Iatrogenic cerebral amyloid angiopathy: A multinational case series and individual patient data analysis of the literature

BACKGROUND

The transmission of amyloid β (Aβ) in humans leading to iatrogenic cerebral amyloid angiopathy (iCAA) is a novel concept with analogies to prion diseases. However, the number of published cases is low, and larger international studies are missing.

AIMS

We aimed to build a large multinational collaboration on iCAA to better understand the clinical spectrum of affected patients.

METHODS

We collected clinical data on patients with iCAA from Austria, Croatia, Italy, Slovenia, and Spain. Patients were included if they met the proposed Queen Square diagnostic criteria (QSC) for iCAA. In addition, we pooled data on disease onset, latency, and cerebrospinal fluid (CSF) biomarkers from previously published iCAA cases based on a systematic literature review.

RESULTS

Twenty-seven patients (22% women) were included in this study. Of these, 19 (70%) met the criteria for probable and 8 (30%) for possible iCAA. Prior neurosurgical procedures were performed in all patients (93% brain surgery, 7% spinal surgery) at median age of 8 (interquartile range (IQR) = 4-18, range = 0-26 years) years. The median symptom latency was 39 years (IQR = 34-41, range = 28-49). The median age at symptom onset was 49 years (IQR = 43-55, range = 32-70). Twenty-one patients (78%) presented with intracranial hemorrhage and 3 (11%) with seizures.

CONCLUSIONS

Our large international case series of patients with iCAA confirms a wide age boundary for the diagnosis of iCAA. Dissemination of awareness of this rare condition will help to identify more affected patients.

Aβ38 and Aβ43 do not differentiate between Alzheimer's disease and cerebral amyloid angiopathy

Differential diagnosis between Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA) using cerebrospinal fluid (CSF) biomarkers is challenging. A recent study suggested that the addition of Aβ38 and Aβ43 to a standard AD biomarker panel (Aβ40, Aβ42, t-tau, p-tau) to improve the differential diagnosis. We tested this hypothesis in an independent German cohort of CAA and AD patients and controls using the same analytical techniques. We found excellent discrimination between AD and controls and between CAA and controls, but not between AD and CAA. Adding Aβ38 and Aβ43 to the panel did not improve the discrimination between AD and CAA.

Identifying diagnostic and prognostic factors in cerebral amyloid angiopathy-related inflammation: A systematic analysis of published and seven new cases

AIMS

Cerebral amyloid angiopathy (CAA)-related inflammation (CAA-RI) is a potentially reversible manifestation of CAA, histopathologically characterised by transmural and/or perivascular inflammatory infiltrates. We aimed to identify clinical, radiological and laboratory variables capable of improving or supporting the diagnosis of or predicting/influencing the prognosis of CAA-RI and to retrospectively evaluate different therapeutic approaches.

METHODS

We present clinical and neuroradiological observations in seven unpublished CAA-RI cases, including neuropathological findings in two definite cases. These cases were included in a systematic analysis of probable/definite CAA-RI cases published in the literature up to 31 December 2021. Descriptive and associative analyses were performed, including a set of clinical, radiological and laboratory variables to predict short-term, 6-month and 1-year outcomes and mortality, first on definite and second on an expanded probable/definite CAA-RI cohort.

RESULTS

Data on 205 definite and 100 probable cases were analysed. CAA-RI had a younger symptomatic onset than non-inflammatory CAA, without sex preference. Transmural histology was more likely to be associated with the co-localisation of microbleeds with confluent white matter hyperintensities on magnetic resonance imaging (MRI). Incorporating leptomeningeal enhancement and/or sulcal non-nulling on fluid-attenuated inversion recovery (FLAIR) enhanced the sensitivity of the criteria. Cerebrospinal fluid pleocytosis was associated with a decreased probability of clinical improvement and longer term positive outcomes. Future lobar haemorrhage was associated with adverse outcomes, including mortality. Immunosuppression was associated with short-term improvement, with less clear effects on long-term outcomes. The superiority of high-dose over low-dose corticosteroids was not established.

CONCLUSIONS

This is the largest retrospective associative analysis of published CAA-RI cases and the first to include an expanded probable/definite cohort to identify diagnostic/prognostic markers. We propose points for further crystallisation of the criteria and directions for future prospective studies.

Comparative methods for quantifying plasma biomarkers in Alzheimer's disease: Implications for the next frontier in cerebral amyloid angiopathy diagnostics

Plasma amyloid beta (Aβ) and tau are emerging as accessible biomarkers for Alzheimer's disease (AD). However, many assays exist with variable test performances, highlighting the need for a comparative assessment to identify the most valid assays for future use in AD and to apply to other settings in which the same biomarkers may be useful, namely, cerebral amyloid angiopathy (CAA). CAA is a progressive cerebrovascular disease characterized by deposition of Aβ40 and Aβ42 in cortical and leptomeningeal vessels. Novel immunotherapies for AD can induce amyloid-related imaging abnormalities resembling CAA-related inflammation. Few studies have evaluated plasma biomarkers in CAA. Identifying a CAA signature could facilitate diagnosis, prognosis, and a safer selection of patients with AD for emerging immunotherapies. This review evaluates studies that compare the diagnostic test performance of plasma biomarker techniques in AD and cerebrovascular and plasma biomarker profiles of CAA; it also discusses novel hypotheses and future avenues for plasma biomarker research in CAA.

[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.

Cerebral amyloid angiopathy: Neuropathological diagnosis, link to Alzheimer's disease and impact on clinics

Cerebral amyloid angiopathy (CAA) is the most frequent cause of lobar hemorrhages in the brains of elderly individuals. It is characterized by the deposition of amyloidogenic proteins in the vessel wall of leptomeningeal and/or intracerebral blood vessels. Different proteins can cause CAA. Most frequently, the amyloid β protein (Aβ) is found to be deposited in CAA and indicates a link to Alzheimer's disease, because Aβ is known to be deposited in amyloid plaques characteristic of Alzheimer's disease. Among other proteins that can also cause CAA, transthyretin (TTR) is the most important one because TTR amyloidosis can be successfully treated. Therefore, it is essential to diagnose TTR-related CAA even in biopsies taken in the context of cerebral hematoma evacuations if possible. The current "Boston criteria version 2.0" for the diagnosis of CAA highlight the importance of autopsy for the definite diagnosis of CAA and biopsies for the diagnosis of probable CAA. Here, we discuss the implications of Aβ-related and non-Aβ-related forms of CAA for their current diagnostic relevance also in the context of neurodegenerative diseases as well as the implications of the Boston criteria version 2.0 for neuropathological diagnosis.

A 53-year-old woman with a rapidly progressive, non-enhancing left frontotemporal lesion

Fifty-three-year-old woman presented with chronic, episodic headache.

Cerebral Amyloid Angiopathy-How to Translate Updated Diagnostic Criteria for This Multifaceted Disorder to Clinical Practice?

This Viewpoint discusses recent efforts to update diagnostic criteria for cerebral amyloid angiopathy as well as questions and challenges in counseling patients about prognosis and deciding on optimal treatment.

Reversible Periventricular Hyperintensity Lesions in Cerebral Amyloid Angiopathy: A Case Mimicking Cerebral Amyloid Angiopathy-related Inflammation

A 59-year-old man with progressive cognitive decline and mood disturbances was admitted to the hospital. Brain magnetic resonance imaging revealed marked white matter hyperintensity (WMH) and widespread lobar cerebral microbleeds. Because he had untreated hypertension, we started antihypertensive treatment and found a significantly improved cognitive function and WMH regression. We diagnosed him with cerebral amyloid angiopathy (CAA) based on the modified Boston Criteria with the rare apolipoprotein E (ApoE) ε2/ε4 genotype. The mechanism underlying reversible leukoencephalopathy in CAA may be related to the loss of autoregulation of brain circulation: cerebrovascular amyloid β deposits damaged the blood-brain barrier of the capillaries, which led to vasogenic edema induced by blood pressure surges.

PSEN1 Compound Heterozygous Mutations Associated with Cerebral Amyloid Angiopathy and Cognitive Decline Phenotype

Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder caused by the deposition of amyloid beta-peptide (Aβ) aggregates. Aβ aggregates lead to vessel rupture and intracerebral hemorrhages, detected by magnetic resonance imaging (MRI). Presenile CAA is usually genetically determined by mutations in the amyloid precursor protein (APP) gene. However, mutations after codon 200 in the presenilin 1 (PSEN1) gene have been reported to facilitate CAA onset. Here, we analyzed the genetic bases in a patient of 55 years old affected by CAA and cognitive decline. DNA was isolated and genetic analysis was performed by Next-Generation Sequencing (NGS). RNA was extracted and retro-transcribed to perform segregation analysis by TOPO-TA cloning. WB analysis was carried out to check the impact of the mutations on protein. Two compound heterozygous mutations in PSEN1 exon 10, such as a novel stop-gain mutation (c.1070C > G) and a pathogenic splice variant (c.1129A > T), were found by NGS. Both mutations altered the presenilin 1 protein, truncating its C-terminal portion. This is the first case of CAA and cognitive decline caused by two compound mutations in PSEN1. With this report, we suggest extending the genetic analysis to PSEN1 when cerebral microbleeds are observed by MRI investigation in a patient affected by presenile cognitive decline.

Current Management and Therapeutic Strategies for Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is characterized by accumulation of amyloid β (Aβ) in walls of leptomeningeal vessels and cortical capillaries in the brain. The loss of integrity of these vessels caused by cerebrovascular Aβ deposits results in fragile vessels and lobar intracerebral hemorrhages. CAA also manifests with progressive cognitive impairment or transient focal neurological symptoms. Although development of therapeutics for CAA is urgently needed, the pathogenesis of CAA remains to be fully elucidated. In this review, we summarize the epidemiology, pathology, clinical and radiological features, and perspectives for future research directions in CAA therapeutics. Recent advances in mass spectrometric methodology combined with vascular isolation techniques have aided understanding of the cerebrovascular proteome. In this paper, we describe several potential key CAA-associated molecules that have been identified by proteomic analyses (apolipoprotein E, clusterin, SRPX1 (sushi repeat-containing protein X-linked 1), TIMP3 (tissue inhibitor of metalloproteinases 3), and HTRA1 (HtrA serine peptidase 1)), and their pivotal roles in Aβ cytotoxicity, Aβ fibril formation, and vessel wall remodeling. Understanding the interactions between cerebrovascular Aβ deposits and molecules that accumulate with Aβ may lead to discovery of effective CAA therapeutics and to the identification of biomarkers for early diagnosis.

[Cerebral amyloid angiopathy: an easily missed diagnosis in patients with transient neurological deficits]

Cerebral amyloid angiopathy (CAA) is a degenerative neurovascular disease in which the protein amyloid-beta accumulates in the vessel wall of cortical and leptomeningeal arteries. This may lead to acute lobar cerebral haemorrhage, which in case of CAA is fatal in 10-30% of cases. CAA may also present with transient focal neurological episodes (TFNE), the symptoms of which may mimic a transient ischaemic attack (TIA). Distinction between the two has important implications for therapy, as antithrombotics are relatively contra-indicated in CAA, but indicated after a TIA. We describe a patient with transient focal neurological deficits who was initially treated with antithrombotic therapy for a suspected TIA. Eventually, the diagnosis CAA was made and antithrombotic treatment was ceased. This case stresses the importance of considering the diagnosis CAA with TFNE in patients presenting with transient neurological deficits, in order to avoid an unnecessarily increased risk of symptomatic and possibly fatal cerebral haemorrhage.

Prediction of amyloid β PET positivity using machine learning in patients with suspected cerebral amyloid angiopathy markers

Amyloid-β(Aβ) PET positivity in patients with suspected cerebral amyloid angiopathy (CAA) MRI markers is predictive of a worse cognitive trajectory, and it provides insights into the underlying vascular pathology (CAA vs. hypertensive angiopathy) to facilitate prognostic prediction and appropriate treatment decisions. In this study, we applied two interpretable machine learning algorithms, gradient boosting machine (GBM) and random forest (RF), to predict Aβ PET positivity in patients with CAA MRI markers. In the GBM algorithm, the number of lobar cerebral microbleeds (CMBs), deep CMBs, lacunes, CMBs in dentate nuclei, and age were ranked as the most influential to predict Aβ positivity. In the RF algorithm, the absence of diabetes was additionally chosen. Cut-off values of the above variables predictive of Aβ positivity were as follows: (1) the number of lobar CMBs > 16.4(GBM)/14.3(RF), (2) no deep CMBs(GBM/RF), (3) the number of lacunes > 7.4(GBM/RF), (4) age > 74.3(GBM)/64(RF), (5) no CMBs in dentate nucleus(GBM/RF). The classification performances based on the area under the receiver operating characteristic curve were 0.83 in GBM and 0.80 in RF. Our study demonstrates the utility of interpretable machine learning in the clinical setting by quantifying the relative importance and cutoff values of predictive variables for Aβ positivity in patients with suspected CAA markers.

CNS vasculopathies: Challenging mimickers of primary angiitis of the central nervous system

Primary angiitis of the central nervous system (CNS) is an inflammatory vasculopathy affecting the brain and spinal cord. It is a difficult diagnosis to make because of its insidious nonspecific course and its multiple mimics. This review identifies and discusses some noninfectious mimickers of primary CNS angiitis, including: reversible cerebral vasoconstriction syndrome, Sneddon's Syndrome, amyloid-beta-related angiopathy, Susac Syndrome, and neurosarcoidosis. Each condition will be reviewed in terms of epidemiology, pathology, clinical presentation, diagnostic approach, and treatment. Distinguishing these mimics from the primary angiitis of the CNS is important for proper treatment and prognosis.

Histopathology of diffusion-weighted imaging-positive lesions in cerebral amyloid angiopathy

Small subclinical hyperintense lesions are frequently encountered on brain diffusion-weighted imaging (DWI) scans of patients with cerebral amyloid angiopathy (CAA). Interpretation of these DWI+ lesions, however, has been limited by absence of histopathological examination. We aimed to determine whether DWI+ lesions represent acute microinfarcts on histopathology in brains with advanced CAA, using a combined in vivo MRI-ex vivo MRI-histopathology approach. We first investigated the histopathology of a punctate cortical DWI+ lesion observed on clinical in vivo MRI 7 days prior to death in a CAA case. Subsequently, we assessed the use of ex vivo DWI to identify similar punctate cortical lesions post-mortem. Intact formalin-fixed hemispheres of 12 consecutive cases with CAA and three non-CAA controls were subjected to high-resolution 3 T ex vivo DWI and T2 imaging. Small cortical lesions were classified as either DWI+/T2+ or DWI-/T2+. A representative subset of lesions from three CAA cases was selected for detailed histopathological examination. The DWI+ lesion observed on in vivo MRI could be matched to an area with evidence of recent ischemia on histopathology. Ex vivo MRI of the intact hemispheres revealed a total of 130 DWI+/T2+ lesions in 10/12 CAA cases, but none in controls (p = 0.022). DWI+/T2+ lesions examined histopathologically proved to be acute microinfarcts (classification accuracy 100%), characterized by presence of eosinophilic neurons on hematoxylin and eosin and absence of reactive astrocytes on glial fibrillary acidic protein-stained sections. In conclusion, we suggest that small DWI+ lesions in CAA represent acute microinfarcts. Furthermore, our findings support the use of ex vivo DWI as a method to detect acute microinfarcts post-mortem, which may benefit future histopathological investigations on the etiology of microinfarcts.

Cerebral Amyloid Angiopathy, Alzheimer's Disease and MicroRNA: miRNA as Diagnostic Biomarkers and Potential Therapeutic Targets

The protein molecules must fold into unique conformations to acquire functional activity. Misfolding, aggregation, and deposition of proteins in diverse organs, the so-called "protein misfolding disorders (PMDs)", represent the conformational diseases with highly ordered assemblies, including oligomers and fibrils that are linked to neurodegeneration in brain illnesses such as cerebral amyloid angiopathy (CAA) and Alzheimer's disease (AD). Recent studies have revealed several aspects of brain pathology in CAA and AD, but both the classification and underlying mechanisms need to be further refined. MicroRNAs (miRNAs) are critical regulators of gene expression at the post-transcriptional level. Increasing evidence with the advent of RNA sequencing technology suggests possible links between miRNAs and these neurodegenerative disorders. To provide insights on the small RNA-mediated regulatory circuitry and the translational significance of miRNAs in PMDs, this review will discuss the characteristics and mechanisms of the diseases and summarize circulating or tissue-resident miRNAs associated with AD and CAA.

Down syndrome, Alzheimer disease, and cerebral amyloid angiopathy: The complex triangle of brain amyloidosis

Down syndrome (DS) is the main genetic cause of intellectual disability worldwide. The overexpression of the Amyloid Precursor Protein, present in chromosome 21, leads to β-amyloid deposition that results in Alzheimer disease (AD) and, in most cases, also to cerebral amyloid angiopathy (CAA) neuropathology. People with DS invariably develop the neuropathological hallmarks of AD at the age of 40, and they are at an ultra high risk for suffering AD-related cognitive impairment thereafter. In the general population, cerebrovascular disease is a significant contributor to AD-related cognitive impairment, while in DS remains understudied. This review describes the current knowledge on cerebrovascular disease in DS and reviews the potential biomarkers that could be useful in the future studies, focusing on CAA. We also discuss available evidence on sporadic AD or other genetically determined forms of AD. We highlight the urgent need of large biomarker-characterized cohorts, including neuropathological correlations, to study the exact contribution of CAA and related vascular factors that play a role in cognition and occur with aging, their characterization and interrelationships. DS represents a unique context in which to perform these studies as this population is relatively protected from some conventional vascular risk factors and they develop significant CAA, DS represents a particular atheroma-free model to study AD-related vascular pathologies. Only deepening on these underlying mechanisms, new preventive and therapeutic strategies could be designed to improve the quality of life of this population and their caregivers and lead to new avenues of treatment also in the general AD population.

[A Case of Cerebral Amyloid Angiopathy-related Subarachnoid Hemorrhage with Parkinson Disease Dementia]

We report a case of cerebral amyloid angiopathy(CAA)-related subarachnoid hemorrhage(SAH)with Parkinson's disease dementia(PDD), along with a literature review. CASE: A 67-year-old woman with a history of Parkinson's disease was diagnosed with SAH(World Federation of Neurosurgical Societies grade I). The plain head CT performed on admission, revealed an atypical hematoma distribution. Blood sampling, MRI and cerebral angiography revealed no vascular abnormalities, meningitis, encephalitis, or primary angiitis of the central nervous system. MRI performed on the third day after admission confirmed the presence of bilateral cortical or subcortical hemorrhage in the parietal lobe, with amyloid-related imaging abnormalities. A preliminary diagnosis of CAA was made, based on the Boston criteria. She was also diagnosed with PDD, based on the cognitive decline during hospitalization. CONCLUSION: Stroke related with CAA, as seen in SAH, may contribute to cognitive decline and the progression of lesions in PDD.

[SPONTANEOUS PARENCHYMAL INTRACRANIAL HEMORRHAGE - A DIAGNOSTIC CHALLENGE]

Non-traumatic intracranial hemorrhage (ICH) is a devastating event associated with a high rate of morbidity and mortality. Patient age, hemorrhage location, number of foci, and underlying diseases are important clues to the etiology. Non-contrast head CT, given its availability and high sensitivity in detecting blood products, is frequently the first tool to readily detect ICH; however, different types of hemorrhages may share a common appearance on CT and the optimal therapeutic approach varies depending on etiology. An additional diagnostic work-up is frequently indicated to make the final diagnosis and to assist in urgent patient management. CT- and MR angiography, and digital angiography can diagnose vascular anomalies, CT venography can reveal cerebral vein thrombosis, diffusion-weighted MRI (DWI) may show hemorrhagic transformation of an infarct, and susceptibility-weighted MRI (SWI) may detect hypertensive and amyloid angiopathy-related microbleeds. MR also has a major role in revealing underlying etiologies such as cavernoma, primary brain tumor or metastases. These imaging tools assist in determining the cause of ICH, and also in assessing the risk of deterioration. Prognostic factors such as size, location, mass effect, and detection of the "spot sign" all play an important role in foreseeing possible deterioration, thus allowing prompt intervention. This study will present cases of intraparenchymal hemorrhage from different etiologies in patients who presented to the Hadassah-Hebrew University Medical Center, with the goal of illustrating the role of imaging in patient management and decision-making.

The Edinburgh CT and genetic diagnostic criteria for lobar intracerebral haemorrhage associated with cerebral amyloid angiopathy: model development and diagnostic test accuracy study

BACKGROUND

Identification of lobar spontaneous intracerebral haemorrhage associated with cerebral amyloid angiopathy (CAA) is important because it is associated with a higher risk of recurrent intracerebral haemorrhage than arteriolosclerosis-associated intracerebral haemorrhage. We aimed to develop a prediction model for the identification of CAA-associated lobar intracerebral haemorrhage using CT features and genotype.

METHODS

We identified adults with first-ever intracerebral haemorrhage diagnosed by CT, who died and underwent research autopsy as part of the Lothian IntraCerebral Haemorrhage, Pathology, Imaging and Neurological Outcome (LINCHPIN) study, a prospective, population-based, inception cohort. We determined APOE genotype and radiologists rated CT imaging appearances. Radiologists were not aware of clinical, genetic, and histopathological features. A neuropathologist rated brain tissue for small vessel diseases, including CAA, and was masked to clinical, radiographic, and genetic features. We used CT and APOE genotype data in a logistic regression model, which we internally validated using bootstrapping, to predict the risk of CAA-associated lobar intracerebral haemorrhage, derive diagnostic criteria, and estimate diagnostic accuracy.

FINDINGS

Among 110 adults (median age 83 years [IQR 76-87], 49 [45%] men) included in the LINCHPIN study between June 1, 2010 and Feb 10, 2016, intracerebral haemorrhage was lobar in 62 (56%) participants, deep in 41 (37%), and infratentorial in seven (6%). Of the 62 participants with lobar intracerebral haemorrhage, 36 (58%) were associated with moderate or severe CAA compared with 26 (42%) that were associated with absent or mild CAA, and were independently associated with subarachnoid haemorrhage (32 [89%] of 36 vs 11 [42%] of 26; p=0·014), intracerebral haemorrhage with finger-like projections (14 [39%] of 36 vs 0; p=0·043), and APOE ɛ4 possession (18 [50%] of 36 vs 2 [8%] of 26; p=0·0020). A prediction model for CAA-associated lobar intracerebral haemorrhage using these three variables had excellent discrimination (c statistic 0·92, 95% CI 0·86-0·98), confirmed by internal validation. For the rule-out criteria, neither subarachnoid haemorrhage nor APOE ɛ4 possession had 100% sensitivity (95% CI 88-100). For the rule-in criteria, subarachnoid haemorrhage and either APOE ɛ4 possession or finger-like projections had 96% specificity (95% CI 78-100).

INTERPRETATION

The CT and APOE genotype prediction model for CAA-associated lobar intracerebral haemorrhage shows excellent discrimination in this cohort, but requires external validation. The Edinburgh rule-in and rule-out diagnostic criteria might inform prognostic and therapeutic decisions that depend on identification of CAA-associated lobar intracerebral haemorrhage.

FUNDING

UK Medical Research Council, The Stroke Association, and The Wellcome Trust.

Imaging features of intracerebral hemorrhage with cerebral amyloid angiopathy: Systematic review and meta-analysis

BACKGROUND

We sought to summarize Computed Tomography (CT)/Magnetic Resonance Imaging (MRI) features of intracerebral hemorrhage (ICH) associated with cerebral amyloid angiopathy (CAA) in published observational radio-pathological studies.

METHODS

In November 2016, two authors searched OVID Medline (1946-), Embase (1974-) and relevant bibliographies for studies of imaging features of lobar or cerebellar ICH with pathologically proven CAA ("CAA-associated ICH"). Two authors assessed studies' diagnostic test accuracy methodology and independently extracted data.

RESULTS

We identified 22 studies (21 cases series and one cross-sectional study with controls) of CT features in 297 adults, two cross-sectional studies of MRI features in 81 adults and one study which reported both CT and MRI features in 22 adults. Methods of CAA assessment varied, and rating of imaging features was not masked to pathology. The most frequently reported CT features of CAA-associated ICH in 21 case series were: subarachnoid extension (pooled proportion 82%, 95% CI 69-93%, I2 = 51%, 12 studies) and an irregular ICH border (64%, 95% CI 32-91%, I2 = 85%, five studies). CAA-associated ICH was more likely to be multiple on CT than non-CAA ICH in one cross-sectional study (CAA-associated ICH 7/41 vs. non-CAA ICH 0/42; χ2 = 7.8, p = 0.005). Superficial siderosis on MRI was present in 52% of CAA-associated ICH (95% CI 39-65%, I2 = 35%, 3 studies).

CONCLUSIONS

Subarachnoid extension and an irregular ICH border are common imaging features of CAA-associated ICH, but methodologically rigorous diagnostic test accuracy studies are required to determine the sensitivity and specificity of these features.

[Not Available]

Zusammenfassung. Zerebrale Mikroangiopathien umfassen eine Gruppe neuropathologischer Prozesse, die die kleinen Perforationsarterien, Arteriolen und Kapillaren beeinflussen. Neuroimaging-Merkmale der Einengung der kleinen Koronararterienäste (Small Vessel Disease) sind ischämische und hämorrhagische Marker: jüngster kleiner subkortikaler Infarkt, Lakune vermuteten vaskulären Ursprungs, Hyperintensität der weissen Masse, perivaskuläre Räume, zerebrale Mikroblutungen, Hirnatrophie, kortikale oberflächliche Siderose und akute subarachnoidale Blutungen. Diese Läsionen gelten als der Hauptrisikofaktor der vaskulären kognitiven Störungen. Die zerebrale Mikroangiopathie wird typischerweise in zwei Hauptformen kategorisiert: die nicht-amyloide Angiopathie, die auch als «hypertensive Arteriopathie» bezeichnet wird, die oft mit fortgeschrittenem Alter und vaskulären Risikofaktoren und der zerebralen Amyloidangiopathie zusammenhängt. Die zerebrale Amyloidangiopathie ist klinisch charakterisiert durch kognitive Beeinträchtigungen, intrazerebrale Blutungen und durch transiente Episoden fokal-neurologischer Defizite aufgrund von Subarachnoidalblutungen.

Rapidly Sequential and Fatal Hemorrhaging in a Case of Cerebral Amyloid Angiopathy

BACKGROUND Cerebral amyloid angiopathy (CAA) is an increasingly recognized cause of lobar intracerebral hemorrhage (ICH) and cognitive impairment in the aging population. Magnetic resonance imaging (MRI) of cerebral microbleeds is the most reliable option for clinical diagnosis of suspected CAA. The pathophysiology of microbleeds and ICH in CAA is not well understood, but it is thought to be the result of vessel weakening and rupture secondary to amyloid deposition. Little evidence has been established pertaining to the time course of recurrent CAA-related microbleeds or larger hemorrhages. Although several risk factors have been associated with an increased risk of ICH in CAA, there are no current treatment guidelines for recurrent hemorrhaging in CAA. CASE REPORT We present a rare case of rapidly sequential and fatal lobar hemorrhaging in the setting of suspected CAA, diagnosed by numerous microbleeds on MRI, compounded by the use of subcutaneous heparin in a 63-year-old female patient. CONCLUSIONS This case broadens our understanding of a rarely identified progression of CAA and illustrates the need for further investigation of the use of subcutaneous heparin in the setting of probable CAA.

Dura mater is a potential source of Aβ seeds

Deposition of amyloid-β (Aβ) in the brain parenchyma and vessels is one of the hallmarks of Alzheimer disease (AD). Recent observations of Aβ deposition in iatrogenic Creutzfeldt-Jakob disease (iCJD) after dural grafting or treatment with pituitary extracts raised concerns whether Aβ is capable of transmitting disease as seen in prion diseases by the disease-associated prion protein. To address this issue, we re-sampled and re-evaluated archival material, including the grafted dura mater of two cases with iCJD (28 and 33-years-old) without mutations in the AβPP, PSEN1 and PSEN2 genes, and carrying ε3/ε3 alleles of the APOE gene. In addition, we evaluated 84 dura mater samples obtained at autopsy (mean age 84.9 ± 0.3) in the community-based VITA study for the presence of Aβ deposition. We show that the dura mater may harbor Aβ deposits (13 %) in the form of cerebral amyloid angiopathy or amorphous aggregates. In both iCJD cases, the grafted dura mater had accumulated Aβ. The morphology and distribution pattern of cerebral Aβ deposition together with the lack of tau pathology distinguishes the Aβ proteinopathy in iCJD from AD, from that seen in young individuals without cognitive decline carrying one or two APOE4 alleles, and from that related to traumatic brain injury. Our novel findings of Aβ deposits in the dura mater, including the grafted dura, and the distinct cerebral Aβ distribution in iCJD support the seeding properties of Aβ. However, in contrast to prion diseases, our study suggests that such Aβ seeding is unable to reproduce the full clinicopathological phenotype of AD.

Cerebral Microbleeds: Detection, Associations and Clinical Implications

Vigorous investigations for cerebral microbleeds (CMBs) have been made since the late 1990s. CMBs on paramagnetic-sensitive magnetic resonance sequences correspond pathologically to clusters of hemosiderin-laden macrophages and have emerged as an important new imaging marker of cerebral small vessel disease, including intracerebral hemorrhage (ICH). The prevalence of CMBs varies according to the specific disease settings (stroke subtypes and dementing disorders) and is highest (60%) in ICH patients. The associations of CMBs with aging, hypertension and apolipoprotein E genotype are consistent with the two major underlying pathogeneses of CMBs: hypertensive arteriopathy and cerebral amyloid angiopathy (CAA). The distributional patterns of CMBs might help us to understand the predominant small vessel disease pathogenesis in the brain; the strictly lobar type of CMBs often reflects the presence of advanced CAA, while the other types of CMBs, such as 'deep or infratentorial CMBs', including the mixed type, are strongly associated with hypertension. CMBs might be associated with cognitive function (especially executive function), gait performance, and cerebrovascular events (spontaneous, antithrombotic drug-related or post-thrombolysis ICH). In the field of CAA, an understanding of CAA-related CMBs might help to guide decision making with regard to new therapeutic approaches, including the use of monoclonal antibodies against vascular amyloid. These concepts of CMBs might allow us to advance research on ICH as well as for dementia.

Prognosis and Outcome of Intracerebral Haemorrhage

Spontaneous intracerebral haemorrhage (ICH) accounts for approximately 15% of all strokes and is a leading cause of disability, with a one-month mortality rate of 40%. Whereas factors predicting short-term mortality are well known, data regarding long-term outcome are scarce and imprecise. The two main underlying vasculopathies responsible for ICH, i.e. deep perforating vasculopathy and cerebral amyloid angiopathy, might have an impact on the overall prognosis of ICH survivors. ICH survivors are at high risk of epileptic seizures, depression and cognitive impairment, which may influence their functional outcome. Lobar location of an ICH, frequently due to cerebral amyloid angiopathy, partly determines the long-term risk of recurrent haemorrhage. Because of common vascular risk factors, patients with ICH are also at considerable risk of serious ischaemic events. Risks of future ischaemic events may be as high as that of recurrent ICH, raising the relevance of antithrombotic treatment in ICH survivors. Future studies of long-term follow-up after ICH are needed to determine predictors of outcome, including biomarkers of the underlying vasculopathies, to tailor preventive strategies to survivors.

Concordance between 11C-PIB-PET and clinical diagnosis in a memory clinic

INTRODUCTION

Today, ligands that bind to fibrillar β-amyloid are detectable by Positron Emission Tomography (PET) allowing for in vivo visualization for Abeta burden. However, amyloid plaques detection per se does not establish Alzheimer's Disease diagnosis. In this sense, the utility of amyloid imaging to improve clinical diagnosis was settled only for specific clinical scenarios and few studies have assessed amyloid molecular neuroimaging in a broader clinical setting. The aim of this study is to determine the frequency of PiB amyloid findings in different diagnostic syndromes grouped into high and low probability pre- test categories, taking into account pre-test clinical assumption of the presence of AD related pathology.

METHODS

144 patients were assigned into categories of high or low pretest probability according to clinical suspicion of AD pathology. The high probability group included: amnestic Mild Cognitive Impairment (MCI), amnestic and other domains MCI, Dementia of Alzheimer's Type (DAT), Posterior Cortical Atrophy (PCA), logopenic Primary Progressive Aphasia (PPA), Cerebral Amyloid Angiopathy and mixed dementia. The low assumption group included: normal controls, non-amnestic MCI, non-logopenic PPA and Frontotemporal Dementia (FTD).

RESULTS

Only normal controls and DAT patients (typical and atypical presentation) were the most consistent across clinical and molecular diagnostics. MCI, non-logopenic PPA and FTD were the syndromic diagnoses that most discrepancies were found.

DISCUSSION

This study demonstrates that detecting in vivo amyloid plaques by molecular imaging is considerably frequent in most of the dementia syndromes and shows that there are frequent discordance between molecular diagnosis and clinical assumption.

Cerebral Amyloid Angiopathy with Angiitis: Emerging Options for Treatment

Two cases of cerebral amyloid angiopathy with features of angiitis are reported. The role of immunosuppressive therapy is reviewed.

[Diffuse superficial siderosis of the central nervous system: four case reports and review of the literature]

INTRODUCTION

Diffuse superficial siderosis of the central nervous system (CNS) is a rare condition due to hemosiderin deposits in the subpial layers of the brain and spinal cord. The source of chronic or recurrent bleeding into the subarachnoid space is detected in only 50 % of cases. The most characteristic symptoms are cerebellar ataxia and sensorineural hearing impairment. T2-weighted gradient echo magnetic resonance imaging constitutes the diagnostic method of choice.

CASE REPORTS

We report four patients of diffuse superficial siderosis of the CNS associated to cerebral amyloid angiopathy, oral anticoagulation, schwannoma VIII, and without known source of bleeding in one case. Two patients developed cerebellar ataxia, three of them present transient focal neurological episodes, one dementia and, the last one, the diffuse superficial siderosis of the CNS is a radiological finding. No clinical progression was observed during follow-up (2-11 years) in three of them. The patient with cerebral amyloid angiopathy progresses to dementia.

CONCLUSIONS

Transient focal neurological episodes were the most common symptom in our cases of diffuse superficial siderosis of the CNS. The natural history of this condition is not very known and may be regarded as a radiological finding.

Cerebral amyloid angiopathy: a transient ischaemic attack mimic

Cerebral amyloid angiopathy is a commonly occurring condition that is not familiar to most clinicians. A common presenting feature may be transient focal neurological symptoms leading to the potential for clinical misdiagnosis as transient ischaemic attack. This may result in the inappropriate use of anti-platelets and anticoagulants or radiological misdiagnosis. It is also being increasingly recognised as an important cause of spontaneous intracerebral haemorrhage and cognitive impairment in the elderly. Cerebral amyloid angiopathy can be diagnosed based on clinical and radiological findings, but clinicians need a high index of suspicion to ensure appropriate investigations are requested. In this article we aim to cover the pathophysiology, clinical findings, radiological appearances and approach to management of cerebral amyloid angiopathy.

Synergistic effects of ischemia and β-amyloid burden on cognitive decline in patients with subcortical vascular mild cognitive impairment

IMPORTANCE

Cerebrovascular disease (CVD) and Alzheimer disease are significant causes of cognitive impairment in the elderly. However, few studies have evaluated the relationship between CVD and β-amyloid burden in living humans or their synergistic effects on cognition. Thus, there is a need for better understanding of mild cognitive impairment (MCI) before clinical deterioration begins.

OBJECTIVE

To determine the synergistic effects of β-amyloid burden and CVD on cognition in patients with subcortical vascular MCI (svMCI).

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study was conducted using a hospital-based sample at a tertiary referral center. We prospectively recruited 95 patients with svMCI; 67 of these individuals participated in the study. Forty-five patients with amnestic MCI (aMCI) were group matched with those with svMCI by the Clinical Dementia Rating Scale Sum of Boxes.

MAIN OUTCOMES AND MEASURES

We measured β-amyloid burden using positron emission tomography with carbon 11-labeled Pittsburgh Compound B (PiB). Cerebrovascular disease was quantified as white matter hyperintensity volume detected by magnetic resonance imaging fluid-attenuated inversion recovery. Detailed neuropsychological tests were performed to determine the level of patients' cognitive impairment.

RESULTS

On evaluation, 22 of the svMCI group (33%) and 28 of the aMCI group (62%) were found to be PiB positive. The mean PiB retention ratio was lower in patients with svMCI than in those with aMCI. In svMCI, the PiB retention ratio was associated with cognitive impairments in multiple domains, including language, visuospatial, memory, and frontal executive functions, but was associated only with memory dysfunction in aMCI. A significant interaction between PiB retention ratio and white matter hyperintensity volume was found to affect visuospatial function in patients with svMCI.

CONCLUSIONS AND RELEVANCE

Most patients with svMCI do not exhibit substantial amyloid burden, and CVD does not increase β-amyloid burden as measured by amyloid imaging. However, in patients with svMCI, amyloid burden and white matter hyperintensity act synergistically to impair visuospatial function. Therefore, our findings highlight the need for accurate biomarkers, including neuroimaging tools, for early diagnosis and the need to relate these biomarkers to cognitive measurements for effective use in the clinical setting.

[Cerebral amyloid angiopathy with familial transthyretin-derived oculoleptomeningeal amyloidosis]

Cerebral amyloid angiopathy (CAA) is caused by the accumulation of amyloid fibrils on vascular walls and is a well-known cause of cerebral hemorrhages in the elderly. This disease manifests as recurrent or multiple simultaneous subcortical hematomas, occasionally leading to fatal hemorrhages. Additionally, it is noteworthy that CAA-related hemorrhages can develop in individuals aged around 50 years. Although a few different amyloid fibril proteins have been isolated from patients with CAA, the most common protein is Aβ, which is also the main component of senile plaques in Alzheimer's disease. Recent studies have suggested that corticosteroid therapy is effective for preventing the recurrence of CAA-related hemorrhages. Hereditary generalized amyloidosis usually manifests as familial amyloid polyneuropathy (FAP), showing severe involvement of peripheral somatic and autonomic nerves. Many variant forms of transthyretin (TTR) with a single amino acid substitution have been identified as causative amyloid precursor proteins in FAP. Moreover, a small number of TTR gene mutations causes a rare phenotype of systemic amyloidosis characterized by preferential deposition of TTR-derived amyloid proteins in the vitreous body in the eye, as well as the leptomeninges and subarachnoidal vessels in the central nervous system (CNS). This disorder is called familial oculoleptomeningeal or leptomeningeal amyloidosis and is characterized clinically by CNS symptoms, including progressive dementia, seizures, ataxia, spastic paresis, and stroke-like episodes. Since the variant forms of TTR in this amyloidosis are derived from the retinal epithelium or choroid plexus, liver transplantation-an effective treatment for FAP-is considered less effective for treating this rare form of TTR-related systemic amyloidosis.

[Diagnosis and treatment of brain microbleeds]

Brain microbleeds (MBs) are represented as low-intensity spotty lesions on T2 *-weighted MR images and are frequently detected in healthy people and not only stroke patients. A recent meta-analysis revealed that MBs were present in 34% of patients with ischemic stroke and 60% with intracerebral hemorrhage, respectively. On the other hand, MBs only occur in approximately 4-6% of subjects without cerebrovascular disease and neurological symptoms. The occurrence of MBs in healthy elderly subjects is associated with advanced age or chronic hypertension. The pathological findings of MBs depend on the region of the brain, in which lobar and deep brain MBs are associated with cerebral amyloid angiopathy and hypertensive vasculopathy, respectively. To prevent stroke, risk factors should be carefully managed in subjects with MBs factors. Since hypertension was also found in all subjects who experienced stroke after presenting with MBs, such patients should be treated with intensive anti-hypertensive medication to prevent subsequent ischemic or hemorrhagic stroke. Additionally, antithrombotic drugs should be carefully used in patients with MBs.

[Management of cerebral small vessel disease for the diagnosis and treatment of dementia]

With the demographic shift in life expectancy inexorably increasing in developed countries, dementia is set to become one of the most important health problems worldwide. In recent years, cerebral small vessel disease (SVD) has received much attention as an important cause of dementia. The reason for this is twofold: firstly, arteriosclerosis (type 1 SVD) is the leading cause of vascular cognitive impairment, and secondly, cerebral amyloid angiopathy (CAA; type 2 SVD) is an almost invariable accompaniment of Alzheimer's disease. SVD is known to induce a variety of pathological changes; for example, type 1 SVD results in lacunar infarction, deep microbleeds, and white matter damage, while type 2 SVD leads to cortical microinfarcts, lobar microbleeds, and white matter damage. SVD is considered a spectrum of abnormalities, with the majority of patients experiencing symptoms from both type 1 and type 2 SVD as the disease progresses. The discouraging results of immunotherapy clinical trials for Alzheimer's disease have shifted the scientific attention from the classical neuron-centric approach towards a novel neurovascular approach. As arteries stiffen with age or with other co-morbid factors such as life-related diseases, amyloid β (Aβ) synthesis becomes upregulated, resulting in the deposition of insoluble Aβ not only in the parenchyma as senile plaques but also in the perivascular drainage pathways as CAA. Therefore, therapeutic strategies such as vasoactive drugs that enhance the patency of this Aβ drainage pathway may facilitate Aβ removal and help prevent cognitive decline in the elderly. Based on this emerging paradigm, clinical trials are warranted to investigate whether a neurovascular therapeutic approach can effectively halt cognitive decline and act as a preemptive medicine for patients at risk of dementia.

[Diagnosis and treatment of superficial siderosis]

Superficial siderosis (SS) is a rare condition in which hemosiderin is deposited on the pial surface of the brain and/or spinal cord. Hemosiderin deposition is the consequence of recurrent or persistent hemorrhage in the subarachnoid space. There are two types of SS. In "classical"-type SS, hypointense MRI signals are observed in the brainstem and cerebellum with diffuse and symmetrical margins. Causes of hemorrhage in the "classical" type include tumor, vascular abnormality, injury, and dural defect. The source of hemorrhage is not apparent in approximately 50% of patients despite extensive examination. In "localized"-type SS, hypointense MRI signals are localized in the cerebral cortex. The most common causes of hemorrhage in the "localized" type are cerebral amyloid angiopathy and/or Alzheimer's disease. Patients with SS usually present with slowly progressive and irreversible cerebellar ataxia, sensorineural hearing loss, and/or myelopathy due to involvement of the acoustic nerve, cerebellum, and spinal cord. T2-weighted imaging (WI) or T2* WI demonstrates characteristic linear low-intensity signals along the surface of the brain and spinal cord. Treatment of SS involves identification and surgical correction of the bleeding source. Deferiprone, which is a lipid-soluble iron chelator that can penetrate the blood-brain barrier, is reportedly effective at improving the clinical symptoms and deposition of hemosiderin. It is thus a hopeful treatment option for SS.

Case report of a "probable" cerebral amyloid angiopathy

Sixty-two year old man was admitted to the department of neurosurgery after stroke episode. CT-scan revealed non-traumatic, non-hypertensive intracerebral hemorrhage in the left temporal lobe; cerebral amyloid angiopathy was suspected. Initially, according to Boston criteria, intracerebral hematoma was interpreted as a result of a "probable" cerebral amyloid angiopathy. Surgical evacuation of the hematoma lead to the partial recourse of speech and cognitive deficit. Four weeks after stroke onset and 3 weeks after surgery CT was performed, which revealed intracerebral hematoma in the right parietal lobe; this fact let to diagnose "probable" cerebral amyloid angiopathy. The second hematoma was evacuated, and surgical treatment together with medical therapy improved patient's quality of life. Treatment strategy for the intracerebral hematomas resulting from cerebral amyloid angiopathy has not been justified yet, which requires further investigations.

Cerebral microbleeds: a review

Cerebral microbleeds (CMBs) are frequent findings in MRI scans of elderly subjects. Depending on the MRI protocols applied 4.7% to 24.4% of community-based subjects show incidental CMBs. The rates reported for various types of ischemic strokes and intracerebral hemorrhages vary between 19.4% and 68.5%. Most studies also demonstrated CMBs in approximately one third of Alzheimer cases. A lobar distribution of CMBs is considered to relate to cerebral amyloid angiopathy, while CMBs located in the basal ganglia or in infratentorial brain regions are thought to relate to hypertensive vasculopathy. Besides age, hypertension, diabetes mellitus, and low serum cholesterol have so far been identified as risk factors for CMBs. Presence of an APOE ε4 allele is the only genetic factor that was consistently shown to increase the risk for CMB development. There are only few longitudinal studies on the predictive value of CMBs. For incident ischemic strokes and intracerebral hemorrhages hazard ratios of 4.48 and 50.2 have been reported. CMBs also doubled the risk for conversion to dementia in MCI patients, and there are indications for CMBs being possible predictors of increased mortality. Given the small number of longitudinal investigations with often small sample sizes the role of CMBs as predictors of disease needs to be further elucidated. CMBs were significantly more common in warfarin-treated stroke patients who developed intracerebral hemorrhages (ICH). These data are cross-sectional. They do not provide enough evidence to consider CMBs as a contraindication for antithrombotic agents in primary and secondary stroke prevention. CMBs are likely to unfavourably affect cognitive functioning. It remains to be determined if direct lesion-related effects are responsible for this finding or if CMBs are sole markers of more extensive tissue damage in the wake of cerebral small vessel disease leading to widespread visible but also non-visible tissue destruction with a high likelihood for cognitive consequences.

Cerebral amyloid angiopathy manifested as a brain tumour. Clinical and neuropathological characteristics of two cases

We present two cases (female and male patients, aged 64 and 38, respectively) of focal mass lesions mimicking a brain tumour: one with cognitive function deficit, memory troubles, behavioral changes and left hemiparesis, the other with difficulty in orientation and right hemiparesis. General physical and neurological examinations, laboratory tests and neuroimaging were used to diagnose the cases. Both of them showed nonspecific changes in the brain tissue and the brain tumour was suspected. In the first case MRI scan revealed two pathological masses in the right frontal region and hemorrhagical focus with destructions inside lesions. Second patient's MRI scan revealed a pathological mass at the interface of the left temporal and occipital regions. The neurosurgical procedure was performed. The final diagnosis was established on the basis of neuropathological examination of postoperative material. On light microscopy examination a severe cerebral amyloid angiopathy (CAA) was revealed. Amyloidoma was excluded due to the absence of amorphous material and eosynophylic masses. Tumefactive CAA is a rare condition. These two cases of focal, tumefactive, masslike lesions of diffuse cerebral amyloid angiopathy are reported because of diagnostic dilemmas. In patients with history of memory disfunction, neurological deterioration and different multiple changes observed in CT and MRI scans, such as hemorrhagic infarcts and ischemic cerebral lesions, CAA should be suspected. The imaging findings make a distinction between tumefactive CAA and brain tumours like gliomas difficult. A differential diagnosis of CAA and amyloidoma plays a significant role in a neuropathological examination.

[Cerebral amyloid angiopathy-related leukodystrophy: a case report]

An 86-year-old woman was admitted following generalized seizure. Postictally she showed disturbance of consciousness, right hemiparesis, and right spatial neglect. Brain fluid attenuated inversion recovery (FLAIR) imaging demonstrated mainly left-sided, but asymmetrical, subcortical white matter lesions. On the second day, level of consciousness improved, along with right hemiparesis and right spatial neglect. Electroencephalography displayed mainly α waves and sporadic θ waves without sharp waves. One week later, however, the patient again experienced somnolence and right hemiparesis. FLAIR revealed day-by-day enlargement of white matter lesions. The possibilities of hypoglycemia, hyperammonemia, hypothyroidism, Hashimoto encephalopathy, collagen disease, antineutrophil cytoplasmic antibody-related angiitis, and infection were excluded based on the results of blood biochemistry and cerebrospinal fluid. We initially suspected intravascular lymphoma, so random skin biopsy was performed, but the results were negative. We then suspected cerebral amyloid angiopathy because of the presence of dementia and multiple microbleeds on T(2)* weighted magnetic resonance imaging. Cerebral biopsy revealed amyloid deposition in cortical arterioles and CD3-positive T cells in the perivascular space. Cerebral amyloid angiopathy-related leukodystrophy was therefore diagnosed and immunosuppressive treatment was started. After 14 days of treatment, clinical symptoms and results of FLAIR imaging were significantly improved. When patients display asymmetrical subcortical white matter lesions with microbleeds on T(2)* weighted imaging, amyloid angiopathy-related inflammation should be considered.

[Cerebral amyloid angiopathy is difficult to diagnose in the intensive care unit]

Cerebral amyloid angiopathy is a common cause of intracerebral haemorrhage in elderly patients. The diagnosis of cerebral amyloid angiopathy is based on the Boston criteria combining clinical and radiological criteria with no other cause of intracerebral haemorrhage. We describe the case of a 60-year-old female admitted to the intensive care unit for agitation and spatial disorientation. She had multiple intracerebral haematomas on brain CT scan. Typical cerebral microbleeds using MRI and the absence of other cause of intracerebral haemorrhage argued in favour of the diagnosis of cerebral amyloid angiopathy. The patient outcome was favourable with a discharge from the intensive care unit on day 16.