Cognitive Impairment Before Intracerebral Hemorrhage Is Associated With Cerebral Amyloid Angiopathy

[Analysis of the prevalence of anticoagulant therapy in patients with cognitive disorders and cerebral amyloid angiopathy (CAA)]

OBJECTIVES

To investigate the prevalence of coincident anticoagulation in patients with cognitive disorders and possible or probable cerebral amyloid angiopathy (CAA) as well as the relationship between the presence of oral anticoagulation and CAA-specific lesion load.

MATERIALS AND METHODS

Patients with subjective cognitive decline (SCD), amnestic and non-amnestic mild cognitive impairment (aMCI/naMCI), Alzheimer's disease (AD), mixed dementia (MD) and vascular dementia (VD) who presented to our outpatient dementia clinic between February 2016 and October 2020 were included in this retrospective analysis. Patients underwent cranial magnetic resonance imaging (MRI). MRI data sets were analyzed regarding the presence of CAA-related MRI biomarkers to determine CAA prevalence. Presence of anticoagulant therapy was determined by chart review.

RESULTS

Within the study period, 458 patients (209 male, 249 female, mean age 73.2 ± 9.9 years) with SCD (n = 44), naMCI (n = 40), aMCI (n = 182), AD (n = 120), MD (n = 68) and VD (n = 4) were analyzed. A total of 109 patients (23.8%) were diagnosed with possible or probable CAA. CAA prevalence was highest in aMCI (39.4%) and MD (28.4%). Of patients with possible or probable CAA, 30.3% were under platelet aggregation inhibition, 12.8% were treated with novel oral anticoagulants and 3.7% received phenprocoumon treatment. Regarding the whole study cohort, patients under oral anticoagulation showed more cerebral microbleeds (p = 0.047). There was no relationship between oral anticoagulation therapy and the frequency of cortical superficial siderosis (p = 0.634).

CONCLUSION

CAA is a frequent phenomenon in older patients with cognitive disorders. Almost half of CAA patients receive anticoagulant therapy. Oral anticoagulation is associated with a higher number of cortical and subcortical microbleeds.

Subcortical hemorrhage caused by cerebral amyloid angiopathy compared with hypertensive hemorrhage

OBJECTIVES

Most published reports on lobular hemorrhage in cerebral amyloid angiopathy (CAA) include patients diagnosed only by imaging studies. This study analyzed patients with subcortical hemorrhage histologically diagnosed as CAA or non-CAA (hypertensive).

METHODS

This is a retrospective study analyzing data from 100 craniotomy cases. Tissue of hematoma cavity wall was collected for histological investigation in hematoma removal by surgery in patients with subcortical hemorrhage. Statistical analyses of blood pressure, hematoma location and volume, outcome, and mortality was performed in CAA and non-CAA groups.

RESULTS

There were 47 CAA and 53 non-CAA cases, and average age was significantly older in the CAA group (p < 0.01). Blood pressure was significantly lower (p < 0.01) but hematoma volume was significantly greater (p < 0.05) in the CAA group. Rebleeding occurred in two CAA cases and one non-CAA case, but no re-operations were required. Average score of modified Rankin Scale, which is used to measure the degree of disability in patients who have had a stroke, at three months after surgery was not significantly different between the two groups (CAA: 3.94 ± 1.28, non-CAA: 3.58 ± 1.50). There were seven deaths in the CAA and six in the non-CAA group, and intraventricular hemorrhage highly complicated in the death cases in both groups. In the CAA group, average age of the fatal cases was significantly older than that of the surviving cases (p < 0.05) and six cases demonstrated dementia before onset of hemorrhage.

CONCLUSIONS

Surgical removal of a subcortical hemorrhage caused by CAA is not contraindicated. However, age > 80 years, complication with intraventricular hemorrhage, hematoma volume ≥ 50 ml, and dementia before onset of hemorrhage contribute to high mortality, and craniotomy should be carefully considered for such patients. A limitation of this study is that comparison between CAA and non-CAA groups was performed in the patients with only surgically indicated ICH, and does not evaluate entire ICH cases with CAA. However, this study appropriately compared pathologically diagnosed CAA and non-CAA in patients with moderate to severe lobular ICH with surgical indications.

When Atrial Fibrillation Meets Cerebral Amyloid Angiopathy: Current Evidence and Strategies

Non-valvular atrial fibrillation (AF) and cerebral amyloid angiopathy (CAA) are two common diseases in elderly populations. Despite the effectiveness of oral anticoagulant therapy in cardioembolic stroke prevention, intracranial hemorrhage represents the most serious complication of these therapies. Cerebral amyloid angiopathy is one of the main risk factors for spontaneous intracranial bleeding, and this risk is highly increased by age and concomitant antithrombotic therapies. Cerebral amyloid angiopathy can be silent for years and then manifest with clinical features simulating TIA (TIA-mimics) or stroke in AF patients, pushing clinicians to rapidly start VKAs or DOACs, thus increasing the risk of intracranial bleeding if the diagnosis of CAA was unknown. Because the cerebral amyloid angiopathy is easily diagnosed with non-contrast MRI, suspecting the disease can avoid catastrophic complications. In this review, we will provide physicians managing anticoagulant therapies with key tips to familiarize themselves with cerebral amyloid angiopathy, with a focus on the possible clinical presentations and on the diagnostic criteria.

Domain-specific neuropsychological investigation of CAA with and without intracerebral haemorrhage

BACKGROUND

Cerebral amyloid angiopathy (CAA) is associated with cognitive impairment, but the contributions of lobar intracerebral haemorrhage (ICH), underlying diffuse vasculopathy, and neurodegeneration, remain uncertain. We investigated the domain-specific neuropsychological profile of CAA with and without ICH, and their associations with structural neuroimaging features.

METHODS

Data were collected from patients with possible or probable CAA attending a specialist outpatient clinic. Patients completed standardised neuropsychological assessment covering seven domains. MRI scans were scored for markers of cerebral small vessel disease and neurodegeneration. Patients were grouped into those with and without a macro-haemorrhage (CAA-ICH and CAA-non-ICH).

RESULTS

We included 77 participants (mean age 72, 65% male). 26/32 (81%) CAA-non-ICH patients and 41/45 (91%) CAA-ICH patients were impaired in at least one cognitive domain. Verbal IQ and non-verbal IQ were the most frequently impaired, followed by executive functions and processing speed. We found no significant differences in the frequency of impairment across domains between the two groups. Medial temporal atrophy was the imaging feature most consistently associated with cognitive impairment (both overall and in individual domains) in both univariable and multivariable analyses.

DISCUSSION

Cognitive impairment is common in CAA, even in the absence of ICH, suggesting a key role for diffuse processes related to small vessel disease and/or neurodegeneration. Our findings indicate that neurodegeneration, possibly due to co-existing Alzheimer's disease pathology, may be the most important contributor. The observation that general intelligence is the most frequently affected domain suggests that CAA has a generalised rather than focal cognitive impact.

Cerebral amyloid angiopathy interacts with neuritic amyloid plaques to promote tau and cognitive decline

Accumulating data suggest that cerebrovascular disease contributes to Alzheimer's disease pathophysiology and progression toward dementia. Cerebral amyloid angiopathy is a form of cerebrovascular pathology that results from the build-up of β-amyloid in the vessel walls. Cerebral amyloid angiopathy commonly co-occurs with Alzheimer's disease pathology in the ageing brain and increases the risk of Alzheimer's disease dementia. In the present study, we examined whether cerebral amyloid angiopathy influences tau deposition and cognitive decline independently or synergistically with parenchymal β-amyloid burden. Secondly, we examined whether tau burden mediates the association between cerebral amyloid angiopathy and cognitive decline. We included data from autopsied subjects recruited from one of three longitudinal clinical-pathological cohort studies: the Rush Memory and Aging Project, the Religious Orders Study and the Minority Aging Research Study. Participants completed annual clinical and cognitive evaluations and underwent brain autopsy. Cerebral amyloid angiopathy pathology was rated as none, mild, moderate or severe. Bielschowsky silver stain was used to visualize neuritic β-amyloid plaques and neurofibrillary tangles. We used linear regression and linear mixed models to test independent versus interactive associations of cerebral amyloid angiopathy and neuritic plaque burden with tau burden and longitudinal cognitive decline, respectively. We used causal mediation models to examine whether tau mediates the association between cerebral amyloid angiopathy and cognitive decline. The study sample included 1722 autopsied subjects (age at baseline = 80.2 ± 7.1 years; age at death = 89.5 ± 6.7 years; 68% females). Cerebral amyloid angiopathy interacted with neuritic plaques to accelerate tau burden and cognitive decline. Specifically, those with more severe cerebral amyloid angiopathy pathology and higher levels of neuritic plaque burden had greater tau burden and faster cognitive decline. We also found that tau mediated the association between cerebral amyloid angiopathy and cognitive decline among participants with higher neuritic plaque burden. In summary, more severe levels of cerebral amyloid angiopathy and higher parenchymal β-amyloid burden interacted to promote cognitive decline indirectly via tau deposition. These results highlight the dynamic interplay between cerebral amyloid angiopathy and Alzheimer's disease pathology in accelerating progression toward dementia. These findings have implications for Alzheimer's disease clinical trials and therapeutic development.

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.

[Cerebrovascular disease with neurocognitive impairment]

In the International Classification of Diseases 11th revision in the section «Diseases of the nervous system», it is proposed to distinguish «Cerebrovascular disorder with neurocognitive impairment», which corresponds to both discirculatory encephalopathy (DEP) or chronic cerebral ischemia (CCI) accepted in our country, and also vascular cognitive impairments. The terminology, prevalence, risk factors and pathological basis of the disease are discussed, in particular multiple infarctions, strategic infarctions, cerebral small vessel disease, specific microangiopathies, intracerebral hemorrhage and global hypoperfusion. Post-stroke cognitive impairments are discussed in detail. The article presents relevant data on the pathogenesis of the disease, highlights the issues of clinical and neuroimaging diagnostics. Based on the data presented in the article, we can conclude that the diagnosis of DEP, CCI should be based on the presence of cerebrovascular disease with neurocognitive impairment, which implies the verification of vascular cognitive impairments and reliable neuroimaging signs of cerebrovascular pathology while excluding other causes. Early diagnosis and effective treatment of cerebrovascular disease with neurocognitive impairment (DEP, CCI) is becoming increasingly important, since treatment can slow the progression of the disease and lead to a decrease in the incidence of stroke and dementia.

[Intracerebral hemorrhage under platelet inhibition and oral anticoagulation in patients with cerebral amyloid angiopathy]

Die Durchführung einer oralen Antikoagulation ist bei Patienten mit einer zerebralen Amyloidangiopathie eine therapeutische Herausforderung. Die Assoziation der zerebralen Amyloidangiopathie mit Lobärblutungen, eine hohe Mortalität intrazerebraler Blutungen insbesondere unter oraler Antikoagulation sowie das hohe Rezidivrisiko solcher Blutungen erfordern eine strenge und interdisziplinäre Risiko-Nutzen-Abwägung. Vitamin-K-Antagonisten erhöhen das Risiko für die mit intrazerebralen Blutungen vergesellschaftete Mortalität um 60 % und sollten daher möglichst vermieden bzw. speziellen klinischen Situationen (z. B. mechanischer Aortenklappenersatz) vorbehalten sein. Auch der Einsatz von neuen oralen Antikoagulanzien und Thrombozytenaggregationshemmern bedarf einer strengen Risiko-Nutzen-Abwägung, da auch diese Substanzen das zerebrale Blutungsrisiko erhöhen. Insbesondere bei Patienten mit einer absoluten Arrhyhtmie bei Vorhofflimmern ist der interventionelle Vorhofohrverschluss eine therapeutische Alternative. Darüber hinaus sind weitere klinische Implikationen bei Patienten mit zerebraler Amyloidangiopathie Gegenstand dieser Literaturübersicht, beispielsweise Besonderheiten nach akutem ischämischem Schlaganfall und erforderlicher Sekundärprophylaxe, bei vorherigen intrazerebralen Blutungen und bei Patienten mit kognitiven Defiziten.

Cognitive Impairment After Intracerebral Hemorrhage: A Systematic Review of Current Evidence and Knowledge Gaps

Background: Cognitive impairment (CI) is commonly observed after intracerebral hemorrhage (ICH). While a growing number of studies have explored this association, several evidence gaps persist. This review seeks to investigate the relationship between CI and ICH.

Methods: A two-stage systematic review of research articles, clinical trials, and case series was performed. Initial search used the keywords [“Intracerebral hemorrhage” OR “ICH”] AND [“Cognitive Impairment” OR “Dementia OR “Cognitive Decline”] within the PubMed (last accessed November 3rd, 2020) and ScienceDirect (last accessed October 27th, 2020) databases, without publication date limits. Articles that addressed CI and spontaneous ICH were accepted if CI was assessed after ICH. Articles were rejected if they did not independently address an adult human population or spontaneous ICH, didn't link CI to ICH, were an unrelated document type, or were not written in English. A secondary snowball literature search was performed using reviews identified by the initial search. The Agency for Healthcare research and Quality's assessment tool was used to evaluate bias within studies. Rates of CI and contributory factors were investigated.

Results: Search yielded 32 articles that collectively included 22,631 patients. Present evidence indicates a high rate of post-ICH CI (65–84%) in the acute phase (<4 weeks) which is relatively lower at 3 (17.3–40.2%) and 6 months (19–63.3%). Longer term follow-up (≥1 year) demonstrates a gradual increase in CI. Advanced age, female sex, and prior stroke were associated with higher rates of CI. Associations between post-ICH CI and cerebral microbleeds, superficial siderosis, and ICH volume also exist. Pre-ICH cognitive assessment was missing in 28% of included studies. The Mini Mental State Evaluation (44%) and Montreal Cognitive Assessment (16%) were the most common cognitive assessments, albeit with variable thresholds and definitions. Studies rarely (<10%) addressed racial and ethnic disparities.

Discussion: Current findings suggest a dynamic course of post-ICH cognitive impairment that may depend on genetic, sociodemographic and clinical factors. Methodological heterogeneity prevented meta-analysis, limiting results. There is a need for the methodologies and time points of post-ICH cognitive assessments to be harmonized across diverse clinical and demographic populations.

Arrangement of boundary electrodes for detection of frontal lobe disease with electrical impedance tomography

Purpose: Caused by brain trauma or blood vessel abnormality, intracerebral hemorrhage and secondary ischemia have become prevalent and severe neurological diseases. The timely and accurate detection of disease is essential for the recovery of patients. As an emerging visualization technique, electrical impedance tomography (EIT) offers an alternative. It is able to reconstruct the conductivity distribution that reflects the pathological variation of human tissue. Approach: In the EIT-based detection, electrodes are usually in uniform arrangement, which may be not suitable in some conditions. To enhance sensitivity in the region of interest, EIT with a novel offset arrangement of boundary electrodes is proposed to image a simulated frontal lobe hemorrhage and secondary ischemia. To cope with the ill-posed inverse problem, the L1 regularization method is developed during the reconstruction. In addition, the impact of noise with a signal-to-noise ratio of 56 dB is studied. Results: Compared with the traditional uniform electrode arrangement, the results demonstrate that EIT with the proposed offset arrangement of electrodes is more advantageous for imaging frontal lobe disease. Conclusions: The proposed offset arrangement of electrodes is superior to the traditional uniform arrangement in imaging frontal lobe disease, especially under the impact of noise.

Visuospatial dysfunction is associated with posterior distribution of white matter damage in non-demented cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy (CAA) is a well-recognized contributor to cognitive decline in the elderly. The posterior cortical predilection of CAA pathology would cause visuospatial dysfunction, which is still underexplored. We aimed to investigate whether the visuospatial dysfunction in CAA is associated with the posterior distribution of small vessel disease (SVD) imaging markers.

METHODS

We recruited 60 non-demented CAA cases from a Chinese prospective cohort and 30 cases with non-CAA SVD as controls. We used the Visual Object and Space Perception (VOSP) battery to evaluate visuospatial abilities, and multivariable regression models to assess their associations with SVD imaging markers.

RESULTS

There was visuospatial dysfunction, especially visual object perception impairment, in CAA compared to controls (Z-score of VOSP: -0.11 ± 0.66 vs. 0.22 ± 0.54, p = 0.023). The VOSP score in CAA was independently related to the fronto-occipital gradient of white matter hyperintensity volumes (coefficient = 0.03, 95% confidence interval [CI] = 0.003-0.05, p = 0.030) and mean fractional anisotropy values on diffusion tensor imaging (coefficient = 4.72, 95% CI = 0.97-8.48, p = 0.015), but not the severity of global SVD imaging markers or the gradient of lobar cerebral microbleeds with adjustments for age and global cognition score.

CONCLUSIONS

This finding suggests that the damage of posterior white matter rather than global disease severity may be a major contributor to visuospatial dysfunction in CAA.

Prevalence of cerebral amyloid angiopathy: A systematic review and meta-analysis

Reported prevalence estimates of sporadic cerebral amyloid angiopathy (CAA) vary widely. CAA is associated with cognitive dysfunction and intracerebral hemorrhage, and linked to immunotherapy‐related side‐effects in Alzheimer's disease (AD). Given ongoing efforts to develop AD immunotherapy, accurate estimates of CAA prevalence are important. CAA can be diagnosed neuropathologically or during life using MRI markers including strictly lobar microbleeds. In this meta‐analysis of 170 studies including over 73,000 subjects, we show that in patients with AD, CAA prevalence based on pathology (48%) is twice that based on presence of strictly lobar cerebral microbleeds (22%); in the general population this difference is three‐fold (23% vs 7%). Both methods yield similar estimated prevalences of CAA in cognitively normal elderly (5% to 7%), in patients with intracerebral hemorrhage (19% to 24%), and in patients with lobar intracerebral hemorrhage (50% to 57%). However, we observed large heterogeneity among neuropathology and MRI protocols, which calls for standardized assessment and reporting of 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.

Small vessel disease burden and intracerebral haemorrhage in patients taking oral anticoagulants

OBJECTIVE

We investigated the contribution of small vessel disease (SVD) to anticoagulant-associated intracerebral haemorrhage (ICH).

METHODS

Clinical Relevance of Microbleeds in Stroke-2 comprised two independent multicentre observation studies: first, a cross-sectional study of patients with ICH; and second, a prospective study of patients taking anticoagulants for atrial fibrillation (AF) after cerebral ischaemia. In patients with ICH, we compared SVD markers on CT and MRI according to prior anticoagulant therapy. In patients with AF and cerebral ischaemia treated with anticoagulants, we compared the rates of ICH and ischaemic stroke according to SVD burden score during 2 years follow-up.

RESULTS

We included 1030 patients with ICH (421 on anticoagulants), and 1447 patients with AF and cerebral ischaemia. Medium-to-high severity SVD was more prevalent in patients with anticoagulant-associated ICH (CT 56.1%, MRI 78.7%) than in those without prior anticoagulant therapy (CT 43.5%, p<0.001; MRI 64.5%, p=0.072). Leukoaraiosis and atrophy were more frequent and severe in ICH associated with prior anticoagulation. In the cerebral ischaemia cohort (779 with SVD), during 3366 patient-years of follow-up the rate of ICH was 0.56%/year (IQR 0.27-1.03) in patients with SVD, and 0.06%/year (IQR 0.00-0.35) in those without (p=0.001); ICH was independently associated with severity of SVD (HR 5.0, 95% CI 1.9 to 12.2,p=0.001), and was predicted by models including SVD (c-index 0.75, 95% CI 0.63 to 0.85).

CONCLUSIONS

Medium-to-high severity SVD is associated with ICH occurring on anticoagulants, and independently predicts ICH in patients with AF taking anticoagulants; its absence identifies patients at low risk of ICH. Findings from these two complementary studies suggest that SVD is a contributory factor in ICH in patients taking anticoagulants and suggest that anticoagulation alone should no longer be regarded as a sufficient 'cause' of ICH.

TRIAL REGISTRATION

NCT02513316.

Accuracy of the Informant Questionnaire on Cognitive Decline in the Elderly for Detecting Preexisting Dementia in Transient Ischemic Attack and Stroke: A Population-Based Study

[Figure: see text].

Taxifolin: A Potential Therapeutic Agent for Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of β-amyloid (Aβ) in the walls of cerebral vessels, leading to complications such as intracerebral hemorrhage, convexity subarachnoid hemorrhage and cerebral microinfarcts. Patients with CAA-related intracerebral hemorrhage are more likely to develop dementia and strokes. Several pathological investigations have demonstrated that more than 90% of Alzheimer's disease patients have concomitant CAA, suggesting common pathogenic mechanisms. Potential causes of CAA include impaired Aβ clearance from the brain through the intramural periarterial drainage (IPAD) system. Conversely, CAA causes restriction of IPAD, limiting clearance. Early intervention in CAA could thus prevent Alzheimer's disease progression. Growing evidence has suggested Taxifolin (dihydroquercetin) could be used as an effective therapy for CAA. Taxifolin is a plant flavonoid, widely available as a health supplement product, which has been demonstrated to exhibit anti-oxidative and anti-inflammatory effects, and provide protection against advanced glycation end products and mitochondrial damage. It has also been shown to facilitate disassembly, prevent oligomer formation and increase clearance of Aβ in a mouse model of CAA. Disturbed cerebrovascular reactivity and spatial reference memory impairment in CAA are completely prevented by Taxifolin treatment. These results highlight the need for clinical trials on the efficacy and safety of Taxifolin in patients with CAA.

[18 F]FDG PET may differentiate cerebral amyloid angiopathy from Alzheimer's disease

BACKGROUND

Cerebral amyloid angiopathy (CAA) is a frequent cause of both intracerebral hemorrhage (ICH) and cognitive impairment in the elderly. Diagnosis relies on the Boston criteria, which use magnetic resonance imaging markers including ≥2 exclusively lobar cerebral microbleeds (lCMBs). Although amyloid positron emission tomography (PET) may provide molecular diagnosis, its specificity relative to Alzheimer's disease (AD) is limited due to the prevalence of positive amyloid PET in cognitively normal elderly. Using early-phase ¹¹ C-Pittsburgh compound B as surrogate for tissue perfusion, a significantly lower occipital/posterior cingulate (O/PC) tracer uptake ratio in probable CAA relative to AD was recently reported, consistent with histopathological lesion distribution. We tested whether this finding could be reproduced using [¹⁸ F]fluorodeoxyglucose (FDG)-PET, a widely available modality that correlates well with early-phase amyloid PET in both healthy subjects and AD.

METHODS

From a large memory clinic database, we retrospectively included 14 patients with probable CAA (Boston criteria) and 21 patients with no lCMB fulfilling AD criteria including cerebrospinal fluid biomarkers. In all, [¹⁸ F]FDG-PET/computed tomography (CT) was available as part of routine care. No subject had a clinical history of ICH. Regional standardized [¹⁸ F]FDG uptake values normalized to the pons (standard uptake value ratio [SUVr]) were obtained, and the O/PC ratio was calculated.

RESULTS

The SUVr O/PC ratio was significantly lower in CAA versus AD (1.02 ± 0.14 vs. 1.19 ± 0.18, respectively; p = 0.024).

CONCLUSIONS

Despite the small sample, our findings are consistent with the previous early-phase amyloid PET study. Thus, [¹⁸ F]FDG-PET may help differentiate CAA from AD, particularly in cases of amyloid PET positivity. Larger prospective studies, including in CAA-related ICH, are however warranted.

Small Vessel Disease and Ischemic Stroke Risk During Anticoagulation for Atrial Fibrillation After Cerebral Ischemia

BACKGROUND AND PURPOSE

The causes of recurrent ischemic stroke despite anticoagulation for atrial fibrillation are uncertain but might include small vessel occlusion. We investigated whether magnetic resonance imaging markers of cerebral small vessel disease (SVD) are associated with ischemic stroke risk during follow-up in patients anticoagulated for atrial fibrillation after recent ischemic stroke or transient ischemic attack.

METHODS

We analyzed data from a prospective multicenter inception cohort study of ischemic stroke or transient ischemic attack anticoagulated for atrial fibrillation (CROMIS-2 [Clinical Relevance of Microbleeds in Stroke Study]). We rated markers of SVD on baseline brain magnetic resonance imaging: basal ganglia perivascular spaces (number ≥11); cerebral microbleeds (number ≥1); lacunes (number ≥1); and white matter hyperintensities (periventricular Fazekas grade 3 or deep white matter Fazekas grade ≥2). We investigated the associations of SVD presence (defined as presence of ≥1 SVD marker) and severity (composite SVD score) with the risk of ischemic stroke during follow-up using a Cox proportional hazards model adjusted for congestive heart failure, hypertension, age >75, diabetes, stroke, vascular disease, age 65-74, female score.

RESULTS

We included 1419 patients (mean age: 75.8 years [SD, 10.4]; 42.1% female). The ischemic stroke rate during follow-up in patients with any SVD was 2.20 per 100-patient years (95% CI, 1.60-3.02), compared with 0.98 per 100 patient-years (95% CI, 0.59-1.62) in those without SVD (P=0.008). After adjusting for congestive heart failure, hypertension, age >75, diabetes, stroke, vascular disease, age 65-74, female score, SVD presence remained significantly associated with ischemic stroke during follow-up (hazard ratio, 1.89 [95% CI, 1.01-3.53]; P=0.046); the risk of recurrent ischemic stroke increased with SVD score (hazard ratio per point increase, 1.33 [95% CI, 1.04-1.70]; P=0.023).

CONCLUSIONS

In patients anticoagulated for atrial fibrillation after ischemic stroke or transient ischemic attack, magnetic resonance imaging markers of SVD are associated with an increased risk of ischemic stroke during follow-up; improved stroke prevention treatments are required in this population. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02513316.

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.

The effects of voluntary running on cerebrovascular morphology and spatial short-term memory in a mouse model of amyloidosis

Physical activity has been correlated with a reduced risk of cognitive decline, including that associated with vascular dementia, mild cognitive impairment (MCI) and Alzheimer's disease (AD); recent literature suggests this may in part result from benefits to the cerebrovascular network. Using a transgenic (Tg) mouse model of AD, we evaluated the effect of running on cortical and hippocampal vascular morphology, cerebral amyloid angiopathy, amyloid plaque load, and spatial memory. TgCRND8 mice present with progressive amyloid pathology, advancing from the cortex to the hippocampus in a time-dependent manner. We postulated that the characteristic progression of pathology could lead to differential, time-dependent effects of physical activity on vascular morphology in these brain regions at 6 months of age. We used two-photon fluorescent microscopy and 3D vessel tracking to characterize vascular and amyloid pathology in sedentary TgCRND8 mice compared those who have a history of physical activity (unlimited access to a running wheel, from 3 to 6 months of age). In sedentary TgCRND8 mice, capillary density was found to be lower in the cortex and higher in the hippocampus compared to non-transgenic (nonTg) littermates. Capillary length, vessel branching, and non-capillary vessel tortuosity were also higher in the hippocampus of sedentary TgCRND8 compared to nonTg mice. Three months of voluntary running resulted in normalizing cortical and hippocampal microvascular morphology, with no significant difference between TgCRND8 and nonTg mice. The benefits of physical activity on cortical and hippocampal vasculature in 6-month old TgCRND8 mice were not paralleled by significant changes on parenchymal and cerebral amyloid pathology. Short-term spatial memory- as evaluated by performance in the Y-maze- was significantly improved in running compared to sedentary TgCRND8 mice. These results suggest that long-term voluntary running contributes to the maintenance of vascular morphology and spatial memory in TgCRND8 mice, even in the absence of an effect on amyloid pathology.

Novel clinicopathological characteristics differentiate dementia with Lewy bodies from Parkinson's disease dementia

Dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD) known as Lewy body dementias have overlapping clinical and neuropathological features. Neuropathology in both includes combination of Lewy body and Alzheimer's disease (AD) pathology. Cerebral amyloid angiopathy (CAA), often seen in AD, is increasingly recognized for its association with dementia.

AIMS

This study investigated clinical and neuropathological differences between DLB and PDD.

METHODS

52 PDD and 16 DLB cases from the Queen Square Brain Bank (QSBB) for Neurological disorders were included. Comprehensive clinical data of motor and cognitive features were obtained from medical records. Neuropathological assessment included examination of CAA, Lewy body and AD pathology.

RESULTS

CAA was more common in DLB than in PDD (P = 0.003). The severity of CAA was greater in DLB than in PDD (P = 0.009), with significantly higher CAA scores in the parietal lobe (P = 0.043), and the occipital lobe (P = 0.008), in DLB than in PDD. The highest CAA scores were observed in cases with APOE ε4/4 and ε2/4. Survival analysis showed worse prognosis in DLB, as DLB reached each clinical milestone sooner than PDD. Absence of dyskinesia in DLB is linked to the significantly lower lifetime cumulative dose of levodopa in comparison with PDD.

CONCLUSIONS

This is the first study which identified prominent concurrent CAA pathology as a pathological substrate of DLB. More prominent CAA and rapid disease progression as measured by clinical milestones distinguish DLB from PDD.

Cerebral amyloid angiopathy vs Alzheimer’s dementia: Diagnostic conundrum

BACKGROUND

Diagnosis of a dementia subtype can be complex and often requires comprehensive cognitive assessment and dedicated neuroimaging. Clinicians are prone to cognitive biases when reviewing such images. We present a case of cognitive impairment and demonstrate that initial imaging may have resulted in misleading the diagnosis due to such cognitive biases.

CASE SUMMARY

A 76-year-old man with no cognitive impairment presented with acute onset word finding difficulty with unremarkable blood tests and neurological examination. Magnetic resonance imaging (MRI) demonstrated multiple foci of periventricular and subcortical microhaemorrhage, consistent with cerebral amyloid angiopathy (CAA). Cognitive assessment of this patient demonstrated marked impairment mainly in verbal fluency and memory. However, processing speed and executive function are most affected in CAA, whereas episodic memory is relatively preserved, unlike in other causes of cognitive impairment, such as Alzheimer’s dementia (AD). This raised the question of an underlying diagnosis of dementia. Repeat MRI with dedicated coronal views demonstrated mesial temporal lobe atrophy which is consistent with AD.

CONCLUSION

MRI brain can occasionally result in diagnostic overshadowing, and the application of artificial intelligence to medical imaging may overcome such cognitive biases.

Cognitive Impairment Before Atrial Fibrillation-Related Ischemic Events: Neuroimaging and Prognostic Associations

Background

It is likely that a proportion of poststroke cognitive impairment is sometimes attributable to unidentified prestroke decline; prestroke cognitive function is also clinically relevant because it is associated with poor functional outcomes, including death. We investigated the radiological and prognostic associations of preexisting cognitive impairment in patients with ischemic stroke or transient ischemic attack associated with atrial fibrillation.

Methods and Results

We included 1102 patients from the prospective multicenter observational CROMIS‐2 (Clinical Relevance of Microbleeds in Stroke 2) atrial fibrillation study. Preexisting cognitive impairment was identified using the 16‐item Informant Questionnaire for Cognitive Decline in the Elderly. Functional outcome was measured using the modified Rankin scale. Preexisting cognitive impairment was common (n=271; 24.6%). The presence of lacunes (odds ratio [OR], 1.50; 95% CI, 1.03–1.05; P=0.034), increasing periventricular white matter hyperintensity grade (per grade increase, OR, 1.38; 95% CI, 1.17–1.63; P<0.0001), deep white matter hyperintensity grade (per grade increase, OR, 1.26; 95% CI, 1.05–1.51; P=0.011), and medial temporal atrophy grade (per grade increase, OR, 1.61; 95% CI, 1.34–1.95; P<0.0001) were independently associated with preexisting cognitive impairment. Preexisting cognitive impairment was associated with poorer functional outcome at 24 months (mRS >2; adjusted OR, 2.43; 95% CI, 1.42–4.20; P=0.001).

Conclusions

Preexisting cognitive impairment in patients with atrial fibrillation–associated ischemic stroke or transient ischemic attack is common, and associated with imaging markers of cerebral small vessel disease and neurodegeneration, as well as with longer‐term functional outcome.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02513316.

Cognitive impairment before and after intracerebral haemorrhage: a systematic review

INTRODUCTION

There is increasing interest in understanding cognitive dysfunction before and after Intracerebral haemorrhage (ICH), given the higher prevalence of dementia reported (ranging from 5 to 44%) for this stroke type. Much of the evidence to date examining cognitive impairment associated with cerebrovascular disease has tended to focus more on ischaemic stroke. The aim of this review was to identify and quantify studies that focused on cognitive dysfunction pre and post ICH.

METHODS

We conducted a systematic search using databases PubMed, Science Direct, Scopus and PsycINFO to identify studies that exclusively assessed cognitive function pre and post ICH. Studies were included in the review if used a measure of global cognition and/or a neuropsychological battery to assess cognitive function. Nineteen studies were deemed relevant for inclusion, where n = 8 studies examined cognitive impairment pre ICH and n = 11 post ICH.

RESULTS

Prevalence of cognitive impairment ranged between 9-29% for pre ICH and 14-88% for post ICH. Predictive factors identified for pre and post ICH were previous stroke, ICH volume and location and markers of cerebral amyloid angiopathy (CAA). Most common cognitive domains affected post ICH were information processing speed, executive function, memory, language and visuo-spatial abilities. Most common cognitive assessments tools were the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) for pre-existing cognitive impairment and the Mini-Mental State Examination for global cognition post ICH and the Trail Making Test where neuropsychological tests were used.

CONCLUSION

Cognitive impairment and dementia affected almost one-third of patients, whether assessed pre or post ICH.

Vascular Cognitive Impairment: Information from Animal Models on the Pathogenic Mechanisms of Cognitive Deficits

Vascular cognitive impairment (VCI) is the second most common cause of cognitive deficit after Alzheimer's disease. Since VCI patients represent an important target population for prevention, an ongoing effort has been made to elucidate the pathogenesis of this disorder. In this review, we summarize the information from animal models on the molecular changes that occur in the brain during a cerebral vascular insult and ultimately lead to cognitive deficits in VCI. Animal models cannot effectively represent the complex clinical picture of VCI in humans. Nonetheless, they allow some understanding of the important molecular mechanisms leading to cognitive deficits. VCI may be caused by various mechanisms and metabolic pathways. The pathological mechanisms, in terms of cognitive deficits, may span from oxidative stress to vascular clearance of toxic waste products (such as amyloid beta) and from neuroinflammation to impaired function of microglia, astrocytes, pericytes, and endothelial cells. Impaired production of elements of the immune response, such as cytokines, and vascular factors, such as insulin-like growth factor 1 (IGF-1), may also affect cognitive functions. No single event could be seen as being the unique cause of cognitive deficits in VCI. These events are interconnected, and may produce cascade effects resulting in cognitive impairment.

Intracerebral hemorrhage outcome: A comprehensive update

Non-traumatic intracerebral hemorrhage (ICH) is associated with a significant global burden of disease, and despite being proportionally less frequent than ischemic stroke, in 2010 it was associated with greater worldwide disability-adjusted life years lost. The focus of outcome assessment after ICH has been mortality in most studies, because of the high early case fatality which reaches 40% in some population-based studies. The most robust and consistent predictors of early mortality include age, severity of neurological impairment, hemorrhage volume and antithrombotic therapy at the time of the event. Long-term outcome assessment is multifaceted and includes not only mortality and functional outcome, but also patient self-assessment of the health-related quality of life, occurrence of cognitive impairment, psychiatric disorders, epileptic seizures, recurrent ICH and subsequent thromboembolic events. Several scores which predict mortality and functional outcome after ICH have been validated and are useful in the daily clinical practice, however they must be used in combination with the clinical judgment for individualized patients. Management of patients with ICH both in the acute and chronic phases, requires health care professionals to have a comprehensive and updated perspective on outcome, which informs decisions that are needed to be taken together with the patient and next of kin.

Vascular cognitive impairment: pathophysiological mechanisms, insights into structural basis, and perspectives in specific treatments

Vascular cognitive impairment (VCI) and vascular dementia are the most common forms of cognitive disorder associated with cerebrovascular disease and related to increased morbidity and mortality among the older population. Growing evidence suggests the contribution of blood-pressure variability, cardiac arrhythmia, hyperactivation of the renin-angiotensin-aldosterone system, endothelial dysfunction, vascular remodeling and stiffness, different angiopathies, neural tissue homeostasis, and systemic metabolic disorders to the pathophysiology of VCI. In this review, we focus on factors contributing to cerebrovascular disease, neurovascular unit alterations, and novel approaches to cognitive improvement in patients with cognitive decline. One of the important factors associated with the neuronal causes of VCI is the S100B protein, which can affect the expression of cytokines in the brain, support homeostasis, and regulate processes of differentiation, repair, and apoptosis of the nervous tissue. Since the pathological basis of VCI is complex and diverse, treatment affecting the mechanisms of cognitive disorders should be developed. The prospective role of a novel complex drug consisting of released-active antibodies to S100 and to endothelial NO synthase in VCI treatment is highlighted.

Progression in Vascular Cognitive Impairment: Pathogenesis, Neuroimaging Evaluation, and Treatment

Vascular cognitive impairment (VCI) defines an entire spectrum of neurologic disorders from mild cognitive impairment to dementia caused by cerebral vascular disease. The pathogenesis of VCI includes ischemic factors (e.g., large vessel occlusion and small vessel dysfunction); hemorrhagic factors (e.g., intracerebral hemorrhage and subarachnoid hemorrhage); and other factors (combined with Alzheimer's disease). Clinical evaluations of VCI mainly refer to neuropsychological testing and imaging assessments, including structural and functional neuroimaging, with different advantages. At present, the main treatment for VCI focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, revascularization, and cognitive training. In this review, we discuss the pathogenesis, neuroimaging evaluation, and treatment of VCI.

Engineered nanoceria cytoprotection in vivo: mitigation of reactive oxygen species and double-stranded DNA breakage due to radiation exposure

Cerium oxide nanomaterials are known to absorb ionizing radiation energy, as well as to neutralize free radicals in solution, by undergoing redox changes. We, therefore, proposed that ceria nanoparticles could be used in biomedical applications as an injectable, radio-protectant material. In this study, we examine the effectiveness of engineered nanoparticles in protecting germ cells from the damaging effects of irradiation-induced cell death, in vivo. C57BL/6J male mice were used as a model and irradiation was localized to the scrotal region at 2.5, 5, and/or 10 Gy intensities. Ceria nanoparticles were introduced as 100 μL injections at 100 nM and 100 μM via tail vein injections, weekly, for one month. Following this, the animals were sacrificed and their organs (heart, brain, kidneys) were harvested. Tissues were fixed, sectioned, and stained for instances of cell death, DNA damage (TUNEL assay), and ROS (nitro-tyrosine evolution). Tissues from mice treated with ceria nanoparticles showed significantly less (∼13% decrease; *P < 0.05) tissue damage (per immunohistochemistry) over controls at up to 5 Gy radiation. DNA damage and ROS also decrease substantially with ceria treatment, confirming ceria's capacity as an injectable, radio-protectant material. The study also highlights the ability of ceria nanoparticles to protect cells/tissues from both direct and indirect effects of ionizing radiation.