Dementia incidence and predictors in cerebral amyloid angiopathy patients without intracerebral hemorrhage

Parental Influence on Intracerebral Hemorrhage Onset in Hereditary Dutch-Type Cerebral Amyloid Angiopathy

INTRODUCTION

Dutch-type cerebral amyloid angiopathy (D-CAA) is an autosomal dominant hereditary form of CAA causing intracerebral hemorrhage (ICH) and cognitive decline. The age of onset of ICH in D-CAA mutation carriers is strikingly variable and ranges from late thirties up to 70 years. We investigated the presence of genetic anticipation and assessed the influence of parental age at onset and sex on age of ICH onset in offspring.

METHODS

We included (potential) D-CAA mutation carriers from our prospective D-CAA family database. Participants were sent a questionnaire by mail and asked for the onset age of symptomatic ICH and the onset age of symptomatic ICH of their affected first-degree relative(s), their siblings and affected parent. We used a Cox regression model with the age of onset of the parent as the covariate and the sex of the offspring as the factor. Next, we replaced the sex of the offspring with a factor with four levels: mother/daughter, mother/son, father/daughter, and father/son. We used a random effect per household.

RESULTS

A total of 66 respondents completed the questionnaire. Reported mean age of first symptomatic ICH was similar (both 52 years, p = 0.87) for D-CAA parents (n = 60) and their offspring (n = 100). Offspring with a mother with D-CAA seemed to have an earlier ICH onset (50 years, standard deviation [SD] ± 7) than offspring with a paternal inheritance (54 years, SD ± 6, p = 0.03). There was no association between onset of first ICH of the parent and offspring after adding sex of the offspring to the Cox regression model: hazard ratio 0.99, 95% CI: 0.94-1.03, p = 0.51. The interaction between parent's sex and child's sex was not significant (p = 0.70). The results with and without random effect were essentially identical.

CONCLUSION

We found no indication for genetic anticipation in D-CAA in general, although maternal inheritance seemed to be associated with an earlier ICH onset.

CSF and plasma biomarkers in cerebral amyloid angiopathy: A single-center study and a systematic review/meta-analysis

INTRODUCTION

There are limited data regarding cerebrospinal fluid (CSF) and plasma biomarkers among patients with Cerebral Amyloid Angiopathy (CAA). We sought to investigate the levels of four biomarkers [β-amyloids (Aβ42 and Aβ40), total tau (tau) and phosphorylated tau (p-tau)] in CAA patients compared to healthy controls (HC) and patients with Alzheimer Disease (AD).

PATIENTS AND METHODS

A systematic review and meta-analysis of published studies, including also a 5 year single-center cohort study, with available data on CSF and plasma biomarkers in symptomatic sporadic CAA versus HC and AD was conducted. Biomarkers' comparisons were investigated using random-effects models based on the ratio of mean (RoM) biomarker concentrations. RoM < 1 and RoM > 1 indicate lower and higher biomarker concentration in CAA compared to another population, respectively.

RESULTS

We identified nine cohorts, comprising 327 CAA patients (mean age: 71 ± 5 years; women: 45%) versus 336 HC (mean age: 65 ± 5 years; women: 45%) and 384 AD patients (mean age: 68 ± 3 years; women: 53%) with available data on CSF biomarkers. CSF Aβ42 levels [RoM: 0.47; 95% CI: 0.36-0.62; p < 0.0001], Aβ40 levels [RoM: 0.70; 95% CI: 0.63-0.79; p < 0.0001] and the ratio Aβ42/Aβ40 [RoM: 0.62; 95% CI: 0.39-0.98; p = 0.0438] differentiated CAA from HC. CSF Aβ40 levels [RoM: 0.73; 95% CI: 0.64-0.83; p = 0.0003] differentiated CAA from AD. CSF tau and p-tau levels differentiated CAA from HC [RoM: 1.71; 95% CI: 1.41-2.09; p = 0.0002 and RoM: 1.44; 95% CI: 1.20-1.73; p = 0.0014, respectively] and from AD [RoM: 0.65; 95% CI: 0.58-0.72; p < 0.0001 and RoM: 0.64; 95% CI: 0.57-0.71; p < 0.0001, respectively]. Plasma Aβ42 [RoM: 1.14; 95% CI: 0.89-1.45; p = 0.2079] and Aβ40 [RoM: 1.07; 95% CI: 0.91-1.25; p = 0.3306] levels were comparable between CAA and HC.

CONCLUSIONS

CAA is characterized by a distinct CSF biomarker pattern compared to HC and AD. CSF Aβ40 levels are lower in CAA compared to HC and AD, while tau and p-tau levels are higher in CAA compared to HC, but lower in comparison to AD patients.

Cerebral perivascular spaces as predictors of dementia risk and accelerated brain atrophy

Cerebral small vessel disease, an important risk factor for dementia, lacks robust, in vivo measurement methods. Perivascular spaces (PVS) on brain MRI are surrogates for small parenchymal blood vessels and their perivascular compartment, and may relate to brain health. We developed a novel, robust algorithm to automatically assess PVS count and size on MRI, and investigated their relationship with dementia risk and brain atrophy. We analyzed 46,478 clinical measurements of cognitive functioning and 20,845 brain MRI scans from 10,004 participants (71.1±9.7 years-old, 56.6% women). Fewer PVS and larger PVS diameter at baseline were associated with higher dementia risk and accelerated brain atrophy. Longitudinal trajectories of PVS markers were significantly different in non-demented individuals who converted to dementia compared with non-converters. In simulated placebo-controlled trials for treatments targeting cognitive decline, screening out participants less likely to develop dementia based on our PVS markers enhanced the power of the trial. These novel radiographic cerebrovascular markers may improve risk-stratification of individuals, potentially reducing cost and increasing throughput of clinical trials to combat dementia.

Early stage of cerebral amyloid angiopathy revealed by follow-up of a minimal head injury

Cerebral amyloid angiopathy (CAA) is an age-related cerebral microangiopathy characterized by the accumulation of amyloid-beta peptide in the wall of leptomeningeal arteries and cortical vessels. Diagnosis of sporadic amyloid angiopathy is most often made in elderly patient with lobar hematoma. We report a case of a 68-year-old female who had minimal head injury. Cerebral CT showed a right cerebellar hematoma. Follow-up MRI after 4 months showed signs of cerebral amyloid angiopathy. Through this observation, we describe the MRI semiology that helps make the diagnosis of cerebral amyloid angiopathy.

Incidence and risk factors associated with seizures in cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy (CAA) is a common cause of intracranial hemorrhage (ICH), which is a risk factor for seizures. The incidence and risk factors of seizures associated with a heterogeneous cohort of CAA patients have not been studied.

METHODS

We conducted a retrospective study of patients with CAA treated at Mayo Clinic Florida between 1 January 2015 and 1 January 2021. CAA was defined using the modified Boston criteria version 2.0. We analyzed electrophysiological and clinical features, and comorbidities including lobar ICH, nontraumatic cortical/convexity subarachnoid hemorrhage (cSAH), superficial siderosis, and inflammation (CAA with inflammation [CAA-ri]). Cognition and mortality were secondary outcomes. Univariate and multivariate analyses were performed to determine risk of seizures relative to clinical presentation.

RESULTS

Two hundred eighty-four patients with CAA were identified, with median follow-up of 35.7 months (interquartile range = 13.5-61.3 months). Fifty-six patients (19.7%) had seizures; in 21 (37.5%) patients, seizures were the index feature leading to CAA diagnosis. Seizures were more frequent in females (p = 0.032) and patients with lobar ICH (p = 0.002), cSAH (p = 0.030), superficial siderosis (p < 0.001), and CAA-ri (p = 0.005), and less common in patients with microhemorrhage (p = 0.006). After controlling for age and sex, lobar ICH (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.1-4.2), CAA-ri (OR = 3.8, 95% CI = 1.4-10.3), and superficial siderosis (OR = 3.7, 95% CI = 1.9-7.0) were independently associated with higher odds of incident seizures.

CONCLUSIONS

Seizures are common in patients with CAA and are independently associated with lobar ICH, CAA-ri, and superficial siderosis. Our results may be applied to optimize clinical monitoring and management for patients with CAA.

Comorbid cerebral amyloid angiopathy in dementia and prodromal stages-Prevalence and effects on cognition

OBJECTIVES

To determine the contribution of cerebral amyloid angiopathy to cognitive impairment in MCI and dementia.

METHODS

Patients with subjective memory impairment (SMI), amnestic and non-amnestic mild cognitive impairment ((n)aMCI), Alzheimer's disease (AD), mixed and vascular dementia (MD/VD) from our memory clinic were included in this retrospective analysis. Patients underwent neuropsychological testing and cranial magnetic resonance imaging (MRI). Magnetic resonance imaging data sets were analyzed regarding the presence of CAA-related MRI biomarkers to determine CAA prevalence. ANOVAs were used to investigate the contribution of CAA to cognitive impairment within diagnostic groups and to determine whether differences in cognitive test performance between the diagnostic groups are mediated by total CAA burden.

RESULTS

475 patients (222 male, 253 female) with SMI (n = 47), naMCI (n = 41), aMCI (n = 189), early AD (n = 9), AD (n = 114), MD (n = 71) and VD (n = 4) were included. Mean age was 73.2 (9.9) years. CAA prevalence was 14.9% in SMI, 14.6% in naMCI, 24.3% in aMCI, 22.2% in early onset AD, 18.4% in late onset AD, 46.5% in MD and 25% in VD. Patients with possible and probable CAA were older than patients without CAA. In particular, diagnosis of aMCI, early onset AD, MD and VD showed high CAA prevalence. In AD but not in aMCI, CAA diagnosis significantly influenced test performance in the CERAD word list recall (F (1,78) = 4505; p = 0.037; partial eta-square = 0.055). Differences in cognitive test performance between the diagnostic groups of naMCI, aMCI, AD and MD were mediated by total CAA burden within AAT simply nouns subtest (F (2,39) = 4059; p = 0.025; partial eta-square = 0.172) and in CERAD verbal fluency test (F (3,129) = 3533; p = 0.017; partial eta-square = 0.076).

CONCLUSION

This retrospective analysis demonstrates high prevalence rates of CAA in cognitive diagnoses. Our data suggest that comorbid CAA independently impacts cognitive test performance in the course of AD with presumably stage-dependent effects. Especially in patients with AD comorbid CAA additionally impairs memory function. Total CAA small vessel disease burden further modulates psychometric differences in cognitive test performance between diagnostic groups regarding word finding and word fluency capabilities.

Progression of cerebral amyloid angiopathy: a pathophysiological framework

Cerebral amyloid angiopathy, which is defined by cerebrovascular deposition of amyloid β, is a common age-related small vessel pathology associated with intracerebral haemorrhage and cognitive impairment. Based on complementary lines of evidence from in vivo studies of individuals with hereditary, sporadic, and iatrogenic forms of cerebral amyloid angiopathy, histopathological analyses of affected brains, and experimental studies in transgenic mouse models, we present a framework and timeline for the progression of cerebral amyloid angiopathy from subclinical pathology to the clinical manifestation of the disease. Key stages that appear to evolve sequentially over two to three decades are (stage one) initial vascular amyloid deposition, (stage two) alteration of cerebrovascular physiology, (stage three) non-haemorrhagic brain injury, and (stage four) appearance of haemorrhagic brain lesions. This timeline of stages and the mechanistic processes that link them have substantial implications for identifying disease-modifying interventions for cerebral amyloid angiopathy and potentially for other cerebral small vessel diseases.

Sex-Specific Patterns of Cerebral Atrophy and Enlarged Perivascular Spaces in Patients with Cerebral Amyloid Angiopathy and Dementia

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy is characterized by amyloid β deposition in leptomeningeal and superficial cortical vessels. Cognitive impairment is common and may occur independent of concomitant Alzheimer disease neuropathology. It is still unknown which neuroimaging findings are associated with dementia in cerebral amyloid angiopathy and whether they are modulated by sex. This study compared MR imaging markers in patients with cerebral amyloid angiopathy with dementia or mild cognitive impairment or who are cognitively unimpaired and explored sex-specific differences.

MATERIALS AND METHODS

We studied 58 patients with cerebral amyloid angiopathy selected from the cerebrovascular and memory outpatient clinics. Clinical characteristics were collected from clinical records. Cerebral amyloid angiopathy was diagnosed on MR imaging on the basis of the Boston criteria. Visual rating scores for atrophy and other imaging features were independently assessed by 2 senior neuroradiologists.

RESULTS

Medial temporal lobe atrophy was higher for those with cerebral amyloid angiopathy with dementia versus those cognitively unimpaired (P = .015), but not for those with mild cognitive impairment. This effect was mainly driven by higher atrophy in men with dementia, compared with women with and without dementia (P = .034, P = .012; respectively) and with men without dementia (P = .012). Enlarged perivascular spaces in the centrum semiovale were more frequent in women with dementia versus men with and without dementia (P = .021, P = .011; respectively) and women without dementia (P = .011).

CONCLUSIONS

Medial temporal lobe atrophy was more prominent in men with dementia, whereas women showed a higher number of enlarged perivascular spaces in the centrum semiovale. Overall, this finding suggests differential pathophysiologic mechanisms with sex-specific neuroimaging patterns in cerebral amyloid angiopathy.

Mediators of cognitive impairment in cerebral amyloid angiopathy

BACKGROUND

Cerebral amyloid angiopathy (CAA) is associated with cognitive decline. CAA has diverse impacts on brain structure and function; however, the brain lesions that mediate the association of CAA with cognition are not understood well.

AIMS

To determine the degree to which CAA neuroimaging biomarkers mediate the association of CAA with cognitive dysfunction.

METHODS

We analyzed cross-sectional data of patients with probable CAA and controls without cognitive impairment from the Functional Assessment of Vascular Reactivity study. Neuropsychological tests were grouped into domains of memory, executive function, and processing speed. Candidate CAA neuroimaging biomarkers were pre-specified based on prior literature, consisting of white matter hyperintensity volume, peak width of skeletonized mean diffusivity (PSMD) on diffusion tensor magnetic resonance imaging (MRI), cerebrovascular reactivity (CVR), cortical thickness, and cortical thickness in a meta-region of interest typically affected by Alzheimer's disease (AD). Cognitive scores and neuroimaging markers were standardized and reported in relation to values in controls. Mediation analysis was used to estimate the total effect of CAA on cognition and the proportion of the total effect that was mediated by neuroimaging biomarkers, controlling for age, sex, and education.

RESULTS

There were 131 participants (67 CAA and 64 controls). Mean age was 72.1 ± 7.7 years, and 54.2% were women. As expected, compared to controls, CAA was associated with lower cognition. In mediation analyses, CAA had direct unmediated effects of 48%, 46%, and 52% on all three cognitive domains. The association of CAA with memory was partially mediated by CVR and PSMD, accounting for 18% and 36% of the total effect of CAA. The association of CAA with executive function was partially mediated by PSMD and mean cortical thickness in the AD meta-region of interest (ROI), accounting for 33% and 31% of the total effect of CAA. The association of CAA with processing speed was partially mediated by CVR and PSMD, accounting for 8% and 34% of the total effect of CAA. Among CAA participants, the presence of cortical superficial siderosis was associated with lower processing speed.

CONCLUSION

Altered white matter diffusivity (i.e. PSMD), CVR, and atrophy, taken together, account for about half the effect of CAA on cognition.

Peak width of skeletonized mean diffusivity in cerebral amyloid angiopathy: Spatial signature, cognitive, and neuroimaging associations

Background

Peak width of skeletonized mean diffusivity (PSMD) is a promising diffusion tensor imaging (DTI) marker that shows consistent and strong cognitive associations in the context of different cerebral small vessel diseases (cSVD).

Purpose

Investigate whether PSMD (1) is higher in patients with Cerebral Amyloid Angiopathy (CAA) than those with arteriolosclerosis; (2) can capture the anteroposterior distribution of CAA-related abnormalities; (3) shows similar neuroimaging and cognitive associations in comparison to other classical DTI markers, such as average mean diffusivity (MD) and fractional anisotropy (FA).

Materials and methods

We analyzed cross-sectional neuroimaging and neuropsychological data from 90 non-demented memory-clinic subjects from a single center. Based on MRI findings, we classified them into probable-CAA (those that fulfilled the modified Boston criteria), subjects with MRI markers of cSVD not attributable to CAA (presumed arteriolosclerosis; cSVD), and subjects without evidence of cSVD on MRI (non-cSVD). We compared total and lobe-specific (frontal and occipital) DTI metrics values across the groups. We used linear regression models to investigate how PSMD, MD, and FA correlate with conventional neuroimaging markers of cSVD and cognitive scores in CAA.

Results

PSMD was comparable in probable-CAA (median 4.06 × 10^–4 mm²/s) and cSVD (4.07 × 10^–4 mm²/s) patients, but higher than in non-cSVD (3.30 × 10^–4 mm²/s; p < 0.001) subjects. Occipital-frontal PSMD gradients were higher in probable-CAA patients, and we observed a significant interaction between diagnosis and region on PSMD values [F(2, 87) = 3.887, p = 0.024]. PSMD was mainly associated with white matter hyperintensity volume, whereas MD and FA were also associated with other markers, especially with the burden of perivascular spaces. PSMD correlated with worse executive function (β = −0.581, p < 0.001) and processing speed (β = −0.463, p = 0.003), explaining more variance than other MRI markers. MD and FA were not associated with performance in any cognitive domain.

Conclusion

PSMD is a promising biomarker of cognitive impairment in CAA that outperforms other conventional and DTI-based neuroimaging markers. Although global PSMD is similarly increased in different forms of cSVD, PSMD’s spatial variations could potentially provide insights into the predominant type of underlying microvascular pathology.

White matter hyperintensities volume and cognition: A meta-analysis

Background

Cerebral small vessel disease (CSVD) is prevalent in the elderly and leads to an increased risk of cognitive impairment and dementia. The volume of white matter hyperintensities (WMHs) increases with age, which affects cognition.

Objective

To explore the relationship between WMH volume and cognitive decline in patients with CSVD.

Methods

We performed a systematic search of PubMed, Embase, and the Web of Science databases from their respective creation dates to the 5 May 2022 to identify all the clinical studies on either mild cognitive impairment (MCI) or dementia in regards to WMH volume in CSVD.

Results

White matter hyperintensities was associated with the risk of both the MCI and dementia, with a 35% increased risk [relative risk (RR) = 1.35; (95% CI: 1.01-1.81)] of progression from cognitively unimpaired (CU) to MCI (six studies, n = 2,278) and a 49% increased risk [RR = 1.49; (95% CI: 1.21-1.84)] of progression to dementia (six studies, n = 6,330). In a subgroup analysis, a follow-up period of over 5 years increased the risk of MCI by 40% [RR = 1.40; (95% CI: 1.07-1.82)] and dementia by 48% [RR = 1.48; (95% CI: 1.15-1.92)].

Conclusion

White matter hyperintensities was found to be substantially correlated with the risk of cognitive impairment. Furthermore, cognitive decline was found to be a chronic process, such that WMH predicted the rate of cognitive decline in CSVD beyond 5 years. The cognitive decline observed in patients with WMH may, therefore, be minimized by early intervention.

Overview of therapeutic targets in management of dementia

Dementia is defined as a gradual cognitive impairment that interferes with everyday tasks, and is a leading cause of dependency, disability, and mortality. According to the current scenario, millions of individuals worldwide have dementia. This review provides with an overview of dementia before moving on to its subtypes (neurodegenerative and non-neurodegenerative) and pathophysiology. It also discusses the incidence and severity of dementia, focusing on Alzheimer's disease with its different hypotheses such as Aβ cascade hypothesis, Tau hypothesis, inflammatory hypothesis, cholinergic and oxidative stress hypothesis. Alzheimer's disease is the most common type and a progressive neurodegenerative illness distinct by neuronal loss and resulting cognitive impairment, leading to dementia. Alzheimer's disease (AD) is considered the most familiar neurodegenerative dementias that affect mostly older population. There are still no disease-modifying therapies available for any dementias at this time, but there are various methods for lowering the risk to dementia patients by using suitable diagnostic and evaluation methods. Thereafter, the management and treatment of primary risk elements of dementia are reviewed. Finally, the future perspectives of dementia (AD) focusing on the impact of the new treatment are discussed.

Effect of vascular amyloid on white matter disease is mediated by vascular dysfunction in cerebral amyloid angiopathy

We postulated that vascular dysfunction mediates the relationship between amyloid load and white matter hyperintensities (WMH) in cerebral amyloid angiopathy (CAA). Thirty-eight cognitively healthy patients with CAA (mean age 70 ± 7.1) were evaluated. WMH was quantified and expressed as percent of total intracranial volume (pWMH) using structural MRI. Mean global cortical Distribution Volume Ratio representing Pittsburgh Compound B (PiB) uptake (PiB-DVR) was calculated from PET scans. Time-to-peak [TTP] of blood oxygen level-dependent response to visual stimulation was used as an fMRI measure of vascular dysfunction. Higher PiB-DVR correlated with prolonged TTP (r = 0.373, p = 0.021) and higher pWMH (r = 0.337, p = 0.039). Prolonged TTP also correlated with higher pWMH (r = 0.485, p = 0.002). In a multivariate linear regression model, TTP remained independently associated with pWMH (p = 0.006) while PiB-DVR did not (p = 0.225). In a bootstrapping model, TTP had a significant indirect effect (ab = 0.97, 95% CI: 0.137-2.461), supporting that the association between PiB-DVR and pWMH is mediated by TTP response. There was no longer a direct effect independent of the hypothesized pathway. Our study suggests that the effect of vascular amyloid load on white matter disease is mediated by vascular dysfunction in CAA. Amyloid lowering strategies might prevent pathophysiological processes leading to vascular dysfunction, therefore limiting ischemic brain injury.

Corpus callosum lesions are associated with worse cognitive performance in cerebral amyloid angiopathy

The impact of vascular lesions on cognition is location dependent. Here, we assessed the contribution of small vessel disease lesions in the corpus callosum to vascular cognitive impairment in cerebral amyloid angiopathy, as a model for cerebral small vessel disease. Sixty-five patients with probable cerebral amyloid angiopathy underwent 3T magnetic resonance imaging, including a diffusion tensor imaging scan, and neuropsychological testing. Microstructural white-matter integrity was quantified by fractional anisotropy and mean diffusivity. Z-scores on individual neuropsychological tests were averaged into five cognitive domains: information processing speed, executive functioning, memory, language and visuospatial ability. Corpus callosum lesions were defined as haemorrhagic (microbleeds or larger bleeds) or ischaemic (microinfarcts, larger infarcts and diffuse fluid-attenuated inversion recovery hyperintensities). Associations between corpus callosum lesion presence, microstructural white-matter integrity and cognitive performance were examined with multiple regression models. The prevalence of corpus callosum lesions was confirmed in an independent cohort of memory clinic patients with and without cerebral amyloid angiopathy (n = 82). In parallel, we assessed corpus callosum lesions on ex vivo magnetic resonance imaging in cerebral amyloid angiopathy patients (n = 19) and controls (n = 5) and determined associated tissue abnormalities with histopathology. A total number of 21 corpus callosum lesions was found in 19/65 (29%) cerebral amyloid angiopathy patients. Corpus callosum lesion presence was associated with reduced microstructural white-matter integrity within the corpus callosum and in the whole-brain white matter. Patients with corpus callosum lesions performed significantly worse on all cognitive domains except language, compared with those without corpus callosum lesions after correcting for age, sex, education and time between magnetic resonance imaging and neuropsychological assessment. This association was independent of the presence of intracerebral haemorrhage, whole-brain fractional anisotropy and mean diffusivity, and white-matter hyperintensity volume and brain volume for the domains of information processing speed and executive functioning. In the memory clinic patient cohort, corpus callosum lesions were present in 14/54 (26%) patients with probable and 2/8 (25%) patients with possible cerebral amyloid angiopathy, and in 3/20 (15%) patients without cerebral amyloid angiopathy. In the ex vivo cohort, corpus callosum lesions were present in 10/19 (53%) patients and 2/5 (40%) controls. On histopathology, ischaemic corpus callosum lesions were associated with tissue loss and demyelination, which extended beyond the lesion core. Together, these data suggest that corpus callosum lesions are a frequent finding in cerebral amyloid angiopathy, and that they independently contribute to cognitive impairment through strategic microstructural disruption of white-matter tracts.

The Value of a Management Plan Based on Risk Factors for Cerebral Infarction Patients with Cerebral Hemorrhage

Cerebral infarction is a neurological disease related to abnormal blood supply to brain tissue. Patients are mainly men between the ages of 50 and 60 years old. In order to explore the value of risk factor-based management programs for preventing hemorrhagic conversion in patients with cerebral infarction, this paper uses single and multifactor methods to analyze the risk factors of cerebral hemorrhage transformation after cerebral infarction and formulate risk factor-based management plans. 240 cases of cerebral infarction who were admitted to our hospital in the past 2 years were evenly divided into an intervention group (intervention based on risk factors) and a routine group (regular care mode) by a simple randomized method. Cerebral hemorrhage is observed in both groups. We assessed the stroke scale of the National Institutes of Health (NIHSS) score. The development of risk factor-based management plans for patients with acute cerebral infarction during the treatment period has important clinical significance for reducing the incidence of hemorrhagic conversion in patients and promoting the recovery of neurological function.

Prevalence of Clinical and Neuroimaging Markers in Cerebral Amyloid Angiopathy: A Systematic Review and Meta-Analysis

BACKGROUND

Limited data exist regarding the prevalence of clinical and neuroimaging manifestations among patients diagnosed with cerebral amyloid angiopathy (CAA). We sought to determine the prevalence of clinical phenotypes and radiological markers in patients with CAA.

METHODS

Systematic review and meta-analysis of studies including patients with CAA was conducted to primarily assess the prevalence of clinical phenotypes and neuroimaging markers as available in the included studies. Sensitivity analyses were performed based on the (1) retrospective or prospective study design and (2) probable or unspecified CAA status. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using the Cochran Q and I² statistics.

RESULTS

We identified 12 prospective and 34 retrospective studies including 7159 patients with CAA. The pooled prevalence rates were cerebral microbleeds (52% [95% CI, 43%-60%]; I²=93%), cortical superficial siderosis (49% [95% CI, 38%-59%]; I²=95%), dementia or mild cognitive impairment (50% [95% CI, 35%-65%]; I²=97%), intracerebral hemorrhage (ICH; 44% [95% CI, 27%-61%]; I²=98%), transient focal neurological episodes (48%; 10 studies [95% CI, 29%-67%]; I²=97%), lacunar infarcts (30% [95% CI, 25%-36%]; I²=78%), high grades of perivascular spaces located in centrum semiovale (56% [95% CI, 44%-67%]; I²=88%) and basal ganglia (21% [95% CI, 2%-51%]; I²=98%), and white matter hyperintensities with moderate or severe Fazekas score (53% [95% CI, 40%-65%]; I²=91%). The only neuroimaging marker that was associated with higher odds of recurrent ICH was cortical superficial siderosis (odds ratio, 1.57 [95% CI, 1.01-2.46]; I²=47%). Sensitivity analyses demonstrated a higher prevalence of ICH (53% versus 16%; P=0.03) and transient focal neurological episodes (57% versus 17%; P=0.03) among retrospective studies compared with prospective studies. No difference was documented between the prevalence rates based on the CAA status.

CONCLUSIONS

Approximately one-half of hospital-based cohort of CAA patients was observed to have cerebral microbleeds, cortical superficial siderosis, mild cognitive impairment, dementia, ICH, or transient focal neurological episodes. Cortical superficial siderosis was the only neuroimaging marker that was associated with higher odds of ICH recurrence. Future population-based studies among well-defined CAA cohorts are warranted to corroborate our findings.

Imaging Markers of Subcortical Vascular Dementia in Patients With Multiple-Lobar Cerebral Microbleeds

Background and Purpose: Small vessel disease (SVD) imaging markers are related to ischemic and hemorrhage stroke and to cognitive dysfunction. This study aimed to clarify the relationship between SVD imaging markers and subcortical vascular dementia in severe SVD burden.

Methods: A total of 57 subjects with multiple lobar cerebral microbleeds (CMBs) and four established SVD imaging markers were enrolled from the dementia and stroke registries of a single center. Visual rating scales that are used to semi-quantify SVD imaging changes were analyzed individually and compositely to make correlations with cognitive domains and subcortical vascular dementia.

Results: Dementia group had higher subcortical and total white matter hyperintensities (WMHs) and SVD composite scores than non-dementia group. Individual imaging markers correlated differently with one another and had distinct cognitive correlations. After adjusting for demographic factors, multivariate logistic regression indicated associations of subcortical WMHs (odds ratio [OR] 2.03, CI 1.24–3.32), total WMHs (OR 1.43, CI 1.09–1.89), lacunes (OR 1.18, CI 1.02–1.35), cerebral amyloid angiopathy-SVD scores (OR 2.33, CI 1.01–5.40), C₁ scores (imaging composite scores of CMB and WMH) (OR 1.41, CI 1.09–1.83), and C₂ scores (imaging composite scores of CMB, WMH, perivascular space, and lacune) (OR 1.38, CI 1.08–1.76) with dementia.

Conclusions: SVD imaging markers might have differing associations with cognitive domains and dementia. They may provide valuable complementary information in support of personalized treatment planning against cognitive impairment, particularly in patients with a heavy SVD load.

Cortical Thickness and Its Association with Clinical Cognitive and Neuroimaging Markers in Cerebral Amyloid Angiopathy

BACKGROUND

Cerebral amyloid angiopathy (CAA) contributes to brain neurodegeneration and cognitive decline, but the relationship between these two processes is incompletely understood.

OBJECTIVE

The purpose of this study is to examine cortical thickness and its association with cognition and neurodegenerative biomarkers in CAA.

METHODS

Data were collected from the Functional Assessment of Vascular Reactivity study and the Calgary Normative Study. In total, 48 participants with probable CAA, 72 cognitively normal healthy controls, and 24 participants with mild dementia due to AD were included. Participants underwent an MRI scan, after which global and regional cortical thickness measurements were obtained using FreeSurfer. General linear models, adjusted for age and sex, were used to compare cortical thickness globally and in an AD signature region.

RESULTS

Global cortical thickness was lower in CAA compared to healthy controls (mean difference (MD) -0.047 mm, 95% confidence interval (CI) -0.088, -0.005, p = 0.03), and lower in AD compared to CAA (MD -0.104 mm, 95% CI -0.165, -0.043, p = 0.001). In the AD signature region, cortical thickness was lower in CAA compared to healthy controls (MD -0.07 mm, 95% CI -0.13 to -0.01, p = 0.02). Within the CAA group, lower cortical thickness was associated with lower memory scores (R2 = 0.10; p = 0.05) and higher white matter hyperintensity volume (R2 = 0.09, p = 0.04).

CONCLUSION

CAA contributes to neurodegeneration in the form of lower cortical thickness, and this could contribute to cognitive decline. Regional overlap with an AD cortical atrophy signature region suggests that co-existing AD pathology may contribute to lower cortical thickness observed in CAA.

Severity of Small Vessel Disease Biomarkers Reduces the Magnitude of Cognitive Recovery after Ischemic Stroke

OBJECTIVE

The objective of this study was to evaluate the impact of radiological biomarkers suggestive of cerebral small vessel disease (SVD) on the evolution of cognitive performances after an ischemic stroke (IS).

METHODS

We studied patients with a supratentorial IS recruited consecutively to a prospective monocentric longitudinal study. A cognitive assessment was performed at baseline, 3 months, and 1 year and was based on a Montreal Cognitive Assessment, an Isaacs set test of verbal fluency (IST), and a Zazzo's cancellation task (ZCT) for the evaluation of attentional functions and processing speed. The following cerebral SVD biomarkers were detected on a 3-T brain MRI performed at baseline: white matter hyperintensities (WMHs), deep and lobar microbleeds, enlarged perivascular spaces in basal ganglia and centrum semiovale, previous small deep infarcts, and cortical superficial siderosis (cSS). Generalized linear mixed models were used to evaluate the relationship between these biomarkers and changes in cognitive performances.

RESULTS

A total of 199 patients (65 ± 13 years, 68% male) were analyzed. Overall, the cognitive performances improved, more significantly in the first 3 months. Severe WMH was identified in 34% of the patients, and focal cSS in 3.5%. Patients with severe WMH and focal cSS had overall worse cognitive performances. Those with severe WMH had less improvement over time for IST (β = -0.16, p = 0.02) and the number of errors to ZCT (β = 0.19, p = 0.02), while those with focal cSS had less improvement over time for ZCT completion time (β = 0.14, p = 0.01) and number of errors (β = 0.17, p = 0.008), regardless of IS volume and location, gray matter volume, demographic confounders, and clinical and cardiovascular risk factors.

CONCLUSION

The severity of SVD biomarkers, encompassing WMH and cSS, seems to reduce the magnitude of cognitive recovery after an IS. The detection of such SVD biomarkers early after stroke might help to identify patients with a cognitive vulnerability and a higher risk of poststroke cognitive impairment.

The Predictive Values of Different Small Vessel Disease Scores on Clinical Outcomes in Mild ICH Patients

Aim: To explore the predictive values of different small vessel disease (SVD) scores on functional recoveries and the clinical cerebrovascular events in mild intracerebral hemorrhage (ICH).

Methods: In this study, we enrolled conscious and mild ICH patients without surgery and further divided them into the cerebral amyloid angiopathy (CAA)-ICH group and hypertension (HTN)-ICH group. The severity of individual SVD markers, including lacunes, cerebral microbleeds (CMBs), enlarged perivascular spaces (EPVS), white matter hyperintensity (WMH), and cortical superficial siderosis (cSS), was evaluated. The original SVD score, modified SVD score, refined SVD score, and CAA-SVD score and the total number of SVD markers were further calculated. Functional recoveries were evaluated using the modified Rankin scale. Recurrences of stroke were defined as readmission to the hospital with a definite diagnosis of stroke.

Results: A total of 163 ICH patients (60 CAA-ICH and 103 HTN-ICH) were included in the study. The CAA-SVD score (OR=3.429; 95% confidence interval (CI)=1.518–7.748) had the best predictive effect on functional dependence in the CAA-ICH group, among which cSS severities probably played a vital role (OR=4.665; 95% CI=1.388–15.679). The total number of SVD markers [hazard ratio (HR)=3.765; 95% CI=1.467–9.663] can better identify stroke recurrences in CAA-ICH. In HTN-ICH, while the total number of SVD markers (HR=2.136; 95% CI=1.218–3.745) also demonstrated association with recurrent stroke, this effect seems to be related with the influence of lacunes (HR=5.064; 95% CI=1.697–15.116).

Conclusions: The CAA-SVD score and the total number of SVD markers might identify mild CAA-ICH patients with poor prognosis. However, it would be better to focus on lacunes rather than on the overall burden of SVD to predict recurrent strokes in HTN-ICH.

Regulatory microRNAs and vascular cognitive impairment and dementia

Vascular cognitive impairment and dementia (VCID) is defined as a progressive dementia disease related to cerebrovascular injury and often occurs in aged populations. Despite decades of research, effective treatment for VCID is still absent. The pathological processes of VCID are mediated by the molecular mechanisms that are partly modulated at the post-transcriptional level. As small endogenous non-coding RNAs, microRNAs (miRs) can regulate target gene expression through post-transcriptional gene silencing. miRs have been reported to play an important role in the pathology of VCID and have recently been suggested as potential novel pharmacological targets for the development of new diagnosis and treatment strategies in VCID. In this review, we summarize the current understanding of VCID, the possible role of miRs in the regulation of VCID and attempt to envision future therapeutic strategies. Since manipulation of miR levels by either pharmacological or genetic approaches has shown therapeutic effects in experimental VCID models, we also emphasize the potential therapeutic value of miRs in clinical settings.

Neurofilament light chain predicts risk of recurrence in cerebral amyloid angiopathy-related intracerebral hemorrhage

Predicting recurrent intracerebral hemorrhage (ICH) related to cerebral amyloid angiopathy (CAA) currently relies on brain images. We aimed to investigate whether blood neurodegenerative biomarkers predict disease severity and ICH recurrence in CAA. We recruited 68 first probable CAA-ICH cases from a Chinese prospective cohort, and 95 controls. We used the single-molecule array to measure acute phase blood amyloid-40, amyloid-42, total tau and neurofilament light chain (NfL). We used multivariable Cox regression models to assess the association between blood biomarkers and CAA-ICH recurrence, and used the concordance (c-) index to assess prediction models. Blood amyloid-42/40, total tau, and NfL levels changed in CAA-ICH cases than controls. During a median follow-up of 2.4 years, NfL was associated with CAA-ICH recurrence (adjusted hazard ratio 2.14, 95% CI 1.57-2.93) independent of MRI burden of small vessel disease (SVD). The performance of a model to predict CAA-ICH recurrence using MRI burden of SVD alone (c-index 0.77) increased with the addition of NfL (c-index 0.88, 95% CI 0.73-1.00, p=0.019). Further, NfL was associated with baseline ICH volume, NIHSS and 6-month mRS score. Blood NfL is associated with severity and prognosis of CAA-ICH and is a promising addition to MRI burden of SVD to predict CAA-ICH recurrence.

White matter hyperintensities and risks of cognitive impairment and dementia: A systematic review and meta-analysis of 36 prospective studies

BACKGROUND

White matter hyperintensities of presumed vascular origin (WMH) are one of the imaging features of cerebral small vessel disease. Controversies persist about the effects of WMH on cognitive dysfunction. This meta-analysis aimed to identify the associations of WMH with risks of cognitive impairment and dementia.

METHODS

We searched PubMed, EMBASE and Cochrane Library for prospective studies. Primary analyses of cognitive dysfunction and sub-analyses of specific outcomes and study characteristics were conducted using random-effect models.

RESULTS

Thirty-six prospective studies with 19,040 participants were included. WMH at baseline conferred a 14 % elevated risk of cognitive impairment and all-cause dementia (ACD). WMH also conferred 25 % elevated risk of Alzheimer's disease and 73 % elevated risk of vascular dementia. Risk effects of high-grade WMH and continually increasing WMH (in volume or severity) on ACD were revealed. Periventricular WMH conferred a 1.51-fold excess risk for dementia.

CONCLUSIONS

WMH were associated with increased risk of cognitive dysfunction and could become a neuroimaging indicator of dementia.

Enlarged Perivascular Spaces and Dementia: A Systematic Review

Perivascular compartments surrounding the penetrating arteries in the brain are part of a physiologic system, which facilitates fluids exchange and clearance of solutes from the brain. The perivascular compartments become visible on MRI when enlarged and are commonly referred to as perivascular spaces (ePVS). Previous studies on the association between ePVS and dementia have been inconsistent due to varying methods of measuring ePVS. As a frame of reference for future MRI studies on ePVS, we systematically review the literature on ePVS as a marker of vascular brain injury related to dementia from population-based as well as hospital-based settings. We identified three longitudinal and ten cross-sectional studies involving 7,581 persons. Potential outcomes were all-cause dementia, Alzheimer's disease, and vascular dementia. There was considerable heterogeneity in ePVS assessment: with studies using either visual inspection or segmentation, examining different brain locations and implementing different grading scales. Moreover, out of the total of 13 studies, all five studies on vascular dementia reported an association with presence of basal ganglia ePVS after adjustment for age, gender, and white matter hyperintensities. For seven studies on Alzheimer's disease and all-cause dementia, the results were ambiguous. This review did not identify an independent association of ePVS with prevalent or incident dementia. Harmonized methods for ePVS assessment, tested across different populations, may benefit future MRI studies on ePVS and dementia.

Predictors for Late Post-Intracerebral Hemorrhage Dementia in Patients with Probable Cerebral Amyloid Angiopathy

BACKGROUND AND OBJECTIVE

Cerebral amyloid angiopathy (CAA) accounts for the majority of lobar intracerebral hemorrhage (ICH); however, the risk factors for dementia conversion after ICH occurrence in CAA patients are unknown, especially in the long-term period after ICH. Therefore, we aimed to unravel the predictors for late post-ICH dementia (6 months after ICH event) in probable CAA patients.

METHODS

From a large consecutive MRI prospective cohort of spontaneous ICH (2006-2017), we identified probable CAA patients (modified Boston criteria) without dementia 6 months post-ICH. Cognitive outcome during follow-up was determined based on the information from standardized clinical visit notes. We used Cox regression analysis to investigate the association between baseline demographic characteristics, past medical history, MRI biomarkers, and late post-ICH dementia conversion (dementia occurred after 6 months).

RESULTS

Among 97 non-demented lobar ICH patients with probable CAA, 25 patients (25.8%) developed dementia during a median follow-up time of 2.5 years (IQR 1.5-3.8 years). Pre-existing mild cognitive impairment, increased white matter hyperintensities (WMH) burden, the presence of disseminated cortical superficial siderosis (cSS), and higher total small vessel disease score for CAA were all independent predictors for late dementia conversion.

CONCLUSION

In probable CAA patients presenting with lobar ICH, high WMH burden and presence of disseminated cSS are useful neuroimaging biomarkers for dementia risk stratification. These findings have implications for clinical practice and future trial design.

Targeting Transcription Factor Nrf2 (Nuclear Factor Erythroid 2-Related Factor 2) for the Intervention of Vascular Cognitive Impairment and Dementia

Vascular cognitive impairment and dementia (VCID) is an age-related, mild to severe mental disability due to a broad panel of cerebrovascular disorders. Its pathobiology involves neurovascular dysfunction, blood-brain barrier disruption, white matter damage, microRNAs, oxidative stress, neuroinflammation, and gut microbiota alterations, etc. Nrf2 (Nuclear factor erythroid 2-related factor 2) is the master regulator of redox status and controls the transcription of a panel of antioxidative and anti-inflammatory genes. By interacting with NF-κB (nuclear factor-κB), Nrf2 also fine-tunes the cellular oxidative and inflammatory balance. Aging is associated with Nrf2 dysfunction, and increasing evidence has proved the role of Nrf2 in mitigating the VCID process. Based on VCID pathobiologies and Nrf2 studies from VCID and other brain diseases, we point out several hypothetical Nrf2 targets for VCID management, including restoration of endothelial function and neurovascular coupling, preservation of blood-brain barrier integrity, reduction of amyloidopathy, promoting white matter integrity, and mitigating oxidative stress and neuroinflammation. Collectively, the Nrf2 pathway could be a promising direction for future VCID research. Targeting Nrf2 would shed light on VCID managing strategies.

Application of an Imaging-Based Sum Score for Cerebral Amyloid Angiopathy to the General Population: Risk of Major Neurological Diseases and Mortality

Objective: To assess the relation between a sum score of imaging markers indicative of cerebral amyloid angiopathy (CAA) and cognitive impairment, stroke, dementia, and mortality in a general population.

Methods: One thousand six hundred twenty-two stroke-free and dementia-free participants of the population-based Rotterdam Study (mean age 73.1 years, 54.3% women) underwent brain MRI (1.5 tesla) in 2005–2011 and were followed for stroke, dementia and death until 2016–2017. Four MRI markers (strictly lobar cerebral microbleeds, cortical superficial siderosis, centrum semiovale perivascular spaces, and white matter hyperintensities) were combined to construct the CAA sum score, ranging from 0 to 4. Neuropsychological testing measured during the research visit closest to scan date were used to assess general cognitive function and cognitive domains. The associations of the CAA sum score with cognition cross-sectionally and with stroke, dementia, and mortality longitudinally were determined using linear regression and Cox proportional hazard modeling adjusted for age, sex, hypertension, cholesterol, lipid lowering medication, atrial fibrillation, antithrombotic medication and APOE-ε2/ε4 carriership. Additionally, we accounted for competing risks of death due to other causes for stroke and dementia, and calculated absolute risk estimates.

Results: During a mean follow-up of 7.2 years, 62 participants suffered a stroke, 77 developed dementia and 298 died. Participants with a CAA score of 1 showed a lower Mini-Mental-State-Exam (fully-adjusted mean difference −0.21, 95% CI (−0.42–0.00) compared to a score of 0. In general, for increased CAA scores we saw a lower g-factor. The age and sex-adjusted hazard ratios (HRs) per point increase of the CAA score were 1.41 for stroke (95% CI, 0.99–2.00), 1.19 for dementia (95% CI, 0.86–1.65), and 1.26 for mortality (95% CI, 1.07–1.48). The results for dementia and stroke risk did not differ after correcting for the competing risk of death. For all outcomes, higher CAA scores showed higher absolute risk estimates over 10 years.

Conclusions: Our results suggest that in this community-dwelling population, a higher CAA score is related to cognitive impairment and a higher risk of stroke, dementia, and death. The composite CAA score can be used to practically quantify the severity of vascular brain injury.

Invited Review: The spectrum of age-related small vessel diseases: potential overlap and interactions of amyloid and nonamyloid vasculopathies

Deep perforator arteriopathy (DPA) and cerebral amyloid angiopathy (CAA) are the commonest known cerebral small vessel diseases (CSVD), which cause ischaemic stroke, intracebral haemorrhage (ICH) and vascular cognitive impairment (VCI). While thus far mainly considered as separate entities, we here propose that DPA and CAA share similarities, overlap and interact, so that 'pure' DPA or CAA are extremes along a continuum of age-related small vessel pathologies. We suggest blood-brain barrier (BBB) breakdown, endothelial damage and impaired perivascular β-amyloid (Aβ) drainage are hallmark common mechanisms connecting DPA and CAA. We also suggest a need for new biomarkers (e.g. high-resolution imaging) to deepen understanding of the complex relationships between DPA and CAA.

Valuing biomarker diagnostics for dementia care: enhancing the reflection of patients, their care-givers and members of the wider public

What is the value of an early (presymptomatic) diagnosis of dementia in the absence of effective treatment? There has been a lively scholarly debate over this question, but until now (future) patients have not played a large role in it. Our study supplements biomedical research into innovative diagnostics with an exlporation of its meanings and values according to (future) patients. Based on seven focusgroups with (future) patients and their care-givers, we conclude that stakeholders evaluate early diagnostics with respect to whether and how they expect it to empower their capacity to (self-) care. They value it, for instance, with respect to whether it (a) explains experienced complaints, (b) allows to start a process of psychological acceptance and social adaptation to the expected degeneration, (c) contributes to dealing with anxieties (with respect to inheritable versions of dementia), (d) informs adequately about when to start preparing for the end of life, (d) informs the planning of a request for euthanasia, or (e) allows society to deal with a growing amount of dementia patients. Our study suggests that information about disease is considered 'harmful' or 'premature' when recipients feel unable to act on that information in their (self-) care. The results of this research offers input to further ethical research. It invites to adopt a care perspective in evaluation and to seek ways to prevent the 'harm' that such diagnostic methods can bring about.

Contact sport participation and chronic traumatic encephalopathy are associated with altered severity and distribution of cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) consists of beta-amyloid deposition in the walls of the cerebrovasculature and is commonly associated with Alzheimer's disease (AD). However, the association of CAA with repetitive head impacts (RHI) and with chronic traumatic encephalopathy (CTE) is unknown. We evaluated the relationship between RHI from contact sport participation, CTE, and CAA within a group of deceased contact sport athletes (n = 357), a community-based cohort (n = 209), and an AD cohort from Boston University AD Center (n = 241). Unsupervised hierarchal cluster analysis demonstrated a unique cluster (n = 11) with increased CAA in the leptomeningeal vessels compared to the intracortical vessels (p < 0.001) comprised of participants with significantly greater frequencies of CTE (7/11) and history of RHI. Overall, participants with CTE (n = 251) had more prevalent (p < 0.001) and severe (p = 0.010) CAA within the frontal leptomeningeal vessels compared to intracortical vessels. Compared to those with AD, participants with CTE had more severe CAA in frontal than parietal lobes (p < 0.001) and more severe CAA in leptomeningeal than intracortical vessels (p = 0.002). The overall frequency of CAA in participants with CTE was low, and there was no significant association between contact sport participation and the presence of CAA. However, in those with CAA, a history of contact sports was associated with increased CAA severity in the frontal leptomeningeal vessels (OR = 4.01, 95% CI 2.52-6.38, p < 0.001) adjusting for AD, APOE ε4 status, and age. Participants with CAA had increased levels of sulcal tau pathology and decreased levels of the synaptic marker PSD-95 (p's < 0.05), and CAA was a predictor of dementia (OR = 1.75, 95% CI 1.02-2.99, p = 0.043) adjusting for age, sex, and comorbid pathology. Overall, contact sport participation and CTE were associated with more severe frontal and leptomeningeal CAA, and CAA was independently associated with worse pathological and clinical outcomes.

Role of Cerebral Microbleeds for Intracerebral Haemorrhage and Dementia

PURPOSE OF REVIEW

Cerebral microbleeds (CMB)-small round or ovoid lesions detected in hyposignal on blood-sensitive MRI sequences-are promising radiological biomarkers of cerebral small vessel disease. Their relations with ischaemic or haemorragic stroke and their potential contribution to dementia have been extensively addressed. This article reviews recent research on the clinical significance of CMB that remains to be determined.

RECENT FINDINGS

The presence, burden and location of CMB allow to obtain a more accurate estimate of intracerebral haemorrhage and ischaemic stroke risk. Most studies evaluating the association between CMB and dementia are hampered by methodological limitations and show conflicting results. CMB mainly reflect the severity of the underlying small vessel disease and should not be interpreted independently of the others neuroimaging biomarkers or the clinical setting. Future large prospective longitudinal studies and randomized controlled trials in various settings are required to determine whether specific therapies are beneficial in case of incidental findings.

Cerebral Amyloid Angiopathy: Similarity in African-Americans and Caucasians with Alzheimer's Disease

Cerebral amyloid angiopathy (CAA) of the Aβ type is variably present in the brains of patients with Alzheimer's disease (AD). CAA contributes to cognitive decline and increases the risk of lobar hemorrhage; because both AD-typical dementia and lobar hemorrhage are more common in African-Americans than in Caucasians, we postulated that African-Americans with AD might be particularly susceptible to CAA. To test this hypothesis, we analyzed CAA histopathologically in the large vessels and capillaries of autopsy-derived frontal, temporal, parietal, and occipital cortical samples from African-Americans (n = 18) and Caucasians (n = 19) with end-stage AD. In the combined cohort of 37 subjects, 22% of the subjects had severe CAA in large vessels, and 11% had severe CAA in capillaries. However, the prevalence and histopathologic characteristics of CAA were similar in the African-Americans and Caucasians. This conclusion was substantiated in an independent sample from the National Alzheimer's Coordinating Center database, in which the degree of CAA was comparable in 1,554 Caucasians and 68 African-Americans with end-stage AD. These findings support a growing consensus that the fundamental histopathologic features of AD are largely impartial to the race of the afflicted.

Effect of small-vessel disease on cognitive trajectory after atrial fibrillation-related ischaemic stroke or TIA

Post-stroke dementia is common but has heterogenous mechanisms that are not fully understood, particularly in patients with atrial fibrillation (AF)-related ischaemic stroke or TIA. We investigated the relationship between MRI small-vessel disease markers (including a composite cerebral amyloid angiopathy, CAA, score) and cognitive trajectory over 12 months. We included patients from the CROMIS-2 AF study without pre-existing cognitive impairment and with Montreal Cognitive Assessment (MoCA) data. Cognitive impairment was defined as MoCA < 26. We defined “reverters” as patients with an “acute” MoCA (immediately after the index event) score < 26, who then improved by ≥ 2 points at 12 months. In our cohort (n = 114), 12-month MoCA improved overall relative to acute performance (mean difference 1.69 points, 95% CI 1.03–2.36, p < 0.00001). 12-month cognitive impairment was associated with increasing CAA score (per-point increase, adjusted OR 4.09, 95% CI 1.36–12.33, p = 0.012). Of those with abnormal acute MoCA score (n = 66), 59.1% (n = 39) were “reverters”. Non-reversion was associated with centrum semi-ovale perivascular spaces (per-grade increase, unadjusted OR 1.83, 95% CI 1.06–3.15, p = 0.03), cerebral microbleeds (unadjusted OR 10.86, 95% CI 1.22–96.34, p = 0.03), and (negatively) with multiple ischaemic lesions at baseline (unadjusted OR 0.11, 95% CI 0.02–0.90, p = 0.04), as well as composite small-vessel disease (per-point increase, unadjusted OR 2.91, 95% CI 1.23–6.88, p = 0.015) and CAA (per-point increase, unadjusted OR 6.71, 95% CI 2.10–21.50, p = 0.001) scores. In AF-related acute ischaemic stroke or TIA, cerebral small-vessel disease is associated both with cognitive performance at 12 months and failure to improve over this period.

Association Between Cortical Superficial Siderosis and Dementia in Patients With Cognitive Impairment: A Meta-Analysis

Background: It remains unclear whether cortical superficial siderosis (cSS) is associated with dementia and its subtypes. We thus performed a meta-analysis to evaluate the relationship between dementia and cSS.

Methods: We searched EMBASE, PubMed, and Web of Science for relevant studies assessing risk of dementia and prevalence of cSS in patients with cognitive impairment. Fixed-effects and random-effects models were performed.

Results: Seven eligible studies including 3,218 patients with definite cognitive impairment were pooled in meta-analysis. The prevalence of cSS was 3.4%. The pooled analysis demonstrates odds ratio for cSS and dementia to be 1.60 (95% CI 1.04–2.44; p = 0.031). Subgroup analysis further indicated a significant association between cSS and Alzheimer's disease (AD) (OR = 2.01, 95% CI 1.34–3.02; p < 0.001), but not non-AD dementia (OR = 0.700, 95% CI 0.435–1.128; p = 0.143).

Conclusions: Our meta-analysis of available published data demonstrates an increased prevalence of dementia in the subjects with pre-existing cSS, especially for AD. These findings suggest cSS to be a candidate imaging indicator for AD. Further longitudinal research is needed to investigate the clinical relevance.

Dementia

Dementia is any decline in cognition that is significant enough to interfere with independent, daily functioning. Dementia is best characterized as a syndrome rather than as one particular disease. The causes of dementia are myriad and include primary neurologic, neuropsychiatric, and medical conditions. It is common for multiple diseases to contribute to any one patient's dementia syndrome. Neurodegenerative dementias, like Alzheimer disease and dementia with Lewy bodies, are most common in the elderly, while traumatic brain injury and brain tumors are common causes in younger adults. While the recent decade has seen significant advancements in molecular neuroimaging, in understanding clinico-pathologic correlation, and in the development of novel biomarkers, clinicians still await disease-modifying therapies for neurodegenerative dementias. Until then, clinicians from varied disciplines and medical specialties are well poised to alleviate suffering, aggressively treat contributing conditions, employ medications to improve cognitive, neuropsychiatric, and motor symptoms, promote evidence-based brain-healthy behaviors, and improve overall quality of life for patients and families.

MRI for in vivo diagnosis of cerebral amyloid angiopathy: Tailoring artifacts to image hemorrhagic biomarkers

Cerebral amyloid angiopathy (CAA) is a frequent age-related small vessel disease (SVD) with cardinal magnetic resonance imaging (MRI) signatures that are hemorrhagic in nature, and include the presence of strictly lobar (superficial) cerebral microbleeds and intracerebral hemorrhages as well as cortical superficial siderosis. When investigating a patient with suspected CAA in the context of intracranial hemorrhage (parenchymal or subarachnoid) or cognitive dysfunction, various MRI parameters influence the optimal detection and characterization (and prognostication) of this frequent SVD. The present report describes the influence of imaging techniques on the detection of the key hemorrhagic CAA imaging signatures in clinical practice, in research studies, and the imaging parameters that must be understood when encountering a CAA patient, as well as reviewing CAA literature.

Can brain impermeable BACE1 inhibitors serve as anti-CAA medicine?

Background

Cerebral amyloid angiopathy (CAA) is characterized by the deposition of ß-amyloid peptides (Aß) in and surrounding the wall of microvasculature in the central nervous system, together with parenchymal amyloid plaques collectively referred to as cerebral amyloidosis, which occurs in the brain commonly among the elderly and more frequently in patients with Alzheimer’s disease (AD). CAA is associated with vascular injury and may cause devastating neurological outcomes. No therapeutic approach is available for this lesion to date.

Main body

ß-Secretase 1 (BACE1) is the enzyme initiating Aß production. Brain permeable BACE1 inhibitors targeting primarily at the parenchymal plaque pathology are currently evaluated in clinical trials. This article presents findings in support of a role of BACE1 elevation in the development of CAA, in addition to plaque pathogenesis. The rationale, feasibility, benefit and strategic issues for developing BACE1 inhibitors against CAA are discussed. Brain impermeable compounds are considered preferable as they might exhibit sufficient anti-CAA efficacy without causing significant neuronal/synaptic side effects.

Conclusion

Early pharmacological intervention to the pathogenesis of CAA is expected to provide significant protection for cerebral vascular health and hence brain health. Brain impermeable BACE1 inhibitors should be optimized and tested as potential anti-CAA therapeutics.