Advancing diagnostic criteria for sporadic cerebral amyloid angiopathy: Study protocol for a multicenter MRI-pathology validation of Boston criteria v2.0

Cortical Microhemorrhage Presentation of Small Vessel Primary Angiitis of the Central Nervous System

OBJECTIVE

Primary angiitis of the central nervous system (PACNS) is a rare vasculitis restricted to the brain, spinal cord, and leptomeninges. This study aimed to describe the imaging characteristics of patients with small vessel PACNS (SV-PACNS) using 7 T magnetic resonance imaging (MRI).

METHODS

This ongoing prospective observational cohort study included patients who met the Calabrese and Mallek criteria and underwent 7 T MRI scan. The MRI protocol includes T1-weighted magnetization-prepared rapid gradient echo imaging, T2 star weighted imaging, and susceptibility-weighted imaging. Two experienced readers independently reviewed the neuroimages. Clinical data were extracted from the electronic patient records. The findings were then applied to a cohort of patients with large vessel central nervous system (CNS) vasculitis.

RESULTS

We included 21 patients with SV-PACNS from December 2021 to November 2023. Of these, 12 (57.14%) had cerebral cortical microhemorrhages with atrophy. The pattern with microhemorrhages was described in detail based on the gradient echo sequence, leading to the identification of what we have termed the "coral-like sign." The onset age of patients with coral-like sign (33.83 ± 9.93 years) appeared younger than that of patients without coral-like sign (42.11 ± 14.18 years) (P = 0.131). Furthermore, the cerebral lesions in patients with cortical microhemorrhagic SV-PACNS showed greater propensity toward bilateral lesions (P = 0.03). The coral-like sign was not observed in patients with large vessel CNS vasculitis.

INTERPRETATION

The key characteristics of the coral-like sign represent cerebral cortical diffuse microhemorrhages with atrophy, which may be an important MRI pattern of SV-PACNS. ANN NEUROL 2024;96:194-203.

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.

Validation of International Classification of Diseases, 10thEdition, Clinical Modification (ICD-10-CM) Code I68.0 for Cerebral Amyloid Angiopathy

Introduction

Cerebral amyloid angiopathy (CAA) is a common cause of intracerebral hemorrhage and cognitive impairment in the elderly. Though definitive diagnosis requires post-mortem pathological analysis, clinical and radiographic criteria allow for noninvasive, in vivo diagnosis. We sought to validate the new ICD-10-CM diagnostic code for CAA with respect to the recently updated Boston criteria, version 2.0.

Methods

We conducted a retrospective study of inpatient and outpatient encounters at a single hospital center, Weill Cornell Medicine (WCM), from 10/1/2015 to 12/31/2018. We randomly selected 25 encounters with the ICD-10-CM code I68.0 and 25 encounters with a primary diagnosis of intracerebral hemorrhage or ischemic stroke, without code I68.0. A single board-certified neurologist, blinded to ICD codes, reviewed detailed medical records and images from brain MRI and CT scans from all 50 selected encounters and identified subjects with possible or probable CAA by Boston criteria 2.0. Sensitivity and specificity of ICD-10-CM code I68.0 was calculated.

Results

Of the 50 selected encounters, 21 (42%) met criteria for possible or probable CAA: 18 (36%) met criteria for probable CAA, 2 (4%) met criteria for probable CAA with supporting pathology, and 1 (2%) met criteria for possible CAA. The ICD-10-CM code I68.0 was found to have a sensitivity of 81% (95% CI, 58-95%) and specificity of 72% (95% CI, 53-87%) for identifying possible or probable CAA.

Conclusion

The ICD-10-CM code I68.0 was found to have good sensitivity and moderate specificity for CAA as defined by current clinical and radiographic diagnostic criteria. Based on our results, this code may be useful for identifying patients with CAA in future research using administrative claims data.

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).

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.

Boston criteria v2.0 for cerebral amyloid angiopathy without hemorrhage: An MRI-neuropathological validation study

BACKGROUND

Updated criteria for the clinical-MRI diagnosis of cerebral amyloid angiopathy (CAA) have recently been proposed. However, their performance in individuals without intracerebral hemorrhage (ICH) or transient focal neurological episodes (TFNE) is unknown. We assessed the diagnostic performance of the Boston criteria version 2.0 for CAA diagnosis in a cohort of individuals presenting without symptomatic ICH.

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 to v1.5 using histopathologically verified CAA as the reference standard.

RESULTS

Median age at MRI was 75 years (IQR 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 (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 was not superior in performance compared to the prior v1.5 criteria for either CAA diagnostic category.

CONCLUSIONS

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.

Harboring Cnm-expressing Streptococcus mutans in the oral cavity relates to both deep and lobar cerebral microbleeds

BACKGROUND

Cerebral microbleeds (CMBs) influence long-term prognoses of stroke patients. Streptococcus mutans expressing the collagen-binding protein Cnm induces cerebrovascular inflammation, impairing blood brain barrier integrity and causing cerebral bleeding. Here, we examine the association of Cnm-positive S. mutans with CMBs.

METHODS

Acute stroke patients were selected from a single-center registry database. Oral carriage of Cnm-positive or Cnm-negative S. mutans was determined using polymerase chain reaction assays. The associations of Cnm-positive S. mutans with CMB number and specifically the presence of >10 CMBs were examined using quasi-Poisson and logistic regression models, respectively.

RESULTS

This study included 3154 stroke patients, of which 428 patients (median [interquartile range] age, 73.0 [63.0-81.0] years; 269 men [62.9%]) underwent oral bacterial examinations. In total, 326 patients harbored S. mutans. After excluding four patients without imaging data, we compared patients with Cnm-positive (n = 72) and Cnm-negative (n = 250) S. mutans. Harboring Cnm-positive S. mutans was independently associated with the presence of >10 CMBs (adjusted odds ratio 2.20 [1.18-4.10]) and higher numbers of deep and lobar CMBs (adjusted risk ratio 1.61 [1.14-2.27] for deep; 5.14 [2.78-9.51] for lobar), but not infratentorial CMBs, after adjusting for age, sex, hypertension, stroke type, National Institutes of Health Stroke Scale score, and cerebral amyloid angiopathy.

CONCLUSIONS

Harboring Cnm-positive S. mutans was independently associated with a higher number of CMBs in deep and lobar locations. Reducing Cnm-positive S. mutans in the oral cavity may serve as a novel therapeutic approach for stroke.

A Postmortem MRI Study of Cerebrovascular Disease and Iron Content at End-Stage of Fragile X-Associated Tremor/Ataxia Syndrome

Brain changes at the end-stage of fragile X-associated tremor/ataxia syndrome (FXTAS) are largely unknown due to mobility impairment. We conducted a postmortem MRI study of FXTAS to quantify cerebrovascular disease, brain atrophy and iron content, and examined their relationships using principal component analysis (PCA). Intracranial hemorrhage (ICH) was observed in 4/17 FXTAS cases, among which one was confirmed by histologic staining. Compared with seven control brains, FXTAS cases showed higher ratings of T2-hyperintensities (indicating cerebral small vessel disease) in the cerebellum, globus pallidus and frontoparietal white matter, and significant atrophy in the cerebellar white matter, red nucleus and dentate nucleus. PCA of FXTAS cases revealed negative associations of T2-hyperintensity ratings with anatomic volumes and iron content in the white matter, hippocampus and amygdala, that were independent from a highly correlated number of regions with ICH and iron content in subcortical nuclei. Post-hoc analysis confirmed PCA findings and further revealed increased iron content in the white matter, hippocampus and amygdala in FXTAS cases compared to controls, after adjusting for T2-hyperintensity ratings. These findings indicate that both ischemic and hemorrhagic brain damage may occur in FXTAS, with the former being marked by demyelination/iron depletion and atrophy, and the latter by ICH and iron accumulation in basal ganglia.

Progression of cerebral amyloid angiopathy: a pathophysiological framework

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

Imaging features of small vessel disease in cerebral amyloid angiopathy among patients with Alzheimer's disease

BACKGROUND AND PURPOSE

Cerebral small vessel disease biomarkers including white matter hyperintensities (WMH), lacunes, and enlarged perivascular spaces (ePVS) are under investigation to identify those specific to cerebral amyloid angiopathy (CAA). In subjects with Alzheimer's disease (AD), we assessed characteristic features and amounts of WMH, lacunes, and ePVS in four CAA categories (no, mild, moderate and severe CAA) and correlated these with Clinical Dementia Rating sum of boxes (CDRsb) score, ApoE genotype, and neuropathological changes at autopsy.

METHODS

The study included patients with a clinical diagnosis of dementia due to AD and neuropathological confirmation of AD and CAA in the National Alzheimer's Coordinating Center (NACC) database. The WMH, lacunes, and ePVS were evaluated using semi-quantitative scales. Statistical analyses compared the WMH, lacunes, and ePVS values in the four CAA groups with vascular risk factors and AD severity treated as covariates, and to correlate the imaging features with CDRsb score, ApoE genotype, and neuropathological findings.

RESULTS

The study consisted of 232 patients, of which 222 patients had FLAIR data available and 105 patients had T2-MRI. Occipital predominant WMH were significantly associated with the presence of CAA (p = 0.007). Among the CAA groups, occipital predominant WMH was associated with severe CAA (β = 1.22, p = 0.0001) compared with no CAA. Occipital predominant WMH were not associated with the CDRsb score performed at baseline (p = 0.68) or at follow-up 2-4 years after the MRI (p = 0.92). There was no significant difference in high grade ePVS in the basal ganglia (p = 0.63) and centrum semiovale (p = 0.95) among the four CAA groups. The WMH and ePVS on imaging did not correlate with the number of ApoE ε4 alleles but the WMH (periventricular and deep) correlated with the presence of infarcts, lacunes and microinfarcts on neuropathology.

CONCLUSION

Among patients with AD, occipital predominant WMH is more likely to be found in patients with severe CAA than in those without CAA. The high-grade ePVS in centrum semiovale were common in all AD patients regardless of CAA severity.

Apathy in Patients With Cerebral Amyloid Angiopathy: A Multimodal Neuroimaging Study

BACKGROUND AND OBJECTIVE

To analyze the prevalence and associated clinical characteristics of apathy in sporadic cerebral amyloid angiopathy and investigate whether apathy was associated with disease burden and disconnections of key structures in the reward circuit through a structural and functional multimodal neuroimaging approach.

METHODS

Thirty-seven participants with probable sporadic cerebral amyloid angiopathy without symptomatic intracranial hemorrhage or dementia (mean age, 73.3 ± 7.2 years, % male = 59.5%) underwent a detailed neuropsychological evaluation, including measures of apathy and depression, and a multimodal MR neuroimaging study. A multiple linear regression analysis was used to assess the association of apathy with conventional small vessel disease neuroimaging markers. A voxel-based morphometry with a small volume correction within regions previously associated with apathy and a whole-brain tract-based spatial statistics were performed to identify differences in the gray matter and white matter between the apathetic and nonapathetic groups. Gray matter regions significantly associated with apathy were further evaluated for their functional alterations as seeds in the seed-based resting-state functional connectivity analysis. Potential confounders, namely, age, sex, and measures of depression, were entered as covariates in all analyses.

RESULTS

A higher composite small vessel disease marker score (CAA-SVD) was associated with a higher degree of apathy (standardized coefficient = 1.35 (0.07-2.62), adjusted R2 = 27.90, p = 0.04). Lower gray matter volume of the bilateral orbitofrontal cortices was observed in the apathetic group than in the nonapathetic group (F = 13.20, family-wise error-corrected p = 0.028). The apathetic group demonstrated a widespread decrease in white matter microstructural integrity compared with the nonapathetic group. These tracts connect key regions within and between related reward circuits. Finally, there were no significant functional alterations between the apathetic and nonapathetic groups.

DISCUSSION

Our findings revealed the orbitofrontal cortex as a key region in the reward circuit associated with apathy in sporadic cerebral amyloid angiopathy, independent from depression. Apathy was shown to be associated with a higher CAA-SVD score and an extensive disruption of white matter tracts, which suggested that a higher burden of CAA pathology and the disruption in large-scale white matter networks may underlie manifestations of apathy.

Role of Enlarged Perivascular Space in the Temporal Lobe in Cerebral Amyloidosis

OBJECTIVE

Although growing evidence suggests that perivascular space (PVS) serves as a clearance route for amyloid and tau, the association between enlarged PVS (EPVS) and Alzheimer disease is highly inconsistent across studies. As the conventional visual rating systems for EPVS were insufficient to predict amyloid/tau/neurodegeneration (A/T/N) status, we developed a new rating scale for EPVS located in the temporal lobe (T-EPVS).

METHODS

EPVS located in the basal ganglia (BG-EPVS), centrum semiovale (CS-EPVS), and T-EPVS was visually rated in 272 individuals (healthy controls, n = 96; mild cognitive impairment, n = 106; dementia, n = 70) who underwent structural magnetic resonance imaging (MRI) and dual positron emission tomography scans (¹⁸ F-flortaucipir and ¹⁸ F-florbetaben). T-EPVS and BG-EPVS were defined as high degree when the counts in any hemisphere were >10, and the CS-EPVS cutoff was >20. Logistic regression models were constructed to investigate whether the regional EPVS burden was predictive of A/T/N status. The derived models were externally validated in a temporal validation cohort (n = 195) that underwent MRI studies using a different scanner.

RESULTS

Compared with those with low-degree T-EPVS (23/136, 16.9%), individuals with high-degree T-EPVS/CS-EPVS but low-degree BG-EPVS were more likely to exhibit amyloid positivity (46/56, 82.1%). High-degree T-EPVS burden (odds ratio [OR] = 7.251, 95% confidence interval [CI] = 3.296-15.952) and low-degree BG-EPVS (OR = 0.241, 95% CI = 0.109-0.530) were predictive of amyloid positivity. Although high-degree T-EPVS was associated with tau positivity, the association was no longer significant after adjusting for amyloid and neurodegeneration status.

INTERPRETATION

Investigating the burden and topographic distribution of EPVS including T-EPVS may be useful for predicting amyloid status, indicating that impaired perivascular drainage may contribute to cerebral amyloidosis. ANN NEUROL 2023.

A postmortem MRI study of cerebrovascular disease and iron content at end-stage of fragile X-associated tremor/ataxia syndrome

Brain changes at end-stage of fragile X-associated tremor/ataxia syndrome (FXTAS) are largely unknown due to mobility impairment. We conducted a postmortem MRI study of FXTAS to quantify cerebrovascular disease, brain atrophy, and iron content and examined their relationships using principal component analysis (PCA). Intracranial hemorrhage (ICH) was observed in 4/17 FXTAS cases among which one was confirmed by histologic staining. Compared with seven control brains, FXTAS cases showed higher ratings of T2-hyperintensities (indicating cerebral small vessel disease) in the cerebellum, globus pallidus, and frontoparietal white matter and significant atrophy in cerebellar white matter, red nucleus, and dentate nucleus. PCA of FXTAS cases revealed negative associations of T2-hyperintensity ratings with anatomic volumes and iron content in the white matter, hippocampus, and amygdala, that were independent from highly correlated number of regions with ICH and iron content in subcortical nuclei. Post hoc analysis confirmed PCA findings and further revealed increased iron content in the white matter, hippocampus, and amygdala in FXTAS cases than controls after adjusting for T2-hyperintensity ratings. These findings indicate that both ischemic and hemorrhagic brain damage may occur in FXTAS, with the former marked by demyelination/iron depletion and atrophy and the latter, ICH and iron accumulation in basal ganglia.

Mediation of Reduced Hippocampal Volume by Cerebral Amyloid Angiopathy in Pathologically Confirmed Patients with Alzheimer's Disease

BACKGROUND

Hippocampal atrophy in cerebral amyloid angiopathy (CAA) has been reported to be similar to that in Alzheimer's disease (AD).

OBJECTIVE

To evaluate if CAA pathology partly mediates reduced hippocampal volume in patients with AD.

METHODS

Patients with a clinical diagnosis of AD and neuropathological confirmation of AD+/-CAA in the National Alzheimer's Coordinating Center database were included in the study. The volumes of temporal lobe structures were calculated on T1-weighted imaging (T1-MRI) using automated FreeSurfer software, from images acquired on average 5 years prior to death. Multivariate regression analysis was performed to compare brain volumes in four CAA groups. The hippocampal volume on T1-MRI was correlated with Clinical Dementia Rating sum of boxes (CDRsb) score, apolipoprotein E (APOE) genotype, and hippocampal atrophy at autopsy.

RESULTS

The study included 231 patients with no (n = 45), mild (n = 70), moderate (n = 67), and severe (n = 49) CAA. Among the four CAA groups, patients with severe CAA had a smaller mean left hippocampal volume (p = 0.023) but this was not significant when adjusted for APOE ɛ4 (p = 0.07). The left hippocampal volume on MRI correlated significantly with the hippocampal atrophy grading on neuropathology (p = 0.0003). Among patients with severe CAA, the left hippocampal volume on T1-MRI: (a) decreased with an increase in the number of APOE ɛ4 alleles (p = 0.04); but (b) had no evidence of correlation with CDRsb score (p = 0.57).

CONCLUSION

Severe CAA was associated with smaller left hippocampal volume on T1-MRI up to five years prior to death among patients with neuropathologically confirmed AD. This relationship was dependent on APOE ɛ4 genotype.

Can novel CT-and MR-based neuroimaging biomarkers further improve the etiological diagnosis of lobar intra-cerebral hemorrhage?

Lobar hematomas represent around half of all supratentorial hemorrhages and have high mortality and morbidity. Their management depends on the underlying cause. Apart from local causes such as vascular malformation, which are rare and can usually be easily excluded thanks to imaging, the vast majority of lobar hematomas equally frequently result from either hypertensive arteriolopathy (HA) or cerebral amyloid angiopathy (CAA). Distinguishing between CAA and HA is important for prognostication (risk of recurrence nearly sevenfold higher in the former), for decision-making regarding, e.g., antithrombotic therapies (for other indications) and for clinical trials of new therapies. Currently, a non-invasive diagnosis of probable CAA can be made using the MR-based modified Boston criteria, which have excellent specificity but moderate sensitivity against histopathological reference, leading to the clinically largely irrelevant diagnosis of "possible CAA". Furthermore, the Boston criteria cannot be applied when both lobar and deep MRI hemorrhagic markers are present, a not uncommon situation. Here we propose to test whether new CT and MR-based imaging biomarkers, namely finger-like projections of the hematoma and adjacent subarachnoid hemorrhage on acute-stage CT or MRI, and remote punctate diffusion-weighted imaging ischemic lesions on acute or subacute-stage MRI, have the potential to improve the performance of the Boston criteria. Furthermore, we also propose to test whether clinical-radiological biomarkers may also allow a positive diagnosis of HA to be made in lobar hematomas, which, if feasible, would not only further reduce the prevalence of "possible CAA" but also permit a diagnosis of HA and/or CAA to be made in the presence of mixed deep and lobar MRI hemorrhagic markers.

The Boston criteria version 2.0 for cerebral amyloid angiopathy: a multicentre, retrospective, MRI-neuropathology diagnostic accuracy study

BACKGROUND

Cerebral amyloid angiopathy (CAA) is an age-related small vessel disease, characterised pathologically by progressive deposition of amyloid β in the cerebrovascular wall. The Boston criteria are used worldwide for the in-vivo diagnosis of CAA but have not been updated since 2010, before the emergence of additional MRI markers. We report an international collaborative study aiming to update and externally validate the Boston diagnostic criteria across the full spectrum of clinical CAA presentations.

METHODS

In this multicentre, hospital-based, retrospective, MRI and neuropathology diagnostic accuracy study, we did a retrospective analysis of clinical, radiological, and histopathological data available to sites participating in the International CAA Association to formulate updated Boston criteria and establish their diagnostic accuracy across different populations and clinical presentations. Ten North American and European academic medical centres identified patients aged 50 years and older with potential CAA-related clinical presentations (ie, spontaneous intracerebral haemorrhage, cognitive impairment, or transient focal neurological episodes), available brain MRI, and histopathological assessment for CAA diagnosis. MRI scans were centrally rated at Massachusetts General Hospital (Boston, MA, USA) for haemorrhagic and non-haemorrhagic CAA markers, and brain tissue samples were rated by neuropathologists at the contributing sites. We derived the Boston criteria version 2.0 (v2.0) by selecting MRI features to optimise diagnostic specificity and sensitivity in a prespecified derivation cohort (Boston cases 1994-2012, n=159), then externally validated the criteria in a prespecified temporal validation cohort (Boston cases 2012-18, n=59) and a geographical validation cohort (non-Boston cases 2004-18; n=123), comparing accuracy of the new criteria to the currently used modified Boston criteria with histopathological assessment of CAA as the diagnostic standard. We also assessed performance of the v2.0 criteria in patients across all cohorts who had the diagnostic gold standard of brain autopsy.

FINDINGS

The study protocol was finalised on Jan 15, 2017, patient identification was completed on Dec 31, 2018, and imaging analyses were completed on Sept 30, 2019. Of 401 potentially eligible patients presenting to Massachusetts General Hospital, 218 were eligible to be included in the analysis; of 160 patient datasets from other centres, 123 were included. Using the derivation cohort, we derived provisional criteria for probable CAA requiring the presence of at least two strictly lobar haemorrhagic lesions (ie, intracerebral haemorrhages, cerebral microbleeds, or foci of cortical superficial siderosis) or at least one strictly lobar haemorrhagic lesion and at least one white matter characteristic (ie, severe visible perivascular spaces in centrum semiovale or white matter hyperintensities in a multispot pattern). The sensitivity and specificity of these criteria were 74·8% (95% CI 65·4-82·7) and 84·6% (71·9-93·1) in the derivation cohort, 92·5% (79·6-98·4) and 89·5% (66·9-98·7) in the temporal validation cohort, 80·2% (70·8-87·6) and 81·5% (61·9-93·7) in the geographical validation cohort, and 74·5% (65·4-82·4) and 95·0% (83·1-99·4) in all patients who had autopsy as the diagnostic standard. The area under the receiver operating characteristic curve (AUC) was 0·797 (0·732-0·861) in the derivation cohort, 0·910 (0·828-0·992) in the temporal validation cohort, 0·808 (0·724-0·893) in the geographical validation cohort, and 0·848 (0·794-0·901) in patients who had autopsy as the diagnostic standard. The v2.0 Boston criteria for probable CAA had superior accuracy to the current Boston criteria (sensitivity 64·5% [54·9-73·4]; specificity 95·0% [83·1-99·4]; AUC 0·798 [0·741-0854]; p=0·0005 for comparison of AUC) across all individuals who had autopsy as the diagnostic standard.

INTERPRETATION

The Boston criteria v2.0 incorporate emerging MRI markers of CAA to enhance sensitivity without compromising their specificity in our cohorts of patients aged 50 years and older presenting with spontaneous intracerebral haemorrhage, cognitive impairment, or transient focal neurological episodes. Future studies will be needed to determine generalisability of the v.2.0 criteria across the full range of patients and clinical presentations.

FUNDING

US National Institutes of Health (R01 AG26484).

Clinical neuroimaging in intracerebral haemorrhage related to cerebral small vessel disease: contemporary practice and emerging concepts

INTRODUCTION

About 80% of all non-traumatic intracerebral haemorrhage (ICH) are caused by the sporadic cerebral small vessel diseases deep perforator arteriopathy (DPA, also termed hypertensive arteriopathy or arteriolosclerosis) and cerebral amyloid angiopathy (CAA), though these frequently co-exist in older people. Contemporary neuroimaging (MRI and CT) detects an increasing spectrum of haemorrhagic and non-haemorrhagic imaging biomarkers of small vessel disease which may identify the underlying arteriopathies.

AREAS COVERED

We discuss biomarkers for cerebral small vessel disease subtypes in ICH, and explore their implications for clinical practice and research.

EXPERT OPINION

ICH is not a single disease, but results from a defined range of vascular pathologies with important implications for prognosis and treatment. The terms "primary" and "hypertensive" ICH are poorly defined and should be avoided, as they encourage incomplete investigation and classification. Imaging-based criteria for CAA will show improved diagnostic accuracy, but specific imaging biomarkers of DPA are needed. Ultra-high-field 7T-MRI using structural and quantitative MRI may provide further insights into mechanisms and pathophysiology of small vessel disease. We expect neuroimaging biomarkers and classifications to allow personalized treatments (e.g. antithrombotic drugs) in clinical practice and to improve patient selection and monitoring in trials of targeted therapies directed at the underlying arteriopathies.

Efficacy and safety of reperfusion treatments in middle-old and oldest-old stroke patients

Introduction

Intravenous thrombolysis (IT) and mechanical thrombectomy (MT) have significantly changed the clinical outcome of acute ischaemic stroke (AIS). Concerns about possible complications often reduce the use of these treatment options for older patients, preferentially managed with antiplatelet therapy (AT). Aim of this study was to evaluate, in a population of middle-old (75–84 years) and oldest-old (≥ 85 years) subjects, the efficacy and safety of different treatments for AIS (IT, IT + MT, MT or AT), mortality and incidence of serious complications.

Patients and methods

All patients aged over 75 years admitted for AIS in two Stroke Units were enrolled. The physician in each case considered all treatment options and chose the best approach. NIHSS and modified Rankin Scale (mRS) were obtained and differences between admission and discharge scores, defined as delta(NIHSS) and delta(mRS), were calculated. The relationship between delta(NIHSS), delta(mRS) and type of procedure was analysed with a GLM/Multivariate model. Differences in mortality and incidence of serious complications were analysed with the chi-square test.

Results

A total of 273 patients, mean age 84.07 (± 5.47) years, were included. The Delta(NIHSS) was significantly lower in patients treated with AT than in those treated with IT and MT (p < 0.009 and p < 0.005, respectively). Haemorrhagic infarction occurrence was significantly lower (p < 0.0001) among patients treated with AT (10.6%) or IT (16.7%) compared to MT (34.9%) or MT + IT (37.0%). No significant difference was observed for in-hospital mortality. Age did not influence the outcome.

Conclusions

Our results suggest that IT and AT are effective and relatively safe approaches in middle-aged and older patients.

Impact of Cerebral Amyloid Angiopathy in Two Transgenic Mouse Models of Cerebral β-Amyloidosis: A Neuropathological Study

The pathological accumulation of parenchymal and vascular amyloid-beta (Aβ) are the main hallmarks of Alzheimer’s disease (AD) and Cerebral Amyloid Angiopathy (CAA), respectively. Emerging evidence raises an important contribution of vascular dysfunction in AD pathology that could partially explain the failure of anti-Aβ therapies in this field. Transgenic mice models of cerebral β-amyloidosis are essential to a better understanding of the mechanisms underlying amyloid accumulation in the cerebrovasculature and its interactions with neuritic plaque deposition. Here, our main objective was to evaluate the progression of both parenchymal and vascular deposition in APP23 and 5xFAD transgenic mice in relation to age and sex. We first showed a significant age-dependent accumulation of extracellular Aβ deposits in both transgenic models, with a greater increase in APP23 females. We confirmed that CAA pathology was more prominent in the APP23 mice, demonstrating a higher progression of Aβ-positive vessels with age, but not linked to sex, and detecting a pronounced burden of cerebral microbleeds (cMBs) by magnetic resonance imaging (MRI). In contrast, 5xFAD mice did not present CAA, as shown by the negligible Aβ presence in cerebral vessels and the occurrence of occasional cMBs comparable to WT mice. In conclusion, the APP23 mouse model is an interesting tool to study the overlap between vascular and parenchymal Aβ deposition and to evaluate future disease-modifying therapy before its translation to the clinic.

Recurrent intracerebral hemorrhage in patients with cerebral amyloid angiopathy: a propensity-matched case-control study

OBJECTIVE

Cerebral amyloid angiopathy (CAA) can present with intracerebral hemorrhage (ICH), convexity subarachnoid hemorrhage (SAH), and rarely acute ischemic stroke (AIS). The objective of our study was to compare the readmission rates for recurrent ICH, SAH, and AIS among patients admitted for ICH with and without CAA.

METHODS

Using the National Readmissions Database 2016-2018 we identified patients admitted for ICH with and without a concomitant diagnosis of CAA. Primary outcome of the study was readmission due to ICH. Secondary outcomes included readmissions due to AIS and SAH. Survival analysis was performed, and Kaplan-Meier curves were created to assess for readmissions.

RESULTS

The study consisted of 194,290 patients with ICH, 8247 with CAA and 186,043 without CAA as a concomitant diagnosis. After propensity matching, we identified 7857 hospitalizations with CAA and 7874 without CAA. Patients with CAA had higher risk of readmission due to ICH as compared to those without CAA [hazards ratio (HR) 3.44, 95% confidence interval (CI) 2.55-4.64, P < 0.001] during the mean follow-up period of 181.4 (SD ± 106.4) days. Patients with CAA were also more likely to be readmitted due to SAH (HR 2.52, 95% CI 1.18-5.37, P 0.017) but not due to AIS (HR 0.74, 95% CI 0.54-1.01, P 0.061). Age (HR 0.96 per year increase in age, 95% CI 0.94-0.98, P < 0.001) and Medicare payer (HR 3.31; 95% CI 1.89-5.78, P < 0.001) were independently associated with readmissions due to ICH.

DISCUSSION

Patients admitted for ICH with a concomitant diagnosis of CAA are three times more likely to have readmissions for recurrent ICH compared to patients without CAA.

Vessels Sing Their ARIAs: The Role of Vascular Amyloid in the Age of Aducanumab

We review the implications of the recently approved aducanumab amyloid-β immunotherapy for treating Alzheimer disease with comorbid cerebral amyloid angiopathy. In clinical trials, amyloid-β immunotherapy has been associated with a high rate of amyloid-related imaging abnormalities, potentially driven by coexisting cerebral amyloid angiopathy. Therefore, immunotherapy's efficacy in patients may be modified by coexisting cerebrovascular pathology. We discuss the contributions of cerebral amyloid angiopathy on the development of amyloid-related imaging abnormalities and propose strategies to identify cerebral amyloid angiopathy in patients considered for immunotherapy.

Evaluating [68Ga]Ga-p14-032 as a Novel PET Tracer for Diagnosis Cerebral Amyloid Angiopathy

Objective: We aimed to investigate the distribution of [⁶⁸Ga]Ga-p14-032, a novel PET ligand that binds to vascular amyloid, in patients diagnosed clinically with probable cerebral amyloid angiopathy (CAA) compared with patients with Alzheimer's disease (AD) and normal controls (NC).

Methods: This longitudinal cohort study was composed of 10 subjects (three probable CAA patients, two AD patients, five NC subjects), recruited from a clinic in China. CAA patients had a history of lobar intracerebral hemorrhage (ICH) and met modified Boston criteria for probable CAA. All participants were aged at least 55 years and underwent [⁶⁸Ga] Ga-p14-032 PET/CT or/and PET/MRI, and the Montreal Cognitive Assessment on initial assessment. Demographics were measured at baseline (diabetes, hypertension, hypercholesterolemia, ischemic stroke, and ICH). Two PET imaging experts reviewed the PET images with cortical standardized uptake value ratio (SUVr) displayed on a color scale and visually classified the images as positive or negative. The mean of SUVr was calculated using the pons as reference.

Results: In CAA patients, PET scans were positive in regions with higher numbers of CMBs. No significant signal was seen in AD subjects or controls. The relative [⁶⁸Ga]Ga-p14-032 retention in the cortex was stronger in patients with CAA than AD and NC (median SUVr 2.68 ± 1.53 vs. 1.77 ± 0.08 and 0.83 ± 0.24).

Conclusions: Our results provide early evidence that the [⁶⁸Ga] Ga-p14-032 PET probe binds preferentially to vascular amyloid and may be a useful tracer for diagnosing CAA.

[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.

Cerebral amyloid angiopathy-related acute lobar intra-cerebral hemorrhage: diagnostic value of plain CT

BACKGROUND

Diagnosing probable cerebral amyloid angiopathy (CAA) after lobar intra-cerebral hemorrhage (l-ICH) currently relies on the MR-based modified Boston criteria (mBC). However, MRI has limited availability and the mBC have moderate sensitivity, with isolated l-ICH being classified as "possible CAA". A recent autopsy-based study reported potential value of finger-like projections (FLP) and subarachnoid hemorrhage (SAH) on acute CT. Here we assessed these markers' performance in a cohort most of whom survived the index episode.

METHODS

We included all patients from a prospective pathology database with non-traumatic l-ICH, admission CT and available tissue sample showing no alternative cause. CT was assessed by two blinded independent neuroradiologists. Interobserver reproducibility was almost perfect for SAH and substantial for FLP.

RESULTS

Sixteen patients were eligible [age 65.8 ± 7.2 yrs; hematoma volume: 39(26, 71)mls; hematoma evacuation sample 15 patients; autopsy one patient]. MRI was available in 11 patients. ICH-related death affected six patients. Aβ_40-42 immunohistochemistry revealed CAA in seven patients (44%). SAH and FLP were present in 12/16 (75%) and 10/16 (62%) patients, respectively. SAH had 100% sensitivity for CAA but low specificity; FLP had lower performance. Using either pathology or MRI as reference standard yielded essentially similar results. All patients with possible CAA on MRI but CAA on pathology had SAH.

CONCLUSIONS

In patients with moderate-size l-ICH who mostly survived the index event, SAH had perfect sensitivity and better performance than FLP. In addition, SAH appeared to add onto MRI in possible CAA, the clinically most relevant scenario. Studies in larger samples are however warranted.

Cerebral Amyloid Angiopathy and the Fibrinolytic System: Is Plasmin a Therapeutic Target?

Cerebral amyloid angiopathy is a devastating cause of intracerebral hemorrhage for which there is no specific secondary stroke prevention treatment. Here we review the current literature regarding cerebral amyloid angiopathy pathophysiology and treatment, as well as what is known of the fibrinolytic pathway and its interaction with amyloid. We postulate that tranexamic acid is a potential secondary stroke prevention treatment agent in sporadic cerebral amyloid angiopathy, although further research is required.

A practical approach to the management of cerebral amyloid angiopathy

Cerebral amyloid angiopathy is a common small vessel disease in the elderly involving vascular amyloid-β deposition. Cerebral amyloid angiopathy is one of the leading causes of intracerebral hemorrhage and a significant contributor to age-related cognitive decline. The awareness of a diagnosis of cerebral amyloid angiopathy is important in clinical practice as it impacts decisions to use lifelong anticoagulation or nonpharmacological alternatives to anticoagulation such as left atrial appendage closure in patients who have concurrent atrial fibrillation, another common condition in older adults. This review summarizes the latest literature regarding the management of patients with sporadic cerebral amyloid angiopathy, including diagnostic criteria, imaging biomarkers for cerebral amyloid angiopathy severity, and management strategies to decrease intracerebral hemorrhage risk. In a minority of patients, the presence of cerebral amyloid angiopathy triggers an autoimmune inflammatory reaction, referred to as cerebral amyloid angiopathy-related inflammation, which is often responsive to immunosuppressive treatment in the acute phase. Diagnosis and management of cerebral amyloid angiopathy-related inflammation will be presented separately. While there are currently no effective therapeutics available to cure or halt the progression of cerebral amyloid angiopathy, we discuss emerging avenues for potential future interventions.

Disparities in diagnosis of cerebral amyloid angiopathy based on hospital characteristics

Cerebral amyloid angiopathy (CAA) categorized as a cerebral small vessel disease can cause lobar intracerebral hemorrhage (ICH), convexity subarachnoid hemorrhage (SAH) and ischemic stroke (IS). The purpose of this study was to evaluate the differences in the diagnosis of CAA based on hospital characteristics and to assess the discharge outcomes of patients with CAA admitted for IS, ICH and SAH. Adult patients admitted with secondary diagnosis of CAA were identified in National Inpatient Sample in 2016 and 2017. Multivariable logistic regression analysis was performed to evaluate outcomes. A total of 16,040 patients had a secondary diagnosis of CAA. Among CAA patients, 1810 (11.3%) patients were admitted for IS, 4765 (29.7%) for ICH and 490 (3.1%) for SAH. Diagnosis of CAA was five-fold higher among patients admitted to urban teaching hospitals (aOR = 5.4;95% CI = 4.1-7.2) compared to rural hospitals and two-fold higher in large bed size hospitals (aOR = 2.3;95% CI = 2.0-2.7) compared to small bed size hospitals. Compared to non-CAA group, patients with history of CAA had lower odds of in-hospital mortality among patients admitted for ICH (10% vs 23%, aOR = 0.35; 95%CI = 0.27-0.44) and SAH (6% vs 19%, aOR = 0.24; 95%CI = 0.10-0.55); and higher odds of discharge to home among patients admitted for ICH (17% vs 18%, aOR = 1.27; 95%CI = 1.05-1.53). CAA diagnosis is less common in rural and small bed size hospitals compared to urban and large bedside hospitals, respectively. Patients with CAA admitted for ICH have better discharge outcomes compared to non-CAA patients admitted for ICH.

[Cerebral amyloid angiopathy, comorbid atrial fibrillation]

Cerebral amyloid angiopathy (CAA) is caused by the deposition of β-amyloid in small vessels in the cerebral cortex and leptomeninges. Nowadays, CAA is recognized more often due to the development of neuroimaging technologies. The frequency of CAA increases in old age that explains its frequent association with cardiovascular diseases. Combination of CAA with atrial fibrillation (AF) causes particular difficulties in managing of the patients, since antithrombotic drugs prescribed to patients with AF mostly contraindicated in CAA because of increased risk of intracerebral hemorrhages. The article presents a case report of the patient with AF who was admitted to the stroke center with acute ischemic stroke. According to MRI, the focus of acute ischemia was small and localized in the cerebellum. This stroke was regarded as having an undetermined etiology according TOAST classification. Small-vessel occlusion subtype was not diagnosed because the TOAST criteria do not attribute an ischemic focus in the cerebellum to a lacunar stroke, while cardioembolic subtype was rejected due to a small (less than 1.5 cm in diameter) size of the focus. Probable CAA in the patient was diagnosed on the basis of the following MRI data: multiple cortical-subcortical micro-hemorrhages (T2*GRE); a single cortical focus with features of the hemorrhage at the stage of intracellular methemoglobin deposition (T1- weighted MR images); bilateral enlargement of perivascular spaces in semioval centers (FLAIR); a negative fronto-occipital gradient (T2-weighted MR images). A diagnosis of CAA was made in accordance with the 2010 Boston criteria and 2019 recommendations of the International CAA Association. The article discusses the hemorrhagic and non-hemorrhagic MRI features of CAA. Frequency of occurrence of cortical microinfarcts in CAA is discussed as well as their differences from small cardioembolic infarcts in AF. Algorithms for antithrombotic therapy for secondary prevention of ischemic stroke in patients with CAA and AF are considered.

Cerebral microbleeds: from depiction to interpretation

Cerebral microbleeds (CMBs) are defined as hypointense foci visible on T2*-weighted and susceptible-weighted MRI sequences. CMBs are increasingly recognised with the widespread use of MRI in healthy individuals as well as in the context of cerebrovascular disease or dementia. They can also be encountered in major critical medical conditions such as in patients requiring extracorporeal mechanical oxygenation. The advent of MRI-guided postmortem neuropathological examinations confirmed that, in the context of cerebrovascular disease, the vast majority of CMBs correspond to recent or old microhaemorrhages. Detection of CMBs is highly influenced by MRI parameters, in particular field strength, postprocessing methods used to enhance T2* contrast and three dimensional sequences. Despite recent progress, harmonising imaging parameters across research studies remains necessary to improve cross-study comparisons. CMBs are helpful markers to identify the nature and the severity of the underlying chronic small vessel disease. In daily clinical practice, presence and numbers of CMBs often trigger uncertainty for clinicians especially when antithrombotic treatments and acute reperfusion therapies are discussed. In the present review, we discuss those clinical dilemmas and address the value of CMBs as diagnostic and prognostic markers for future vascular events.

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

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

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

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

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

[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.

Association of Cerebral Small Vessel Disease and Cognitive Decline After Intracerebral Hemorrhage

OBJECTIVE

To determine whether MRI-based cerebral small vessel disease (CSVD) burden assessment, in addition to clinical and CT data, improved prediction of cognitive impairment after spontaneous intracerebral hemorrhage (ICH).

METHODS

We analyzed data from ICH survivors enrolled in a single-center prospective study. We employed 3 validated CSVD burden scores: global, cerebral amyloid angiopathy (CAA)-specific, and hypertensive arteriopathy (HTNA)-specific. We quantified cognitive performance by administering the modified Telephone Interview for Cognitive Status test. We utilized linear mixed models to model cognitive decline rates, and survival models for new-onset dementia. We calculated CSVD scores' cutoffs to maximize predictive performance for dementia diagnosis.

RESULTS

We enrolled 612 ICH survivors, and followed them for a median of 46.3 months (interquartile range 35.5-58.7). A total of 214/612 (35%) participants developed dementia. Higher global CSVD scores at baseline were associated with faster cognitive decline (coefficient -0.25, standard error [SE] 0.02) and dementia risk (sub-hazard ratio 1.35, 95% confidence interval 1.10-1.65). The global score outperformed the CAA and HTNA scores in predicting post-ICH dementia (all p < 0.05). Compared to a model including readily available clinical and CT data, inclusion of the global CSVD score resulted in improved prediction of post-ICH dementia (area under the curve [AUC] 0.89, SE 0.02 vs AUC 0.81, SE 0.03, p = 0.008 for comparison). Global CSVD scores ≥2 had highest sensitivity (83%) and specificity (91%) for dementia diagnosis.

CONCLUSIONS

A validated MRI-based CSVD score is associated with cognitive performance after ICH and improved diagnostic accuracy for predicting new onset of dementia.

Discovering the Italian phenotype of cerebral amyloid angiopathy (CAA): the SENECA project

Cerebral amyloid angiopathy (CAA) is one of the major types of cerebral small vessel disease, and a leading cause of spontaneous intracerebral hemorrhage and cognitive decline in elderly patients. Although increasingly detected, a number of aspects including the pathophysiology, the clinical and neuroradiological phenotype, and the disease course are still under investigation. The incomplete knowledge of the disease limits the implementation of evidence-based guidelines on patient's clinical management and the development of treatments able to prevent or reduce disease progression. The SENECA (SEarchiNg biomarkErs of Cerebral Angiopathy) project is the first Italian multicenter cohort study aimed at better defining the disease natural history and identifying clinical and neuroradiological markers of disease progression. By a multidisciplinary approach and the collection of a large and well-phenotyped series and biorepository of CAA patients, the study is ultimately expected to improve the diagnosis and the knowledge of CAA pathophysiological mechanisms.

Reduced Levels of Cerebrospinal Fluid/Plasma Aβ40 as an Early Biomarker for Cerebral Amyloid Angiopathy in RTg-DI Rats

The accumulation of fibrillar amyloid β-protein (Aβ) in blood vessels of the brain, the condition known as cerebral amyloid angiopathy (CAA), is a common small vessel disease that promotes cognitive impairment and is strongly associated with Alzheimer’s disease. Presently, the clinical diagnosis of this condition relies on neuroimaging markers largely associated with cerebral macro/microbleeds. However, these are markers of late-stage disease detected after extensive cerebral vascular amyloid accumulation has become chronic. Recently, we generated a novel transgenic rat model of CAA (rTg-DI) that recapitulates multiple aspects of human CAA disease with the progressive accumulation of cerebral vascular amyloid, largely composed of Aβ40, and the consistent emergence of subsequent microbleeds. Here, we investigated the levels of Aβ40 in the cerebrospinal fluid (CSF) and plasma of rTg-DI rats as CAA progressed from inception to late stage disease. The levels of Aβ40 in CSF and plasma precipitously dropped at the early onset of CAA accumulation at three months of age and continued to decrease with the progression of disease. Notably, the reduction in CSF/plasma Aβ40 levels preceded the emergence of cerebral microbleeds, which first occurred at about six months of age, as detected by in vivo magnetic resonance imaging and histological staining of brain tissue. These findings support the concept that reduced CSF/plasma levels of Aβ40 could serve as a biomarker for early stage CAA disease prior to the onset of cerebral microbleeds for future therapeutic intervention.