Sensitivity of the Edinburgh Criteria for Lobar Intracerebral Hemorrhage in Hereditary Cerebral Amyloid Angiopathy

A review of concepts and methods for FTIR imaging of biomarker changes in the post-stroke brain

Stroke represents a core area of study in neurosciences and public health due to its global contribution toward mortality and disability. The intricate pathophysiology of stroke, including ischemic and hemorrhagic events, involves the interruption in oxygen and nutrient delivery to the brain. Disruption of these crucial processes in the central nervous system leads to metabolic dysregulation and cell death. Fourier transform infrared (FTIR) spectroscopy can simultaneously measure total protein and lipid content along with a number of key biomarkers within brain tissue that cannot be observed using conventional techniques. FTIR imaging provides the opportunity to visualize this information in tissue which has not been chemically treated prior to analysis, thus retaining the spatial distribution and in situ chemical information. Here we present a review of FTIR imaging methods for investigating the biomarker responses in the post-stroke brain.

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.

Clinical considerations in early-onset cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is an important cerebral small vessel disease associated with brain haemorrhage and cognitive change. The commonest form, sporadic amyloid-β CAA, usually affects people in mid- to later life. However, early-onset forms, though uncommon, are increasingly recognized and may result from genetic or iatrogenic causes that warrant specific and focused investigation and management. In this review, we firstly describe the causes of early-onset CAA, including monogenic causes of amyloid-β CAA (APP missense mutations and copy number variants; mutations of PSEN1 and PSEN2) and non-amyloid-β CAA (associated with ITM2B, CST3, GSN, PRNP and TTR mutations), and other unusual sporadic and acquired causes including the newly-recognized iatrogenic subtype. We then provide a structured approach for investigating early-onset CAA, and highlight important management considerations. Improving awareness of these unusual forms of CAA amongst healthcare professionals is essential for facilitating their prompt diagnosis, and an understanding of their underlying pathophysiology may have implications for more common, late-onset, forms of the disease.

Blend Sign and Haemorrhage Location and Volume Predict Late Recurrence and Mortality in Intracerebral Haemorrhage Patients

BACKGROUND

Studies on risk factors for primary intracerebral haemorrhage (ICH) focus on short-term predictive values of distinct clinical parameters or computed tomography (CT) markers and disregard the others. We, therefore, studied independent predictive values of demographic, clinical, and CT markers regarding ICH expansion, late ICH recurrence, and late mortality.

METHODS

In a retrospective study of 288 patients with primary ICH, ICH localization (158 lobar, 81 deep, and 49 cerebellar), volume, blend sign, spot sign, finger-like projections, and subarachnoid haemorrhages were evaluated. ICH localization-specific differences for demographic (age, sex), clinical parameters (vascular risk factors, antiplatelet, and anticoagulation therapy), and CT markers were evaluated using logistic regression. We applied Cox proportional hazards modelling using these parameters to predict risk factors for ICH expansion, late ICH recurrence, and late mortality.

RESULTS

The blend sign in lobar ICH relates to increased risk of ICH expansion (HR2.3), late ICH recurrence (HR2.3), and mortality (HR1.6). Age, conditions requiring antiplatelet medication, deep ICH localization, volume, and blend sign represented the most important independent factors impacting overall mortality.

CONCLUSIONS

Blend sign at baseline ICH is a manifestation of underlying detrimental vascular processes that signal increased ICH expansion risk, although is also indicative of long-term risks for late recurrent ICH and late mortality.

Applicability of the Edinburgh CT Criteria for Lobar Intracerebral Hemorrhage Associated with Cerebral Amyloid Angiopathy

OBJECTIVE

Based on histopathology, Edinburgh diagnostic criteria were proposed to consider a nontraumatic intracerebral lobar hemorrhage (ICH) as related to cerebral amyloid angiopathy (CAA) using the initial computed tomography (CT) scan and the APOE genetic status. We aimed to externally validate the Edinburgh prediction model, excluding the APOE genotyping and based on the modified Boston criteria on the MRI for CAA diagnosis METHODS: We included patients admitted for spontaneous lobar ICH in the emergency department between 2016 and 2019 who underwent noncontrast CT scan and MRI. According to the MRI, patients were classified into the CAA group or into the non-CAA group in the case of other causes of ICH. Two neuroradiologists, blinded to the final retained diagnosis, rated each radiological feature on initial CT scan described in the Edinburgh study on initial CT scan RESULTS: A total of 102 patients were included, of whom 36 were classified in the CAA group, 46 in the non-CAA causes group and 20 of undetermined cause (excluded from the primary analysis). The Edinburgh prediction model, including finger-like projections and subarachnoid extension showed an area under receiver operating characteristic curves (AUC) of 0.760 (95% confidence interval, CI: 0.660-0.859) for the diagnosis of CAA. The AUC reached 0.808 (95% CI: 0.714-0.901) in a new prediction model integrating a third radiologic variable: the ICH cortical involvement.

CONCLUSION

Using the Boston MRI criteria as a final assessment, we provided a new external confirmation of the radiological Edinburgh CT criteria, which are directly applicable in acute settings of spontaneous lobar ICH and further proposed an original 3‑set model considering finger-like projections, subarachnoid extension, and cortical involvement that may achieve a high discrimination performance.

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.

MRI and CT imaging biomarkers of cerebral amyloid angiopathy in lobar intracerebral hemorrhage

BACKGROUND

Cerebral amyloid angiopathy (CAA), a common cause of intracerebral hemorrhage (ICH), is diagnosed using the Boston criteria including magnetic resonance imaging (MRI) biomarkers (cerebral microbleeds (CMBs) and cortical superficial siderosis (cSS). The simplified Edinburgh criteria include computed tomography (CT) biomarkers (subarachnoid extension (SAE) and finger-like projections (FLPs)). The underlying mechanisms and diagnostic accuracy of CT compared to MRI biomarkers of CAA are unknown.

METHODS

We included 140 survivors of spontaneous lobar supratentorial ICH with both acute CT and MRI. We assessed associations between MRI and CT biomarkers and the diagnostic accuracy of CT- compared to MRI-based criteria.

RESULTS

FLPs were more common in patients with strictly lobar CMB (44.7% vs 23.5%; p = 0.014) and SAE was more common in patients with cSS (61.3% vs 31.2%; p = 0.002). The high probability of the CAA category of the simplified Edinburgh criteria showed 87.2% (95% confidence interval (CI): 78.3-93.4) specificity, 29.6% (95% CI: 18.0-43.6) sensitivity, 59.3% (95% CI: 38.8-77.6) positive predictive value, and 66.4% (95%: CI 56.9-75.0) negative predictive value, 2.3 (95% CI: 1.2-4.6) positive likelihood ratio and 0.8 (95% CI 0.7-1.0) negative likelihood ratio for probable CAA (vs non-probable CAA), defined by the modified Boston criteria; the area under the receiver operating characteristic curve (AUROC) was 0.62 (95% CI: 0.54-0.71).

CONCLUSION

In lobar ICH survivors, we found associations between putative biomarkers of parenchymal CAA (FLP and strictly lobar CMBs) and putative biomarkers of leptomeningeal CAA (SAE and cSS). In a hospital population, CT biomarkers might help rule-in probable CAA (diagnosed using the Boston criteria), but their absence is probably not as useful to rule it out, suggesting an important continued role for MRI in ICH survivors with suspected CAA.

The prognostic value of the Charlson comorbidity index in aged patients with intracerebral hemorrhage

BACKGROUND

Comorbidities are common in aged intracerebral hemorrhage patients. The purpose of this study was to assess whether the Charlson Comorbidity Index (CCI) was associated with in-hospital death and short-term functional outcome in elderly patients (age ≥ 70) with intracerebral hemorrhage (ICH).

METHODS

This was a retrospective cohort of aged ICH patients (≥70 years old) admitted within 24 hours of ICH onset. The CCI was derived using hospital discharge ICD-9 CM codes and patient history obtained from standardized case report forms. Multivariable logistic regression was used to determine the independent effect of the CCI score on clinical outcomes.

RESULTS

In this cohort of 248 aged ICH patients, comorbid conditions were common, with CCI scores ranging from 2 to 12. Logistic regression showed that the CCI score was independently predictive of 1-month functional outcome (OR = 1.642, P < 0.001) and in-hospital death (OR = 1.480, P = 0.003). Neither ICH volume nor the presence of IVH was an independent predictive factor for 1-month functional outcome or in-hospital mortality (P < 0.05).

CONCLUSION

Comorbid medical conditions as assessed by the CCI independently influence short-term outcomes in aged ICH patients. The characteristics of the hematoma itself, such as ICH volume and the presence of IVH, seem to have a reduced effect on it.

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.

Simplified Edinburgh and modified Boston criteria in relation to amyloid PET for lobar intracerebral hemorrhage

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Amyloid PET was positive in 63% of patients with lobar ICH.

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Simplified Edinburgh criteria and amyloid PET have similar accuracy vs Boston criteria.

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Simplified Edinburgh and Boston criteria have similar accuracy vs amyloid PET.

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Amyloid PET could assist in diagnosing CAA.

Background

Histopathological evidence of cerebral vascular amyloid β accumulation is the gold standard to diagnose cerebral amyloid angiopathy (CAA). Neuroimaging findings obtained with CT and MRI can suggest the presence of CAA when histopathology is lacking. We explored the role of amyloid PET in patients with lobar intracerebral hemorrhage (ICH) as this may provide molecular evidence for CAA as well.

Methods

In this retrospective, monocenter analysis, we included consecutive patients with non-traumatic lobar ICH who had undergone amyloid PET. We categorized patients according to amyloid PET status and compared demographics and neuroimaging findings. We calculated sensitivity and specificity of the simplified Edinburgh criteria and amyloid PET with probable modified Boston criteria as reference standard, as well as sensitivity and specificity of the simplified Edinburgh and modified Boston criteria with amyloid PET status as molecular marker for presence or absence of CAA.

Results

We included 38 patients of whom 24 (63%) were amyloid PET positive. Amyloid PET positive patients were older at presentation (p = 0.004). We observed no difference in prevalence of subarachnoid hemorrhages, fingerlike projections or microbleeds between both groups, but cortical superficial siderosis (p = 0.003) was more frequent in the amyloid PET positive group. In 5 out of 38 patients (13%), the modified Boston criteria were not fulfilled due to young age or concomitant vitamin K antagonist use with INR > 3.0. With the modified Boston criteria as reference standard, there was no difference in sensitivity nor specificity between the simplified Edinburgh criteria and amyloid PET status. With amyloid PET status as reference standard, there was also no difference in sensitivity nor specificity between the simplified Edinburgh and modified Boston criteria.

Conclusions

Amyloid PET was positive in 63% of lobar ICH patients. Under certain circumstances, patients might not be diagnosed with probable CAA according to the modified Boston criteria and in these cases, amyloid PET may be useful. Accuracy to predict CAA based on amyloid PET status did not differ between the simplified Edinburgh and modified Boston criteria.

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.