Cerebrovascular Risk-Factors of Prevalent and Incident Brain Infarcts in the General Population: The AGES-Reykjavik Study

Silent brain infarct in migraine: Systematic review and meta-analysis

BACKGROUND

While migraine, particularly migraine with aura, is a recognized risk factor for ischemic stroke, the association of migraine with silent brain infarction is a matter of debate, as studies on this topic have yielded conflicting results.

METHODS

A systematic review of the literature was conducted of studies reporting migraine and silent brain infarction, assessed by magnetic resonance imaging, between January 1980 and April 2022, by consulting Medline and Embase databases. Studies with a control group were included in a meta-analysis of population-based studies. An exploratory meta-analysis of both population-based and clinical-based studies was further performed to test the association between migraine with aura and silent brain infarction.

RESULTS

A total of 2,408 articles were identified, among which 24 were included in the systematic review and 10 in the meta-analysis. The meta-analysis of population-based studies showed no association of migraine with silent brain infarction (odds ratio (OR)=1.32 [95% CI 0.92;1.90], P=0.13) and migraine with aura with silent brain infarction (OR=1.56 [0.74;3.30], P=0.24). However, in the exploratory meta-analysis of population-based and clinical-based studies, migraine with aura was significantly associated with silent brain infarction (OR=1.91 [1.02;3.59], P=0.04) and to silent cerebellar infarcts (OR=2.57 [1.01;6.56], P=0.05).

CONCLUSION

In this updated systematic review and meta-analysis of population-based studies, migraine and migraine with aura were not associated with silent brain infarction.

Associations of plasma NfL, GFAP, and t-tau with cerebral small vessel disease and incident dementia: longitudinal data of the AGES-Reykjavik Study

We investigated the associations of plasma neurofilament light (NfL), glial fibrillary acidic protein (GFAP), and total tau (t-tau) with markers of cerebral small vessel disease (SVD) and with incident dementia. We also investigated whether associations of NfL, GFAP, and t-tau with incident dementia were explained by SVD. Data are from a random subsample (n = 1069) of the population-based AGES-Reykjavik Study who underwent brain MRI and in whom plasma NfL, GFAP, and t-tau were measured at baseline (76.1 ± 5.4 years/55.9% women/baseline 2002-2006/follow-up until 2015). A composite SVD burden score was calculated using white matter hyperintensity volume (WMHV), subcortical infarcts, cerebral microbleeds, and large perivascular spaces. Dementia was assessed in a 3-step process and adjudicated by specialists. Higher NfL was associated with a higher SVD burden score. Dementia occurred in 225 (21.0%) individuals. The SVD burden score significantly explained part of the association between NfL and incident dementia. WMHV mostly strongly contributed to the explained effect. GFAP was not associated with the SVD burden score, but was associated with WMHV, and WMHV significantly explained part of the association between GFAP and incident dementia. T-tau was associated with WMHV, but not with incident dementia. In conclusion, the marker most strongly related to SVD is plasma NfL, for which the association with WMHV appeared to explain part of its association with incident dementia. This study suggests that plasma NfL may reflect the contribution of co-morbid vascular disease to dementia. However, the magnitude of the explained effect was relatively small, and further research is required to investigate the clinical implications of this finding.

Where is VALDO? VAscular Lesions Detection and segmentatiOn challenge at MICCAI 2021

Imaging markers of cerebral small vessel disease provide valuable information on brain health, but their manual assessment is time-consuming and hampered by substantial intra- and interrater variability. Automated rating may benefit biomedical research, as well as clinical assessment, but diagnostic reliability of existing algorithms is unknown. Here, we present the results of the VAscular Lesions DetectiOn and Segmentation (Where is VALDO?) challenge that was run as a satellite event at the international conference on Medical Image Computing and Computer Aided Intervention (MICCAI) 2021. This challenge aimed to promote the development of methods for automated detection and segmentation of small and sparse imaging markers of cerebral small vessel disease, namely enlarged perivascular spaces (EPVS) (Task 1), cerebral microbleeds (Task 2) and lacunes of presumed vascular origin (Task 3) while leveraging weak and noisy labels. Overall, 12 teams participated in the challenge proposing solutions for one or more tasks (4 for Task 1-EPVS, 9 for Task 2-Microbleeds and 6 for Task 3-Lacunes). Multi-cohort data was used in both training and evaluation. Results showed a large variability in performance both across teams and across tasks, with promising results notably for Task 1-EPVS and Task 2-Microbleeds and not practically useful results yet for Task 3-Lacunes. It also highlighted the performance inconsistency across cases that may deter use at an individual level, while still proving useful at a population level.

Assessment of Subclinical Atherosclerosis in Asymptomatic People In Vivo: Measurements Suitable for Biomarker and Mendelian Randomization Studies

BACKGROUND

One strategy to reduce the burden of cardiovascular disease is the early detection and treatment of atherosclerosis. This has led to significant interest in studies of subclinical atherosclerosis, using different phenotypes, not all of which are accurate reflections of the presence of asymptomatic atherosclerotic plaques. The aim of part 2 of this series is to provide a review of the existing literature on purported measures of subclinical disease and recommendations concerning which tests may be appropriate in the prevention of incident cardiovascular disease.

METHODS

We conducted a critical review of measurements used to infer the presence of subclinical atherosclerosis in the major conduit arteries and focused on the predictive value of these tests for future cardiovascular events, independent of conventional cardiovascular risk factors, in asymptomatic people. The emphasis was on studies with >10 000 person-years of follow-up, with meta-analysis of results reporting adjusted hazard ratios (HRs) with 95% CIs. The arterial territories were limited to carotid, coronary, aorta, and lower limb arteries.

RESULTS

In the carotid arteries, the presence of plaque (8 studies) was independently associated with future stroke (pooled HR, 1.89 [1.04-3.44]) and cardiac events (7 studies), with a pooled HR, 1.77 (1.19-2.62). Increased coronary artery calcium (5 studies) was associated with the risk of coronary heart disease events, pooled HR, 1.54 (1.07-2.07) and increasing severity of calcification (by Agaston score) was associated with escalation of risk (13 studies). An ankle/brachial index (ABI) of <0.9, the pooled HR for cardiovascular death from 7 studies was 2.01 (1.43-2.81). There were insufficient studies of either, thoracic or aortic calcium, aortic diameter, or femoral plaque to synthesize the data based on consistent reporting of these measures.

CONCLUSIONS

The presence of carotid plaque, coronary artery calcium, or abnormal ankle pressures seems to be a valid indicator of the presence of subclinical atherosclerosis and may be considered for use in biomarker, Mendelian randomization and similar studies.

Establishment and Validation of the Nomogram Model and the Probability of Silent Cerebral Infarction After Ablation Atrial Fibrillation

BACKGROUND

The objective of this study is to establish and validate a nomogram model for predicting the probability of silent cerebral infarction following ablation of atrial fibrillation.

METHODS AND RESULTS

A retrospective observational study was conducted on the data of 238 patients with atrial fibrillation who underwent radiofrequency ablation in our hospital from October 2019 to December 2022. LASSO regression and multivariate logistics regression analysis were used to assess the independent risk factors for silent cerebral infarction after ablation. The AUC of the predictive model was 0.733 (95% CI, 0.649-0.816) and the internal validation (bootstrap = 1000) of the bootstrap method was 0.733 (95% CI 0.646-0.813). The Hosmer-Lemeshow test yields an insignificant p-value of X-squared = 10.212 and p-value = 0.2504, thus indicating an insignificant difference between predicted and observed values and good calibration results. The clinical impact curve (CIC) and clinical decision curve also prove that this graph is useful in the clinical setting.

CONCLUSION

We developed an easy-to-use nomogram model to predict the probability of silent cerebral infarction following radiofrequency ablation of atrial fibrillation. This model can provide a valid assessment of the probability of postoperative silent cerebral infarction in patients undergoing radiofrequency ablation of atrial fibrillation.

Diabetes Mellitus Is a Strong Independent Negative Prognostic Factor in Patients with Brain Metastases Treated with Radiotherapy

BACKGROUND

Brain metastases (BM) cause relevant morbidity and mortality in cancer patients. The presence of cerebrovascular diseases can alter the tumor microenvironment, cellular proliferation and treatment resistance. However, it is largely unknown if the presence of distinct cerebrovascular risk factors may alter the prognosis of patients with BM.

METHODS

Patients admitted for the radiotherapy of BM at a large tertiary cancer center were included. Patient and survival data, including cerebrovascular risk factors (diabetes mellitus (DM), smoking, arterial hypertension, peripheral arterial occlusive disease, hypercholesterolemia and smoking) were recorded.

RESULTS

203 patients were included. Patients with DM (n = 39) had significantly shorter overall survival (OS) (HR 1.75 (1.20-2.56), p = 0.003, log-rank). Other vascular comorbidities were not associated with differences in OS. DM remained prognostically significant in the multivariate Cox regression including established prognostic factors (HR 1.92 (1.20-3.06), p = 0.006). Furthermore, subgroup analyses revealed a prognostic role of DM in patients with non-small cell lung cancer, both in univariate (HR 1.68 (0.97-2.93), p = 0.066) and multivariate analysis (HR 2.73 (1.33-5.63), p = 0.006), and a trend in melanoma patients.

CONCLUSION

DM is associated with reduced survival in patients with BM. Further research is necessary to better understand the molecular mechanisms and therapeutic implications of this important interaction.

Stroke territory and atherosclerosis in ischemic stroke patients with a history of migraine with aura

Introduction

The mechanisms subtending the increased stroke risk in migraine with aura (MA) are not fully understood. Our study aims to evaluate if the clinical profile in stroke patients with MA differentiates from those without MA.

Methods

We retrieved the prospective registered electronic clinical dossiers of adult patients younger than 60 years with acute ischemic stroke admitted in four hospitals between January 2016 and June 2022. Patients were classified by the history of MA (MA+ and MA-).

Results

We identified 851 stroke patients (59 MA+, 6.9%). Compared to MA-, MA+ patients were characterized by younger age (44.0 ± 10.6 vs 50.1 ± 8.2 years), female sex (59.3% vs 29.0%), and affected by cryptogenic (OR 2.594 95% CI 1.483-4.537), and cerebellar stroke (OR 3.218 95% CI 1.657-6.250; p ≤ 0.001 for all comparisons). After adjusting for age and sex, MA+ patients presented less frequently hypertension (OR 0.349 95% CI 0.167-0.470; p=0.005) and dyslipidemia (OR 0.523 95% CI 0.280-0.974; p = 0.041). After adjusting also for risk factors, the MA+ group had less frequently symptomatic large vessel stenosis (OR 0.126 95% CI 0.017-0,924; p = 0.042) and clinical atherosclerosis (OR 0.103 95% CI 0.014-0.761; p = 0.026), while intima-media thickness did not differ (p = 0.395).

Discussion

Cryptogenic and cerebellar stroke and fewer vascular risk factors and clinical atherosclerosis seem to characterize stroke patients with MA.

A Systematic Review of the Impact of Physical Exercise-Induced Increased Resting Cerebral Blood Flow on Cognitive Functions

Brain perfusion declines with aging. Physical exercise represents a low-cost accessible form of intervention to increase cerebral blood flow; however, it remains unclear if exercise-induced amelioration of brain perfusion has any impact on cognition. We aimed to provide a state-of-the art review on this subject. A comprehensive search of the PubMed (MEDLINE) database was performed. On the basis of the inclusion and exclusion criteria, 14 studies were included in the analysis. Eleven of the studies conducted well-controlled exercise programs that lasted 12–19 weeks for 10–40 participants and two studies were conducted in much larger groups of subjects for more than 5 years, but the exercise loads were indirectly measured, and three of them were focused on acute exercise. Literature review does not show a direct link between exercise-induced augmentation of brain perfusion and better cognitive functioning. However, in none of the reviewed studies was such an association the primary study endpoint. Carefully designed clinical studies with focus on cognitive and perfusion variables are needed to provide a response to the question whether exercise-induced cerebral perfusion augmentation is of clinical importance.