Lower cerebral blood flow is associated with faster cognitive decline in Alzheimer's disease

OBJECTIVE: To determine whether lower cerebral blood flow (CBF) is associated with faster cognitive decline in patients with Alzheimer's disease (AD). METHODS: We included 88 patients with dementia due to AD from the Amsterdam Dementia Cohort. Mean follow-up was 2 ± 1 years. Linear mixed models were used to determine associations of lower whole brain and regional pseudo-continuous arterial spin labelling measured CBF with rate of cognitive decline as measured with repeated mini-mental state examination (MMSE). Model 1 was adjusted for age, sex, and education. Model 2 was additionally adjusted for normalized gray matter volume, medial temporal lobe atrophy, white matter hyperintensities, microbleeds, and lacunes. Analyses were repeated after partial volume correction (PVC) of CBF. Statistical significance was set at p ≤ 0.05. RESULTS: Patients were 65 ± 7 years old, 44 (50 %) were women, and mean baseline MMSE was 22 ± 4. Annual decline (β[SE]) on the MMSE was estimated at -2.11 (0.25) points per year. Lower whole brain (β[SE]-0.50[0.25]; p ≤ 0.05) and parietal (β[SE]-0.59[0.25]; p < 0.05) CBF were associated with faster cognitive decline. PVC cortical CBF was not associated with cognitive decline. CONCLUSIONS: Lower CBF, in particular in the posterior brain regions, may have value as a prognostic marker for rate of cognitive decline in AD. KEY POINTS: • In AD, lower CBF is associated with more rapid cognitive decline. • Decreasing CBF does not reach a plateau early in AD. • PcASL-CFB has additive value to conventional structural MRI measures in AD

Vascular Cognitive Impairment and cognitive decline; a longitudinal study comparing different types of vascular brain injury - The TRACE-VCI study

Background: Little is known about the trajectories of cognitive decline in relation to different types of vascular brain injury in patients presenting at a memory clinic with Vascular Cognitive Impairment (VCI). / Methods: We included 472 memory clinic patients (age 68 (±8.2) years, 44% female, MMSE 25.9 (±2.8), 210 (44.5%) dementia) from the prospective TRACE-VCI cohort study with possible VCI, defined as cognitive complaints and vascular brain injury on MRI and at least 1 follow-up cognitive assessment (follow-up time 2.5 (±1.4) years, n = 1172 assessments). Types of vascular brain injury considered lacune(s) (≥1; n = 108 patients (23%)), non-lacunar infarct(s) (≥1; n = 54 (11%)), white matter hyperintensities (WMH) (none/mild versus moderate/severe (n = 211 patients (45%)) and microbleed(s) (≥1; n = 202 patients (43%)). We assessed cognitive functioning at baseline and follow-up, including the Rey Auditory Verbal Learning Test (RAVLT), Trail Making Test (TMT) A and B, category naming task and MMSE. The association of different types of vascular brain injury with cognitive decline was evaluated with linear mixed models, including one type of vascular brain injury (dichotomized), time and vascular brain injury*time, adjusted for sex, age, dementia status (yes/no), education (Verhage scale) and medial temporal lobe atrophy (MTA) score (dichotomized as ≥ 1.5). / Results: Across the population, performance declined over time on all tests. Linear mixed models showed that lacune(s) were associated with worse baseline TMTA (Beta(SE)) (8.3 (3.8), p = .03) and TMTB (25.6 (10.3), p = .01), albeit with a slower rate of decline on MMSE, RAVLT and category naming. By contrast, patients with non-lacunar infarct(s) showed a steeper rate of decline on TMTB (29.6 (7.7), p = .00), mainly attributable to patients with dementia (62.9 (15.5), p = .00). / Conclusion: Although different types of vascular brain injury have different etiologies and different patterns, they show little differences in cognitive trajectories depending on type of vascular brain injury

Comorbid amyloid-β pathology affects clinical and imaging features in VCD

INTRODUCTION: To date, the clinical relevance of comorbid amyloid-β (Aβ) pathology in patients with vascular cognitive disorders (VCD) is largely unknown. METHODS: We included 218 VCD patients with available cerebrospinal fluid Aβ42 levels. Patients were divided into Aβ+ mild-VCD (n = 84), Aβ- mild-VCD (n = 68), Aβ+ major-VCD (n = 31), and Aβ- major-VCD (n = 35). We measured depression with the Geriatric Depression Scale, cognition with a neuropsychological test battery and derived white matter hyperintensities (WMH) and gray matter atrophy from MRI. RESULTS: Aβ- patients showed more depressive symptoms than Aβ+. In the major-VCD group, Aβ- patients performed worse on attention (P = .02) and executive functioning (P = .008) than Aβ+. We found no cognitive differences in patients with mild VCD. In the mild-VCD group, Aβ- patients had more WMH than Aβ+ patients, whereas conversely, in the major-VCD group, Aβ+ patients had more WMH. Atrophy patterns did not differ between Aβ+ and Aβ- VCD group. DISCUSSION: Comorbid Aβ pathology affects the manifestation of VCD, but effects differ by severity of VCD

Prediction of poor clinical outcome in vascular cognitive impairment: TRACE-VCI study

INTRODUCTION: Prognostication in memory clinic patients with vascular brain injury (eg possible vascular cognitive impairment [VCI]) is often uncertain. We created a risk score to predict poor clinical outcome. METHODS: Using data from two longitudinal cohorts of memory clinic patients with vascular brain injury without advanced dementia, we created (n = 707) and validated (n = 235) the risk score. Poor clinical outcome was defined as substantial cognitive decline (change of Clinical Dementia Rating ≥1 or institutionalization) or major vascular events or death. Twenty‐four candidate predictors were evaluated using Cox proportional hazard models. RESULTS: Age, clinical syndrome diagnosis, Disability Assessment for Dementia, Neuropsychiatric Inventory, and medial temporal lobe atrophy most strongly predicted poor outcome and constituted the risk score (C‐statistic 0.71; validation cohort 0.78). Of note, none of the vascular predictors were retained in this model. The 2‐year risk of poor outcome was 6.5% for the lowest (0‐5) and 55.4% for the highest sum scores (10‐13). DISCUSSION: This is the first, validated, prediction score for 2‐year clinical outcome of patients with possible VCI

Design of the ExCersion-VCI study: The effect of aerobic exercise on cerebral perfusion in patients with vascular cognitive impairment

There is evidence for a beneficial effect of aerobic exercise on cognition, but underlying mechanisms are unclear. In this study, we test the hypothesis that aerobic exercise increases cerebral blood flow (CBF) in patients with vascular cognitive impairment (VCI). This study is a multicenter single-blind randomized controlled trial among 80 patients with VCI. Most important inclusion criteria are a diagnosis of VCI with Mini-Mental State Examination ≥22 and Clinical Dementia Rating ≤0.5. Participants are randomized into an aerobic exercise group or a control group. The aerobic exercise program aims to improve cardiorespiratory fitness and takes 14 weeks, with a frequency of three times a week. Participants are provided with a bicycle ergometer at home. The control group receives two information meetings. Primary outcome measure is change in CBF. We expect this study to provide insight into the potential mechanism by which aerobic exercise improves hemodynamic status

Ondersteuning bij visuele problemen in het kader van posterieure corticale atrofie - een casus

Posterieure corticale atrofie (PCA) is een neurodegeneratieve aandoening waarbij visuele problemen op de voorgrond staan. De meest voorkomende onderliggende oorzaak van PCA is de ziekte van Alzheimer. Er is geen curatieve therapie voor PCA; visuele ondersteuning bij PCA kan echter een uitkomst bieden. In deze casus beschrijven we een patiënt met PCA die ondersteuning krijgt bij een revalidatiecentrum dat zich richt op patiënten met visuele problematiek. Daarnaast geven we een overzicht van de huidige behandelmethoden en mogelijkheden bij visuele problematiek in het kader van PCA. Passende ondersteuning bij visuele klachten en psychische factoren van een patiënt met PCA en diens mantelzorger is belangrijk bij het zo veel mogelijk zelfstandig kunnen blijven functioneren van een patiënt en het voorkomen of verminderen van psychische klachten van patiënt en mantelzorger

Impact of white matter hyperintensity location on depressive symptoms in memory-clinic patients : a lesion–symptom mapping study

Background: We investigated the association between white matter hyperintensity location and depressive symptoms in a memory-clinic population using lesion–symptom mapping. Methods: We included 680 patients with vascular brain injury from the TRACE-VCI cohort (mean age ± standard deviation: 67 ± 8 years; 52% female): 168 patients with subjective cognitive decline, 164 with mild cognitive impairment and 348 with dementia. We assessed depressive symptoms using the Geriatric Depression Scale. We applied assumption-free voxel-based lesion–symptom mapping, adjusted for age, sex, total white matter hyperintensity volume and multiple testing. Next, we applied exploratory region-of-interest linear regression analyses of major white matter tracts, with additional adjustment for diagnosis. Results: Voxel-based lesion–symptom mapping identified voxel clusters related to the Geriatric Depression Scale in the left corticospinal tract. Region-of-interest analyses showed no relation between white matter hyperintensity volume and the Geriatric Depression Scale, but revealed an interaction with diagnosis in the forceps minor, where larger regional white matter hyperintensity volume was associated with more depressive symptoms in subjective cognitive decline (β = 0.26, p < 0.05), but not in mild cognitive impairment or dementia. Limitations: We observed a lack of convergence of findings between voxel-based lesion–symptom mapping and region-of-interest analyses, which may have been due to small effect sizes and limited lesion coverage despite the large sample size. This warrants replication of our findings and further investigation in other cohorts. Conclusion: This lesion–symptom mapping study in depressive symptoms indicates the corticospinal tract and forceps minor as strategic tracts in which white matter hyperintensity is associated with depressive symptoms in memory-clinic patients with vascular brain injury. The impact of white matter hyperintensity on depressive symptoms is modest, but it appears to depend on the location of white matter hyperintensity and disease severity

Cerebral blood flow and cognitive functioning in a community-based, multi-ethnic cohort: The SABRE study

© 2018 Leeuwis, Smith, Melbourne, Hughes, Richards, Prins, Sokolska, Atkinson, Tillin, Jäger, Chaturvedi, Flier and Barkhof. Introduction: Lower cerebral blood flow (CBF) is associated with cardiovascular disease and vascular risk factors, and is increasingly acknowledged as an important contributor to cognitive decline and dementia. In this cross-sectional study, we examined the association between CBF and cognitive functioning in a community-based, multiethnic cohort. Methods: From the SABRE (Southall and Brent Revisited) study, we included 214 European, 151 South Asian and 87 African Caribbean participants (71 ± 5 years; 39%F). We used 3T pseudo-continuous arterial spin labeling to estimate whole-brain, hematocrit corrected CBF. We measured global cognition and three cognitive domains (memory, executive functioning/attention and language) with a neuropsychological test battery. Associations were investigated using linear regression analyses, adjusted for demographic variables, vascular risk factors and MRI measures. Results: Across groups, we found an association between higher CBF and better performance on executive functioning/attention (standardized ß [stß] = 0.11, p < 0.05). Stratification for ethnicity showed associations between higher CBF and better performance on memory and executive functioning/attention in the white European group (stß = 0.14; p < 0.05 and stß = 0.18; p < 0.01 respectively), associations were weaker in the South Asian and African Caribbean groups. Conclusions: In a multi-ethnic community-based cohort we showed modest associations between CBF and cognitive functioning. In particular, we found an association between higher CBF and better performance on executive functioning/attention and memory in the white European group. The observations are consistent with the proposed role of cerebral hemodynamics in cognitive decline

Sex differences in memory clinic patients with possible vascular cognitive impairment

Introduction: We aimed to establish sex differences in vascular brain damage of memory clinic patients with possible vascular cognitive impairment (VCI). Methods: A total of 860 memory clinic patients (aged 67.7 ± 8.5; 46% female) with cognitive complaints and vascular brain damage (ie, possible VCI) from the prospective TRACE-VCI (Utrecht-Amsterdam Clinical Features and Prognosis in Vascular Cognitive Impairment) cohort study with 2-year follow-up were included. Age-adjusted female-to-male differences were calculated with general linear models, for demographic variables, vascular risk factors, clinical diagnosis, cognitive performance, and brain magnetic resonance imaging markers. Results: We found no difference in age nor distribution of clinical diagnoses between females and males. Females performed worse on the MMSE (Mini-Mental State Examination) and CAMCOG (Cognitive and Self-Contained Part of the Cambridge Examination for Mental Disorders of the Elderly). Females had a larger white matter hyperintensity volume, while males more often showed (lacunar) infarcts. There was no difference in microbleed prevalence. Males had smaller normalized total brain and gray matter volumes. During follow-up, occurrence of cognitive decline and institutionalization was comparable, but mortality was higher in males. Discussion: Our results suggest that susceptibility and underlying etiology of VCI might differ by sex. Males seem to have more large vessel brain damage compared to females that have more small vessel brain damage