Search

Objective: To examine, first, whether the co-occurrence of executive dysfunction (ED) and poststroke depression (PSD) shows different associations with neuroimaging markers and the course of depression and executive function, and second, whether it is associated with a different course on other cognitive domains and quality of life., Methods: The present study included 245 stroke patients (35.9% female, mean age 67.5 years (SD=11.9). All patients completed neuropsychological and neuropsychiatric assessment 3 months poststroke, which were repeated at 6-month and 12-month follow-up. A subset (n=186) received 3-Tesla brain MRI at baseline to evaluate lesion-related imaging markers, white matter hyperintensity volume, global brain atrophy and total cerebral small vessel disease burden., Results: Patients with 'depression-executive dysfunction syndrome' (DES) showed higher white matter hyperintensity volumes compared with all other groups and more frequently showed left-sided lesions compared with ED only and PSD only. They also had more frequently old infarcts and higher total cerebral small vessel disease burden compared with PSD only and patients with neither ED nor PSD, and more global brain atrophy compared with PSD only. Longitudinal analyses showed that patients with DES had a more chronic course of depressive symptoms relative to PSD only, and a stable pattern of worse cognitive performance similar to patients with ED only., Conclusions: The co-occurrence of ED and PSD is associated with a worse prognosis of depression, persistent cognitive impairment and a higher amount of vascular and degenerative brain pathology. Future studies are needed to examine whether these patients represent a more severe subtype within the PSD spectrum., Clinical Trial Registration: NCT02585349;Results., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Importance: Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials., Objective: To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia., Design, Setting, and Participants: This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017., Main Outcomes and Measures: Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype., Results: Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P = .16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P < .001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P < .001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years., Conclusions and Relevance: Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.

Background: Cerebrovascular disease (CVD) and amyloid-β (Aβ) often coexist, but their influence on neurodegeneration and cognition in predementia stages remains unclear. We investigated the association between CVD and Aβ on neurodegenerative markers and cognition in patients without dementia., Methods: We included 271 memory clinic patients with subjective or objective cognitive deficits but without dementia from the BioBank Alzheimer Center Limburg cohort (n = 99) and the LeARN (n = 50) and DESCRIPA (n = 122) multicenter studies. CSF Aβ 1-42 and white matter hyperintensities (WMH) on magnetic resonance imaging (MRI) scans were used as measures of Aβ and CVD, respectively. Individuals were classified into four groups based on the presence (+) or absence (-) of Aβ and WMH. We investigated differences in phosphorylated tau, total tau (t-tau), and medial temporal lobe atrophy (MTA) between groups using general linear models. We examined cognitive decline and progression to dementia using linear mixed models and Cox proportional hazards models. All analyses were adjusted for study and demographics., Results: MTA and t-tau were elevated in the Aβ - WMH+, Aβ + WMH-, and Aβ + WMH+ groups. MTA was most severe in the Aβ + WMH+ group compared with the groups with a single pathology. Both WMH and Aβ were associated with cognitive decline, but having both pathologies simultaneously was not associated with faster decline., Conclusions: In the present study, we found an additive association of Aβ and CVD pathology with baseline MTA but not with cognitive decline. Because our findings may have implications for diagnosis and prognosis of memory clinic patients and for future scientific research, they should be validated in a larger sample with longer follow-up.

Background: Early-onset dementia patients often present with atypical clinical symptoms, hampering an accurate clinical diagnosis. The purpose of the present study was to assess the diagnostic impact of the amyloid-positron emission tomography (PET) imaging agent [ 18 F]flutemetamol in early-onset dementia patients, in terms of change in (confidence in) diagnosis and patient management plan., Methods: This prospective bi-center study included 211 patients suspected of early-onset dementia who visited a tertiary memory clinic. Patients were eligible with Mini Mental State Examination ≥ 18 and age at diagnosis ≤ 70 years and in whom the diagnostic confidence was <90% after routine diagnostic work-up. All patients underwent [ 18 F]flutemetamol PET, which was interpreted as amyloid-negative or amyloid-positive based on visual rating. Before and after disclosing the PET results, we assessed the diagnostic confidence (using a visual analog scale of 0-100%) and clinical diagnosis. The impact of [ 18 F]flutemetamol PET on the patient management plan was also evaluated., Results: [ 18 F]flutemetamol PET scans were positive in 133 out of 211 (63%) patients, of whom 110 out of 144 (76%) patients had a pre-PET Alzheimer's disease (AD) diagnosis and 23 out of 67 (34%) patients had a non-AD diagnosis. After disclosure of PET results, 41/211 (19%) diagnoses changed. Overall, diagnostic confidence increased from 69 ± 12% to 88 ± 15% after disclosing PET results (P < 0.001; in 87% of patients). In 79 (37%) patients, PET results led to a change in patient management and predominantly the initiation of AD medication when PET showed evidence for amyloid pathology., Conclusions: [ 18 F]flutemetamol PET changed clinical diagnosis, increased overall diagnostic confidence, and altered the patient management plan. Our results suggest that amyloid PET may have added value over the standardized diagnostic work-up in early-onset dementia patients with uncertain clinical diagnosis. This study provides evidence for the recommendations put forward in the appropriate use criteria for amyloid PET in clinical practice., Trial Registration: Nederlands Trial Register NTR3743 . Registered 7 December 2012.

Background: Cognitive impairment and neuropsychiatric syndromes, like depression and apathy, are frequent residual consequences of stroke. These have a large impact on quality of life and long-term prognosis. Several factors are involved in the development of these residual syndromes, although their exact role and their interrelationships remain still rather unclear. The Cognition and Affect after Stroke: a Prospective Evaluation of Risks (CASPER) study has been primarily designed to examine whether stroke-specific (e.g. lesion location, volume, type, severity), cerebrovascular and neurodegenerative (e.g. white matter changes, atrophy, microbleeds, perivascular spaces), inflammatory, endothelial, and (epi)genetic markers are associated with cognitive impairment, post-stroke depression, and post-stroke apathy, and whether they predict their course over 12 months. The secondary aims are to investigate how the above-mentioned markers interact with each other, and to determine if patients with apathy and depression after stroke differ in pathogenesis, course, and outcome (e.g. functional outcome, neurocognitive performance, quality of life)., Methods/design: CASPER is a 1-year prospective clinical cohort follow-up study in 250 stroke patients recruited at the neurological in- and outpatient services at Maastricht University Medical Center (MUMC+, Maastricht, The Netherlands), and Zuyderland Medical Center (Sittard and Heerlen, The Netherlands). At baseline (3 months post-stroke), a neuropsychological assessment, neuropsychiatric interview, blood sample, and brain magnetic resonance imaging (MRI) scan are conducted. Assessment of neuropsychiatric and neurocognitive status are repeated 6 and 12 months later., Discussion: The CASPER study investigates stroke-specific, vascular, neurodegenerative, inflammatory, and genetic markers of the development of vascular cognitive impairment, depression, and apathy after stroke. This creates the possibility to study not only the contribution of these individual markers but also their joint contribution, which differentiates this study from earlier stroke cohorts who lacked long-term follow-up data, a large sample size, an extensive MRI protocol, and markers from the blood. The knowledge we derive from this study might help in identifying markers that are associated with, or can predict the onset, maintenance, and progression of vascular cognitive impairment, depression, and apathy after stroke, and could provide new insights into possibilities for treatment and rehabilitation that result in better functional outcome after stroke., Trial Registration: ClinicalTrials.gov NCT02585349.

Importance: Cerebral amyloid-β aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies., Objective: To use individual participant data meta-analysis to estimate the prevalence of amyloid pathology as measured with biomarkers in participants with normal cognition, subjective cognitive impairment (SCI), or mild cognitive impairment (MCI)., Data Sources: Relevant biomarker studies identified by searching studies published before April 2015 using the MEDLINE and Web of Science databases and through personal communication with investigators., Study Selection: Studies were included if they provided individual participant data for participants without dementia and used an a priori defined cutoff for amyloid positivity., Data Extraction and Synthesis: Individual records were provided for 2914 participants with normal cognition, 697 with SCI, and 3972 with MCI aged 18 to 100 years from 55 studies., Main Outcomes and Measures: Prevalence of amyloid pathology on positron emission tomography or in cerebrospinal fluid according to AD risk factors (age, apolipoprotein E [APOE] genotype, sex, and education) estimated by generalized estimating equations., Results: The prevalence of amyloid pathology increased from age 50 to 90 years from 10% (95% CI, 8%-13%) to 44% (95% CI, 37%-51%) among participants with normal cognition; from 12% (95% CI, 8%-18%) to 43% (95% CI, 32%-55%) among patients with SCI; and from 27% (95% CI, 23%-32%) to 71% (95% CI, 66%-76%) among patients with MCI. APOE-ε4 carriers had 2 to 3 times higher prevalence estimates than noncarriers. The age at which 15% of the participants with normal cognition were amyloid positive was approximately 40 years for APOE ε4ε4 carriers, 50 years for ε2ε4 carriers, 55 years for ε3ε4 carriers, 65 years for ε3ε3 carriers, and 95 years for ε2ε3 carriers. Amyloid positivity was more common in highly educated participants but not associated with sex or biomarker modality., Conclusions and Relevance: Among persons without dementia, the prevalence of cerebral amyloid pathology as determined by positron emission tomography or cerebrospinal fluid findings was associated with age, APOE genotype, and presence of cognitive impairment. These findings suggest a 20- to 30-year interval between first development of amyloid positivity and onset of dementia.

Alzheimer's disease-related pathology results in tremendous structural and functional changes in the brain. These morphological changes might lead to a less precise performance of automated brain segmentation techniques in AD-patients, which in turn could possibly lead to false allocations of gray matter, white matter or cerebrospinal fluid. FreeSurfer has been shown to operate as an accurate and reliable instrument to measure cortical thickness and volume of neuroanatomical structures. Considering the principal role of FreeSurfer in the imaging field of AD, the present study aims to investigate the robustness of FreeSurfer to capture morphological changes in the brain against varying processing variables in comparison to manual measurements (the gold standard). T1-weighted MRI scan data were used pertaining to a sample of 53 individuals (18 healthy participants, 18 patients with mild cognitive impairment, and 18 patients with mild AD). Data were analyzed with different FreeSurfer versions (v4.3.1, v4.5.0, v5.0.0, v5.1.0), on a custom-built cluster (LINUX) and a Macintosh (UNIX) workstation. Group differences across versions and workstations were most consistent for both the hippocampus and posterior cingulate, regions known to be affected in the earliest stages of the disease. The results showed that later versions of FreeSurfer were more sensitive to identify group differences and corresponded best with the results of gold standard manual volumetric methods. In conclusion, later versions of FreeSurfer were more accurate than earlier versions, especially in medial temporal and posterior parietal regions. This development is very promising for future applications of FreeSurfer in research studies and encourages the future role of FreeSurfer output as a candidate marker in clinical practice.

White matter hyperintensities are associated with an increased risk of Alzheimer's disease (AD). White matter hyperintensities are believed to disconnect brain areas. We examined the topographical association between white matter hyperintensities and cortical thickness in controls, mild cognitive impairment (MCI), and AD patients. We examined associations between white matter hyperintensities and cortical thickness among 18 older cognitively healthy participants, 18 amnestic MCI, and 17 mild AD patients. These associations were cluster-size corrected for multiple comparisons. In controls, a positive association between white matter hyperintensities and cortical thickness was found in lateral temporal gyri. In MCI patients, white matter hyperintensities were positively related to cortical thickness in frontal, temporal, and parietal areas. Positive associations between white matter hyperintensities and cortical thickness in AD patients were confined to parietal areas. The results of the interaction group by white matter hyperintensities on cortical thickness were consistent with the findings of positive associations in the parietal lobe for MCI and AD patients separately. In the frontal areas, controls and AD patients showed inverse associations between white matter hyperintensities and cortical thickness, while MCI patients still showed a positive association. These results suggest that a paradoxical relationship between white matter hyperintensities and cortical thickness could be a consequence of neuroinflammatory processes induced by AD-pathology and white matter hyperintensities. Alternatively, it might reflect a region-specific and disease-stage dependent compensatory hypertrophy in response to a compromised network.

The present study compares four different structural magnetic resonance imaging techniques used to measure gray matter (GM) atrophy in Alzheimer's disease (AD): manual and automated volumetry, cortical thickness (CT) and voxel-based morphometry (VBM). These techniques are used interchangeably in AD research and thus far it is unclear which technique is superior in detecting abnormalities early in the disease process. 18 healthy participants without any memory impairment, 18 patients with MCI, and 17 patients with mild AD were included and between-group differences were investigated in AD signature regions (areas in the prefrontal cortex (PFC), medial temporal lobe (MTL) and posterior parietal cortex (PPC)). Both manual volumetric measurements and VBM were able to detect GM atrophy in the early stages (differentiation controls and MCI), mainly in the MTL. In the early phase, automated volumetric measurements showed GM differences in the PPC but not in the MTL. In our sample, CT measurements were not sensitive for group differences in the early stages. PFC regions showed abnormalities in the later stages (controls vs AD) when manual volumetric measurements or VBM are employed. Manual volumetric measurements together with VBM are preferred techniques for assessing GM differences showing abnormalities in most of the investigated regions, with a predominance of the MTL in the early phase. Automated FreeSurfer volumetric measurements show similar performances in the early phase, displaying group differences in the PPC but not in MTL regions. Measurements of CT are less sensitive in the MCI stage and its sensitivity is restricted to the MTL and PPC regions in later stages of the disease (AD).

Background: [(11)C]Pittsburgh compound B ([(11)C]PIB) and [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) PET measure fibrillar amyloid-β load and glucose metabolism, respectively. We evaluated the impact of these tracers on the diagnostic process in a memory clinic population., Methods: One hundred fifty-four patients underwent paired dynamic [(11)C]PIB and static [(18)F]FDG PET scans shortly after completing a standard dementia screening. Two-year clinical follow-up data were available for 39 patients. Parametric PET images were assessed visually and results were reported to the neurologists responsible for the initial diagnosis. Outcome measures were (change in) clinical diagnosis and confidence in that diagnosis before and after disclosing PET results., Results: [(11)C]PIB scans were positive in 40 of 66 (61%) patients with a clinical diagnosis of Alzheimer's disease (AD), 5 of 18 (28%) patients with frontotemporal dementia (FTD), 4 of 5 (80%) patients with Lewy body dementia, and 3 of 10 (30%) patients with other dementias. [(18)F]FDG uptake patterns matched the clinical diagnosis in 38 of 66 (58%) of AD patients, and in 6 of 18 (33%) FTD patients. PET results led to a change in diagnosis in 35 (23%) patients. This only occurred when prior diagnostic certainty was <90%. Diagnostic confidence increased from 71 ± 17% before to 87 ± 16% after PET (p < .001). Two-year clinical follow-up (n = 39) showed that [(11)C]PIB and [(18)F]FDG predicted progression to AD for patients with mild cognitive impairment, and that the diagnosis of dementia established after PET remained unchanged in 96% of patients., Conclusions: In a memory clinic setting, combined [(11)C]PIB and [(18)F]FDG PET are of additional value on top of the standard diagnostic work-up, especially when prior diagnostic confidence is low., (Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

Background/aims: The aim of this study was to determine the consistency of neuropsychiatric subsyndromes of the Neuropsychiatric Inventory across several clinical and demographic subgroups (e.g. dementia subtypes, dementia severity, medication use, age and gender) in a large sample of outpatients with dementia., Methods: Cross-sectional data of 2,808 patients with dementia from 12 centres from the European Alzheimer's Disease Consortium were collected. Principal component analysis was used for factor analysis. Subanalyses were performed for dementia subtypes, dementia severity, medication use, age and gender., Results: The results showed the relatively consistent presence of the 4 neuropsychiatric subsyndromes 'hyperactivity', 'psychosis', 'affective symptoms' and 'apathy' across the subanalyses. The factor structure was not dependent on dementia subtypes, age and gender but was dependent on dementia severity and cholinesterase use. The factors hyperactivity and affective symptoms were present in all subanalyses, but the presence of the factors apathy and psychosis was dependent on use of cholinesterase inhibitors and dementia severity, respectively., Conclusion: The present study provided evidence of the relative consistency of neuropsychiatric subsyndromes across dementia subtypes, age and gender, thereby stressing the importance of thinking about neuropsychiatric subsyndromes instead of separate symptoms. However, the subsyndromes apathy and psychosis were dependent on use of cholinesterase inhibitors and dementia severity., ((c) 2007 S. Karger AG, Basel.)

Background/aims: The aim of this study was to identify neuropsychiatric subsyndromes of the Neuropsychiatric Inventory in a large sample of outpatients with Alzheimer's disease (AD)., Methods: Cross-sectional data of 2,354 patients with AD from 12 centres from the European Alzheimer's Disease Consortium were collected. Principal component analysis was used for factor analysis., Results: The results showed the presence of 4 neuropsychiatric subsyndromes: hyperactivity, psychosis, affective symptoms and apathy. The subsyndrome apathy was the most common, occurring in almost 65% of the patients., Conclusion: This large study has provided additional robust evidence for the existence of neuropsychiatric subsyndromes in AD., ((c) 2007 S. Karger AG, Basel.)