Neurovascular coupling in early stage dementia - A case-control study

Cerebral amyloid angiopathy (CAA) is frequently found post mortem in Alzheimer's dementia, but often undetected during life especially since in vivo hallmarks of CAA and its vascular damage become overt relatively late in the disease process. Decreased neurovascular coupling to visual stimulation has been put forward as an early MRI marker for CAA disease severity. The current study investigates the role of neurovascular coupling in AD related dementia and its early stages. We included 25 subjective cognitive impairment, 33 mild cognitive impairment and 17 dementia patients and 44 controls. All participants underwent magnetic resonance imaging of the brain and neuropsychological assessment. Univariate general linear modeling analyses were used to assess neurovascular coupling between patient groups and controls. Moreover, linear regression analyses was used to assess the associations between neurovascular coupling and cognition. Our data show that BOLD amplitude is lower in dementia (mean 0.8 ± 0.2, p = 0.001) and MCI patients (mean 0.9 ± 0.3, p = 0.004) compared with controls (mean 1.1 ± 0.2). A low BOLD amplitude was associated with low scores in multiple cognitive domains. We conclude that cerebrovascular dysfunction, most likely due CAA, is an important comorbidity in early stages of dementia and has an independent effect on cognition.

Enhancing Cerebral Amyloid Angiopathy-Related Inflammation Diagnosis With PET Using Pittsburgh Compound B

ABSTRACT

Cerebral amyloid angiopathy-related inflammation is a rare encephalopathy characterized by inflammation against amyloid protein accumulated in cerebral small vessels. A 50-year-old man was presented with a subacute consciousness disorder. Brain MRI revealed high intensity lesions in the white matter of the right parietal and occipital lobes on fluid-attenuated inversion recovery sequences and cerebral microbleeds in the right parietal and occipital lobes on T2*-weighted images. Pittsburgh compound B-PET demonstrated accumulation in the right temporoparietal lobe, confirming a potential diagnosis of probable cerebral amyloid angiopathy-related inflammation without brain biopsy. Steroid pulse therapy was initiated, with good results.

Boston Criteria v2.0 for Cerebral Amyloid Angiopathy Without Hemorrhage: An MRI-Neuropathologic Validation Study

BACKGROUND AND OBJECTIVES

Updated criteria for the clinical-MRI diagnosis of cerebral amyloid angiopathy (CAA) have recently been proposed. However, their performance in individuals without symptomatic intracerebral hemorrhage (ICH) presentations is less defined. We aimed to assess the diagnostic performance of the Boston criteria version 2.0 for CAA diagnosis in a cohort of individuals ranging from cognitively normal to dementia in the community and memory clinic settings.

METHODS

Fifty-four participants from the Mayo Clinic Study of Aging or Alzheimer's Disease Research Center were included if they had an antemortem MRI with gradient-recall echo sequences and a brain autopsy with CAA evaluation. Performance of the Boston criteria v2.0 was compared with v1.5 using histopathologically verified CAA as the reference standard.

RESULTS

The median age at MRI was 75 years (interquartile range 65-80) with 28/54 participants having histopathologically verified CAA (i.e., moderate-to-severe CAA in at least 1 lobar region). The sensitivity and specificity of the Boston criteria v2.0 were 28.6% (95% CI 13.2%-48.7%) and 65.3% (95% CI 44.3%-82.8%) for probable CAA diagnosis (area under the receiver operating characteristic curve [AUC] 0.47) and 75.0% (55.1-89.3) and 38.5% (20.2-59.4) for any CAA diagnosis (possible + probable; AUC 0.57), respectively. The v2.0 Boston criteria were not superior in performance compared with the prior v1.5 criteria for either CAA diagnostic category.

DISCUSSION

The Boston criteria v2.0 have low accuracy in patients who are asymptomatic or only have cognitive symptoms. Additional biomarkers need to be explored to optimize CAA diagnosis in this population.

The relation of a cerebrospinal fluid profile associated with Alzheimer's disease with cognitive function and neuropsychiatric symptoms in sporadic cerebral amyloid angiopathy

BACKGROUND

Patients with sporadic cerebral amyloid angiopathy (sCAA) frequently report cognitive or neuropsychiatric symptoms. The aim of this study is to investigate whether in patients with sCAA, cognitive impairment and neuropsychiatric symptoms are associated with a cerebrospinal fluid (CSF) biomarker profile associated with Alzheimer's disease (AD).

METHODS

In this cross-sectional study, we included participants with sCAA and dementia- and stroke-free, age- and sex-matched controls, who underwent a lumbar puncture, brain MRI, cognitive assessments, and self-administered and informant-based-questionnaires on neuropsychiatric symptoms. CSF phosphorylated tau, total tau and Aβ42 levels were used to divide sCAA patients in two groups: CAA with (CAA-AD+) or without a CSF biomarker profile associated with AD (CAA-AD-). Performance on global cognition, specific cognitive domains (episodic memory, working memory, processing speed, verbal fluency, visuoconstruction, and executive functioning), presence and severity of neuropsychiatric symptoms, were compared between groups.

RESULTS

sCAA-AD+ (n=31; mean age: 72 ± 6; 42%, 61% female) and sCAA-AD- (n=23; 70 ± 5; 42% female) participants did not differ with respect to global cognition or type of affected cognitive domain(s). The number or severity of neuropsychiatric symptoms also did not differ between sCAA-AD+ and sCAA-AD- participants. These results did not change after exclusion of patients without prior ICH.

CONCLUSIONS

In participants with sCAA, a CSF biomarker profile associated with AD does not impact global cognition or specific cognitive domains, or the presence of neuropsychiatric symptoms.

Superficial small cerebellar infarcts in cerebral amyloid angiopathy on 3 T MRI: A preliminary study

BACKGROUND

Strictly superficial cerebellar microbleeds and cerebellar superficial siderosis have been considered markers of advanced cerebral amyloid angiopathy (CAA), but there are few studies on cerebellar ischemic lesions in CAA. We investigated the presence of superficial small cerebellar infarct (SCI) ≤15 mm and its relation to magnetic resonance imaging (MRI) markers in patients with probable CAA.

METHODS

Eighty patients with probable CAA were retrospectively evaluated. The presence of superficial SCIs was examined, along with cerebellar microbleeds and cerebellar superficial siderosis, using 3-T MRI. Lobar cerebral microbleeds, cortical superficial siderosis (cSS), enlargement of the perivascular space in the centrum semiovale, and white matter hyperintensity were assessed and the total CAA-small vessel disease (SVD) score was calculated.

RESULTS

Nine of the 80 patients (11.3%) had a total of 16 superficial SCIs. By tentatively defining SCI <4 mm as cerebellar microinfarcts, 8 out of 16 (50%) superficial SCIs corresponded to cerebellar microinfarcts. The total CAA-SVD score was significantly higher in patients with superficial SCIs (p = 0.01). The prevalence of cSS (p = 0.018), cortical cerebral microinfarct (p = 0.034), and superficial cerebellar microbleeds (p = 0.006) was significantly higher in patients with superficial SCIs. The number of superficial cerebellar microbleeds was also significantly higher in patients with superficial SCIs (p = 0.001).

CONCLUSIONS

Our results suggest that in patients with CAA, superficial SCIs (including microinfarcts) on MRI may indicate more severe, advanced-stage CAA. These preliminary findings should be verified by larger prospective studies in the future.

Neuropsychiatric symptoms with focus on apathy and irritability in sporadic and hereditary cerebral amyloid angiopathy

BACKGROUND

Neuropsychiatric symptoms (NPS) may affect cognition, but their burden in cerebral amyloid angiopathy (CAA), one of the main causes of intracerebral hemorrhage (ICH) and dementia in the elderly, remains unclear. We investigated NPS, with emphasis on apathy and irritability in sporadic (sCAA) and Dutch-type hereditary (D-)CAA.

METHODS

We included patients with sCAA and (pre)symptomatic D-CAA, and controls from four prospective cohort studies. We assessed NPS per group, stratified for history of ICH, using the informant-based Neuropsychiatric Inventory (NPI-Q), Starkstein Apathy scale (SAS), and Irritability Scale. We modeled the association of NPS with disease status, executive function, processing speed, and CAA-burden score on MRI and investigated sex-differences.

RESULTS

We included 181 participants: 82 with sCAA (mean[SD] age 72[6] years, 44% women, 28% previous ICH), 56 with D-CAA (52[11] years, 54% women, n = 31[55%] presymptomatic), and 43 controls (69[9] years, 44% women). The NPI-Q NPS-count differed between patients and controls (sCAA-ICH+:adj.β = 1.4[95%CI:0.6-2.3]; sCAA-ICH-:1.3[0.6-2.0]; symptomatic D-CAA:2.0[1.1-2.9]; presymptomatic D-CAA:1.2[0.1-2.2], control median:0[IQR:0-3]), but not between the different CAA-subgroups. Apathy and irritability were reported most frequently: n = 12[31%] sCAA, 19[37%] D-CAA had a high SAS-score; n = 12[29%] sCAA, 14[27%] D-CAA had a high Irritability Scale score. NPS-count was associated with decreased processing speed (adj.β=-0.6[95%CI:-0.8;-0.4]) and executive function (adj.β=-0.4[95%CI:-0.6;-0.1]), but not with radiological CAA-burden. Men had NPS more often than women.

DISCUSSION

According to informants, one third to half of patients with CAA have NPS, mostly apathy, even in presymptomatic D-CAA and possibly with increased susceptibility in men. Neurologists should inform patients and caregivers of these disease consequences and treat or refer patients with NPS appropriately.

Imaging of Amyloid-Related Imaging Abnormalities (ARIA)

Patients with Alzheimer's disease (AD) can now be treated with monoclonal antibodies aiming at clearing amyloid plaques from the brain parenchyma. Weeks after initiation of this drug therapy, patients may develop so-called amyloid-related imaging abnormalities (ARIA) on MRI. ARIA comprise vasogenic edema and leptomeningeal effusions (ARIA-E) as well as microbleeds and superficial hemosiderosis (ARIA-H). The prevalence is drug- and dose-dependent (up to 40 % of patients), the apolipoprotein E4 variant and concomitant cerebral amyloid angiopathy (CAA) increase the risk. With regard to MRI characteristics, ARIA strongly resembles the so-called inflammatory subtype of CAA (CAA-ri). While patients with CAA-ri are typically detected due to symptoms such as headaches, lethargy, confusion, and rarely epileptic seizures, around 20 % of ARIA patients show symptoms. Management of ARIA is not yet clearly established. In asymptomatic patients, discontinuation of the drug might be sufficient. KEY POINTS:   · Amyloid-related imaging abnormalities (ARIA) occur in around 20 % of patients who are treated with monoclonal antibodies against amyloid β.. · There are 2 types: ARIA-E (edema effusion) und ARIA-H (hemorrhage).. · Depending on the severity, therapy with monoclonal antibodies is either interrupted or finished.. CITATION FORMAT: · Urbach H, Linn J, Hattingen E et al. Imaging of Amyloid-Related Imaging Abnormalities (ARIA). Fortschr Röntgenstr 2024; 196: 363 - 369.

Spatial colocalization of imaging markers in iatrogenic cerebral amyloid angiopathy with the site of surgery: A metaanalysis

INTRODUCTION

Iatrogenic cerebral amyloid angiopathy (iCAA) is a rare form of CAA. Imaging features are overlapping with spontaneous CAA. However, in iCAA imaging features have not been systematically described so far. The aim of this metaanalysis was to evaluate if any of the described imaging features showed colocalization with the initial site of surgery.

MATERIAL AND METHODS

A systematic review of the medical literature was performed. Patients with probable iCAA were included if the route of potential entry of amyloid into the CNS was unambiguous.

RESULTS

24 patients from 19 reports could be included. 84 ICHs were reported. 11 of the first ever ICH (69%, p = 0.0498, Fisher's exact test) occurred ipsilateral to the site of the initial surgery, whereas 59% of all ICH (n = 63, p = 0.126, Fisher's exact test) occurred ipsilateral to the site of the initial surgery. No cerebellar hemorrhages (0%) were reported. In 5 of 8 patients, ipsilateral hemorrhagic and non-hemorrhagic manifestations were present before symptom onset and/or occurrence of ICH.

DISCUSSION

This metananalysis of the imaging markers of iCAA revealed a spatial colocalization of first ICH with the site of the surgery. Imaging studies with patients at risk for iCAA after exposure to lyophilized dura should be conducted.

Differences in lobar microbleed topography in cerebral amyloid angiopathy and hypertensive arteriopathy

Lobar cerebral microbleeds are a characteristic neuroimaging finding in cerebral amyloid angiopathy (CAA) but can also be found in hypertensive arteriolosclerosis. We aimed to investigate whether CAA is more associated with intracortical lobar microbleeds than hypertensive arteriosclerosis. Ninety-one survivors of spontaneous intracerebral hemorrhage with at least one lobar microbleed were included and underwent brain MRI and amyloid PET. We categorized lobar microbleeds as intracortical, juxtacortical, or subcortical. We assessed the associations between the lobar microbleed categories and microangiopathy subtypes or cerebral amyloid load based on the Pittsburgh Compound-B PET standardized uptake value ratio (SUVR). Patients with CAA had a higher prevalence of intracortical lobar microbleeds (80.0% vs. 50.8%, P = 0.011) and lower prevalence of subcortical lobar microbleeds (13.3% vs. 60.1%, P < 0.001) than patients with hypertensive arteriolosclerosis. Strictly intracortical/juxtacortical lobar microbleeds were associated with CAA (OR 18.9 [1.9-191.4], P = 0.013), while the presence of subcortical lobar microbleeds was associated with hypertensive arteriolosclerosis (OR 10.9 [1.8-68.1], P = 0.010). Amyloid retention was higher in patients with strictly intracortical/juxtacortical CMBs than those without (SUVR = 1.15 [1.05-1.52] vs. 1.08 [1.02-1.19], P = 0.039). Amyloid retention positively correlated with the number of intracortical lobar microbleeds (P < 0.001) and negatively correlated with the number of subcortical lobar microbleeds (P = 0.018). CAA and cortical amyloid deposition are more strongly associated with strictly intracortical/juxtacortical microbleeds than subcortical lobar microbleeds. Categorization of lobar microbleeds based on anatomical location may help differentiate the underlying microangiopathy and potentially improve the accuracy of current neuroimaging criteria for cerebral small vessel disease.

Amyloid accumulation in cases of suspected comorbid cerebral amyloid angiopathy and isolated cortical venous thrombosis

BACKGROUND AND AIM

The differentiation of isolated cortical venous thrombosis (ICVT) from cerebral amyloid angiopathy (CAA) can be difficult because both diseases share similar neurological symptoms and imaging findings. N-methyl-11C-2-(4'-methylaminophenyl)-6-hydroxybenzo-thiazole (11C-PiB) positron emission tomography (PET) functions as a diagnostic modality for CAA by detecting amyloid deposition. The present prospective study evaluated amyloid deposition using 11C-PiB-PET in consecutive patients with suspected ICVT.

METHOD

This study was a prospective observational study. Patients who attended or were hospitalized between May 2019 and March 2020 were included in the analysis. Consecutive patients who met the criteria for suspicion of ICVT were enrolled in the study, and the clinical course, symptoms, imaging findings (including magnetic resonance imaging), and the 11C-PiB-PET findings of each case were analyzed.

RESULTS

The study cohort included four patients (64-82 years of age, all women). In one younger patient, 11C-PiB-PET afforded no findings suggestive of CAA, whereas the remaining three patients exhibited 11C-PiB-PET findings suggestive of CAA.

CONCLUSION

Although 11C-PiB-PET would be a reasonable modality for distinguishing ICVT from CAA, especially in younger patients, it might be difficult to differentiate ICVT from CAA in elderly patients because of the potential deposition of amyloid.

CLINICAL TRIAL REGISTRATION

URL: https://www.umin.ac.jp/ctr/ Unique identifier: UMIN 000037101.

In-vivo diagnosis of cerebral amyloid angiopathy: an updated review

PURPOSE OF REVIEW

Sporadic cerebral amyloid angiopathy (CAA) is a highly prevalent small vessel disease in ageing population with potential severe complications including lobar intracerebral hemorrhage (ICH), cognitive impairment, and dementia. Although diagnosis of CAA was made only with postmortem neuropathological examination a few decades ago, diagnosing CAA without pathological proof is now allowed in living patients. This review focuses on recently identified biomarkers of CAA and current diagnostic criteria.

RECENT FINDINGS

Over the past few years, clinicians and researchers have shown increased interest for CAA, and important advances have been made. Thanks to recent insights into mechanisms involved in CAA and advances in structural and functional neuroimaging, PET amyloid tracers, cerebrospinal fluid and plasma biomarkers analysis, a growing number of biomarkers of CAA have been identified. Imaging-based diagnostic criteria including emerging biomarkers have been recently developed or updated, enabling accurate and earlier diagnosis of CAA in living patients.

SUMMARY

Recent advances in neuroimaging allow diagnosing CAA in the absence of pathological examination. Current imaging-based criteria have high diagnostic performance in patients presenting with ICH, but is more limited in other clinical context such as cognitively impaired patients or asymptomatic individuals. Further research is still needed to improve diagnostic accuracy.

Lobar Microbleeds in the Posterior Cortical Atrophy Syndrome: A Comparison to Typical Alzheimer's Disease

PURPOSE OF THE STUDY

Posterior cortical atrophy is a clinico-radiographical syndrome that presents with higher-order visual dysfunction and is most commonly due to Alzheimer's disease. Understanding factors associated with atypical presentations of Alzheimer's disease, such as posterior cortical atrophy (PCA), holds promise to shape our understanding of AD pathophysiology. Thus, we aimed to compare MRI evidence of lobar microbleeds (LMBs) in posterior cortical atrophy (PCA) syndrome to typical AD (tAD) and to assess and compare MRI evidence of cerebral amyloid angiopathy (CAA) in each group.

FINDINGS

We retrospectively collected clinical and MRI data from participants with PCA (n = 26), identified from an institutional PCA registry, and participants with tAD (n = 46) identified from electronic health records from a single institution. LMBs were identified on susceptibility-weighted imaging (SWI); the Fazekas grade of white matter disease was assessed using FLAIR images, and Boston criteria version 2.0 for cerebral amyloid angiopathy were applied to all data. The proportion of participants with PCA and LMB (7.7%) was lower than for tAD (47.8%) (p = 0.005). The frequency of "probable" CAA was similar in both groups, while "possible" CAA was more frequent in tAD (30.4%) than PCA (0%) (p = 0.001). The Fazekas grades were not different between groups. Lobar microbleeds on SWI were not more common in PCA than in typical AD. Clinicopathological investigations are necessary to confirm these findings. The factors that contribute to the posterior cortical atrophy phenotype are unknown.

Imaging of Amyloid-beta-related Arteritis

Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder marked by the accumulation of amyloid-beta peptide (Aβ) within the leptomeninges and smaller blood vessels of the brain. CAA can be both noninflammatory and inflammatory, and the inflammatory version includes Aβ-related angiitis (ABRA). ABRA is a vasculitis of the central nervous system related to an inflammatory response to Aβ in the vascular walls, which necessitates differentiating ABRA from noninflammatory CAA, as ABRA may require immunosuppressive treatment. MR imaging is typically the most effective imaging modality of choice to screen for these conditions, and they should be obtained at varying time points to track disease progression.

Apolipoprotein E ɛ2 Is Associated with the White Matter Hyperintensity Multispot Pattern in Spontaneous Intracerebral Hemorrhage

The white matter hyperintensity (WMH) multispot pattern, as multiple punctate subcortical foci, could differentiate cerebral amyloid angiopathy (CAA) from hypertensive arteriolopathy. Nevertheless, the pathophysiology underlying the multispot sign is still inexplicit. We aimed to explore risk factors for multispot patterns in cerebral small vessel disease (CSVD)-related intracerebral hemorrhage (ICH). Between June 2018 and January 2020, we retrospectively rated the WMH multispot pattern while blinded to our prospective spontaneous ICH cohort's clinical data. Demographic, genetic, and neuroimaging characteristics were applied in establishing the multispot pattern models via multiple logistic regression. In total, 268 participants were selected from our cohort. The possession of apolipoprotein E (APOE) ε2 (P = 0.051) was associated with multispot WMH in univariate analysis. Multispot WMHs were accompanied by multiple CAA features, such as centrum semiovale (CSO)-perivascular space (PVS) predominance (P = 0.032) and severe CSO-PVS (P < 0.001). After adjusting for confounding factors, APOE ε2 possession (OR 2.99, 95% CI [1.07, 8.40]; P = 0.037), severe CSO-PVS (OR 2.39, 95% CI [1.09, 5.26]; P = 0.031), and large posterior subcortical patches (P = 0.001) were independently correlated with the multispot pattern in multivariate analysis. Moreover, APOE ε2 possession (OR 4.34, 95% CI [1.20, 15.62]; P = 0.025) and severe CSO-PVS (OR 3.39, 95% CI [1.23, 9.34]; P = 0.018) remained statistically significant among the participants older than 55 years of age and with categorizable CSVD. APOE ε2 and severe CSO-PVS contribute to the presence of WMH multispot patterns. Because the multispot pattern is a potential diagnostic biomarker in CAA, genetics-driven effects shed light on its underlying vasculopathy. Clinical Trial Registration: URL- http://www.chictr.org.cn . Unique identifier: ChiCTR-ROC-2000039365. Registration date 2020/10/24 (retrospectively registered).

Association Between Hippocampal Volumes and Cognition in Cerebral Amyloid Angiopathy

BACKGROUND AND OBJECTIVES

Accumulating evidence suggests that gray matter atrophy, often considered a marker of Alzheimer disease (AD), can also result from cerebral small vessel disease (CSVD). Cerebral amyloid angiopathy (CAA) is a form of sporadic CSVD, diagnosed through neuroimaging criteria, that often co-occurs with AD pathology and leads to cognitive impairment. We sought to identify the role of hippocampal integrity in the development of cognitive impairment in a cohort of patients with possible and probable CAA.

METHODS

Patients were recruited from an ongoing CAA study at Massachusetts General Hospital. Composite scores defined performance in the cognitive domains of memory, language, executive function, and processing speed. Hippocampal subfields' volumes were measured from 3T MRI, using an automated method, and multivariate linear regression models were used to estimate their association with each cognitive domain and relationship to CAA-related neuroimaging markers.

RESULTS

One hundred twenty patients, 36 with possible (age mean [range]: 75.6 [65.6-88.9]), 67 with probable CAA (75.9 [59.0-94.0]), and 17 controls without cognitive impairment and CSVD (72.4 [62.5-82.7]; 76.4% female patients), were included in this study. We found a positive association between all investigated hippocampal subfields and memory and language, whereas specific subfields accounted for executive function (CA4 [Estimate = 5.43; 95% CI 1.26-9.61; p = 0.020], subiculum [Estimate = 2.85; 95% CI 0.67-5.02; p = 0.022]), and processing speed (subiculum [Estimate = 1.99; 95% CI 0.13-3.85; p = 0.036]). These findings were independent of other CAA-related markers, which did not have an influence on cognition in this cohort. Peak width of skeletonized mean diffusivity (PSMD), a measure of white matter integrity, was negatively associated with hippocampal subfields' volumes (CA3 [Estimate = -0.012; 95% CI -0.020 to -0.004; p = 0.034], CA4 [Estimate = -0.010; 95% CI -0.020 to -0.0007; p = 0.037], subiculum [Estimate = -0.019; 95% CI -0.042 to -0.0001; p = 0.003]).

DISCUSSION

These results suggest that hippocampal integrity is an independent contributor to cognitive impairment in patients with CAA and that it might be related to loss of integrity in the white matter. Further studies exploring potential causes and directionality of the relationship between white matter and hippocampal integrity may be warranted.

[Two cases of cerebral amyloid angiopathy in which white matter lesions appearing after brain biopsy got improvement without immunotherapy]

The first case was a 75-year-old woman with intermittent sensory impairment of the left hand. FLAIR of the head MRI revealed hyperintensity along the pia mater in the right parieto-temporal lobe with few microbleeds. Our second case was a 78-year-old man who presented with motor aphasia. His MRI showed swollen cortex on FLAIR and cortical hemosiderosis on T2* weighted imaging of the right cerebral hemisphere. Pathological findings indicated the first case as cerebral amyloid angiopathy (CAA)-related inflammation and the second case as CAA. Additionally, after brain biopsy, widespread white matter lesions were detected in the area surrounding the biopsy site. However, both patients showed improvement without immunotherapy. Therefore, it is important to consider whether immunotherapy is required when white matter lesions appear in the area surrounding the biopsy site.

Sensitivity and Specificity of the Boston Criteria Version 2.0 for the Diagnosis of Cerebral Amyloid Angiopathy in a Community-Based Sample

BACKGROUND AND OBJECTIVES

The Boston criteria are a set of clinical and neuroimaging features that enable accurate diagnosis of cerebral amyloid angiopathy (CAA) without invasive methods such as brain biopsies or autopsy. The last updates to the Boston criteria, named version 2.0, were recently released and incorporated new nonhemorrhagic MRI features. These criteria have been validated in symptomatic samples, with improved diagnostic yield. We set out to investigate the accuracy of the Boston criteria v2.0 for the diagnosis of CAA in a community-based sample.

METHODS

Participants were recruited from longitudinal clinical-pathologic studies of aging conducted at the Rush Alzheimer's Disease Center in Chicago: the Religious Orders Study and the Rush Memory and Aging Project. Deceased participants with in vivo 3T MRI and detailed pathologic data available were included in the analysis. We compared the diagnostic yield of the current and earlier versions of the Boston criteria in our sample. Among those classified as probable CAA according to the Boston criteria v2.0, we investigated the ability of each neuroimaging marker to distinguish between false-positive and true-positive cases.

RESULTS

In total, 134 individuals were included in the study (mean age = 82.4 ± 6.0 years; 69.4% F), and 49 of them were considered pathology-proven definite cases with CAA (mean age = 82.9 ± 6.0 years; 63.3% F). The Boston criteria versions 1.0 and 1.5 yielded similar sensitivity (26.5%, both), specificity (90.6% and 89.4%, respectively), and predictive values (negative: 68.1% and 67.9%; positive: 61.9% and 59.1%, respectively). The recently released Boston criteria v2.0 offered higher sensitivity (38.8%) and slightly lower specificity (83.5%). Among those classified as probable CAA (v2.0), pathology-proven true-positive cases had higher numbers of strictly cortical lobar microbleeds compared with false-positive cases (p = 0.004).

DISCUSSION

Similar to findings from symptomatic samples, the inclusion of nonhemorrhagic neuroimaging markers in the updated Boston criteria offered a 12.3% gain in sensitivity among community-dwelling individuals, at the expense of a 5.9% drop in specificity. In cases with probable CAA, the cortical location of microbleeds may represent a promising distinguishing feature between true-positive and false-positive cases. Despite its improved performance, the diagnostic sensitivity of the updated criteria in a community-based sample remains limited.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that the Boston criteria v2.0 accurately distinguishes people with CAA from those without CAA.

CADMUS: A Novel MRI-Based Classification of Spontaneous Intracerebral Hemorrhage Associated With Cerebral Small Vessel Disease

BACKGROUND AND OBJECTIVES

Cerebral small vessel disease (SVD) is the major cause of intracerebral hemorrhage (ICH). There is no comprehensive, easily applicable classification of ICH subtypes according to the presumed underlying SVD using MRI. We developed an MRI-based classification for SVD-related ICH.

METHODS

We performed a retrospective study in the prospectively collected Swiss Stroke Registry (SSR, 2013-2019) and the Stroke InvestiGation in North And central London (SIGNAL) cohort. Patients with nontraumatic, SVD-related ICH and available MRI within 3 months were classified as Cerebral Amyloid angiopathy (CAA), Deep perforator arteriopathy (DPA), Mixed CAA-DPA, or Undetermined SVD using hemorrhagic and nonhemorrhagic MRI markers (CADMUS classification). The primary outcome was inter-rater reliability using Gwet's AC1. Secondary outcomes were recurrent ICH/ischemic stroke at 3 months according to the CADMUS phenotype. We performed Firth penalized logistic regressions and competing risk analyses.

RESULTS

The SSR cohort included 1,180 patients (median age [interquartile range] 73 [62-80] years, baseline NIH Stroke Scale 6 [2-12], 45.6% lobar hematoma, systolic blood pressure on admission 166 [145-185] mm Hg). The CADMUS phenotypes were as follows: mixed CAA-DPA (n = 751 patients, 63.6%), undetermined SVD (n = 203, 17.2%), CAA (n = 154, 13.1%), and DPA (n = 72, 6.3%), with a similar distribution in the SIGNAL cohort (n = 313). Inter-rater reliability was good (Gwet's AC1 for SSR/SIGNAL 0.69/0.74). During follow-up, 56 patients had 57 events (28 ICH, 29 ischemic strokes). Three-month event rates were comparable between the CADMUS phenotypes.

DISCUSSION

CADMUS, a novel MRI-based classification for SVD-associated ICH, is feasible and reproducible and may improve the classification of ICH subtypes in clinical practice and research.

Using Neuroimaging to Study Cerebral Amyloid Angiopathy and Its Relationship to Alzheimer's Disease

Cerebral amyloid angiopathy (CAA) is characterized by amyloid-β aggregation in the media and adventitia of the leptomeningeal and cortical blood vessels. CAA is one of the strongest vascular contributors to Alzheimer's disease (AD). It frequently co-occurs in AD patients, but the relationship between CAA and AD is incompletely understood. CAA may drive AD risk through damage to the neurovascular unit and accelerate parenchymal amyloid and tau deposition. Conversely, early AD may also drive CAA through cerebrovascular remodeling that impairs blood vessels from clearing amyloid-β. Sole reliance on autopsy examination to study CAA limits researchers' ability to investigate CAA's natural disease course and the effect of CAA on cognitive decline. Neuroimaging allows for in vivo assessment of brain function and structure and can be leveraged to investigate CAA staging and explore its associations with AD. In this review, we will discuss neuroimaging modalities that can be used to investigate markers associated with CAA that may impact AD vulnerability including hemorrhages and microbleeds, blood-brain barrier permeability disruption, reduced cerebral blood flow, amyloid and tau accumulation, white matter tract disruption, reduced cerebrovascular reactivity, and lowered brain glucose metabolism. We present possible areas for research inquiry to advance biomarker discovery and improve diagnostics.

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.

Serum YKL-40 as a Predictive Biomarker of Cerebral Amyloid Angiopathy-Related Intracerebral Hemorrhage Recurrence

Background

Neuroinflammation is a major cause of secondary brain injury in intracerebral hemorrhage (ICH). To date, the prognostic value of YKL-40 (chitinase-3-like-1 protein), a biomarker of neuroinflammation, in cerebral amyloid angiopathy-related intracerebral hemorrhage (CAA-ICH) remains undiscovered.

Objective

To evaluate the relationships between serum YKL-40 and CAA-ICH recurrence.

Methods

Clinical and imaging information of 68 first-onset probable CAA-ICH cases and 95 controls were collected at baseline. Serum YKL-40 was measured by Luminex assay. Cox proportional hazards model was used to analyze the associations between YKL-40 level and CAA-ICH recurrence.

Results

Serum YKL-40 level was significantly higher in CAA-ICH cases than healthy controls (median [interquartile range, IQR], 46.1 [19.8, 93.4] versus 24.4 [13.9, 59.0] ng/mL, p = 0.004). Higher level of YKL-40 predicted increased risk of CAA-ICH recurrence adjusted for age, ICH volume and enlarged perivascular space score (ePVS) (above versus below 115.5 ng/ml, adjusted hazard ratios 4.721, 95% confidence intervals 1.829-12.189, p = 0.001) within a median follow-up period of 2.4 years. Adding YKL-40 to a model of only MRI imaging markers including ICH volume and ePVS score improved the discriminatory power (concordance index from 0.707 to 0.772, p = 0.001) and the reclassification power (net reclassification improvement 28.4%; integrated discrimination index 11.0%).

Conclusions

Serum YKL-40 level might be a candidate prognostic biomarker for CAA-ICH recurrence.

[Cerebral amyloid angiopathy]

Cerebral amyloid angiopathy (CAA) is a progressive disease characterized by the deposition of β-amyloid in the walls of blood vessels in the brain, which leads to their damage and disruption of normal blood flow. Morphologically, CAA is characterized by both isolated lesions (microhemorrhages with the appearance of cortical superficial siderosis, lacunar infarctions) and widespread changes (hyperintensity of the deep and periventricular white matter, expansion of the perivascular spaces) of cortical and subcortical localization. CAA is considered a major cause of cognitive impairment and intracerebral microbleeds, especially in patients with Alzheimer's disease. The review presents modern ideas about the etiology, pathogenesis, clinical manifestations of CAA, and also outlines the provisions of the Boston principles of CAA, revised in 2022. Understanding the features of pathogenetic methods of CAA is crucial for adjusting the accuracy of diagnosis and developing treatment methods to preserve and prolong cognitive health.

Fatal iatrogenic cerebral β-amyloid-related arteritis in a woman treated with lecanemab for Alzheimer's disease

We report the case of a 79-year-old woman with Alzheimer's disease who participated in a Phase III randomized controlled trial called CLARITY-AD testing the experimental drug lecanemab. She was randomized to the placebo group and subsequently enrolled in an open-label extension which guaranteed she received the active drug. After the third biweekly infusion, she suffered a seizure characterized by speech arrest and a generalized convulsion. Magnetic resonance imaging revealed she had multifocal swelling and a marked increase in the number of cerebral microhemorrhages. She was treated with an antiepileptic regimen and high-dose intravenous corticosteroids but continued to worsen and died after 5 days. Post-mortem MRI confirmed extensive microhemorrhages in the temporal, parietal and occipital lobes. The autopsy confirmed the presence of two copies of APOE4, a gene associated with a higher risk of Alzheimer's disease, and neuropathological features of moderate severity Alzheimer's disease and severe cerebral amyloid angiopathy with perivascular lymphocytic infiltrates, reactive macrophages and fibrinoid degeneration of vessel walls. There were deposits of β-amyloid in meningeal vessels and penetrating arterioles with numerous microaneurysms. We conclude that the patient likely died as a result of severe cerebral amyloid-related inflammation.

Etiology of Primary Cerebellar Intracerebral Hemorrhage Based on Topographic Localization

BACKGROUND

Cerebellar intracerebral hemorrhage (cICH) is often attributed to hypertension or cerebral amyloid angiopathy (CAA). However, deciphering the exact etiology can be challenging. A recent study reported a topographical etiologic relationship with superficial cICH secondary to CAA. We aimed to reexamine this relationship between topography and etiology in a separate cohort of patients and using the most recent Boston criteria version 2.0.

METHODS

We performed a retrospective analysis of consecutive patients with primary cICH admitted to a tertiary academic center between 2000 and 2022. cICH location on brain computed tomography/magnetic resonance imaging scan(s) was divided into strictly superficial (cortex, surrounding white matter, vermis) versus deep (cerebellar nuclei, deep white matter, peduncular region) or mixed (both regions). Magnetic resonance imaging was rated for markers of cerebral small vessel disease. We assigned possible/probable versus absent CAA using Boston criteria 2.0.

RESULTS

We included 197 patients; 106 (53.8%) were females, median age was 74 (63-82) years. Fifty-six (28%) patients had superficial cICH and 141 (72%) deep/mixed cICH. Magnetic resonance imaging was available for 112 (57%) patients (30 [26.8%] with superficial and 82 [73.2%] with deep/mixed cICH). Patients with superficial cICH were more likely to have possible/probable CAA (48.3% versus 8.6%; odds ratio [OR], 11.43 [95% CI, 3.26-40.05]; P<0.001), strictly lobar cerebral microbleeds (51.7% versus 6.2%; OR, 14.18 [95% CI, 3.98-50.50]; P<0.001), and cortical superficial siderosis (13.8% versus 1.2%; OR, 7.70 [95% CI, 0.73-80.49]; P=0.08). Patients with deep/mixed cICH were more likely to have deep/mixed cerebral microbleeds (59.2% versus 3.4%; OR, 41.39 [95% CI, 5.01-341.68]; P=0.001), lacunes (54.9% versus 17.2%; OR, 6.14 [95% CI, 1.89-19.91]; P=0.002), severe basal ganglia enlarged perivascular spaces (36.6% versus 7.1%; OR, 7.63 [95% CI, 1.58-36.73]; P=0.01), hypertension (84.4% versus 62.5%; OR, 3.43 [95% CI, 1.61 to -7.30]; P=0.001), and higher admission systolic blood pressure (172 [146-200] versus 146 [124-158] mm Hg, P<0.001).

CONCLUSIONS

Our results suggest that superficial cICH is strongly associated with CAA whereas deep/mixed cICH is strongly associated with hypertensive arteriopathy.

The prevalence of radiological cerebral amyloid angiopathy-related inflammation in patients with cerebral amyloid angiopathy

OBJECTIVES

Cerebral amyloid angiopathy (CAA) related inflammation (CAA-RI) is an autoimmune inflammatory condition occurring in patients with CAA. We aimed to determine the prevalence of radiological CAA-RI amongst patients with CAA and to describe their presenting clinical features.

METHODS

We performed a retrospective review of electronic medical records across multiple centers within a single healthcare network. Patients who met radiological modified Boston 2.0 criteria for CAA and had white matter hyperintensity (WMH) were included. Scans were analyzed by a vascular neurologist and confirmed by a neuroradiologist blinded to clinical information for meeting criteria for possible or probable radiographic CAA-RI.

RESULTS

Out of 1100 patients reviewed, 511 patients met radiological modified Boston criteria for CAA and 193 patients had WMH on MRI. A total of 55 (28.5 % of those with CAA and WMH, and 10.8 % of all CAA with or without WMH) patients had MRI brain imaging suggestive of possible or probable radiographic CAA-RI. The diagnosis of CAA-RI was reported in only 10 (18.2 %) patients initially while 20 (36.4 %) were diagnosed up to 74 months later (median 0, IQR 0-9 months). At the time of earliest probable CAA-RI findings on imaging, the most common concurrent findings were cognitive impairment (74.5 %), macro-hemorrhages (52.7 %), headache (30.9 %), seizures (14.5 %), and ischemic infarcts (14.5 %). Only 18 (32.7 %) patients were treated with immunosuppression.

CONCLUSIONS

The prevalence of radiographic CAA-RI was high, and most cases were unrecognized and untreated. Further studies are needed to assess if earlier detection and treatment of radiologic CAA-RI may halt disease progression and prevent cognitive decline in these patients.

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.

Exploring cerebral amyloid angiopathy: Insights into pathogenesis, diagnosis, and treatment

Cerebral Amyloid Angiopathy (CAA) is a neurological disorder characterized by the deposition of amyloid plaques in the walls of cerebral blood vessels. This condition poses significant challenges in terms of understanding its underlying mechanisms, accurate diagnosis, and effective treatment strategies. This article aims to shed light on the complexities of CAA by providing insights into its pathogenesis, diagnosis, and treatment options. The pathogenesis of CAA involves the accumulation of amyloid beta (Aβ) peptides in cerebral vessels, leading to vessel damage, impaired blood flow, and subsequent cognitive decline. Various genetic and environmental factors contribute to the development and progression of CAA, and understanding these factors is crucial for targeted interventions. Accurate diagnosis of CAA often requires advanced imaging techniques, such as magnetic resonance imaging (MRI) or positron emission tomography (PET) scans, to detect characteristic amyloid deposits in the brain. Early and accurate diagnosis enables appropriate management and intervention strategies. Treatment of CAA focuses on preventing further deposition of amyloid plaques, managing associated symptoms, and reducing the risk of complications such as cerebral hemorrhage. Currently, there are no disease-modifying therapies specifically approved for CAA. However, several experimental treatments targeting Aβ clearance and anti-inflammatory approaches are being investigated in clinical trials, offering hope for future therapeutic advancements.

Histopathological Correlates of Lobar Microbleeds in False-Positive Cerebral Amyloid Angiopathy Cases

OBJECTIVE

A definite diagnosis of cerebral amyloid angiopathy (CAA), characterized by the accumulation of amyloid β in walls of cerebral small vessels, can only be obtained through pathological examination. A diagnosis of probable CAA during life relies on the presence of hemorrhagic markers, including lobar cerebral microbleeds (CMBs). The aim of this project was to study the histopathological correlates of lobar CMBs in false-positive CAA cases.

METHODS

In 3 patients who met criteria for probable CAA during life, but showed no CAA upon neuropathological examination, lobar CMBs were counted on ex vivo 3T magnetic resonance imaging (MRI) and on ex vivo 7T MRI. Areas with lobar CMBs were next sampled and cut into serial sections, on which the CMBs were then identified.

RESULTS

Collectively, there were 25 lobar CMBs on in vivo MRI and 22 on ex vivo 3T MRI of the analyzed hemispheres. On ex vivo MRI, we targeted 12 CMBs for sampling, and definite histopathological correlates were retrieved for 9 of them, of which 7 were true CMBs. No CAA was found on any of the serial sections. The "culprit vessels" associated with the true CMBs instead showed moderate to severe arteriolosclerosis. Furthermore, CMBs in false-positive CAA cases tended to be located more often in the juxtacortical or subcortical white matter than in the cortical ribbon.

INTERPRETATION

These findings suggest that arteriolosclerosis can generate lobar CMBs and that more detailed investigations into the exact localization of CMBs with respect to the cortical ribbon could potentially aid the diagnosis of CAA during life. ANN NEUROL 2023;94:856-870.

Cerebral Microbleed Patterns and Cortical Amyloid-β: The ARIC-PET Study

BACKGROUND

Cerebral microbleeds (CMBs) are associated with cognitive decline, but their importance outside of cerebral amyloid angiopathy and the mechanisms of their impact on cognition are poorly understood. We evaluated the cross-sectional association between CMB patterns and cerebral Aβ (amyloid-β) deposition, by florbetapir positron emission tomography.

METHODS

The longitudinal ARIC study (Atherosclerosis Risk in Communities) recruited individuals from 4 US communities from 1987 to 1989. From 2012 to 2014, the ARIC-PET (Atherosclerosis Risk in Communities - Positron Emission Tomography) ancillary recruited 322 nondemented ARIC participants who completed 3T brain magnetic resonance imaging with T2*GRE as part of ARIC visit 5 to undergo florbetapir positron emission tomography imaging. Magnetic resonance imaging images were read for CMBs and superficial siderosis; on positron emission tomography, global cortical standardized uptake value ratio >1.2 was considered a positive Aβ scan. Multivariable logistic regression models evaluated CMB characteristics in association with Aβ positivity. Effect modification by sex, race, APOE status, and cognition was evaluated.

RESULTS

CMBs were present in 24% of ARIC-PET participants. No significant associations were found between CMBs and Aβ positivity, but a pattern of isolated lobar CMBs or superficial siderosis was associated with over 4-fold higher odds of elevated Aβ when compared with those with no CMBs (odds ratio, 4.72 [95% CI, 1.16-19.16]). A similar elevated risk was not observed in those with isolated subcortical or mixed subcortical and either lobar CMBs or superficial siderosis. Although no significant interactions were found, effect estimates for elevated Aβ were nonsignificantly lower (P>0.10, odds ratio, 0.4-0.6) for a mixed CMB pattern, and odds ratios were nonsignificantly higher for lobar-only CMBs for 4 subgroups: women (versus men); Black participants (versus White participants), APOE ε4 noncarriers (versus carriers), and cognitively normal (versus mild cognitive impairment).

CONCLUSIONS

In this community-based cohort of nondemented adults, lobar-only pattern of CMBs or superficial siderosis is most strongly associated with brain Aβ, with no elevated risk for a mixed CMB pattern. Further studies are needed to understand differences in CMB patterns and their meaning across subgroups.

Convexity subarachnoid haemorrhage: a practical guide

Atraumatic convexity subarachnoid haemorrhage describes spontaneous bleeding into the convexities of the brain sulci without parenchymal involvement. Its many causes include reversible cerebral vasoconstriction syndrome, cerebral sinus venous thrombosis, posterior reversible encephalopathy syndrome and (in older people) cerebral amyloid angiopathy. We describe the clinical and radiological features of non-traumatic convexity subarachnoid haemorrhage with its various presentations, causes, treatments and prognoses, and use clinical vignettes to highlight important clinical points and pitfalls.

Cerebral amyloid angiopathy-related inflammation: clinical features and treatment response in a case series

INTRODUCTION

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is an entity characterised by an inflammatory response to β-amyloid deposition in the walls of cerebral microvessels.

METHODS

We conducted a retrospective review of a series of patients with a diagnosis of CAA-ri according to histopathological study findings or clinical-radiological diagnostic criteria.

RESULTS

The study included 7 patients (5 men) with a mean age of 79 years. Disease onset was acute or subacute in 6 patients. The most frequent symptoms were cognitive impairment (n = 6), behavioural alterations (n = 5), epileptic seizures (n = 5), focal neurological signs (n = 4), and headache (n = 2). Cerebrospinal fluid was abnormal in 3 patients (lymphocytic pleocytosis and high protein levels). The most frequent MRI findings were microbleeds (n = 7), subcortical white matter hyperintensities on T2-FLAIR sequences (n = 7), and leptomeningeal enhancement (n = 6). Lesions were bilateral in 3 patients and most frequently involved the parieto-occipital region (n = 5). Amyloid PET studies were performed in 2 patients, one of whom showed pathological findings. Two patients underwent brain biopsy, which confirmed diagnosis. All patients received immunosuppressive therapy. An initially favourable clinical-radiological response was observed in all cases, with 2 patients presenting radiological recurrence after treatment withdrawal, with a subsequent improvement after treatment was resumed.

CONCLUSIONS

Early diagnosis of CAA-ri is essential: early treatment has been shown to improve prognosis and reduce the risk of recurrence. Although a histopathological study is needed to confirm diagnosis, clinical-radiological criteria enable diagnosis without biopsy.

Iatrogenic cerebral amyloid angiopathy: An illustrative case of a newly introduced disease

BACKGROUND AND PURPOSE

Iatrogenic cerebral amyloid angiopathy (iCAA) is a specific type of cerebral amyloid angiopathy which is becoming increasingly diagnosed. It has been hypothesized that iCAA might arise as a late consequence of past neurosurgical interventions involving dural patch grafts. Positron emission tomography (PET) scans with amyloid tracers and the assay of beta-amyloid levels in cerebrospinal fluid (CSF) are auxiliary criteria, however, definite diagnosis remains histopathologically determined.

METHODS

Case report.

RESULTS

We present a 48-year-old patient who suffered multiple lobar cerebral haemorrhages from the age of 47. The patient had undergone surgery for remolval of hemangioblastoma with lyophilized dural graft at the age of 11, in 1987. Brain MRI, amiloid PET and CSF analysis led to a diagnosis of probable iCAA.

CONCLUSION

It is necessary to increase the awareness of iCAA, in order to avoid overlooking the potential causal involvement of surgical procedures which took place far back in time. Moreover, the diagnostic relevance of amyloid PET and beta-amyloid levels in CSF must be emphasised.

Neuropathologic correlates of cerebral microbleeds in community-based older adults

Cerebral microbleeds (CMBs) appearing as hypointense foci on T2*-weighted magnetic resonance images are small hemorrhages that have been linked to cognitive decline and increased mortality. However, the neuropathologic correlates of CMBs in community-based older adults are poorly understood. The present study investigated the association of age-related neuropathologies with CMBs in community-based older adults. Cerebral hemispheres from 289 participants of the Rush Memory and Aging Project, Religious Orders Study, Minority Aging Research Study, and Rush Alzheimer's Disease Clinical Core underwent ex vivo MRI and detailed neuropathologic examination. Following Bonferroni correction, CMBs in the cerebrum overall and in the frontal lobe were associated with cerebral amyloid angiopathy, CMBs in the frontal lobe were also associated with arteriolosclerosis, and CMBs in the basal ganglia showed a borderline significant association with microinfarcts. These findings suggest that CMBs can aid in the prediction of small vessel disease in community-based older adults. Finally, CMBs were not associated with dementia, suggesting that CMBs in community-based older adults may not be linked to substantial cognitive impairment.

[Classical cortical superficial siderosis presenting as extensive higher brain dysfunction with hypoperfusion in the frontoparietal lobe on the 123I-IMP-SPECT: a case report]

A 72-year-old male developed neurological symptoms such as difficulty in charging his electronic money card and making his mobile-phone call ten months before admission. On admission, neurological examination revealed extensive higher brain dysfunction such as impairment in recent memory, executive function disorders, constructional disturbance, agraphia and acalculia. Brain MRI revealed a low intensity lesion on the surface of the cerebral cortex diffusely and symmetrically on T2*-weighted images. MRI images are consistent with superficial siderosis. However, the lack of hemosiderin deposition in the brain stem and cerebellar hemisphere was atypical of the classical type of superficial siderosis. 123I-IMP-SPECT revealed hypoperfusion dominantly in the left hemisphere, particularly in the left frontal and parietal lobes. According to the Boston criteria, the patient with the cerebral microbleeds and cortical superficial siderosis was diagnosed with probable CAA (cerebral amyloid angiopathy).

Association of the Presence and Pattern of MRI Markers of Cerebral Small Vessel Disease With Recurrent Intracerebral Hemorrhage

BACKGROUND AND OBJECTIVES

Assessing the risk of recurrent intracerebral hemorrhage (ICH) is of high clinical importance. MRI-based cerebral small vessel disease (SVD) markers may help establish ICH etiologic subtypes (including cryptogenic ICH) relevant for recurrence risk.

METHODS

We investigated the risk of recurrent ICH in a large cohort of consecutive ICH survivors with available MRI at baseline. Patients with macrovascular, structural, or other identified secondary causes (other than SVD) were excluded. Based on MRI findings, ICH etiology was defined as probable cerebral amyloid angiopathy (CAA) according to the Boston 2.0 criteria, arteriolosclerosis (nonlobar ICH and additional markers of arteriolosclerosis, absent lobar hemorrhagic lesions), mixed SVD (mixed deep and lobar hemorrhagic changes), or cryptogenic ICH (no MRI markers of SVD). Recurrent ICH was determined using electronic health records and confirmed by neuroimaging. Data from an independent multicenter cohort (CROMIS-2 ICH) were used to confirm core findings.

RESULTS

Of 443 patients with ICH (mean age 67 ± 13 years, 41% female), ICH etiology was mixed SVD in 36.7%, arteriolosclerosis in 23.6%, CAA in 23.0%, and cryptogenic ICH in 16.7%. During a median follow-up period of 5.7 years (interquartile range 2.9-10.0, 2,682 patient-years), recurrent ICH was found in 59 individual patients (13.3%). The highest recurrence rate per 100 person-years was detected in patients with CAA (8.5, 95% CI 6.1-11.7), followed by that in those with mixed SVD (1.8, 95% CI 1.1-2.9) and arteriolosclerosis (0.6, 95% CI 0.3-1.5). No recurrent ICH occurred in patients with cryptogenic ICH during 510 person-years follow-up (97.5% CI 0-0.7); this finding was confirmed in an independent cohort (CROMIS-2 ICH, n = 216), in which also there was no recurrence in patients with cryptogenic ICH. In patients with CAA, cortical superficial siderosis was the imaging feature strongest related to ICH recurrence (hazard ratio 5.7, 95% CI 2.4-13.6).

DISCUSSION

MRI-based etiologic subtypes are helpful in determining the recurrence risk of ICH; while the highest recurrence risk was found in CAA, recurrence risk was low for arteriolosclerosis and negligible for cryptogenic ICH.

Mechanistic Implications of Cortical Superficial Siderosis in Patients With Mixed Location Intracerebral Hemorrhage and Cerebral Microbleeds

BACKGROUND AND OBJECTIVES

Hypertensive cerebral small vessel disease (HTN-cSVD) is the predominant microangiopathy in patients with a combination of lobar and deep cerebral microbleeds (CMBs) and intracerebral hemorrhage (mixed ICH). We tested the hypothesis that cerebral amyloid angiopathy (CAA) is also a contributing microangiopathy in patients with mixed ICH with cortical superficial siderosis (cSS), a marker strongly associated with CAA.

METHODS

Brain MRIs from a prospective database of consecutive patients with nontraumatic ICH admitted to a referral center were reviewed for the presence of CMBs, cSS, and nonhemorrhagic CAA markers (lobar lacunes, centrum semiovale enlarged perivascular spaces [CSO-EPVS], and multispot white matter hyperintensity [WMH] pattern). The frequencies of CAA markers and left ventricular hypertrophy (LVH), a marker for hypertensive end-organ damage, were compared between patients with mixed ICH with cSS (mixed ICH/cSS[+]) and without cSS (mixed ICH/cSS[-]) in univariate and multivariable models.

RESULTS

Of 1,791 patients with ICH, 40 had mixed ICH/cSS(+) and 256 had mixed ICH/cSS(-). LVH was less common in patients with mixed ICH/cSS(+) compared with those with mixed ICH/cSS(-) (34% vs 59%, p = 0.01). The frequencies of CAA imaging markers, namely multispot pattern (18% vs 4%, p < 0.01) and severe CSO-EPVS (33% vs 11%, p < 0.01), were higher in patients with mixed ICH/cSS(+) compared with those with mixed ICH/cSS(-). In a logistic regression model, older age (adjusted odds ratio [aOR] 1.04 per year, 95% CI 1.00-1.07, p = 0.04), lack of LVH (aOR 0.41, 95% CI 0.19-0.89, p = 0.02), multispot WMH pattern (aOR 5.25, 95% CI 1.63-16.94, p = 0.01), and severe CSO-EPVS (aOR 4.24, 95% CI 1.78-10.13, p < 0.01) were independently associated with mixed ICH/cSS(+) after further adjustment for hypertension and coronary artery disease. Among ICH survivors, the adjusted hazard ratio of ICH recurrence in patients with mixed ICH/cSS(+) was 4.65 (95% CI 1.38-11.38, p < 0.01) compared with that in patients with mixed ICH/cSS(-).

DISCUSSION

The underlying microangiopathy of mixed ICH/cSS(+) likely includes both HTN-cSVD and CAA, whereas mixed ICH/cSS(-) is likely driven by HTN-cSVD. These imaging-based classifications can be important to stratify ICH risk but warrant confirmation in studies incorporating advanced imaging/pathology.

Age-related macular degeneration is associated with probable cerebral amyloid angiopathy: A case-control study

BACKGROUND

Age-related macular degeneration (AMD) is a common retinal degenerative disorder among older individuals. Amyloid deposits, a hallmark of cerebral amyloid angiopathy (CAA), may be involved in the pathogenesis of AMD. Since amyloid deposits may contribute to the development of both AMD and CAA, we hypothesized that patients with AMD have a higher prevalence of CAA.

OBJECTIVE

To compare the prevalence of CAA in patients with or without AMD matched for age.

METHODS

We conducted a cross-sectional, 1:1 age-matched, case-control study of patients ≥40 years of age at the Mayo Clinic who had undergone both retinal optical coherence tomography and brain MRI from 2011 to 2015. Primary dependent variables were probable CAA, superficial siderosis, and lobar and deep cerebral microbleeds (CMBs). The relationship between AMD and CAA was assessed using multivariable logistic regression and was compared across AMD severity (none vs early vs late AMD).

RESULTS

Our analysis included 256 age-matched pairs (AMD 126, no AMD 130). Of those with AMD, 79 (30.9%) had early AMD and 47 (19.4%) had late AMD. The mean age was 75±9 years, and there was no significant difference in vascular risk factors between groups. Patients with AMD had a higher prevalence of CAA (16.7% vs 10.0%, p=0.116) and superficial siderosis (15.1% vs 6.2%, p=0.020), but not deep CMB (5.2% vs 6.2%, p=0.426), compared to those without AMD. After adjusting for covariates, having late AMD was associated with increased odds of CAA (OR 2.83, 95% CI 1.10-7.27, p=0.031) and superficial siderosis (OR 3.40, 95%CI 1.20-9.65, p=0.022), but not deep CMB (OR 0.7, 95%CI 0.14-3.51, p=0.669).

CONCLUSIONS

AMD was associated with CAA and superficial siderosis but not deep CMB, consistent with the hypothesis that amyloid deposits play a role in the development of AMD. Prospective studies are needed to determine if features of AMD may serve as biomarkers for the early diagnosis of CAA.

Quantitative measurement of cortical superficial siderosis in cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is a cerebrovascular disease affecting the small arteries in the brain with hallmark depositions of amyloid-β in the vessel wall, leading to cognitive decline and intracerebral hemorrhage (ICH). An emerging MRI marker for CAA is cortical superficial siderosis (cSS) as it is strongly related to the risk of (recurrent) ICH. Current assessment of cSS is mainly done on T2*- weighted MRI using a qualitative score consisting of 5 categories of severity which is hampered by ceiling effects. Therefore, the need for a more quantitative measurement is warranted to better map disease progression for prognosis and future therapeutic trials. We propose a semi-automated method to quantify cSS burden on MRI and investigated it in 20 patients with CAA and cSS. The method showed excellent inter-observer (Pearson's 0.991, P < 0.001) and intra-observer reproducibility (ICC 0.995, P < 0.001). Furthermore, in the highest category of the multifocality scale a large spread in the quantitative score is observed, demonstrating the ceiling effect in the traditional score. We observed a quantitative increase in cSS volume in two of the 5 patients who had a 1 year follow up, while the traditional qualitative method failed to identify an increase because these patients were already in the highest category. The proposed method could therefore potentially be a better way of tracking progression. In conclusion, semi-automated segmenting and quantifying cSS is feasible and repeatable and may be used for further studies in CAA cohorts.