Most rapid cognitive decline in APOE epsilon4 negative Alzheimer's disease with early onset

BACKGROUND

We aimed to compare the rate of cognitive decline in patients with early and late onset Alzheimer's disease (AD) and to investigate the potentially modifying influence of the apolipoprotein E (APOE) genotype.

METHOD

We included 99 patients with early onset AD (age 65 years) and 192 patients with late onset AD (age >65 years) who had at least two scores on the Mini-Mental State Examination (MMSE) (range 2-14) obtained at least 1 year apart. Linear mixed models were performed to investigate the rate of cognitive decline dependent on age at onset (AAO) and APOE genotype.

RESULTS

The mean (S.D.) age for patients with early onset AD was 57.7 (4.5) years, and 74.5 (5.1) years for patients with late onset AD. AAO was not associated with baseline MMSE [beta (S.E.)=0.8 (0.5), p=0.14]. However, patients with early onset showed a faster decline on the MMSE [beta (S.E.)=2.4 (0.1) points/year] than those with late onset [beta (S.E.)=1.7 (0.1) points/year, p=0.00]. After stratification according to APOE genotype, APOE epsilon4 non-carriers with early onset showed faster cognitive decline than non-carriers with late onset [2.4 (0.3) v. 1.3 (0.3) points/year, p=0.01]. In APOE epsilon4 carriers, no difference in rate of cognitive decline was found between patients with early and late onset [beta (S.E.)=0.2 (0.2), p=0.47].

CONCLUSION

Patients with early onset AD show more rapid cognitive decline than patients with late onset, suggesting that early onset AD follows a more aggressive course. Furthermore, this effect seems to be most prominent in patients with early onset who do not carry the genetic APOE epsilon4 risk factor for AD.

White matter hyperintensities and medial temporal lobe atrophy in clinical subtypes of mild cognitive impairment: the DESCRIPA study

BACKGROUND

Clinical subtypes of mild cognitive impairment (MCI) may represent different underlying aetiologies.

METHODS

This European, multicentre, memory clinic based study (DESCRIPA) of non-demented subjects investigated whether MCI subtypes have different brain correlates on MRI and whether the relation between subtypes and brain pathology is modified by age. Using visual rating scales, medial temporal lobe atrophy (MTA) (0-4) and white matter hyperintensities (WMH) (0-30) were assessed.

RESULTS

Severity of MTA differed between MCI subtypes (p<0.001), increasing from a mean of 0.8 (SD 0.7) in subjective complaints (n = 77) to 1.3 (0.8) in non-amnestic MCI (n = 93), and from 1.4 (0.9) in single domain amnestic MCI (n = 70) to 1.7 (0.9) in multiple domain amnestic MCI (n = 89). The association between MCI subtype and MTA was modified by age and mainly present in subjects >70 years of age. Severity of WMH did not differ between MCI subtypes (p = 0.21). However, the combination of MTA and WMH differed between MCI subtypes (p = 0.02)

CONCLUSION

We conclude that MCI subtypes may have different brain substrates, especially in older subjects. Isolated MTA was mainly associated with amnestic MCI subtypes, suggesting AD as the underlying cause. In non-amnestic MCI, the relatively higher prevalence of MTA in combination with WMH may suggest a different pathophysiological origin.

CSF biomarkers in relationship to cognitive profiles in Alzheimer disease

OBJECTIVE

To investigate the relationship between CSF biomarkers and cognitive profiles in Alzheimer disease (AD).

METHODS

We included 177 patients with AD. Digit Span, Visual Association Test (VAT), VAT object naming, Trail Making Test (TMT), and category fluency were used to assess cognitive functions. Disease severity was assessed using Mini-Mental State Examination; functional impairment was rated by Clinical Dementia Rating. In CSF, levels of amyloid-beta 1-42 (Abeta(1-42)), tau, and tau phosphorylated at threonine 181 (p-tau) were measured. K-means cluster analysis was performed with the three biomarkers to obtain three clusters. Multivariate analysis of variance for repeated measures was performed with CSF cluster as between-subjects factor, neuropsychological z scores as within-subjects variable, and age, sex, and education as covariates.

RESULTS

Cluster 1 consisted of 88 patients (49%) with relatively high levels of Abeta(1-42) and low levels of tau and p-tau. Cluster 2 contained 72 patients (41%) with relatively low levels of Abeta(1-42) and high levels of tau and p-tau. Cluster 3 was made up of 17 patients (10%) with low levels of Abeta(1-42) and very high levels of tau and p-tau. No differences between clusters on age, sex, education, APOE genotype, disease duration, functional impairment, or disease severity were found. Patients in cluster 3 performed worse on VAT, TMT-A and -B, and fluency.

CONCLUSIONS

Clusters of CSF biomarker levels are related to cognitive profiles in Alzheimer disease. A subgroup of patients with extremely high CSF levels of tau and tau phosphorylated at threonine 181 shows a distinct cognitive profile with more severe impairment of memory, mental speed, and executive functions, which cannot be explained by disease severity.

Heterogeneity of White Matter Hyperintensities in Alzheimer's Disease: Post-Mortem Quantitative MRI and Neuropathology

White matter hyperintensities (WMH) are frequently seen on T2-weighted MRI scans of elderly subjects with and without Alzheimer's disease. WMH are only weakly and inconsistently associated with cognitive decline, which may be explained by heterogeneity of the underlying neuropathological substrates. The use of quantitative MRI could increase specificity for these neuropathological changes. We assessed whether post-mortem quantitative MRI is able to reflect differences in neuropathological correlates of WMH in tissue samples obtained post-mortem from Alzheimer's disease patients and from non-demented elderly.

Thirty-three formalin-fixed, coronal brain slices from II Alzheimer's disease patients (mean age: 83 ± 10 years, eight females) and 15 slices from seven non-demented controls (mean age: 78 ± 10 years, four females) with WMH were scanned at 1.5 T using qualitative (fluid-attenuated inversion recovery, FLAIR) and quantitative MRI [diffusion tensor imaging (DTI) including estimation of apparent diffusion coefficient (ADC) and fractional anisotropy (FA), and T1-relaxation time mapping based on flip-angle array). A total of 104 regions of interest were defined on FLAIR images in WMH and normal appearing white matter (NAWM). Neuropathological examination included (semiquantitative assessment of axonal density (Bodian), myelin density (LFB), astrogliosis (GFAP) and microglial activation (HLA-DR). Patient groups (Alzheimer's disease versus controls) and tissue types (WMH versus NAWM) were compared with respect to QMRI and neuropathological measures. Overall, Alzheimer's disease patients had significantly lower FA ( P < 0.01) and higher T1-values than controls ( P = 0.04). WMH showed lower FA ( P < 0.01) and higher T1-values ( P < 0.001) than NAWM in both patient groups. A significant interaction between patient group and tissue type was found for the T1 measurements, indicating that the difference in T1-relaxation time between NAWM and WMH was larger in Alzheimer's disease patients than in non-demented controls. All neuropathological measures showed differences between WMH and NAWM, although the difference in microglial activation was specific for Alzheimer's disease. Multivariate regression models revealed that in Alzheimer's disease, axonal density was an independent determinant of FA, whereas T1 was independently determined by axonal and myelin density and microglial activation. Quantitative MRI techniques reveal differences in WMH between Alzheimer's disease and non-demented elderly, and are able to reflect the severity of the neuropathological changes involved.

Associations between patterns of EEG abnormalities and diagnosis in a large memory clinic cohort

AIM

To describe associations of abnormalities in the electroencephalogram (EEG) with the most prevalent diagnoses in a memory clinic cohort.

METHODS

Associations between visual EEG findings and diagnoses in 1,116 consecutive patients [382 Alzheimer's disease (AD), 274 subjective complaints, 190 mild cognitive impairment (MCI), 118 psychiatric disorder, 61 frontotemporal lobar degeneration, 53 vascular dementia (VaD), 38 dementia with Lewy bodies (DLB)] were determined by prevalence ratio (PR).

RESULTS

Diagnoses of subjective complaints [PR = 1.6; 95% confidence interval (CI) = 1.4-1.9] and psychiatric disorder (1.4; 95% CI = 1.1-1.9) were associated with a normal EEG, while subjects with both focal and diffuse EEG disturbances were more likely to have DLB (3.5; 95% CI = 2.1-5.6), VaD (2.3; 95% CI = 1.4-3.6) or AD (1.5; 95% CI = 1.3-1.8). Subjects with only diffuse EEG abnormalities were more likely to have AD (PR = 1.5; 95% CI = 1.3-1.9). The prevalence of MCI was higher among those with only focal EEG abnormalities (PR = 1.3; 95% CI = 1.0-1.7).

CONCLUSIONS

A normal EEG argues for subjective complaints or psychiatric diagnosis. An EEG with only focal abnormalities supports MCI. An EEG with only diffuse abnormalities argues for AD. An EEG with both focal and diffuse abnormalities argues for DLB, VaD or AD.

A worldwide multicentre comparison of assays for cerebrospinal fluid biomarkers in Alzheimer's disease

BACKGROUND

Different cerebrospinal fluid (CSF) amyloid-beta 1-42 (Abeta(1-42)), total Tau (Tau) and Tau phosphorylated at threonine 181 (P-Tau) levels are reported, but currently there is a lack of quality control programmes. The aim of this study was to compare the measurements of these CSF biomarkers, between and within centres.

METHODS

Three CSF-pool samples were distributed to 13 laboratories in 2004 and the same samples were again distributed to 18 laboratories in 2008. In 2004 six laboratories measured Abeta(1-42), Tau and P-Tau and seven laboratories measured one or two of these marker(s) by enzyme-linked immunosorbent assays (ELISAs). In 2008, 12 laboratories measured all three markers, three laboratories measured one or two marker(s) by ELISAs and three laboratories measured the markers by Luminex.

RESULTS

In 2004, the ELISA intercentre coefficients of variance (interCV) were 31%, 21% and 13% for Abeta(1-42), Tau and P-Tau, respectively. These were 37%, 16% and 15%, respectively, in 2008. When we restricted the analysis to the Innotest (N = 13) for Abeta(1-42), lower interCV were calculated (22%). The centres that participated in both years (N = 9) showed interCVs of 21%, 15% and 9% and intra-centre coefficients (intraCV) of variance of 25%,18% and 7% in 2008.

CONCLUSIONS

The highest variability was found for Abeta(1-42). The variabilities for Tau and P-Tau were lower in both years. The centres that participated in both years showed a high intraCV comparable to their interCV, indicating that there is not only a high variation between but also within centres. Besides a uniform standardization of (pre)analytical procedures, the same assay should be used to decrease the inter/intracentre variation.

Hippocampal atrophy rates in Alzheimer disease: added value over whole brain volume measures

OBJECTIVE

To investigate the added value of hippocampal atrophy rates over whole brain volume measurements on MRI in patients with Alzheimer disease (AD), patients with mild cognitive impairment (MCI), and controls.

METHODS

We included 64 patients with AD (67 +/- 9 years; F/M 38/26), 44 patients with MCI (71 +/- 6 years; 21/23), and 34 controls (67 +/- 9 years; 16/18). Two MR scans were performed (scan interval: 1.8 +/- 0.7 years; 1.0 T), using a coronal three-dimensional T1-weighted gradient echo sequence. At follow-up, 3 controls and 23 patients with MCI had progressed to AD. Hippocampi were manually delineated at baseline. Hippocampal atrophy rates were calculated using regional, nonlinear fluid registration. Whole brain baseline volumes and atrophy rates were determined using automated segmentation and registration tools.

RESULTS

All MRI measures differed between groups (p < 0.005). For the distinction of MCI from controls, larger effect sizes of hippocampal measures were found compared to whole brain measures. Between MCI and AD, only whole brain atrophy rate differed significantly. Cox proportional hazards models (variables dichotomized by median) showed that within all patients without dementia, hippocampal baseline volume (hazard ratio [HR]: 5.7 [95% confidence interval: 1.5-22.2]), hippocampal atrophy rate (5.2 [1.9-14.3]), and whole brain atrophy rate (2.8 [1.1-7.2]) independently predicted progression to AD; the combination of low hippocampal volume and high atrophy rate yielded a HR of 61.1 (6.1-606.8). Within patients with MCI, only hippocampal baseline volume and atrophy rate predicted progression.

CONCLUSION

Hippocampal measures, especially hippocampal atrophy rate, best discriminate mild cognitive impairment (MCI) from controls. Whole brain atrophy rate discriminates Alzheimer disease (AD) from MCI. Regional measures of hippocampal atrophy are the strongest predictors of progression to AD.

A systematic review of Instrumental Activities of Daily Living scales in dementia: room for improvement

BACKGROUND

Instrumental Activities of Daily Living (IADL) questionnaires can be helpful in diagnosing dementia and are often used for clinical follow-up and treatment evaluation in dementia patients. Despite the large number of questionnaires, their quality has received little attention.

OBJECTIVE

To systematically review the measurement properties of all available structured informant-based (I)ADL questionnaires, developed or validated for use in demented patients.

METHODS

A systematic literature search was conducted in MEDLINE, PsycINFO and EMBASE for psychometric articles on (I)ADL questionnaires. In addition, reference lists of all retrieved articles were screened. Standardised criteria were used to assess the quality of the measurement properties. When possible, investigators were contacted to obtain missing information. Two authors independently extracted studies and performed the quality assessment of the questionnaires.

FINDINGS

Thirty-two articles were selected, covering 12 (I)ADL questionnaires. Information on 52.3% of the quality aspects was not available, 32.4% of the ratings were indeterminate, 8.1% were positive, and 7.2% were negative. Out of eight measurement properties, two scales (the DAD and the Bristol ADL) received two positive ratings and were classified as of moderate quality. Five scales (ADL-PI, ADL-IS, B-ADL, CSADL and Lawton IADL) received one positive rating.

INTERPRETATION

The findings indicate that improvements in and more data on psychometric properties of (I)ADL questionnaires for dementia patients are necessary in order to justify their use.

Heterogeneity of white matter hyperintensities in Alzheimer's disease: post-mortem quantitative MRI and neuropathology

White matter hyperintensities (WMH) are frequently seen on T(2)-weighted MRI scans of elderly subjects with and without Alzheimer's disease. WMH are only weakly and inconsistently associated with cognitive decline, which may be explained by heterogeneity of the underlying neuropathological substrates. The use of quantitative MRI could increase specificity for these neuropathological changes. We assessed whether post-mortem quantitative MRI is able to reflect differences in neuropathological correlates of WMH in tissue samples obtained post-mortem from Alzheimer's disease patients and from non-demented elderly. Thirty-three formalin-fixed, coronal brain slices from 11 Alzheimer's disease patients (mean age: 83 +/- 10 years, eight females) and 15 slices from seven non-demented controls (mean age: 78 +/- 10 years, four females) with WMH were scanned at 1.5 T using qualitative (fluid-attenuated inversion recovery, FLAIR) and quantitative MRI [diffusion tensor imaging (DTI) including estimation of apparent diffusion coefficient (ADC) and fractional anisotropy (FA), and T(1)-relaxation time mapping based on flip-angle array). A total of 104 regions of interest were defined on FLAIR images in WMH and normal appearing white matter (NAWM). Neuropathological examination included (semi-)quantitative assessment of axonal density (Bodian), myelin density (LFB), astrogliosis (GFAP) and microglial activation (HLA-DR). Patient groups (Alzheimer's disease versus controls) and tissue types (WMH versus NAWM) were compared with respect to QMRI and neuropathological measures. Overall, Alzheimer's disease patients had significantly lower FA (P < 0.01) and higher T(1)-values than controls (P = 0.04). WMH showed lower FA (P < 0.01) and higher T(1)-values (P < 0.001) than NAWM in both patient groups. A significant interaction between patient group and tissue type was found for the T(1) measurements, indicating that the difference in T(1)-relaxation time between NAWM and WMH was larger in Alzheimer's disease patients than in non-demented controls. All neuropathological measures showed differences between WMH and NAWM, although the difference in microglial activation was specific for Alzheimer's disease. Multivariate regression models revealed that in Alzheimer's disease, axonal density was an independent determinant of FA, whereas T(1) was independently determined by axonal and myelin density and microglial activation. Quantitative MRI techniques reveal differences in WMH between Alzheimer's disease and non-demented elderly, and are able to reflect the severity of the neuropathological changes involved.

Efficacy, safety and tolerability of rivastigmine capsules in patients with probable vascular dementia: the VantagE study

OBJECTIVE

The aim was to evaluate the efficacy, safety and tolerability of rivastigmine capsules in patients diagnosed with probable vascular dementia (VaD).

METHODS

VantagE (Vascular Dementia trial studying Exelon) was a 24-week, multicentre, double-blind study. VaD patients aged 50-85 years were randomized to rivastigmine capsules (3-12 mg/day) or placebo. Efficacy assessments included global and cognitive performances, activities of daily living and neuropsychiatric symptoms. Adverse events were recorded. Additional exploratory analyses determined whether heterogeneity in pathologies and symptoms extended to differential treatment effects.

TRIAL REGISTRATION

NCT00099216.

RESULTS

710 patients were randomized. Rivastigmine demonstrated superiority over placebo on three measures of cognitive performance (Vascular Dementia Assessment Scale, Alzheimer's Disease Assessment Scale cognitive subscale, Mini-Mental State Examination; all p< or = 0.05, intent-to-treat population [ITT]), but not other outcomes. Predominant adverse events were nausea and vomiting. Exploratory analyses indicated that older patients (> or =75 years old), assumed more likely to also have Alzheimer's disease (AD) pathology, demonstrated significant cognitive responses to rivastigmine and a safety profile similar to that seen in AD patients. Younger patients, assumed less likely to have concomitant AD pathology, showed no efficacy response and were associated with slight elevations of blood pressure, cerebrovascular accidents and mortality. Rivastigmine-placebo differences in patients with, versus those without, medial temporal atrophy (also suggestive of concomitant AD) showed a numerical difference similar to that seen between the older versus younger patients, but did not attain statistical significance.

CONCLUSION

Consistent with trials evaluating other cholinesterase inhibitors, rivastigmine did not provide consistent efficacy in probable VaD. The efficacy apparent on cognitive outcomes was derived from effects in older patients likely to have concomitant Alzheimer pathology. This is supportive of an existing argument that the putative cholinergic deficit in VaD reflects the presence of concomitant Alzheimer pathology.

Distortions in rest–activity rhythm in aging relate to white matter hyperintensities

Distortions in the rest-activity rhythm in aging are commonly observed. Neurodegenerative changes of the suprachiasmatic nucleus have been proposed to underlie this disrupted rhythm. However, based on previous studies, it can be proposed that white matter hyperintensities (WMH) may also play a role in the altered rest-activity rhythm in aging. The present study focused on the rest-activity rhythm, as assessed with actigraphy, and WMH in nondemented aging. With regard to the rest-activity rhythm, the interdaily stability (IS), intradaily variability (IV) and the amplitude (AMP) of the rhythm were of interest. The white matter hyperintensities were examined separately for the periventricular (PVH) and deep white matter (DWMH) regions, while distinguishing between the various locations within these regions (e.g. occipital PVH). The results indicated that frontal DWMH related to both IS and AMP. A reduction in the most active 10-h period mediated the relationship between frontal DWMH and AMP. Possible underlying mechanisms of these associations are discussed.

Self-perceived memory impairment and cognitive performance in an elderly independent population with age-related white matter changes

OBJECTIVES

To determine whether self-perceived memory impairment is associated with the severity of white matter changes (WMC) and is related to cognitive impairment.

METHODS

Data were drawn from the multinational Leukoaraiosis and Disability Study (LADIS), which investigates the impact of WMC on global functioning. WMC severity was rated using the Fazekas scale. Medial temporal lobe atrophy (MTA) was scored visually and mean values were calculated. The neuropsychological battery consisted of the Mini-Mental State Examination, a modified version of the VADAS-Cog, Trail making and Stroop tests. A question about self-perceived memory impairment was used as a measure for presence of memory complaints. Cognitive performance was analysed test-by-test and in three main domains: memory, executive functions and speed/motor control. The Geriatric Depression Scale (GDS) was used as a measure of depressive symptoms.

RESULTS

Six hundred and thirty-eight subjects were included in this study. No association was found between memory complaints and the severity of WMC. Subjects with memory complaints (n = 399) had a higher GDS score [t((637)) = -7.15; p<0.02] and performed worse on almost all cognitive tests and on the three cognitive domains. Multiple linear regression showed that the worse performance on the memory domain was associated with memory complaints independently of depressive symptoms, WMC severity and MTA (R(2) = 0.183; F = 17.09, beta = -0.126; p<0.05).

CONCLUSION

In a sample of non-disabled elderly subjects with WMC, self-perceived memory impairment is significantly associated with objective memory impairment independently of the WMC severity, depressive symptoms and MTA.

Small vessel versus large vessel vascular dementia: risk factors and MRI findings

OBJECTIVE

The aim of this study was a cross-sectional comparison of clinical and MRI characteristics and risk factor profiles between patients with small vessel disease (lacunae and white matter hyperintensities) and large vessel disease (large territorial or strategical infarcts) in a large cohort of VaD patients.

METHODS

Patients with VaD (NINDS-AIREN) were included in a large multicenter treatment trial (the VantagE study). All patients were examined by a neurologist and interviewed about their medical history. Based on MRI, patients were classified as having large vessel VaD, small vessel VaD, or a combination. Other MRI characteristics included white matter hyperintensities (WMH), medial temporal lobe atrophy (MTA) and general cortical atrophy.

RESULTS

Of the 706 patients, 522 (74 %) had small vessel disease, 126 (18 %) had large vessel disease and 58 (8 %) had both. Patients with small vessel disease were older and less educated, and showed more cortical and medial temporal lobe atrophy than patients with large vessel disease. The most prevalent vascular risk factors (hypertension, diabetes and smoking) were equally distributed between the different types of VaD. However, patients with large vessel disease had more hypercholesterolemia and cardiac risk factors compared to patients with small vessel disease.

CONCLUSION

Cerebrovascular disease underlying VaD consists in the majority of small vessel disease and in about one fifth of large vessel disease. This study demonstrates heterogeneity between these two groups with regard to risk factor profile and atrophy scores on MRI.

Distribution of APOE genotypes in a memory clinic cohort

AIM

To describe the distribution of apolipoprotein E (APOE) genotypes in a cohort of memory clinic patients.

METHODS

We included 749 memory clinic patients. Diagnoses were made in a multidisciplinary consensus meeting and the APOE genotype was determined. The community-based cohort of the Longitudinal Aging Study Amsterdam was used as control population (n = 2,233).

RESULTS

In the memory clinic sample, there were 173 patients with subjective complaints, 125 patients with mild cognitive impairment (MCI), 251 patients with Alzheimer disease (AD), 107 patients with another type of dementia, and 93 patients with another neurologic or psychiatric diagnosis. The APOE allele distribution differed among groups. There was no difference in the prevalence of the epsilon2 allele, but there were differences in distribution of the epsilon3 and epsilon4 alleles. Compared with the control population (15%), the prevalence of APOE epsilon4 was increased among patients with subjective complaints (22%), MCI (36%), AD (42%) and other types of dementia (25%).

CONCLUSION

We observed an increased prevalence of APOE epsilon4 in patients with MCI and subjective complaints. This finding is of great clinical importance as nondemented patients positive for APOE epsilon4 could be identified as being at genetic risk of AD, and for that reason monitored more closely.

White matter changes contribute to corpus callosum atrophy in the elderly: the LADIS study

BACKGROUND AND PURPOSE

The corpus callosum (CC) is the most important structure involved in the transmission of interhemispheric information. The aim of this study was to investigate the potential correlation between regional age-related white matter changes (ARWMC) and atrophy of CC in elderly subjects.

MATERIALS AND METHODS

In 578 subjects with ARWMC from the Leukoaraiosis And DISability (LADIS) study, the cross-sectional area of the CC was automatically segmented on the normalized midsagittal MR imaging section and subdivided into 5 regions. The ARWMC volumes were measured quantitatively by using a semiautomated technique and segmented into 6 brain regions.

RESULTS

Significant correlation between the area of the rostrum and splenium regions of the CC and the ARWMC load in most brain regions was identified. This correlation persisted after correction for global atrophy.

CONCLUSION

Increasing loads of ARWMC volume were significantly correlated with atrophy of the CC and its subregions in nondisabled elderly subjects with leukoaraiosis. However, the pattern of correlation between CC subregions and ARWMC was not specifically related to the topographic location of ARWMC. The results suggest that ARWMC may lead to a gradual loss of CC tissue.

Whole-brain atrophy rate in Alzheimer disease: identifying fast progressors

OBJECTIVE

To assess which baseline clinical and MRI measures influence whole-brain atrophy rates, measured from serial MR imaging.

METHODS

We recruited 65 patients with Alzheimer disease (mean +/- SD age 70 +/- 8 y, 58% women, Mini-Mental State Examination [MMSE] 22 +/- 5), scanned with an average interval of 1.7 +/- 0.6 years. Whole-brain atrophy rates were used as outcome measure. Baseline normalized brain volume, hippocampal volume, and whole-brain atrophy rates were measured using three-dimensional T1-weighted imaging. The influence of age, sex, apolipoprotein E genotype (APOE), baseline MMSE, baseline hippocampal volume, and baseline normalized brain volume on whole-brain atrophy rates was assessed using linear regression.

RESULTS

The mean whole-brain atrophy rate was -1.9 +/- 0.9% per year. In the multivariate model, younger age (beta [SE] = 0.03 [0.01]; p = 0.04), absence of APOE epsilon 4 (beta [SE] = 0.61 [0.28]; p = 0.03), and a low MMSE (beta [SE] = 0.11 [0.03]; p < 0.001) were associated with a higher whole-brain atrophy rate. Furthermore, a relatively spared hippocampus predicted faster decline for patients with a smaller baseline brain volume (p = 0.09), and with a lower MMSE (p = 0.07). Finally, a smaller brain volume was associated with a higher rate of atrophy in younger patients (p = 0.03).

CONCLUSIONS

Our results suggest it is possible to characterize a subgroup of patients with Alzheimer disease (AD) who are at risk of faster loss of brain volume. Patients with more generalized, rather than focal hippocampal atrophy, who often have an onset before the age of 65, and are APOE epsilon 4 negative, seem to be at risk of faster whole-brain atrophy rates than the more commonly seen patients with AD, who are older, are APOE epsilon 4 positive, and have pronounced hippocampal atrophy.

Development of screening guidelines and clinical criteria for predementia Alzheimer's disease. The DESCRIPA Study

BACKGROUND

There is an urgent need to identify subjects with Alzheimer's disease (AD) in the predementia phase, but validated diagnostic approaches are currently lacking. In this paper, we present the background, design and methods of a study, which aims to develop clinical criteria for predementia AD. We also present baseline characteristics of the subjects included. The study was part of the multicentre DESCRIPA project, which is being conducted within the network of the European Alzheimer's Disease Consortium.

METHODS

Clinical criteria will be based on a prospective cohort study of non-demented subjects older than 55 years and referred to a memory clinic. At baseline, a number of markers and risk factors for AD were collected, including demographic variables, measures of performance in activities of daily living, cognitive, neuroimaging and genetic markers, and serum and cerebrospinal fluid markers. Subjects will be reassessed annually for 2-3 years, and we will evaluate which combination of variables best predicts AD-type dementia at follow-up.

RESULTS

Between 2003 and 2005, 881 subjects were included from 20 memory clinics. Subjects were on average 70.3 years old, and had 10.4 years of education. The average score on the Mini-Mental State Examination was 27.4.

Cerebral blood flow by using pulsed arterial spin-labeling in elderly subjects with white matter hyperintensities

BACKGROUND AND PURPOSE

On MR imaging, white matter hyperintensities (WMH) on T2-weighted images are generally considered as a surrogate marker of ischemic small vessel disease in elderly subjects. Pulsed arterial spin-labeling (PASL) is a noninvasive MR perfusion-weighted technique. We hypothesized that elderly subjects with diffuse confluent WMH should have lower cerebral blood flow (CBF) measurements than subjects with punctiform or beginning confluent WMH.

MATERIALS AND METHODS

MR images of 21 subjects (13 women; mean age, 76 years; SD, 5), stratified for the degree of WMH, from a single center within the multinational Leukoaraiosis and Disability (LADIS) study, were investigated. CBF images were obtained by means of quantitative imaging of perfusion by using a single-subtraction second version, with thin-section TI periodic saturation PASL. Values of cortical gray matter, subcortical (including white matter and deep gray matter), and global CBF were calculated. CBF measurements of subjects with diffuse confluent WMH (n = 7) were compared with those of subjects with punctiform or beginning confluent WMH (n = 14).

RESULTS

Subjects with diffuse confluent WMH were found to have approximately 20% lower mean global CBF (43.5 mL/100 mL/min; SD, 6.3) than subjects with punctiform or beginning confluent WMH (57.9 mL/100 mL/min; SD, 8.6; P < .01), as well as approximately 20% lower mean subcortical (P < .01) and cortical gray matter CBF (P < .05).

CONCLUSION

PASL revealed a significant reduction of CBF measurements in elderly subjects with diffuse confluent WMH.