CBF measured with 3D pseudocontinuous ASL MR imaging helps detect functional changes in the prodromal and more advanced stages of AD and is a marker for disease severity.

IMPORTANCE It remains unclear if and how associations between cerebral small-vessel disease and Alzheimer disease (AD) pathology lead to cognitive decline and dementia.OBJECTIVE To determine associations between small-vessel disease and AD pathology. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional study from January 2002 to December 2012 using the memory clinic-based Amsterdam Dementia Cohort. The study included 914 consecutive patients with available cerebrospinal fluid (CSF) and magnetic resonance imaging; 547 were patients diagnosed as having AD (54% female, mean [SD], 67 [8]; Mini-Mental State Examination score, mean [SD], 21 [5]), 30 were patients diagnosed as having vascular dementia (37% female, mean [SD], 76 [9]; Mini-Mental State Examination score, mean [SD], 24 [4]), and 337 were control participants with subjective memory complaints (42% female, mean [SD], 59 [59]; Mini-Mental State Examination score, mean [SD], 28 [2]). Linear regressions were performed with CSF biomarkers (log transformed) as dependent variables and magnetic resonance imaging measures (dichotomized) as independent, adjusted for sex, age, mediotemporal lobe atrophy, and diagnosis. An interaction term for diagnosis by magnetic resonance imaging measures was used for estimates per diagnostic group. MAIN OUTCOMES AND MEASURESWe examined the associations of magnetic resonance imaging white matter hyperintensities (WMH), lacunes, microbleeds with CSF β-amyloid 42 (Aβ42), total tau, and tau phosphorylated at threonine 181 (P-tau 181 ) as well as for a subset of apolipoprotein E (APOE) ε4 carriers and noncarriers.RESULTS Microbleed presence was associated with lower CSF Aβ42 in AD and vascular dementia (standardized beta = −0.09, P = .003; standardized beta = −0.30, P = .01), and higher CSF tau in controls (standardized beta = 0.10, P = .03). There were no effects for P-tau 181 . The presence of WMH was associated with lower Aβ42 in control participants and patients with vascular dementia (standardized beta = −0.18, P = .002; standardized beta = −0.32, P = .02) but not in patients with AD. There were no effects for tau or P-tau 181 . The presence of lacunes was associated with higher Aβ42 in vascular dementia (standardized beta = 0.17, P = .07) and lower tau in AD (standardized beta = −0.07, P = .05) but there were no effects for Aβ42 or P-tau 181 . Stratification for apolipoprotein E genotype revealed that these effects were mostly attributable to ε4 carriers. CONCLUSIONS AND RELEVANCEDeposition of amyloid appears aggravated in patients with cerebral small-vessel disease, especially in apolipoprotein E ε4 carriers, providing evidence for pathophysiological synergy between these 3 biological factors.

ObjectivesTo investigate arterial spin-labelling (ASL) cerebral blood flow (CBF) changes in predementia stages of Alzheimer’s disease (AD).MethodsData were obtained from 177 patients with subjective complaints, mild cognitive impairment and AD from the Amsterdam Dementia Cohort. AD stages were based on diagnosis and cerebrospinal fluid biomarkers amyloid-β (Aβ) and total-tau (tau). General-linear-models were used to assess relationships between AD stages and total and regional CBF, correcting for age and sex.ResultsDecreasing CBF was related to more advanced AD stages in all supratentorial regions (p for trend < 0.05). Post-hoc testing revealed that CBF was lower in AD compared to controls and stage-1 predementia patients (i.e. abnormal Aβ and normal tau) in temporal and parietal regions, and compared to stage-2 predementia patients (i.e. abnormal Aβ and tau) in temporal regions. CBF values of stage-2 predementia patients were numerically in between those of stage-1 predementia patients and AD.ConclusionThe continuing decrease of CBF along the continuum of AD indicates the potential of ASL-CBF as a measure for disease progression.Key Points• Decreasing CBF relates to more advanced AD stages in all supratentorial regions.• The reduction of CBF does not reach a bottom level.• ASL-CBF has potential as a measure for disease progression in AD.

Our results suggest that CBF may have potential as a functional marker of disease severity.

Aim: To assess the associations of age and diagnosis with visual ratings of medial temporal lobe atrophy (MTA), parietal atrophy (PA), global cortical atrophy (GCA), and white matter hyperintensities (WMH) and to investigate their clinical value in a large memory clinic cohort.Methods: We included 2,934 patients (age 67 ± 9 years; 1,391 [47%] female; MMSE 24 ± 5) from the Amsterdam Dementia Cohort (1,347 dementia due to Alzheimer's disease [AD]; 681 mild cognitive impairment [MCI]; 906 controls with subjective cognitive decline). We analyzed the effect of age, APOE e4 and diagnosis on visual ratings using linear regression analyses. Subsequently, we compared diagnostic and predictive value in three age-groups (<65 years, 65–75 years, and >75 years).Results: Linear regression analyses showed main effects of age and diagnosis and an interaction age*diagnosis for MTA, PA, and GCA. For MTA the interaction effect indicated steeper age effects in MCI and AD than in controls. PA and GCA increased with age in MCI and controls, while AD patients have a high score, regardless of age. For WMH we found a main effect of age, but not of diagnosis. For MTA, GCA and PA, diagnostic value was best in patients <65 years (optimal cut-off: ≥1). PA and GCA only discriminated in patients <65 years and MTA in patients <75 years. WMH did not discriminate at all. Taking into account APOE did not affect the identified optimal cut-offs. When we used these scales to predict progression in MCI using Cox proportional hazard models, only MTA (cut-off ≥2) had any predictive value, restricted to patients >75 years.Conclusion: Visual ratings of atrophy and WMH were differently affected by age and diagnosis, requiring an age-specific approach in clinical practice. Their diagnostic value seems strongest in younger patients.