[Age- and education-specific reference values for the cognitive test of the SIDAM (Structured interview for the diagnosis of dementia of the Alzheimer type, multi-infarct dementia and dementias of other etiology according to ICD-10 and DSM-IV)]

Prediction of dementia of Alzheimer type by different types of subjective cognitive decline

INTRODUCTION

Subjective cognitive decline (SCD) is a risk condition for dementia, including dementia of Alzheimer type (DAT).

METHODS

We report sensitivity, specificity, positive and negative predictive values (PPV, NPV) for conversion to all-cause dementia, and DAT in different SCD types (decline in memory, assocated worries, longitudinal consitency, of the AgeCoDe study (n = 2.402, 12 years follow-up).

RESULTS

82.7% of those converting to any dementia and 84.4% of those converting with DAT at follow-up, reported memory decline and fulfilled criteria of SCD at least at one time point before. SCD with worries at two consecutive time points showed a specificity of 92.2% for any dementia and also for DAT as well as a PPV of 44.3% for any dementia and of 36.9% for DAT at follow-up at the expense of low sensitivity.

DISCUSSION

Different SCD subtypes were either sensitive or specific for future all-cause dementia and DAT in cognitively unimpaired individuals. Modest PPV of the most specific SCD subtypes were achieved in this low prevalence population.

Childhood trauma and PTSD symptoms increase the risk of cognitive impairment in a sample of former indentured child laborers in old age

A growing body of evidence suggests a link between early childhood trauma, post-traumatic stress disorder (PTSD) and higher risk for dementia in old age. The aim of the present study was to investigate the association between childhood trauma exposure, PTSD and neurocognitive function in a unique cohort of former indentured Swiss child laborers in their late adulthood. To the best of our knowledge this is the first study ever conducted on former indentured child laborers and the first to investigate the relationship between childhood versus adulthood trauma and cognitive function. According to PTSD symptoms and whether they experienced childhood trauma (CT) or adulthood trauma (AT), participants (n = 96) were categorized as belonging to one of four groups: CT/PTSD+, CT/PTSD-, AT/PTSD+, AT/PTSD-. Information on cognitive function was assessed using the Structured Interview for Diagnosis of Dementia of Alzheimer Type, Multi-infarct Dementia and Dementia of other Etiology according to ICD-10 and DSM-III-R, the Mini-Mental State Examination, and a vocabulary test. Depressive symptoms were investigated as a potential mediator for neurocognitive functioning. Individuals screening positively for PTSD symptoms performed worse on all cognitive tasks compared to healthy individuals, independent of whether they reported childhood or adulthood adversity. When controlling for depressive symptoms, the relationship between PTSD symptoms and poor cognitive function became stronger. Overall, results tentatively indicate that PTSD is accompanied by cognitive deficits which appear to be independent of earlier childhood adversity. Our findings suggest that cognitive deficits in old age may be partly a consequence of PTSD or at least be aggravated by it. However, several study limitations need to considered. Consideration of cognitive deficits when treating PTSD patients and victims of lifespan trauma (even without a diagnosis of a psychiatric condition) is crucial. Furthermore, early intervention may prevent long-term deficits in memory function and development of dementia in adulthood.

The assessment of changes in cognitive functioning in the elderly: age- and education-specific reliable change indices for the SIDAM

BACKGROUND/AIMS

The diagnostic criteria for dementia include reliable evidence of cognitive deterioration over time measured by cognitive tests. The Structured Interview for the Diagnosis of Dementia of the Alzheimer Type, Multi-infarct Dementia and Dementia of other Etiology according to DSM-III-R, DSM-IV and ICD-10 (SIDAM) is a neuropsychological instrument to determine cognitive status in patients with mild cognitive impairment (MCI) and dementia. Normative data for changes in cognitive functioning that normally occur in cognitively healthy individuals are required to interpret changes in SIDAM test scores.

METHODS

A sample of 1,090 cognitively healthy individuals participating in the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe) aged 75 years and older was assessed four times at 1.5-year intervals over a period of 4.5 years using the SIDAM. Age- and education-specific reliable change indices (RCIs) accounting for probable measurement error and practice effects were computed for a 90% confidence interval.

RESULTS

Across different age and education subgroups, changes from at least 3-5 points indicated significant (i.e. reliable) changes in SIDAM test scores at the 90% confidence level.

CONCLUSION

This study offers age- and education-specific normative data for the SIDAM based upon established RCI methods. The RCI scores provided in this study may help clinicians and researchers to interpret cognitive changes in SIDAM test scores and may contribute to the early detection and diagnosis of MCI and dementia in the elderly.

Assessing cognitive changes in the elderly: reliable change indices for the Mini-Mental State Examination

OBJECTIVE

The diagnosis of dementia includes evidence of decline in cognitive functioning over time measured by objective cognitive tasks. Normative data for changes adjusted for the impact of socio-demographic factors on cognitive test performance are lacking to interpret changes in Mini-Mental State Examination (MMSE) test scores.

METHOD

As part of the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe Study), a sample of 1090 cognitively healthy individuals, aged 75 years and older, was assessed at 1.5-year intervals over a period of 4.5 years using the MMSE. Age- and education-specific Reliable Change Indices (RCIs) were computed.

RESULTS

Age and education were significantly associated with MMSE test performance, and gender indicated no impact. Across different age and education subgroups, changes from at least 2 up to 3 points indicated significant (i.e., reliable) changes in MMSE test scores at the 90% confidence level. Furthermore, the calculation of RCIs for individual patients is demonstrated.

CONCLUSION

This study provides age- and education-specific MMSE norms based upon RCI methods to interpret cognitive changes in older age groups. The computation of RCI scores improves the interpretation of changes in MMSE test scores by controlling for measurement error, practice effects, or regression to the mean.

Spezifische Normierung des Trierer Inventars zum chronischen Stress (TICS) zur diagnostischen Anwendung im Spitzensport

Zusammenfassung: In diesem Beitrag wird das Trierer Inventar zum chronischen Stress (TICS; Schulz, Schlotz & Becker, 2004 ) vorgestellt und seine Eignung für die Anwendung im Spitzensport diskutiert. Dazu werden spezifische Normen für die Gruppe der Spitzensportler präsentiert. Das TICS misst chronischen Stress differenziert in neun Stressbereichen. Seine inhaltliche Struktur lässt sich faktorenanalytisch aus den Testwerten von Spitzensportlern replizieren. Die Skalen besitzen gute bis sehr gute interne Konsistenzen. Das Instrument kann in seiner Originalform zur Diagnostik im Spitzensport herangezogen werden. Für die Interpretation von Testergebnissen werden jedoch spezifische Normen für Spitzensportler empfohlen. Die Normstichprobe besteht aus 395 A- bis D-Kaderathleten olympischer Sportarten ab einem Alter von 16 Jahren. Berechnet wurden standardisierte Normen (T-Werte) auf der Basis der Gesamtstichprobe sowie separat für beide Geschlechter. Diese ermöglichen den Vergleich mit Testwerten von Spitzensportlern und gewährleisten eine den Besonderheiten der Zielgruppe angepasste Interpretation von Testergebnissen. Zur Interpretation werden mehrere Orientierungsmaße und ein Anwendungsbeispiel bereitgestellt.

Influence of social support on cognitive change and mortality in old age: results from the prospective multicentre cohort study AgeCoDe

Background

Social support has been suggested to positively influence cognition and mortality in old age. However, this suggestion has been questioned due to inconsistent operationalisations of social support among studies and the small number of longitudinal studies available. This study aims to investigate the influence of perceived social support, understood as the emotional component of social support, on cognition and mortality in old age as part of a prospective longitudinal multicentre study in Germany.

Methods

A national subsample of 2,367 primary care patients was assessed twice over an observation period of 18 months regarding the influence of social support on cognitive function and mortality. Perceived social support was assessed using the 14-item version of the FSozU, which is a standardised and validated questionnaire of social support. Cognition was tested by the neuropsychological test battery of the Structured Interview for the Diagnosis of Dementia (SIDAM). The influence of perceived support on cognitive change was analysed by multivariate ANCOVA; mortality was analysed by multivariate logistic and cox regression.

Results

Sample cognitive change (N = 1,869): Mean age was 82.4 years (SD 3.3) at the beginning of the observation period, 65.9% were female, mean cognition was 49 (SD 4.4) in the SIDAM. Over the observation period cognitive function declined in 47.2% by a mean of 3.4 points. Sample mortality (N = 2,367): Mean age was 82.5 years (SD 3.4), 65.7% were female and 185 patients died during the observation period. Perceived social support showed no longitudinal association with cognitive change (F = 2.235; p = 0.135) and mortality (p = 0.332; CI 0.829-1.743).

Conclusions

Perceived social support did not influence cognition and mortality over an 18 months observation period. However, previous studies using different operationalisations of social support and longer observation periods indicate that such an influence may exist. This influence is rather small and the result of complex interaction mechanisms between different components of social support; the emotional component seems to have no or only a limited effect. Further research is needed to describe the complex interactions between components of social support. Longer observation periods are necessary and standardised operationalisations of social support should be applied.

Direct costs associated with mild cognitive impairment in primary care

BACKGROUND/AIMS

Little is known about the direct costs of individuals with Mild Cognitive Impairment (MCI). This study investigates the direct costs associated with MCI according to recent diagnostic criteria from a societal perspective.

METHODS

Four hundred and fifty-two primary care patients aged 75+ from Leipzig, Germany, were investigated in face-to-face interviews regarding MCI according to the current diagnostic criteria of the International Working Group on MCI, resource utilisation and costs (questionnaire of service utilisation and costs), as well as chronic medical illness (Chronic Disease Score). Resource utilisation was monetarily valued using 2004/2005 prices.

RESULTS

Mean annual direct costs were 4,443 euro for patients with MCI (n=39) and 3,814 euro for patients without MCI (n=413) (p=0.34). Looking at the cost components, patients with and without MCI only significantly differed regarding pharmaceutical costs (1,210 euro vs 1,062 euro; p<0.05) not caused by antidementive drugs.

CONCLUSION

Direct costs of individuals having MCI are not significantly increased in comparison to direct costs of individuals without cognitive deficits.

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.

Measuring cognitive change in older adults: reliable change indices for the Mini-Mental State Examination

BACKGROUND

In clinical and research settings, the Mini-Mental State Examination (MMSE) is commonly used to measure cognitive change over time. The interpretation of changes in MMSE is often difficult. They do not necessarily result from true clinical change. Their interpretation requires comparison with normative data for change. However, MMSE change norms are lacking for long intervals.

OBJECTIVE

To examine what is a reliable change in MMSE for long follow-up periods commonly used in clinic. To provide normative data for change.

METHODS

A sample of 119 cognitively normal individuals, aged 75 years and over, who participated in the Leipzig Longitudinal Study of the Aged (LEILA 75+). All participants were tested six times at 1.5 year intervals with the MMSE over a mean period of 7.1 years. Reliable change indices were computed for a common confidence interval (90%).

RESULTS

In repeated assessments with 1.5 year intervals, a change in MMSE of at least 2-4 points indicated a reliable change at the 90% confidence level.

CONCLUSION

Small changes in MMSE can be interpreted only with great uncertainty. They have a reasonable probability of being caused by measurement error, regression to the mean or practice.

Measuring cognitive change in older adults: reliable change indices for the SIDAM

BACKGROUND

In clinical settings, neuropsychological tests and screening instruments are often used to measure cognitive change over time. However, the interpretation of changes in test scores is often difficult. For most instruments there is no information how much change occurs normally in cognitively healthy individuals.

AIM

To examine what is a reliable change for a widely used screening instrument for cognitive impairment and dementia.

METHODS

A Sample of 119 cognitively normal elderly individuals aged 75 and over participated in the Leipzig Longitudinal Study of the Aged (LEILA 75+). All participants have been tested six times at 1.5 year intervals with the test part of the SIDAM over a mean period of 7.1 years. Reliable change indices (RCI) were computed for a common confidence interval (90%). It is demonstrated how to compute RCI for individual patients.

RESULTS

In repeated assessments with 1.5 year intervals, a change in SIDAM score of at least 4 to 7 points (dependent on which of the six assessments were compared) indicates a reliable change at the 90% confidence level. Smaller changes can be interpreted only with high uncertainty.

CONCLUSION

The interpretation of changes in test scores in older adults should account for potential practice effect, normal decline and regression to the mean.

SIDAM: Alters- und bildungsspezifische Normen des kognitiven Leistungsteiles nach der neuen CASMIN-Bildungsklassifikation

Zusammenfassung: Mit dem SIDAM (Strukturiertes Interview für die Diagnose einer Demenz vom Alzheimer Typ, der Multiinfarkt- Demenz und Demenzen anderer Ätiologie nach DSM-III-R, DSM-IV und ICD-10) liegt ein standardisiertes Interview vor, welches Screening und Diagnose von Demenzen und leichten kognitiven Beeinträchtigungen ermöglicht. Alters- und bildungsspezifische Normen für den kognitiven Leistungsteil sind dabei unerlässlich, ihrerseits jedoch stark von der zugrunde liegenden Bildungsklassifikation abhängig. In der vorliegenden Arbeit werden bevölkerungsrepräsentative alters- und bildungsspezifische Normen des kognitiven SIDAM-Leistungsteiles auf der Grundlage einer aktuellen, nachvollziehbaren und international anerkannten Bildungsklassifikation (newCASMIN; Brauns & Steinmann, 1999 ) vorgelegt. Für die Trennung dementer von nichtdementen Personen werden Cut-off-Werte des SIDAM-Gesamtscores vorgeschlagen. Ermittelte statistische Kennwerte der einzelnen SIDAM-Subskalen ermöglichen zudem die Diagnose leichter kognitiver Beeinträchtigungen nach neuen Konsensuskriterien ( Winblad et al., 2004 ). Diese Veröffentlichung wurde im Rahmen des Kompetenznetzes Demenzen erstellt und vom Bundesministerium für Bildung und Forschung (BMBF) gefördert (Förderkennzeichen: O1 GI 0420).

Successful verbal retrieval in elderly subjects is related to concurrent hippocampal and posterior cingulate activation

OBJECTIVE

Memory decline and hippocampal atrophy are two major aspects of Alzheimer's disease. Using a response-related fMRI design, we investigated the relationship between successful verbal retrieval and concurrent cerebral activation in elderly subjects in different stages of cognitive decline. We chose a correlational over the more traditional categorical approach to increase the power of detecting relevant activations.

METHODS

Eleven subjects with Alzheimer's disease, 21 elderly subjects with mild cognitive impairment, and 29 age-matched cognitively unimpaired subjects learned 180 nouns. While measuring brain activation with fMRI, the subjects had to classify these 180 learned plus 180 new distractor words as known or new. Response-related fMRI analysis was used to identify cerebral activation by correctly remembered words (hits) that correlated with retrieval success in the whole group.

RESULTS

Successful verbal retrieval was significantly correlated with concurrent activation of the left hippocampus and posterior cingulate gyrus.

CONCLUSION

The study confirms the importance of adequate hippocampal function for successful verbal retrieval in the elderly. In addition, our study supports connectivity studies indicating a functional relationship between the hippocampus and the posterior cingulate gyrus during successful verbal retrieval in the elderly in different stages of cognitive decline.

Progression of mild cognitive impairment to dementia: a challenge to current thinking

BACKGROUND

Studies of conversion from mild cognitive impairment to dementia suggest a linear progression over time. Conversion rates during lifetime may extend to 80-90%.

AIMS

This study examines the time-dependent evolution from mild cognitive impairment to dementia. Current assumptions regarding yearly and lifetime conversion rates are challenged.

METHOD

A community sample of 1045 dementia-free individuals aged 75 years and over was examined by neuropsychological testing based on 6 years of observation.

RESULTS

Approximately 60-65% of people with mild cognitive impairment develop clinical dementia during their life. Progression from mild cognitive impairment to dementia appears to be time dependent, occurring primarily within the initial 18 months.

CONCLUSIONS

Further long-term studies are needed to examine the time-dependent evolution from mild cognitive impairment to dementia and to establish age-specific conversion rates during lifetime.

Mild cognitive impairment (MCI) and actual retrieval performance affect cerebral activation in the elderly

Cerebral activation in the elderly may depend on general cognitive decline as well as actual retrieval performance. Consequently, activation between subjects with and without Mild Cognitive Impairment (MCI), and between remembered and non-remembered words was compared. Twenty-one MCI and 29 healthy control subjects learned 180 nouns. During retrieval, subjects had to discriminate these and 180 distractor words. fMRI identified response-related activation. Most retrieval-related activation was comparable in both groups. However, MCI subjects showed more activation in the prefrontal cortex than controls during processing of hits and correct rejections. Hits showed increased activation than misses in the precuneus and left lateral parieto-occipital cortex; misses showed more activation than correct rejections in the precuneus to cuneus. Verbal retrieval activated a large common network in the elderly independently of MCI. Increased activation in MCI subjects in prefrontal cortex depends on response category. Activation differences between response categories might reflect success (hits) and effort (misses). Increased retrieval-related activation may be used as early marker in subjects at risk of Alzheimer's disease.

Structural correlates of mild cognitive impairment

The structural correlates of mild cognitive impairment (MCI) were examined in 105 elderly subjects whose cognitive function ranged from intact to demented, including 38 subjects with MCI. Hippocampal volumes (left and right HcV), brain volume (BV), and grey matter volume (GMV) and white matter volume (WMV) were segmented from high resolution magnetic resonance data sets and normalised to intracranial volume (ICV). Hippocampal volume reductions, but not global brain, white or grey matter atrophy, were associated with MCI. White matter lesion severity did not differ over cognitive states. In multiple logistic regression models, normalised HcV and ICV (indicating premorbid brain volume) were significant predictors of MCI versus normality. Normalised BV and ICV significantly predicted dementia versus MCI. Absolute volumetric measures of HcV and BV yielded comparable classification accuracies. Hippocampal atrophy may be the crucial step for the transition from normality to MCI. Widespread brain atrophy may be the step to determine the transition from MCI to dementia. Brain volume reserve effects appear to be involved in both of these steps.

The relationship between head size and intracranial volume in elderly subjects

OBJECTIVE

To study the relationship between parenchymal head volume (PHV) and intracranial volume (ICV), and to compare the ability of these two measurements to reflect the association between maximum mature brain volume and late-life cognition.

METHODS

An elderly sample of humans with a range of cognitive functions from normality, via mild cognitive impairment (MCI) to dementia (mean age 78.6, S.D. 2.8; mean MMSE 25.4, S.D. 4.2) was examined. Head-to-head measurements of ICV and parenchymal head volume (PHV) were obtained from three-dimensional T1 weighted magnetic resonance images using automated procedures. Analyses of cognitive functions were based on continuous and categorial variables.

RESULTS

PHV explained 55% of the variance in ICV. The ratio between PHV and ICV remained constant with increasing age and cognitive impairment. Measurements of PHV and ICV yielded comparable correlations with global cognitive performance. Group differences over gender and cognitive states were equally present in ICV and PHV. The relative risks of cognitive impairment that were associated with either small ICV or PHV were comparable.

CONCLUSIONS

Measures of PHV can be considered as useful estimates of ICV and cerebral volume reserve.