Annual conversion to alzheimer disease among patients with memory complaints attending an outpatient memory clinic: the influence of amnestic mild cognitive impairment and the predictive value of neuropsychological testing

Visuoconstructional Abilities of Patients With Subjective Cognitive Decline, Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

Via the Vienna Visuoconstructional Test 3.0 (VVT 3.0) delayed recall we combined the assessment of visuoconstructive abilities and memory and investigated the test's potential to support diagnostic processes, including staging and the elaboration of a cognitive profile.

METHODS

We retrospectively analysed the data of 368 patients of the Department of Neurology, Medical University of Vienna, between 04/2014 and 10/2020 that had performed the VVT 3.0. Our sample involved 70 healthy controls (HC), 29 patients with subjective cognitive decline (SCD), 154 patients with mild cognitive impairment (MCI) and 115 patients with Alzheimer's disease (AD). We investigated the differences in the VVT 3.0 scores, as well as the VVT's ability to differentiate between AD and nonAD by calculating receiver-operating-characteristic (ROC) curves, ideal cut-offs and a logistic regression model.

RESULTS

Results stated that the VVT 3.0 delayed recall scores were able to differentiate between all diagnostic groups, respectively, except HC-SCD and SCD-MCI. The ROC analyses determined an AUC of 0.890, 95% CI [0.855; 0.925], P < .001, and the ideal cut-off at 29.5 points that maximised sensitivity at 0.896 and specificity at 0.81. The logistic regression model classified 83.4% of AD patients correctly and delivered a significant Cohen's Kappa of 0.619 (P < .001).

CONCLUSION

As the VVT 3.0 revealed satisfactory values of diagnostic accuracy in our sample, it could enrich clinical diagnosing. However, for more clarity about its informative value in other populations, there remains a need for future studies with other samples.

Altered intrinsic default mode network functional connectivity in patients with remitted geriatric depression and amnestic mild cognitive impairment

OBJECTIVES

Patients with geriatric depression exhibit a spectrum of symptoms ranging from mild to severe cognitive impairment which could potentially lead to the development of Alzheimer's disease (AD). The aim of the study is to assess the alterations of the default mode network (DMN) in remitted geriatric depression (RGD) patients and whether it could serve as an underlying neuropathological mechanism associated with the risk of progression of AD.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 154 participants, comprising 66 RGD subjects (which included 27 patients with comorbid amnestic mild cognitive impairment [aMCI] and 39 without aMCI [RGD]), 45 aMCI subjects without a history of depression (aMCI), and 43 matched healthy comparisons (HC), were recruited.

MEASUREMENTS

All participants completed neuropsychological tests and underwent resting-state functional magnetic resonance imaging (fMRI). Posterior cingulate cortex (PCC)-seeded DMN functional connectivity (FC) along with cognitive function were compared among the four groups, and correlation analyses were conducted.

RESULTS

In contrast to HC, RGD, aMCI, and RGD-aMCI subjects showed significant impairment across all domains of cognitive functions except for attention. Furthermore, compared with HC, there was a similar and significant decrease in PCC-seed FC in the bilateral medial superior frontal gyrus (M-SFG) in the RGD, aMCI, and RGD-aMCI groups.

CONCLUSIONS

The aberrations in rsFC of the DMN were associated with cognitive deficits in RGD patients and might potentially reflect an underlying neuropathological mechanism for the increased risk of developing AD. Therefore, altered connectivity in the DMN could serve as a potential neural marker for the conversion of geriatric depression to AD.

Urban-rural disparities in mild cognitive impairment and its functional subtypes among community-dwelling older residents in central China

BACKGROUND

Substantial variations in the prevalence of mild cognitive impairment (MCI) and its subtypes have been reported, although mostly in geographically defined developed countries and regions. Less is known about MCI and its subtypes in rural areas of less developed central China.

AIMS

The study aimed to compare the prevalence of MCI and its subtypes in residents aged 65 years or older in urban and rural areas of Hubei Province, China.

METHODS

Participants aged 65 years or older were recruited between 2018 and 2019. Inperson structured interviews and clinical and neuropsychological assessments were performed at city health community centres and township hospitals.

RESULTS

Among 2644 participants without dementia, 735 had MCI, resulting in a prevalence of 27.8% for total MCI, 20.9% for amnestic MCI (aMCI) and 6.9% for non-amnestic MCI (naMCI). The prevalence of MCI in urban and rural areas was 20.2% and 44.1%, respectively. After adjusting for demographic factors, the prevalence of total MCI, aMCI and naMCI differed significantly between rural and urban areas (adjusted odds ratio (OR) 2.10, 1.44 and 3.76, respectively). Subgroup analysis revealed an association between rural socioeconomic and lifestyle disadvantage and MCI and its subtypes.

CONCLUSIONS

Our findings suggest that the prevalence of MCI among urban residents in central China is consistent with that in other metropolis areas, such as Shanghai, but the prevalence in rural areas is twice that in urban areas. Prospective studies and dementia prevention in China should focus on rural areas.

Characteristics of Individuals Who Converted to Dementia during a 5-Year Follow-Up

INTRODUCTION

Early diagnosis of dementia is important; however, the diagnostic criteria for the preclinical stage of dementia, including biomarkers and pathophysiological markers, are not suitable for application in patients in real-world clinical settings. One potential noninvasive method to predict the risk of dementia conversion is the neuropsychological test. Therefore, in this study, we examined the results of various assessments, such as comprehensive neuropsychological tests, and the daily function of participants who were evaluated periodically for 5 years.

METHODS

All participants were outpatients or inpatients with subjective cognitive complaints, who visited a local university hospital for neuropsychiatric evaluation, between January 2011 and January 2019. Of a total of 1,652 subjects who underwent initial screening during this period, 107 were nondemented individuals. These participants underwent periodic comprehensive cognitive tests for up to 5 years. Survival and factors affecting dementia conversion were analyzed using the time-dependent Cox regression analysis. Assessment items included demographic information, including age, sex, and education; 5 cognitive domains of a comprehensive neuropsychological test including memory, language, attention, visuospatial functions, and frontal (executive) function; Barthel's activities of daily living; the mini-mental state examination findings; and clinical dementia rating (CDR) scores.

RESULTS

This study included 61 participants (21 women and 40 men) who developed dementia during the study period. Verification of the cognitive variables affecting dementia conversion revealed that better memory was associated with a lower risk of conversion (hazard ratio [HR] = 0.614, p = 0.005) and higher attention was associated with a higher risk of conversion (HR = 1.602, p = 0.023). In the analysis of the subscales of the CDR, a higher community affairs score (i.e., less social activities) was associated with a higher risk of conversion (HR = 10.814, p = 0.028).

CONCLUSION

Individuals with prominent memory decline or problems with social activities should be carefully observed for dementia conversion. Cognitive intervention techniques for cognitive stimulation, such as social and leisure activities, as well as cognitive training need to be actively used for patients in whom dementia is a concern.

Neuropsychological Contribution to Predict Conversion to Dementia in Patients with Mild Cognitive Impairment Due to Alzheimer's Disease

BACKGROUND

Diagnosis of Alzheimer's disease (AD) confirmed by biomarkers allows the patient to make important life decisions. However, doubt about the fleetness of symptoms progression and future cognitive decline remains. Neuropsychological measures were extensively studied in prediction of time to conversion to dementia for mild cognitive impairment (MCI) patients in the absence of biomarker information. Similar neuropsychological measures might also be useful to predict the progression to dementia in patients with MCI due to AD.

OBJECTIVE

To study the contribution of neuropsychological measures to predict time to conversion to dementia in patients with MCI due to AD.

METHODS

Patients with MCI due to AD were enrolled from a clinical cohort and the effect of neuropsychological performance on time to conversion to dementia was analyzed.

RESULTS

At baseline, converters scored lower than non-converters at measures of verbal initiative, non-verbal reasoning, and episodic memory. The test of non-verbal reasoning was the only statistically significant predictor in a multivariate Cox regression model. A decrease of one standard deviation was associated with 29% of increase in the risk of conversion to dementia. Approximately 50% of patients with more than one standard deviation below the mean in the z score of that test had converted to dementia after 3 years of follow-up.

CONCLUSION

In MCI due to AD, lower performance in a test of non-verbal reasoning was associated with time to conversion to dementia. This test, that reveals little decline in the earlier phases of AD, appears to convey important information concerning conversion to dementia.

Alpha Power and Functional Connectivity in Cognitive Decline: A Systematic Review and Meta-Analysis

Background:

Mild cognitive impairment (MCI) is a stage between expected age-related cognitive decline and dementia. Dementias have been associated with changes in neural oscillations across the frequency spectrum, including the alpha range. Alpha is the most prominent rhythm in human EEG and is best detected during awake resting state (RS). Though several studies measured alpha power and synchronization in MCI, findings have not yet been integrated.

Objective:

To consolidate findings on power and synchronization of alpha oscillations across stages of cognitive decline.

Methods:

We included studies published until January 2020 that compared power or functional connectivity between 1) people with MCI and cognitively healthy older adults (OA) or people with a neurodegenerative dementia, and 2) people with progressive and stable MCI. Random-effects meta-analyses were performed when enough data was available.

Results:

Sixty-eight studies were included in the review. Global RS alpha power was lower in AD than in MCI (ES = –0.30; 95% CI = –0.51, –0.10; k = 6), and in MCI than in OA (ES = –1.49; 95% CI = –2.69, –0.29; k = 5). However, the latter meta-analysis should be interpreted cautiously due to high heterogeneity. The review showed lower RS alpha power in progressive than in stable MCI, and lower task-related alpha reactivity in MCI than in OA. People with MCI had both lower and higher functional connectivity than OA. Publications lacked consistency in MCI diagnosis and EEG measures.

Conclusion:

Research indicates that RS alpha power decreases with increasing impairment, and could—combined with measures from other frequency bands—become a biomarker of early cognitive decline.

Susceptibility and Volume Measures of the Mammillary Bodies Between Mild Cognitively Impaired Patients and Healthy Controls

Purpose

To investigate the baseline values and differences for susceptibility and volume of the mammillary bodies between mild cognitively impaired (MCI) patients and healthy controls (HCs), and further explore their differences in relation to gender, MCI subtypes and apolipoprotein E (APOE) genotypes.

Methods

T1-weighted and multi-echo gradient echo imaging sequences were acquired on a 3T MR scanner to evaluate the T1W based volume and susceptibility differences in the mammillary body for 47 MCI and 47 HCs. T-tests were performed to compare volume and susceptibility between groups, and right and left hemispheres. Correlation analysis was used to relate the volume and mean susceptibility as a function of age in MCI and HC groups separately, and to investigate the relationship of susceptibility with the neuro-psychological scales in the MCI group.

Results

Susceptibility was found to be elevated within the right mammillary body in MCI patients compared to HCs (p < 0.05). There were no differences for the mammillary body volumes between the MCI and HC groups, although there was a reduction in volume with age for the MCI group (p = 0.007). Women showed decreased mammillary body volume compared to men in the HC group (p = 0.004). No significant differences were found in relation to MCI subtypes and APOE genotypes. No significant correlations were observed between mammillary body susceptibility with neuro-psychological scales.

Conclusion

This work provides a quantitative baseline for both the volume and susceptibility of the mammillary body which can be used for future studies of cognitive impairment patients underlying the pathology of the Papez circuit.

Verbal fluency as a screening tool for mild cognitive impairment

OBJECTIVES

The goal of this study was to evaluate the ability of semantic (animal naming) and phonemic (FAS) fluency in their ability to discriminate between normal aging, amnestic-Mild Cognitive Impairment (a-MCI), and Alzheimer's disease (AD).

DESIGN

We used binary logistic regressions, multinomial regressions, and discriminant analysis to evaluate the predictive value of semantic and phonemic fluency in regards to specific diagnostic classifications.

SETTING

Outpatient geriatric neuropsychology clinic.

PARTICIPANTS

232 participants (normal aging = 99, a-MCI = 90, AD = 43; mean age = 65.75 years).

MEASUREMENTS

Mini-mental State Examination (MMSE), Controlled Oral Word Association Test.

RESULTS

Results indicate that semantic and phonemic fluency were significant predictors of diagnostic classification, and semantic fluency explained a greater amount of the discriminant ability of the model.

CONCLUSIONS

These results suggest that verbal fluency, particularly semantic fluency, may be an accurate and efficient tool in screening for early dementia in time-limited medical settings.

Determining the effects of LLD and MCI on brain decline according to machine learning and a structural covariance network analysis

BACKGROUND

Late-life depression (LLD) and mild cognitive impairment (MCI) are risk factors for Alzheimer disease (AD). However, the interactive effect between LLD and MCI in the progression to AD remains unknown. The purpose of this research is to clarify whether this interaction exists and determined the characteristics of the structural change patterns in LLD and MCI.

METHOD

To address this question, a total 225 participants (91 with intact cognitive function (IC), 34 with MCI, 35 with LLD-IC, 47 with LLD-MCI and 18 with AD) were recruited for the current study and their T1 scanning were acquired. Machine learning was applied to estimate the brain's age gap according to grey matter information (thickness and volume was calculated based on the Human Connectome Project Multi-Modal Parcellation version 1.0 and the Desikan atlas). A structural covariance network (SCN) was constructed based on grey matter volume. Rich-club analysis, global network properties and the Jaccard distance were utilized to describe the topological features in each cohort. Their cognitive functions (executive function, processing speed and memory) were evaluated by a full-scale battery of neuropsychological tests.

RESULT

The interactive effect between LLD and MCI was detected through the brain age gap. The estimated age was positively correlated with processing speed and memory in LLD and non-LLD subjects. In the SCN analysis, the rich-club coefficient and global network properties were disrupted in the MCI group, but remained normal in the LLD-IC, LLD-MCI and AD groups. There was a significant discrepancy in brain structural change patterns between the AD and other cohorts by the Jaccard distance.

CONCLUSION

The application of machine learning reflects that synergies between LLD and MCI could increase the risk of developing AD. According to the SCN, the structural coordination was disrupted in MCI and was kept normal in the other cohorts, while the discrepancies in brain structural change patterns appeared in AD. Overall, the brain age gap could be a potential predictor of AD, and the Jaccard distance has the potential to be a new type of SCN analysis indicator.

Changes in Plasma Amyloid and Tau in a Longitudinal Study of Normal Aging, Mild Cognitive Impairment, and Alzheimer's Disease

BACKGROUND

Changes in cerebrospinal fluid, neuroimaging, and cognitive functions have been used as diagnostic biomarkers of Alzheimer's disease (AD). This study aimed to investigate the temporal trajectories of plasma biomarkers in subjects with mild cognitive impairment (MCI) and patients with AD relative to healthy controls (HCs).

METHODS

In this longitudinal study, 82 participants (31 HCs, 33 MCI patients, and 18 AD patients) were enrolled. After 3 years, 7 HCs had transitioned to MCI and 10 subjects with MCI had converted to AD. We analyzed plasma amyloid beta (Aβ) and tau proteins at baseline and annually to correlate with biochemical data and neuropsychological scores.

RESULTS

Longitudinal data analysis showed an evolution of Aβ-related biomarkers over time within patients, whereas tau-related biomarkers differed primarily across diagnostic classifications. An initial steady increase in Aβ42 in the MCI stage was followed by a decrease just prior to clinical AD onset. Hyperphosphorylated tau protein levels correlated with cognitive decline in the MCI stage, but not in the AD stage.

CONCLUSION

Plasma Aβ and tau levels change in a dynamic, nonlinear, nonparallel manner over the AD continuum. Changes in plasma Aβ concentration are time-dependent, whereas changes in hyperphosphorylated tau protein levels paralleled the clinical progression of MCI. It remains to be clarified whether diagnostic efficiency can be improved by combining multiple plasma markers or combining plasma markers with other diagnostic biomarkers.

Neuropsychological predictors of cognitive deterioration in non-demented individuals

Introduction: Previous studies performed neuropsychological tests in non-demented patients, especially those with mild cognitive impairment (MCI), to predict dementia. Few recent studies reported that subjective cognitive decline (SCD) itself predicts dementia conversion. We evaluated certain characteristics and neuropsychological tests to predict cognitive deterioration in non-demented individuals.Methods: This study included 106 participants with subjective cognitive complaints (SCCs) classified as non-demented (90 MCI and 16 SCD). Data were collected at baseline and follow-up, wherein participants completed a comprehensive neuropsychological assessment to assess their cognitive and daily functions.Results: During the follow-up of all participants, 52 converted to dementia, while 54 did not. There were significant differences in age and education years, as well as language, memory, frontal lobe function, and Barthel's Activities of Daily Living Index between the groups. Correlation analysis showed a significant correlation between the deterioration of the Clinical Dementia Rating scores and baseline language, memory, and frontal lobe function scores.Conclusion(s): SCDs consistently worrying about their SCCs and those identified with SCD by their caregivers were prone to cognitive function deterioration over time. Changes in language, memory, and frontal lobe function in neurocognitive tests were significantly different between the dementia converters and non dementia converters group. Particularly, SCD and MCI individuals with significantly poor initial executive function and memory abilities should be closely monitored for future cognitive decline.

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.

Identifying brain changes related to cognitive aging using VBM and visual rating scales

Aging is often associated with changes in brain structures as well as in cognitive functions. Structural changes can be visualized with Magnetic Resonance Imaging (MRI) using voxel-based grey matter morphometry (VBM) and visual rating scales to assess atrophy level. Several MRI studies have shown that possible neural correlates of cognitive changes can be seen in normal aging. It is still not fully understood how cognitive function as measured by tests and demographic factors are related to brain changes in the MRI. We recruited 55 healthy elderly subjects aged 50–79 years. A battery of cognitive tests was administered to all subjects prior to MRI scanning. Our aim was to assess correlations between age, sex, education, cognitive test performance, and the said two MRI-based measures. Our results show significant differences in VBM grey matter volume for education level (≤ 12 vs. > 12 years), with a smaller amount of grey matter volume in subjects with lower educational levels, and for age in interaction with education, indicating larger grey matter volume for young, higher educated adults. Also, grey matter volume was found to be correlated with working memory function (Digit Span Backward). Furthermore, significant positive correlations were found between visual ratings and both age and education, showing larger atrophy levels with increasing age and decreasing level of education. These findings provide supportive evidence that MRI-VBM detects structural differences for education level, and correlates with educational level and age, and working memory task performance.

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VBM grey matter volume differences were significant for the interaction of age and education level.

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Grey matter volume correlated with education level and working memory function (Digit Span Backward).

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Significant correlations were found between visual rating scales and both age and education.

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VBM is able to detect structural differences for age and education, and correlates with education and working memory.

Late-Life Depression versus Amnestic Mild Cognitive Impairment: Alzheimer's Disease Incidence in 4 Years of Follow-Up

BACKGROUND/AIM

The aim of the study was to evaluate the prognostic power of late-life depression (LLD) compared with amnestic mild cognitive impairment (aMCI) for the onset of Alzheimer's disease (AD) within 4 years of follow-up.

METHODS

We estimated the incidence of AD in 60 patients presenting with aMCI, 115 patients suffering of LLD treated with antidepressants with good compliance, and 66 healthy control (HC) patients, followed for 4 years.

RESULTS

The risk to develop AD, within 4 years, was 68.33% for aMCI and 49.57% for LLD. In AD patients 5.60% deteriorated without depression, and 72.20% deteriorated with depression after 4 years of follow-up (p < 0.0001). No HC patients deteriorated to AD or any other dementia type.

CONCLUSION

In our results, aMCI was the first predictive condition that increased the risk to develop AD. Depression is a potentially preventable medical condition across the lifespan and may be a modifiable risk factor.

Screening for dementia with the Vienna Visuo-Constructional Test 3.0 screening (VVT 3.0 screening)

BACKGROUND

Visuo-constructive functions are an important cognitive domain for the diagnosis and early detection of dementia. Using the Vienna Visuo-Constructional Test 3.0 Screening (VVT 3.0 Screening), we assessed visuo-constructive performance in subjective cognitive decline (SCD), mild cognitive impairment (MCI), Alzheimer's disease (AD), and healthy control (HC) groups to determine whether VVT scores can be used to distinguish the mentioned diagnostic groups and predict disease progression to more advanced stages.

METHODS

We analyzed the data of 422 patients referred to the Department of Neurology, Medical University of Vienna, for assessment of neurocognitive status. We also examined 110 of these patients in a follow-up with regard to stability of performance and disease progression. We compared VVT performance across diagnostic groups and explored associations with relevant sociodemographic and clinical variables. Predictive validity was assessed using receiver operator characteristic (ROC) curves and multinomial logistic regression analyses.

RESULTS

We found that most diagnostic groups differed significantly regarding VVT scores. These were shown to reliably identify cases suffering from visuo-constructive impairment but were not sufficient for classification into all diagnostic groups. Progression to more advanced disease stages could not be reliably predicted using VVT scores, possibly because subsamples of progressors were quite small.

CONCLUSION

VVT scores are useful indicators for identifying visuo-constructive impairment but are limited by factors such as similar disease manifestations when used to discriminate between several diagnostic groups. The same factors complicate the use of VVT scores for predicting disease progression to more advanced stages.

The characteristic of cognitive dysfunction in remitted late life depression and amnestic mild cognitive impairment

Remitted late life depression exhibits persistent cognitive impairments and enhances the risk of dementia. This study aimed to examine the characteristics of cognitive dysfunction in remitted late life depression and amnestic mild cognitive impairment (MCI). Remitted late life depression (n=61), amnestic MCI (n=61) and age-education-matched controls (n=65) were evaluated with a battery of neuropsychological tests grouped into executive function, memory, processing speed, attention and visuospatial domains. Compared with control subjects, amnestic MCI individuals showed more severe cognitive impairments in all domains, while remitted late life depression individuals performed worse in executive function and memory. The pattern of cognitive profiles significantly differed between remitted late life depression and amnestic MCI groups, which might be mainly attributed to worse impairments in memory and executive function in amnestic MCI individuals. Executive function was the core impaired cognitive domain mediating the influence of predictors on other cognitions in both remitted late life depression and amnestic MCI groups, which indicated a possible etiopathogenic mechanism underlying the conversion to dementia.

Self-reported and informant-reported memory functioning and awareness in patients with mild cognitive impairment and Alzheimer´s disease

Background

Awareness of subjective memory is an important factor for adequate treatment of patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). This study served to find out whether awareness of subjective memory complies with objective performance, if differences in awareness are observed longitudinally and whether decrease of awareness can serve as a predictor of AD in MCI patients.

Methods

Thirty-four patients with MCI seeking help in a memory outpatient clinic were included. All participants underwent thorough neuropsychological examination. Awareness of subjective memory was obtained by calculating difference scores between patient and informant ratings on a 16-item questionnaire concerning complaints about loss of memory in every-day life. Retesting was performed after a mean follow-up period of 24 months.

Results

Whole group analyses showed that awareness remained relatively stable across time. Self-reported memory complaints correlated with episodic memory at baseline and with performance on a language task at follow-up. Retests displayed decrease of awareness. At group level differences in awareness between both times of assessment were not significant for MCI and MCI patients converting to mild AD at follow-up. The predictive value of awareness was low.

Conclusions

Awareness of subjective memory deficit is linked to episodic memory function and decreases with decline of cognitive ability. Further studies evaluating predictive power of awareness of subjective memory should include a larger patient sample.

Subjective Memory Complaints and Conversion to Dementia in Patients with Subjective Cognitive Decline and Patients with Mild Cognitive Impairment

Abstract. Background: Subjective cognitive complaints and their clinical significance are discussed controversially. Objectives: To determine the clinical validity of subjective cognitive complaints among subjects with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). Design: Longitudinal study with one follow up examination at a University based out-patient memory clinic. Participants: A clinical sample of patietns with SCD and MCI (n = 141), aged 50 and older, who came to the memory outpatient clinic. Results: No significant differences between converters and non converters regarding subjective cognitive complaints were detected. MCI patients had a higher risk than the patients with SCD developing AD (OR = 7.3 [CI 0.9 to 61.2]. Verbal memory testing using the Verbal Selektive Reminding Test (VSRT) showed better diagnostic validity than subjective cognitive complaints using the Forgetfulness Assessment Inventory (FAI) in predicting conversion to dementia. Conclusion: Verbal memory testing was superior in predicting conversion to dementia compared to subjective cognitive complaints.

Patients with mild cognitive impairment have an abnormal upper-alpha event-related desynchronization/synchronization (ERD/ERS) during a task of temporal attention

There are several evidences indicating that an impairment in attention-executive functions is present in prodromal Alzheimer's disease and predict future global cognitive decline. In particular, the issue of temporal orienting of attention in patients with mild cognitive impairment (MCI) due to Alzheimer's disease has been overlooked. The present research aimed to explore whether subtle deficits of cortical activation are present in these patients early in the course of the disease. We studied the upper-alpha event-related synchronization/desynchronization phenomenon during a paradigm of temporal orientation of attention. MCI patients (n = 27) and healthy elderly controls (n = 15) performed a task in which periodically omitted tones had to be predicted and their virtual onset time had to be marked by pressing a button. Single-trial responses were measured, respectively, before and after the motor response. Then, upper-alpha responses were compared to upper-alpha power during eyes-closed resting state. The time course of the task was characterized by two different behavioral conditions: (1) a pre-event epoch, in which the subject awaited the virtual onset of the omitted tone, (2) a post-event epoch (after button pressing), in which the subject was in a post-motor response condition. The principal findings are: (1) during the waiting epoch, only healthy elderly had an upper-alpha ERD at the level of both temporal and posterior brain regions; (2) during the post-motor epoch, the aMCI patients had a weaker upper-alpha ERS on prefrontal regions; (3) only healthy elderly showed a laterality effect: (a) during the waiting epoch, the upper-alpha ERD was greater at the level of the right posterior-temporal lead; during the post-motor epoch, the upper alpha ERS was greater on the left prefrontal lead. The relevance of these findings is that the weaker upper-alpha response observed in aMCI patients is evident even if the accuracy of the behavioral performance (i.e., button pressing) is still spared. This abnormal upper-alpha response might represent an early biomarker of the attention-executive network impairment in MCI due to Alzheimer's disease.

In vivo parahippocampal white matter pathology as a biomarker of disease progression to Alzheimer's disease

Noninvasive diagnostic tests for Alzheimer's disease (AD) are limited. Postmortem diagnosis is based on density and distribution of neurofibrillary tangles (NFTs) and amyloid-rich neuritic plaques. In preclinical stages of AD, the cells of origin for the perforant pathway within the entorhinal cortex are among the first to display NFTs, indicating its compromise in early stages of AD. We used diffusion tensor imaging (DTI) to assess the integrity of the parahippocampal white matter in mild cognitive impairment (MCI) and AD, as a first step in developing a noninvasive tool for early diagnosis. Subjects with AD (N = 9), MCI (N = 8), or no cognitive impairment (NCI; N = 20) underwent DTI-MRI. Fractional anisotropy (FA) and mean (MD) and radial (RD) diffusivity measured from the parahippocampal white matter in AD and NCI subjects differed greatly. Discriminant analysis in the MCI cases assigned statistical membership of 38% of MCI subjects to the AD group. Preliminary data 1 year later showed that all MCI cases assigned to the AD group either met the diagnostic criteria for probable AD or showed significant cognitive decline. Voxelwise analysis in the parahippocampal white matter revealed a progressive change in the DTI patterns in MCI and AD subjects: whereas converted MCI cases showed structural changes restricted to the anterior portions of this region, in AD the pathology was generalized along the entire anterior-posterior axis. The use of DTI for in vivo assessment of the parahippocampal white matter may be useful for identifying individuals with MCI at highest risk for conversion to AD and for assessing disease progression.

The unbearable lightness of MCI

The title of this Editorial, with apologies to Milan Kundera (Kundera, 1985) implies no lack of gravitas in the concept of Mild Cognitive Impairment (MCI). Rather, it refers to the current definitions of MCI being somewhat free-floating, loosely anchored to diagnostic frameworks, and more conceptual than operational. In their defense, we cannot completely obliterate the flexibility clinicians need in order to exercise expert judgment and take individual patients’ circumstances into account when making clinical diagnoses. Further, it would be imprudent to prematurely codify diagnostic criteria for MCI; after all, we are still gathering basic information about the wide range of mildly impaired states that we encounter in different clinical settings and in the population at large.

Development of the ubiquitous spaced retrieval-based memory advancement and rehabilitation training program

OBJECTIVE

The Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program was developed by transforming the spaced retrieval-based memory training which consisted of 24 face-to-face sessions into a self-administered program with an iPAD app. The objective of this study was to evaluate the feasibility and efficacy of USMART in elderly subjects with mild cognitive impairment (MCI).

METHODS

Feasibility was evaluated by checking the satisfaction of the participants with a 5-point Likert scale. The efficacy of the program on cognitive functions was evaluated by the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery before and after USMART.

RESULTS

Among the 10 participants, 7 completed both pre- and post-USMART assessments. The overall satisfaction score was 8.0±1.0 out of 10. The mean Word List Memory Test (WLMT) scores significantly increased after USMART training after adjusting for age, educational levels, baseline Mini-Mental Status Examination scores, and the number of training sessions (pre-USMART, 16.0±4.1; post-USMART, 17.9±4.5; p=0.014, RM-ANOVA). The magnitude of the improvements in the WLMT scores significantly correlated with the number of training sessions during 4 weeks (r=0.793; p=0.033).

CONCLUSION

USMART was effective in improving memory and was well tolerated by most participants with MCI, suggesting that it may be a convenient and cost-effective alternative for the cognitive rehabilitation of elderly subjects with cognitive impairments. Further studies with large numbers of participants are necessary to examine the relationship between the number of training sessions and the improvements in memory function.

Vascular predictors of cognitive decline in patients with mild cognitive impairment

Our aim in this study was to assess the relationship between the state of cerebral vessels and the risk of conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD). We included 117 MCI patients. They underwent an ultrasonographic assessment of common carotid arteries intima-media thickness (IMT) and carotid plaque index. Cerebrovascular reactivity to hypercapnia in the middle cerebral arteries was calculated with the Breath-Holding Index (BHI). After a 12-month follow-up period, neuropsychological examinations demonstrated a progression to dementia in 21 patients. Pathological values of BHI and IMT significantly increased the risk of conversion (BHI: odds ratio, 5.80; 95% confidence interval, 1.83-18.37, p < 0.05; IMT: odds ratio, 3.08; 95% confidence interval, 1.02-9.33; p < 0.05, multinomial logistic regression analysis). Comparison between patients with all normal values and those with the simultaneous alteration of the 2 vascular indexes showed an increase in the risk of conversion from 9% to 33% (ordinal regression analysis). Our findings show that alterations of cerebral vessel functional and anatomic status increase the risk of conversion from MCI to dementia.

Data mining methods in the prediction of Dementia: A real-data comparison of the accuracy, sensitivity and specificity of linear discriminant analysis, logistic regression, neural networks, support vector machines, classification trees and random forests

Background

Dementia and cognitive impairment associated with aging are a major medical and social concern. Neuropsychological testing is a key element in the diagnostic procedures of Mild Cognitive Impairment (MCI), but has presently a limited value in the prediction of progression to dementia. We advance the hypothesis that newer statistical classification methods derived from data mining and machine learning methods like Neural Networks, Support Vector Machines and Random Forests can improve accuracy, sensitivity and specificity of predictions obtained from neuropsychological testing. Seven non parametric classifiers derived from data mining methods (Multilayer Perceptrons Neural Networks, Radial Basis Function Neural Networks, Support Vector Machines, CART, CHAID and QUEST Classification Trees and Random Forests) were compared to three traditional classifiers (Linear Discriminant Analysis, Quadratic Discriminant Analysis and Logistic Regression) in terms of overall classification accuracy, specificity, sensitivity, Area under the ROC curve and Press'Q. Model predictors were 10 neuropsychological tests currently used in the diagnosis of dementia. Statistical distributions of classification parameters obtained from a 5-fold cross-validation were compared using the Friedman's nonparametric test.

Results

Press' Q test showed that all classifiers performed better than chance alone (p < 0.05). Support Vector Machines showed the larger overall classification accuracy (Median (Me) = 0.76) an area under the ROC (Me = 0.90). However this method showed high specificity (Me = 1.0) but low sensitivity (Me = 0.3). Random Forest ranked second in overall accuracy (Me = 0.73) with high area under the ROC (Me = 0.73) specificity (Me = 0.73) and sensitivity (Me = 0.64). Linear Discriminant Analysis also showed acceptable overall accuracy (Me = 0.66), with acceptable area under the ROC (Me = 0.72) specificity (Me = 0.66) and sensitivity (Me = 0.64). The remaining classifiers showed overall classification accuracy above a median value of 0.63, but for most sensitivity was around or even lower than a median value of 0.5.

Conclusions

When taking into account sensitivity, specificity and overall classification accuracy Random Forests and Linear Discriminant analysis rank first among all the classifiers tested in prediction of dementia using several neuropsychological tests. These methods may be used to improve accuracy, sensitivity and specificity of Dementia predictions from neuropsychological testing.

Cognitive function in elderly marathon runners: cross-sectional data from the marathon trial (APSOEM)

BACKGROUND

Cognitive impairment of the elderly contributes to morbidity, loss of quality of life, and impairment of work ability in aging western societies. Thus strategies to maintain cognitive function at an advanced age imply a great challenge to Occupational Medicine.

AIM

To study whether intensive endurance exercise training is associated with better cognitive performance and increases brain-derived neurotrophic factor (BDNF) and insulin-like growth factor (IGF).

METHODS

Active elderly marathon runners or bicyclists older than 60 years were recruited and matched with an inactive control group according to age, sex, and education years. After exclusion of various diseases according to the study protocol 56 athletes and 58 controls could be selected for follow-up studies. The influence of endurance training on cognitive function was assessed by the use of the Vienna Neuropsychological Test Battery and the CERAD test battery. Other relevant outcomes were the levels of BDNF, IGF-1, Apo e4 carrier state, and self-ratings.

RESULTS

The elderly marathon group performed better only in one specific cognitive task (the Five Point Test, p = 0.04) and almost significantly better in one additional test (the NAI Stroop Test, p = 0.08). Neither BDNF nor IGF-1 was related to the duration of daily exercise and no differences in the basal levels of these humoral growth factors in the exercise and the control cohort were found. Interestingly, we also found significantly decreased BDNF levels in subjects with Alzheimer's disease in the family in spite of the maintained normal cognitive performance (p = 0.01).

CONCLUSION

These results suggest that extensive endurance exercise training might be beneficial for maintaining cognitive function in elderly persons. Our data demonstrate that beneficial endurance training effects are not linked to the upregulation of the examined neurotrophins. Since we found reduced BDNF-levels in subjects with a positive family history of Alzheimer's disease, we speculate that BDNF-reduction might precede cognitive impairment.

Cognitive intervention programs for individuals with mild cognitive impairment: systematic review of the literature

This systematic literature review addressed the efficacy of 15 cognitive intervention programs that have been tested in individuals presenting with mild cognitive impairment of the amnestic type (MCI-A) possibly at risk to progress toward dementia. MEDLINE, PsycINFO, and Current Content databases were searched using the following key terms: cognitive training, cognitive stimulation, cognitive rehabilitation, neuropsychological intervention, memory training, memory stimulation, and Mild Cognitive Impairment. The data showed statistically significant improvements at the end of training on 44% of objective measures of memory, when compared with 12% of objective measures of cognition other than memory. Statistically significant improvements after treatment were obtained on 49% of subjective measures of memory, quality of life, or mood. Samples sizes ranged from 1 to 193 patients with MCI-A but were usually < or =30. Five studies were randomized controlled trials, eight were quasiexperimental designs, and two were single-case investigations. Some programs focused only on memory, whereas other programs used multifaceted approaches targeting two or more cognitive functions. Eight were offered in groups, and seven took place on an individual basis. Recommendations to improve cognitive interventions in MCI-A are proposed, such as using large samples and a robust experimental design, as well as the implementation of a standardized cognitive training manual. Well standardized and validated direct and indirect measures of efficacy and noncognitive outcomes are also a crucial issue. A consensus meeting among all the experts working on cognitive training in this population should occur to provide guidelines to improve this treatment option.

A comparison study of mild cognitive impairment with 3 memory tests among Chinese individuals

OBJECTIVE

To examine whether 3 common memory tests differ statistically in terms of mild cognitive impairment (MCI) discrimination rates and conversion rates to Alzheimer disease.

METHODS

A sample of 329 Chinese patients who consulted our memory clinic in Shanghai were tested using tasks including the auditory verbal learning test (AVLT), the logical memory (LM) test, the Rey-Osterrieth complex figure test, and other neuropsychologic tasks. One hundred and forty-nine of these patients were tested again using the identical tests 2 years later. The diagnose standard of probable Alzheimer disease is the same as the standard of the National Institute of Neurological and Communicative Diseases and Stroke-Alzheimer Disease and Related Disorders Association.

RESULTS

The results of the MCI discrimination rates are as follows: AVLT-II (51%) >AVLT-I (31%) > complex figure test-II (27%) >LM-I (21%)=LM-II (21%) (I-immediate recall; II-delayed recall). The MCI group categorized based on LM-II cutoff has a higher conversion rate per year (24%), but also a higher reversal rate and missed diagnosis rate, whereas the group based on AVLT-II cutoff has a lower conversion rate per year (12%), but also a lower reversal rate and missed diagnosis rate.

CONCLUSIONS

The MCI discrimination rate and the conversion rate among different episodic memory tests are differ considerably.

Balneotherapy, prevention of cognitive decline and care the Alzheimer patient and his family: outcome of a multidisciplinary workgroup

According to the latest forecasts of the INSEE - Institut National de la Statistique et des Etudes Economiques (National Statistics and Economic Studies Institute), ageing of the French population will increase between 2005 and 2050: whereas 20.8% of the population living in continental France reached the age of 60 years or more in 2005, this proportion would be of 30.6% in 2035 and 31.9% in 2050. In 2050, 22.3 million persons will have reached the age of 60 years or more compared to 12.6 million in 2005, increasing by 80% in a 45-year period. In line with the actual age pyramid, ageing is unavoidable, as those who will reach 60 years of age in 2050 are already born (in 1989 or before). This expansion will be most important between 2006 and 2035, when the numerous "baby-boom" generations born between 1946 and 1975, will reach these ages. In future years, lifespan improvement will only emphasize this increase. Even if life expectancy stabilizes at the 2005 level, the number of seniors reaching 60 years or more would still increase to 50% between 2005 and 2050. This issue is identical in all countries of the European Union. Ageing is a major risk factor for dementia that will considerably worsen in the next years, if no curative therapies are found. Today, 25 million persons in the world suffer from Alzheimer's disease (AD). In France, it is estimated that 860,000 persons are affected and that 225,000 news cases are annually diagnosed. After 75 years of age, more than 20% of women and 13% of men are concerned. Forecasts for the coming years are frightening. Considering ageing of the population, the number of Alzheimer's disease cases should raise to 1.3 million in 2020 (20 patients for 1000 inhabitants) ant 2.1 million in 2040 (30 patients for 1000 inhabitants).

Screening for mild cognitive impairment: a systematic review

OBJECTIVE

Patients with mild cognitive impairment account for a significant number of referrals to old age psychiatry services and specialist memory clinics. The cognitive evaluation of such patients is commonly restricted to brief dementia screens, with no consideration to their suitability for assessing MCI. Here, we review the utility of such cognitive screens for MCI and provide an overview of validated instruments.

METHODS

We identified papers published after Petersen and colleagues 1999 MCI criteria (Petersen et al., 1999) and examining face-to-face cognitive screening for MCI from publication databases using combinations of the search terms 'mild cognitive impairment' and 'cognitive screening'. We also combined the former search with the names of 39 screening tests recently identified in a relevant review (Cullen et al., 2007).

RESULTS

Fifteen cognitive screening instruments were identified, 11 cover a restricted range of cognitive domains. High sensitivity and specificity for MCI relative to healthy controls were reported for two comprehensive and two noncomprehensive screening instruments, adequate test-retest and inter-rater reliability for only one of these. With the exception of three studies, sample sizes were universally small (i.e. n </= 100), and prognostic values were reported for only two of the identified 15 screening measures. Sensitivities of the full domain measures were universally high, but information about their specificity against psychiatric and non-progressive neurological conditions and predictive validity is lacking.

CONCLUSION

Several cognitive screening instruments afford the clinician the ability to detect MCI, early AD, and in some cases non-AD dementia, but they cannot currently be used to make reliable inferences about the course and eventual outcome of MCI.

Psychological distress and risk for dementia

The concept of mild cognitive impairment (MCI) primarily emphasizes changes in individuals' mental abilities, but it has recently been suggested that neuropsychiatric symptoms should also be considered important factors in age-related neurodegeneration. Psychological distress, defined as a reaction of an individual to external and internal stresses, is characterized by a mixture of psychological symptoms. It also may be considered a neuropsychiatric symptom encompassing depression, anxiety, and apathy. This paper reviews and summarizes recent evidence and relevant issues regarding the presence of psychological distress in healthy older adults and MCI patients and its relationship to risk for developing dementia. Results presented in this review show that psychological distress and depressive, anxious, and apathetic symptoms can be present in MCI and may predict progression to dementia. This article also provides suggestions for future research.

Prevention of progression to dementia in the elderly: rationale and proposal for a health-promoting memory consultation (an IANA Task Force)

Alzheimer's disease (AD) is the most frequent form of dementia and according to the most recent estimation it affects nearly 27 million people in the world. The onset of the disease is generally insidious. It is becoming increasingly evident that the underlying pathophysiological mechanisms are active long before the appearance of the clinical symptoms of the disease. In the current context, it is important to develop strategies to delay the onset of cognitive decline. Delaying the onset by 5 years would reduce the prevalence by half at term, and a delay of 10 years would reduce it by three-quarters. The effectiveness of currently suggested preventive approaches remains to be confirmed, but certain strategies could be applied straight away to at-risk subjects. We propose that a health-promoting memory consultation should be set up for elderly persons who have attended a specialized memory consultation and in whom the diagnosis of dementia and of AD in particular, has not been established by standardized tools. Through this consultation, they would be offered full multidimensional investigation of all aspects of their health status, follow-up could be organized, general practitioners in private practice could be made more conscious of this population and the elderly could be made more aware of the risk factors to which they are exposed. The development of an information policy for the elderly would meet a present need. In our reflection, we must take into account the question of how to give this preventive consultation its due place in the healthcare pathway of the elderly person in order to ensure coordinated follow-up with all the other health professionals involved. The principle of the health-promoting memory consultation is undergoing validation in a large French multicentre preventive trial in 1200 frail elderly persons aged 70 years followed for three years, the Multidomain Alzheimer Preventive Trial (MAPT).

The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases

Hyperhomocysteinemia (HHcy) is related to central nervous system diseases. Epidemiological studies show a positive, dose-dependent relationship between plasma total homocysteine (tHcy) concentration and neurodegenerative disease risk. tHcy is a marker of B-vitamin (folate, B(12), B(6)) status. Hypomethylation, caused by low B-vitamin status and HHcy, is linked to key pathomechanisms of dementia; B-vitamin supplementation could potentially reduce neurological damage. In retrospective studies, the association between tHcy and cognition is impressive; there is also evidence that tHcy-lowering treatment could be effective in primary and secondary stroke prevention. Increased tHcy and low serum folate occur in patients with Parkinson's disease, especially those receiving L-dopa. There is also an association between HHcy and multiple sclerosis, and between B-vitamin status and depression. Studies also confirm a causal role for tHcy in epilepsy, and certain anti-epileptics enhance HHcy. B-vitamin status should be optimized by ensuring sufficient intake in patients with neuropsychiatric diseases. HHcy occurs commonly in the elderly and can contribute to age-related neurodegeneration. Treatment with folic acid, B(12) and B(6) lowers tHcy. For secondary and primary prevention from several neuropsychiatric disorders, it seems prudent to actively identify deficient subjects and ensure sufficient vitamin intake.

Primary care physicians' attitudes related to cognition enhancers in early dementia: a representative eight-year follow-up study in Lower Saxony, Germany

OBJECTIVE

By means of a representative follow-up survey, we investigated changes in family physicians' (FPs) attitudes towards cognition enhancers in early dementia during 1993 and 2001.

METHODS

One hundred and twenty-two FPs (response rate 71.8%) in Lower Saxony, Germany, were randomly assigned to one of two written case samples presenting a patient with cognitive decline suggestive of early Alzheimer's disease (DAT; case A: female patient vs case B: male patient). Using a structured face-to-face interview, they were asked to suggest their potential drug treatment. The results were compared to corresponding data from our previous survey in 1993.

RESULTS

FPs' readiness to start antidementia drug treatment decreased from 70.4% in 1993 to 43.4% at follow-up, although underlying DAT was significantly more frequently suggested (11.0% vs 26.2%, p < 0.05). Substances with questionable efficacy such as Piracetame were prescribed less frequently in 2001 whereas evidence-based medication like cholinesterase inhibitors (ChEIs) failed to compensate for this drop. Compared to 1993, when 55.2% of FPs expected no therapeutic impact, at follow-up, 75.4% expected slowdown of disease progression, stabilisation or improvement of symptoms (p < 0.05).

CONCLUSIONS

Our results demonstrate a significant decrease of therapeutic nihilism in primary care within eight years. However, in patients with suspicion of DAT, this is not reflected accordingly in potential treatment.

Clinical referral patterns and cognitive profile in mild cognitive impairment

BACKGROUND

There is current interest in exploring the different subtypes of mild cognitive impairment (MCI), in terms of both their epidemiology and their cognitive profile.

AIMS

To examine the frequency of MCI subtypes presenting to a memory clinic and to document detailed neuropsychological profiles of patients with the amnestic subtype.

METHOD

Consecutive tertiary referrals (n=187) were psychiatrically evaluated; 45 patients met criteria for amnestic mild cognitive impairment (aMCI). A subgroup of 33 patients with aMCI as well as 21 healthy controls took part in a thorough neuropsychological examination.

RESULTS

Of the patients who were examined in greater neuropsychological detail, ten had pure aMCI (none with visual memory impairment only). Fifteen met criteria for non-amnestic MCI. Fifteen had normal neuropsychological profiles. Using more than one test increased sensitivity to detect episodic memory impairment.

CONCLUSIONS

Amnestic MCI is an important diagnosis in secondary and tertiary memory clinics. There is scope to improve the efficacy and sensitivity of the clinical assessment of this impairment.

Towards a cognitive stimulation program using an errorless learning paradigm in amnestic mild cognitive impairment

Considering the high risk for amnestic mild cognitive impairment (A-MCI) individuals to progress towards dementia, it is crucial to study the efficacy of innovative treatment strategies such as cognitive stimulation techniques. The present study is a case report of two individuals presenting with A-MCI who were enrolled in a memory training program. After a broad neuropsychological assessment, the two participants were trained with an errorless (EL) learning paradigm on an individual basis, twice a week, over three weeks. Two follow-up sessions took place one and five weeks after the end of the training. Results showed that the program was well tolerated and feasible, and enhanced daily memory abilities. For the second participant only, a re-evaluation of her cognitive profile was completed 23 months after her first assessment and training. In addition, EL was directly compared with a control condition using an errorful (EF) learning paradigm to teach her new names over two sessions (one session for each condition). Her improvement on the trained material supported the preliminary efficacy of EL compared with EF for learning episodic material. These results are compatible with previous work that has preliminarily demonstrated the efficacy of an EL paradigm in patients with dementia.

Die Kosten von "Gehirnerkrankungen" in Österreich im Jahr 2004

OBJECTIVES

The costs of twelve selected neurological, neuro-surgical and psychiatric disorders in Austria in the year 2004 will be presented. The present paper is part of the "Cost of Disorders of the Brain in Europe" study.

METHODS

The data for the present calculations are based on systematic reviews of epidemiological and health-economic studies. For all European countries identical methods were applied. All economic data were transformed to Euros for Austria in the year 2004 ("Purchasing Power Parity adjusted").

RESULTS

The highest costs per case per disorder were caused by brain tumors (49,800 Euro) and multiple sclerosis (30,500 Euro). One-year-prevalence estimates (Austrian population 8.1 million) were highest for anxiety disorders (848,000 cases), followed by migraine (537,000 cases) and affective disorders (479,000 cases). The total costs (i.e. for all cases of a specific disorder in Austria) were highest for affective disorders and addiction (alcohol and illegal drugs). The total cost of all included disorders (addiction, affective disorders, anxiety disorders, brain tumours, dementia, epilepsy, migraine, multiple sclerosis, Parkinson's disease, psychotic disorders, stroke and brain trauma) was estimated at 8.8 billion Euros for Austria in the year 2004. Direct health care cost amounted to Euros 3.2 billion (37% of total cost), direct non-medical cost totalled Euros 1.5 billion (17%), and indirect cost Euros 4.1 billion (47%).

DISCUSSION

Even when considering that such estimates based on international studies have methodological limitations, the total cost of the twelve included disorders is considerable. The total cost of these twelve disorders constitutes 4% of the gross national product of Austria. Taken together, these disorders cost each Austrian citizen Euros 1 090 per year.