2 versus cluster 3. In subjects with only a few depressive symptoms, delayed recall discriminated between cluster 1 versus clusters 2 and 3.

CONCLUSIONS

In SMI subjects with only a minor number of depressive symptoms, memory complaints are associated with delayed recall. As delayed recall is a sensitive predictor for future cognitive decline, SMI may be the first manifestation of future dementia in elderly subjects without depression.

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.

Utilization Rates of Ecologically Oriented Instruments Among Clinical Neuropsychologists

The ecological validity of neuropsychological instruments has become an important topic in recent decades, as neuropsychologists are asked to address real-world outcomes with increasing frequency. Although novel instruments that tap skills required for everyday functioning have been developed, it is unclear whether these instruments are migrating from research laboratories into the applied settings of clinical neuropsychologists. The current study surveyed assessment practices of neuropsychologists with regard to their utilization of instruments designed with ecological concerns in mind. Respondents included 747 North American, doctorate-level psychologists (40% usable response rate) affiliated with Division 40 of the American Psychological Association, National Academy of Neuropsychology, or the International Neuropsychological Society. Results indicated that approximately one-third of respondents reported use of ecologically oriented instruments (EOIs), and these instruments were generally utilized with much less frequency than traditional measures. Additionally, certain practice demographics affected usage rates of EOIs. Study findings are interpreted in the context of a growing body of literature that calls attention to the importance of developing and utilizing instruments that are able to handle the complex, real-world issues increasingly addressed during the neuropsychological assessment process.

Subjective memory complaints, mood, and memory deficits among HIV/AIDS patients in Hong Kong

Diagnosis of HIV-associated neurobehavioral disorders often heavily relies upon patient complaints of cognitive difficulties. Yet, research in North America suggests that such complaints may be heavily influenced by affective factors. However, no work in this area has been done in China. The present study examined the relationships among depressed mood, anxiety, memory performance and subjective memory complaints among HIV/AIDS patients in Hong Kong. A total of 90 individuals with HIV were administered the Beck Depression Inventory (BDI), State-Trait Anxiety Inventory, Patient's Assessment of Own Functioning Inventory (PAOF), and Hong Kong List Learning Test. Forward regression analysis indicated that the BDI Cognitive-Affective score was the most significant predictor of subjective memory complaints on the PAOF. Furthermore, present results also supported previous findings that some individuals with HIV infection are more "accurate" than others in the self-appraisal of their memory ability. Given inaccuracies that exist in subjective memory complaints, these findings highlight the importance of comprehensive cognitive assessment when evaluating the neuropsychological status of individuals of HIV.

Predictors of subjective cognitive difficulties in older adults with atherosclerotic vascular disease

OBJECTIVE

The objective of this study was to describe the relationship among cognitive test performance, psychological symptoms, and subjective cognitive difficulties in older adults with atherosclerotic vascular disease.

METHOD

Participants were 80 adults over the age of 55 with an unequivocal diagnosis of atherosclerotic vascular disease. Participants completed measures of neuropsychological functioning, psychological symptoms, and two measures of subjective cognitive difficulties.

RESULTS

Psychological symptoms were most strongly associated with higher levels of reported cognitive difficulties. Overall neuropsychological functioning was modestly related to subjective cognitive difficulties but did not remain significant after controlling for psychological symptoms.

CONCLUSIONS

In this sample of older adults with atherosclerotic vascular disease, self-reported cognitive difficulties were most strongly related to overall level of psychological distress and not to actual cognitive test scores. Therefore, psychological factors may play an important role in the phenomenon of self-perceived cognitive decline in geriatric populations.

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.

Memory complaints are related to Alzheimer disease pathology in older persons

OBJECTIVE

To study the relationship between Alzheimer disease (AD) pathology and memory complaints proximate to death.

METHODS

A group of 90 older persons underwent detailed clinical evaluations and brain autopsy at death. The evaluations included administration of questions on subjective memory complaints and clinical classification of dementia and AD. On postmortem examination, neuritic plaques, diffuse plaques, and neurofibrillary tangles in tissue samples from five cortical regions were counted, and a summary measure of overall AD pathology was derived. In addition, amyloid load and tau tangles were quantified in eight regions.

RESULTS

In multiple linear regression models adjusted for age, sex, and education, memory complaints were associated with AD pathology, including both amyloid and tau tangles. Subsequent analyses demonstrated that the relationship between memory complaints and AD pathology was present in those with and without dementia, and could not be explained by the potentially confounding effects of depressive symptoms or coexisting common chronic health problems.

CONCLUSION

Memory complaints in older persons may indicate self awareness of a degenerative process.

Subjective complaints and self-evaluation of memory test performance in Questionable dementia

BACKGROUND

The clinical significance of subjective memory complaints in elderly subjects has been an area of active research. In this study, we evaluated subjective complaints and self-evaluation of memory test performance in subjects with Questionable dementia (QD) and mild Alzheimer's disease (AD).

METHODS

Ninety-two subjects (35 cognitively intact normal controls NC, 33 QD, and 24 mild AD) were assessed. Subjective memory complaints were evaluated using a memory inventory for the Chinese (MIC); objective assessment of awareness was assessed by the self-evaluation of own memory test performance. Cognitive function was assessed with the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Category Verbal Fluency Test (CVFT) and Executive Interview (EXIT-25). Depressive symptoms were evaluated with the Cornell Scale for Depression in Dementia (CSDD).

RESULTS

The total number of subjective memory complaints (MI-tol) were significantly different between different subject groups (Kruskal Wallis test, chi2 = 13.19, p = 0.001). Significant correlations between scores of the MI-tol and CSDD (r = 0.33, p < 0.001), CMMSE (r = -0.33, p < 0.001), CDR (r = 0.36, p < 0.001) were found. In self-evaluation of memory test performance, the NC group tended to under-estimate while the AD subjects tended to over-estimate their performance. Group differences in the discrepancies of self-evaluation of memory performance were significant for both the immediate (Kruskal Wallis test, chi2 = 9.86, p = 0.007) and delayed recall (Kruskal Wallis test, chi2 = 10.55, p < 0.001) trials.

CONCLUSIONS

Subjects with QD and mild AD showed higher frequency of subjective memory complaints, reflecting that the subjects still retain some ability to appreciate own memory function. However, the trend for over-estimation of performance in AD subjects suggests that the precision of estimation may be suboptimal. Moreover, depressive symptoms may affect the presentation of memory complaints and this factor should be carefully considered in future prospective studies.

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.

Volume reduction of the entorhinal cortex in subjective memory impairment

To examine the biological basis of subjective memory impairment (SMI), defined as the feeling of memory worsening with normal memory performance, we measured the volume of the entorhinal cortex (EC) and the hippocampus in SMI subjects, patients with mild cognitive impairment (MCI), patients with Alzheimer's disease (AD) and healthy controls (CO). Compared with controls, the EC was smaller in the SMI group (left: p=0.060; right: p=0.045) and in the other two groups in the following order: CO>SMI>MCI>AD. The same sequence was observed with regard to hippocampal volumes, but the volume reduction of the left hippocampus in the SMI group only reached a trend towards significance (p=0.072) and the right was not significantly smaller compared with controls (p=0.37). Compared with controls the average (left/right) volume reduction of the EC was 18% (SMI), 26% (MCI) and 44% (AD). The mean volume reduction of the hippocampus was 6% (SMI), 16% (MCI) and 19% (AD). Our results mirror the temporal sequence of neurodegeneration in AD and support the concept of SMI as the first clinical manifestation of dementia.