Cerebral Amyloid Angiopathy Associated with Inflammation: Report of 3 Cases and Systematic Review

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We present clinical and neuroradiological observations in seven unpublished CAA-RI cases, including neuropathological findings in two definite cases.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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cerebral Amyloid Angiopathy-Related Inflammation: A Case Report and Literature Review

Cerebral amyloid angiopathy-related inflammation (CAA-RI) is an encephalopathy caused by inflammation of β-amyloid peptide deposition in cerebrovascular vessels. It is a rare disease that mainly occurs in the elderly and is characterized by rapidly progressive dementia, headache, seizures, and focal neurologic deficits. CAA-RI can demonstrate characteristic brain MRI findings and can be reversed by steroids or other immunosuppressive therapies. Here, we report a case of CAA-RI, which was initially misdiagnosed as a subacute infarction but was diagnosed while reviewing follow-up brain MRI images, and spontaneous remission was achieved.

Rare forms of cerebral amyloid angiopathy: pathogenesis, biological and clinical features of CAA-ri and iCAA

Thanks to a more widespread knowledge of the disease, and improved diagnostic techniques, the clinical spectrum of cerebral amyloid angiopathy (CAA) is now broad. Sporadic CAA, hereditary CAA, CAA-related inflammation (CAA-ri) and iatrogenic CAA (iCAA) create a clinical and radiological continuum which is intriguing and only partially discovered. Despite being relatively rare, CAA-ri, an aggressive subtype of CAA with vascular inflammation, has gained growing attention also because of the therapeutic efficacy of anti-inflammatory and immunomodulating drugs. More recently, diagnostic criteria have been proposed for an unusual variant of CAA, probably related to an iatrogenic origin (iCAA), toward which there is mounting scientific interest. These atypical forms of CAA are still poorly known, and their recognition can be challenging and deserve to be pursued in specialized referral centres. The aim of this brief review is to focus current developments in the field of rare forms of CAA, its pathogenesis as well as clinical and biological features in order to increase awareness of these rare forms.

[A case of multiple small cerebral infarcts in the cerebellum and bilateral cerebrum, diagnosed with amyloid angiopathy by brain biopsy]

An 82-year-old woman had been suffering from progressive forgetfulness and abnormal speech and behavior for One month. Findings of the MRI of the head indicated scattered small cerebral infarcts in the cerebellum and in bilateral cerebral cortex/subcortical white matter. After admission, she experienced a subcortical hemorrhage, and the percentage of small cerebral infarcts increased over time. Based on the suspicion of central primary vasculitis or malignant lymphoma, we performed a brain biopsy targeting the right temporal lobe hemorrhage site, and the patient was diagnosed with cerebral amyloid angiopathy (CAA). We conclude that CAA can cause multiple small progressive cerebral infarcts.

Inflammatory Cerebral Amyloid Angiopathy: A Broad Clinical Spectrum

Cerebral amyloid angiopathy (CAA) is a common central nervous system (CNS) vasculopathy, which in some cases is associated with subacute encephalopathy, seizures, headaches, or strokes due to vascular inflammation directed against vascular amyloid accumulation. The pathological subtypes of inflammatory CAA include CAA-related inflammation (CAAri) with mostly perivascular lymphocytic infiltrates, or amyloid-beta (Aβ)-related angiitis (ABRA) with transmural granulomatous inflammation. CAAri and ABRA probably represent part of the spectrum of CNS vasculopathies, intermediate between CAA and primary CNS vasculitis, and they are closely related to Aβ-related imaging abnormalities and other manifestations of an inflammatory response directed against Aβ in the leptomeninges and cerebral parenchyma. As treatment strategies in Alzheimer's disease shift toward potentially effective antiamyloid immunotherapy, the incidence rate of inflammatory CAA (which is probably an underrecognized condition) is likely to increase. Its clinical features are varied and include subacute encephalopathy, behavioral symptoms, headaches, seizures, and focal neurological deficits, which necessitate a high degree of suspicion for this disorder that often responds to treatment. The recent definition of the typical clinical and radiological syndrome has increased its recognition and may eliminate the need for invasive histological sampling in at least some affected patients. Here we review the pathophysiology, clinical spectrum, and approach to diagnosis, and discuss illustrative cases that highlight the wide range of clinical presentations.

Cerebral Amyloid Angiopathy-Related Inflammation (CAA-rI): Three Heterogeneous Case Reports and a Focused Literature Review

Cerebral amyloid angiopathy-related inflammation (CAA-rI) is a largely reversible, subacute encephalopathy, which is considered as a rare variant of cerebral amyloid angiopathy (CAA). Although the diagnosis of this inflammatory vasculopathy is generally clinico-pathologic, a probable or possible diagnosis can often be established based on current clinico-radiological diagnostic criteria. This is important since CAA-rI is considered as a treatable disorder, which most commonly occurs in the elderly population. Behavioral changes and cognitive deterioration are highlighted as the most common clinical signs of CAA-rI, followed by a heterogeneous spectrum of typical and atypical clinical presentations. However, despite the well-established clinical and radiological features incorporated in the current diagnostic criteria for this CAA variant, this rare disorder is still insufficiently recognized and treated. Here, we have shown three patients diagnosed with probable CAA-rI, with significant heterogeneity in the clinical and neuroradiological presentations, followed by different disease courses and outcomes after the introduction of immunosuppressive treatment. Moreover, we have also summarized up-to-date literature data about this rare, yet underdiagnosed, immune-mediated vasculopathy.

Clinical, laboratory, and radiological features of cerebral amyloid angiopathy-related inflammation (CAA-ri): retrospective, observational experience of a single centre

BACKGROUND

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a subtype of CAA with an inflammatory response to the vascular β-amyloid deposits. Reliable and non-invasive clinical diagnostic methods may allow patients to avoid the side effects of brain biopsy.

OBJECTIVE

In this observational study, we retrospectively analyzed the clinical, laboratory, radiological features, treatment, and outcome of patients diagnosed with CAA-ri. The main purpose is to enhance knowledge of CAA-ri and to avoid misdiagnosis.

METHODS

We described 15 consecutive patients with probable or possible CAA-ri at Henan Provincial People's Hospital according to a validation study of proposed criteria for the diagnosis of CAA-ri. The clinical features, imaging, laboratory findings, and treatment which included the response to immunotherapy were revealed in the study.

RESULTS

The median age of 15 patients was 67.0 years (range 48.0-90.0 years), and the male-to-female ratio was 7: 8. In our study, the most common clinical manifestations were cognitive decline (7/15, 46.7%), focal neurologic deficit (6/15, 40.0%), and headache (5/15, 33.3%). In terms of imaging results, white matter hyperintensity (WMH) lesions were rarely seen in the cerebellum and brainstem, while no hemorrhagic lesion was observed in the brainstem of all 15 patients. In addition, 12 patients (80.0%) showed improvement or stability for the clinical and radiological outcomes after immunotherapy.

CONCLUSION

CAA-ri should be considered as a differential diagnosis when brain MRI shows typical features in the elderly. Once the diagnosis is established, immunotherapy should be initiated as early as possible to promote neurological function recovery and reduce recurrence.

Epilepsy in cerebral amyloid angiopathy: an observational retrospective study of a large population

OBJECTIVE

Cerebral amyloid angiopathy (CAA) is a major cause of spontaneous intracranial hemorrhage in older adults. Epilepsy represents a possible sequela of the disease. To date, studies on epilepsy in CAA are lacking, and the few data available mainly focus on CAA-related inflammation (CAA-ri), the inflammatory form of the disease.

METHODS

In this retrospective observational study, we consecutively recruited CAA patients observed over a time span of 10 years, collecting demographic, clinical, and instrumental data. Significant baseline characteristics were evaluated as potential risk factors for the development of epilepsy in the CAA population, and in the subgroups of CAA-ri and CAA without inflammatory reaction (CAA-nri). The effect of potential risk factors for epilepsy was measured as odds ratio with 95% confidence interval.

RESULTS

Within 96 recruited CAA cases, 33 (34.4%) developed epilepsy during follow-up (median = 13.5 months). The prevalent type of seizure was focal (81.3%); 12.1% of the epileptic patients presented status epilepticus, and 6.1% developed drug-resistant epilepsy. Electroencephalographic traces revealed slow and epileptic discharge activity in the majority of epileptic patients, but also in those without epilepsy. The presence of focal or disseminated cortical superficial siderosis (cSS) was associated with an increased risk of epilepsy in the CAA-nri group, and the association with CAA-ri and epilepsy was present in the overall population.

SIGNIFICANCE

Epilepsy is a common manifestation during the course of CAA, where CAA-ri and cSS represent predisposing factors for the development of seizures. These data suggest the importance of a deep characterization of CAA patients, to better select those more prone to develop epilepsy.

Clinical, Neuroimaging, and Genetic Markers in Cerebral Amyloid Angiopathy-Related Inflammation: A Systematic Review and Meta-Analysis

BACKGROUND

There are limited data regarding the prevalence of distinct clinical, neuroimaging and genetic markers among patients diagnosed with cerebral amyloid angiopathy-related inflammation (CAA-ri). We sought to determine the prevalence of clinical, radiological, genetic and cerebrospinal fluid biomarker findings in patients with CAA-ri.

METHODS

A systematic review and meta-analysis of published studies including patients with CAA-ri was conducted to determine the prevalence of clinical, neuroimaging, genetic and cerebrospinal fluid biomarker findings. Subgroup analyses were performed based on (1) prospective or retrospective study design and (2) CAA-ri diagnosis with or without available biopsy. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using Cochran-Q and I²-statistics.

RESULTS

We identified 4 prospective and 17 retrospective cohort studies comprising 378 patients with CAA-ri (mean age, 71.5 years; women, 52%). The pooled prevalence rates were as follows: cognitive decline at presentation 70% ([95% CI, 54%-84%]; I²=82%), focal neurological deficits 55% ([95% CI, 40%-70%]; I²=82%), encephalopathy 54% ([95% CI, 39%-68%]; I²=43%), seizures 37% ([95% CI, 27%-49%]; I²=65%), headache 31% ([95% CI, 22%-42%]; I²=58%), T2/fluid-attenuated inversion recovery-hyperintense white matter lesions 98% ([95% CI, 93%-100%]; I²=44%), lobar cerebral microbleeds 96% ([95% CI, 92%-99%]; I²=25%), gadolinium enhancing lesions 54% ([95% CI, 42%-66%]; I²=62%), cortical superficial siderosis 51% ([95% CI, 34%-68%]; I²=77%) and lobar macrohemorrhage 40% ([95% CI, 11%-73%]; I²=88%). The prevalence rate of the ApoE (Apolipoprotein E) ε4/ε4 genotype was 34% ([95% CI, 17%-53%]; I²=76%). Subgroup analyses demonstrated no differences in these prevalence rates based on study design and diagnostic strategy.

CONCLUSIONS

Cognitive decline was the most common clinical feature. Hyperintense T2/fluid-attenuated inversion recovery white matter lesions and lobar cerebral microbleeds were by far the most prevalent neuroimaging findings. Thirty-four percent of patients with CAA-ri have homozygous ApoE ε4/ε4 genotype and scarce data exist regarding the cerebrospinal fluid biomarkers and its significance in these patients.

Cerebral Amyloid Angiopathy-Related Inflammation: A Single-Center Experience and a Literature Review

Background: Limited data exist regarding the prevalence of clinical, neuroimaging, and genetic markers among patients diagnosed with Cerebral Amyloid Angiopathy−related inflammation (CAA-ri). We sought to determine these characteristics in patients diagnosed in our center and to summarize available literature published either as single-case reports or small case series (<5 patients). Methods: We reported our single-center experience of patients diagnosed with CAA-ri according to international criteria during a seven-year period (2015−2022), and we abstracted data from 90 previously published cases. Results: Seven patients (43% women, mean age 70 ± 13 years) were diagnosed with CAA-ri in our center. The most common symptom at presentation was focal neurological dysfunction (71%), and the most prevalent radiological finding was the presence of T2/FLAIR white matter hyperintensities (100%). All patients were treated with corticosteroids and had a favorable functional outcome. Among 90 previously published CAA-ri cases (51% women, mean age 70 ± 9 years), focal neurological dysfunction was the most common symptom (76%), followed by a cognitive decline (46%) and headache (34%). The most prevalent neuroimaging findings were cerebral microbleeds (85%), asymmetric T2/FLAIR white matter hyperintensities (81%), and gadolinium-enhancing T1-lesions (37%). Genetic testing for the Apolipoprotein-E gene was available in 27 cases; 59% carried the APOE ε4/ε4 genotype. The majority of the published CAA-ri cases (78%) received corticosteroid monotherapy, while 17 patients (19%) were treated with additional immunosuppressive treatment. Favorable functional outcome following treatment was documented in 70% of patients. Conclusion: Improving the vigilance of clinicians regarding the early recognition and accurate diagnosis of CAA-ri is crucial for swift therapy initiation, which may result in improved functional outcomes.

Updated Outlook of Cerebral Amyloid Angiopathy and Inflammatory Subtypes: Pathophysiology, Clinical Manifestations, Diagnosis and Management

Cerebral amyloid angiopathy (CAA) is a common untreatable cause of lobar hemorrhages and cognitive decline in the older population. Subset of patients present with its inflammatory subtype with rapid decline in cognitive functions and neurological deficits. Most commonly the underlying pathophysiology of this disease is deposition of insoluble amyloid protein into blood vessel walls which results in vessel fragility leading to local neurotoxicity which may eventually leads to lobar hemorrhages and cognitive decline. The term “Amyloid Spell” encompasses transient focal neurological deficits which is commonly misdiagnosed as seizures or transient ischemic attack in the emergency department. Radiologic findings in these patients may reveal microbleeds, cortical superficial siderosis, white matter hyperintensities, and cerebral edema which support the clinical diagnosis which could be otherwise challenging. CAA diagnostic criteria require CT (Edinburgh Criteria) or MRI imaging, or neuropathology. The diagnosis can be suspected without imaging or neuropathology but cannot be confirmed. This review article provides a critical outlook on different types of presentations, updated diagnostic criteria and management of CAA patients illustrating underlying mechanisms associated with neuronal injury secondary to amyloid deposition.

Biopsy-Proven Amyloid-Beta Related Angiitis with Unusual Presentation and Long-Term Follow-Up

Amyloid-beta related angiitis (ABRA) is a rare central nervous system inflammatory and vasculitic process. It is seen in patients with cerebral amyloid angiopathy (CAA) and thought to be mediated by an autoimmune reaction against cerebrovascular β-amyloid. We describe the case of a patient with ABRA with clinical information and brain imaging over a 10-year period. The patient was hospitalized in 2018 for altered mental status, paranoia and hallucinations. Her symptoms started in 2009 with an episode of vertigo and loss of consciousness. From 2011-2019, she had multiple episodes of transient focal neurological deficits with overall cumulative progressive decline in cognition and functional status. Retrospective and comparative reviews of brain magnetic resonance imaging (MRI) from 2009-2019 showed waxing and waning vasogenic cerebral edema with overall progression of white matter hyperintensities and peripheral micro-hemorrhages consistent with inflammatory CAA. Re-examination of a brain biopsy from 2009 showed ABRA, and immunostaining was positive for β-amyloid. She was treated with intravenous steroids with minimal symptomatic improvement. She was lost to our follow-up after hospital discharge. We describe the temporal progression of ABRA through serial brain imaging over a 10-year period. To our knowledge, this is the longest published follow-up duration of ABRA. The patient in our case had severe cognitive impairment and disability despite treatment with steroids.

Different clinical outcomes between cerebral amyloid angiopathy-related inflammation and non-inflammatory form

OBJECTIVE

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rare manifestation related to CAA, thought to be more severe. We aimed to compare the clinical and radiological outcomes of CAA-ri and non-inflammatory CAA.

MATERIALS AND METHODS

We retrospectively included all patients with CAA-ri from 13 French centers. We constituted a sex- and age-matched control cohort with non-inflammatory CAA and similar disease duration. Survival, autonomy and cognitive evolution were compared after logistic regression. Cerebral microbleeds (CMB), intracerebral hemorrhage, cortical superficial siderosis and hippocampal atrophy were analyzed as well as CSF biomarker profile and APOE genotype when available. Outcomes were compared using Kaplan-Meier curves and log-rank tests.

RESULTS

Data from 48 CAA-ri patients including 28 already reported and 20 new patients were analyzed. Over a mean of 3.1 years, 11 patients died (22.9%) and 18 (37.5%) relapsed. CAA-ri patients were more frequently institutionalized than non-inflammatory CAA patients (30% vs 8.3%, p < 0.001); mortality rates remained similar. MMSE and modified Rankin scale scores showed greater severity in CAA-ri at last follow-up. MRI showed a higher number of CMB at baseline and last follow-up in CAA-ri (p < 0.001 and p = 0.004, respectively). CSF showed lower baseline levels of Aß42 in CAA-ri than non-inflammatory CAA (373.3 pg/ml vs 490.8 pg/ml, p = 0.05). CAA-ri patients more likely carried at least one APOE ε4 allele (76% vs 37.5%, adjusted p = 0.05) particularly as homozygous status (56% vs 6.2%, p < 0.001).

INTERPRETATION

CAA-ri appears to be more severe than non-inflammatory CAA with a significant loss of autonomy and global higher amyloid burden, shown by more CMB and a distinct CSF profile. This burden may be partially promoted by ε4 allele.

Acute progression of cerebral amyloid angiopathy-related inflammation diagnosed by biopsy in an elderly patient: A case report

Background:

Cerebral amyloid angiopathy-related inflammation (CAA-I) presents with slowly progressive nonspecific neurological symptoms, such as headache, cognitive function disorder, and seizures. Pathologically, the deposition of amyloid-β proteins at the cortical vascular wall is a characteristic and definitive finding. Differential diagnoses include infectious encephalitis, neurosarcoidosis, primary central nervous system lymphoma, and glioma. Here, we report a case of CAA-I showing acute progression, suggesting a glioma without enhancement, in which a radiological diagnosis was difficult using standard magnetic resonance imaging.

Case Description:

An 80-year-old woman was admitted due to transient abnormal behavior. Her initial imaging findings were similar to those of a glioma. She presented with rapid progression of the left hemiplegia and disturbance of consciousness for 6 days after admission and underwent emergent biopsy with a targeted small craniotomy under general anesthesia despite her old age. Intraoperative macroscopic findings followed by a pathological study revealed CAA-I as the definitive diagnosis. Steroid pulse therapy with methylprednisolone followed by oral prednisolone markedly improved both the clinical symptoms and imaging findings.

Conclusion:

Differential diagnosis between CAA-I and nonenhancing gliomas may be difficult using standard imaging studies in cases presenting with acute progression. A pathological diagnosis under minimally invasive small craniotomy may be an option, even for elderly patients.

Cognitive Impairment in Primary and Secondary Headache Disorders

Purpose of Review

To critically evaluate the recent literature on cognitive impairment and headache.

Recent Findings

Neurocognitive symptoms are prevalent, debilitating, and occur often with both primary and secondary headache disorders.

Summary

This is a “narrative review of the current literature in PubMed on cognitive function and headache.” Migraine is associated with cognitive impairment years before a migraine diagnosis. In young and middle-aged adults, migraine is associated with deficits in attention, executive function, processing speed, and memory. It is unlikely that migraine is associated with dementia. Although methodologically difficult to assess, there does not seem to be an association between tension-type headache and cognitive dysfunction. In early to midlife, cluster headache seems to be associated with executive dysfunction. Several secondary headache syndromes relevant to clinicians managing headache disorders are associated with poorer cognitive performance or distinctive cognitive patterns, including those attributed to chronic cerebral or systemic vascular disorders, trauma, and derangements of intracranial pressure and volume, including frontotemporal brain sagging syndrome.

Spontaneous ARIA-like Events in Cerebral Amyloid Angiopathy-Related Inflammation: A Multicenter Prospective Longitudinal Cohort Study

BACKGROUND AND OBJECTIVES

The goal of this work was to investigate the natural history and outcomes after treatment for spontaneous amyloid-related imaging abnormalities (ARIA)-like in cerebral amyloid angiopathy-related inflammation (CAA-ri).

METHODS

This was a multicenter, hospital-based, longitudinal, prospective observational study of inpatients meeting CAA-ri diagnostic criteria recruited through the Inflammatory Cerebral Amyloid Angiopathy and Alzheimer's Disease βiomarkers International Network from January 2013 to March 2017. A protocol for systematic data collection at first-ever presentation and at subsequent in-person visits, including T1-weighted, gradient recalled echo-T2*, fluid-suppressed T2-weighted (fluid-attenuated inversion recovery), and T1 postgadolinium contrast-enhanced images acquired on 1.5T MRI, was used at the 3-, 6-, 12-, and 24-month follow-up. Centralized reads of MRIs were performed by investigators blinded to clinical, therapeutic, and time-point information. Main outcomes were survival, clinical and radiologic recovery, intracerebral hemorrhage (ICH), and recurrence of CAA-ri.

RESULTS

The study enrolled 113 participants (10.6% definite, 71.7% probable, and 17.7% possible CAA-ri). Their mean age was 72.9 years; 43.4% were female; 37.1% were APOEε4 carriers; 36.3% had a history of Alzheimer disease; and 33.6% had a history of ICH. A history of ICH and the occurrence of new ICH at follow-up were more common in patients with cortical superficial siderosis at baseline (52.6% vs 14.3%, p < 0.0001 and 19.3% vs 3.6%, p < 0.009, respectively). After the first-ever presentation of CAA-ri, 70.3% (95% confidence interval [CI] 61.6%-78.5%) and 84.1% (95% CI 76.2%-90.6%) clinically recovered within 3 and 12 months, followed by radiologic recovery in 45.1% (95% CI 36.4%-54.8%) and 77.4% (95% CI 67.7%-85.9%), respectively. After clinicoradiologic resolution of the first-ever episode, 38.3% (95% CI 22.9%-59.2%) had at least 1 recurrence within the following 24 months. Recurrence was more likely if IV high-dose corticosteroid pulse therapy was suddenly stopped compared to slow oral tapering off (hazard ratio 4.68, 95% CI 1.57-13.93; p = 0.006).

DISCUSSION

These results from the largest longitudinal cohort registry of patients with CAA-ri support the transient and potentially relapsing inflammatory nature of the clinical-radiologic acute manifestations of the disease and the effectiveness of slow oral tapering off after IV corticosteroid pulse therapy in preventing recurrences. Our results highlight the importance of differential diagnosis for spontaneous ARIA-like events in β-amyloid-driven diseases, including treatment-related ARIA in patients with Alzheimer disease exposed to immunotherapy drugs.

Clinical and radiological evolution of cerebral amyloid angiopathy-related inflammation in the context of anti-PD-1 immunotherapy

Immune-related adverse events (irAEs) are a frequent complication of immunotherapy, but neurological irAEs are rare and varied. Here, we present a case of cerebral amyloid angiopathy-related inflammation (CAA-ri) attributable to nivolumab monotherapy, which has not been previously reported. The context of immunotherapy and availability of serial imaging also provide unique insights into the pathogenesis and evolution of CAA-ri. Routine surveillance neuroimaging in a patient with metastatic melanoma, in remission after treatment with nivolumab, demonstrated progressive microhaemorrhages and associated oedema, suspicious for CAA-ri. These changes progressed despite cessation of nivolumab. The patient was initially asymptomatic, but later developed an acute confusional state, warranting brain biopsy, which confirmed the diagnosis of CAA-ri. Treatment with methylprednisolone resulted in resolution of the oedema, and a marked decrease in the subsequent accumulation of microhaemorrhages. The temporal evolution prior to symptom development and subsequently related to treatment suggests that inflammation may be an important component of the pathogenesis of CAA-ri, rather than simply a secondary response. Given that immunotherapy is in its relative infancy, it is important to consider rare irAEs in patients exhibiting unusual imaging findings.

Pseudotumoral Presentation of Cerebral Amyloid-Beta Angiopathy: Case Report and Review of Literature

OBJECTIVE

Cerebral amyloid angiopathy-related inflammation (CAA-RI) is a rare and potentially treatable encephalopathy that usually affects people older than 50 years old and has an acute or subacute clinical presentation characterized by rapidly evolving cognitive decline, focal deficits and seizures. In a small subset of patients the disease can adopt a pseudotumoral form in the neuroimages that represents a very difficult diagnostic challenge.

METHODS

Here in we report a patient with a tumour-like presentation of histopathologically confirmed CAA-RI.

RESULTS

We also conducted a search and reviewed the clinical and radiological features of 41 cases of pseudotumoral CAA-RI previously reported in the literature in order to identify those characteristics that should raise diagnostic suspicions of the disease, there by avoiding unnecessary surgical treatments.

CONCLUSION

The therapy of CAA-RI with steroids is usually effective and clinical and radiological remission can be achieved in the first month in approximately 70% of cases.

Cerebral amyloid angiopathy and related inflammatory disorders

Inflammatory cerebral amyloid angiopathy is a largely reversible inflammatory vasculopathy that develops in an acute or subacute fashion in reaction to amyloid protein deposition in the central nervous system blood vessels. There are two recognized pathologically characterized variants: cerebral amyloid angiopathy-related inflammation (CAAri) and A beta-related angiitis (ABRA). Both variants produce a clinical picture that resembles primary angiitis of the CNS but is distinguished by a characteristic radiologic appearance. Although originally defined as a clinicopathologic diagnosis, it can now often be diagnosed based on clinicoradiologic criteria, though confirmation with brain and meningeal biopsy is still required in some cases. This disorder typically responds to steroids but addition of other immune suppressants may be needed in some cases to control the disease.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cerebral amyloid angiopathy-related inflammation: current status and future implications

ABSTRACT

Cerebral amyloid angiopathy-related inflammation (CAA-RI) is a rare but increasingly recognized subtype of CAA. CAA-RI consists of two subtypes: inflammatory cerebral amyloid angiopathy and amyloid β (Aβ)-related angiitis. Acute or subacute onset of cognitive decline or behavioral changes is the most common symptom of CAA-RI. Rapid progressive dementia, headache, seizures, or focal neurological deficits, with patchy or confluent hyperintensity on T2 or fluid-attenuated inversion recovery sequences and evidence of strictly lobar microbleeds or cortical superficial siderosis on susceptibility-weighted imaging imply CAA-RI. The gold standard for diagnosis is autopsy or brain biopsy. However, biopsy is invasive; consequently, most clinically diagnosed cases have been based on clinical and radiological data. Other diagnostic indexes include the apolipoprotein E ε4 allele, Aβ and anti-Aβ antibodies in cerebral spinal fluid and amyloid positron emission tomography. Many diseases with similar clinical manifestations should be carefully ruled out. Immunosuppressive therapy is effective both during initial presentation and in relapses. The use of glucocorticoids and immunosuppressants improves prognosis. This article reviews the pathology and pathogenesis, clinical and imaging manifestations, diagnostic criteria, treatment, and prognosis of CAA-RI, and highlights unsolved problems in the existing research.

Slightly Symptomatic Cerebral Amyloid Angiopathy-Related Inflammation with Spontaneous Remission in Four Months

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rare variant of CAA with autoimmune inflammation. A 77-year-old female experienced light-headedness during walking and mild ataxic gait without any other objective neuropsychological deficits. Brain magnetic resonance imaging (MRI) revealed an area of abnormal signal and mild parenchymal swelling in the right parietal lobe, indicating vasogenic edema. T2⁎-weighted gradient echo imaging revealed some subcortical microbleeds in the same lesion. Based on the proposed criteria for CAA-ri, she was diagnosed with probable CAA-ri. After 4 months, the spontaneous improvement was noted in the patient's clinical and radiological findings. This report presents a rare and atypical case of CAA-ri in which the diagnosis was established after the patient underwent neuroimaging for only mild neurological symptoms, and the patient's clinical and radiological findings displayed spontaneous improvement. Despite typical and striking MRI findings of CAA-ri, this patient only presented a minimal symptom; this dissociation could highlight the significance of not misinterpreting any new neurological symptoms. Thus, increased availability of MRI and growing awareness of CAA-ri might result in more incidentally diagnosed cases in the future. Furthermore, this case suggests that it would be better to strictly monitor the clinical-radiological findings of patients with probable CAA-ri who only present with minimal symptoms without the initiation of immunosuppressive therapy.

Cerebral amyloid angiopathy-related inflammation with epilepsy mimicking a presentation of brain tumor: A case report and review of the literature

INTRODUCTION

Cerebral amyloid angiopathy-related inflammation (CAA-ri), a rare and treatable variant of cerebral amyloid angiopathy, lacks specific imaging and clinical features, and requires invasive brain biopsy to confirm the diagnosis. We report the case of a patient with nonconvulsive status epilepticus (NCSE) caused by CAA-ri in the right occipital lobe.

PRESENTATION OF CASE

A 78-year-old man with a history of hypertension and rheumatoid arthritis was admitted to our hospital following an episode of seizures. CT scan showed a low-attenuating subcortical lesion in the right occipital lobe. MRI revealed the lesion as hypointense on T1-weighted imaging (WI) and hyperintense on T2-WI, showing no enhancement on T1-WI contrast-enhanced with gadolinium. In addition, T2*-weighted gradient-recalled echo (T2*-GRE) and susceptibility-weighted imaging (SWI) revealed extensive cortical microbleeds. Biopsy to determine the exact diagnosis revealed histological findings of reactive changes and perivascular inflammatory infiltration associated with amyloid deposition in vessel walls. These findings were consistent with CAA-ri. Corticosteroid therapy with dexamethasone was initiated for a short period as a diagnostic and therapeutic maneuver, resulting in marked reductions in the lesion.

DISCUSSION

CAA is generally associated with intracerebral hemorrhage, dementia, and small cerebral infarctions in the elderly population, but in a small proportion of cases is related to inflammatory responses to vascular deposits of Aβ, as so-called CAA-ri.

CONCLUSION

CAA-ri should be considered among the differential diagnoses for causes of unprovoked seizure onset in elderly individuals, when associated with petechial hemorrhages on T2*-GRE and SWI sequences on MRI.

Multiple intracranial lesions as the unusual imaging features of Hashimoto's encephalopathy: A case report

RATIONALE

Hashimoto's encephalopathy (HE) is associated with autoimmune thyroid disease and is complex, diverse, and easily misdiagnosed. However, if HE is diagnosed and treated in a timely manner, an optimal prognosis may be achieved.

PATIENT CONCERNS

We presented a case of a 63-year-old female patient with paroxysmal dizziness, unsteady gait, emotion apathy, progressive cognitive impairment, and unusual magnetic resonance imaging (MRI) findings.

DIAGNOSES

After suffering for almost 8 years, the patient was diagnosed with HE based on clinical manifestation, abnormal electroencephalogram, unusual MRI findings, sensitivity to cortisol treatment, and characteristic high antithyroid peroxidase antibody (TpoAb) titer.

INTERVENTIONS

The patient continued regular glucocorticoids therapy after intravenous methylprednisolone pulse therapy, neurotrophic drugs, traditional Chinese medicine and rehabilitation to relieve hypermyotonia and cognitive impairment.

OUTCOMES

After combined treatment, the patient's symptoms, electroencephalogram (EEG), MRI, and the TpoAb titer gradually improved. However, the patient had to stop glucocorticoids treatment because of severe osteoporosis, fractures and other adverse reactions. Her symptoms fluctuated, and her TpoAb titer increased again.

LESSONS

HE may cause highly heterogeneous clinical features, particularly MRI findings. Withdrawal of the systematic glucocorticoids treatment can lead to varied outcomes in these patients.

Cerebral amyloid angiopathy associated with inflammation: A systematic review of clinical and imaging features and outcome

Background

Cerebral amyloid angiopathy associated with inflammation is an increasingly recognized condition, characterized by an inflammatory response to the vascular deposits of β-amyloid within the brain that are the hallmark of cerebral amyloid angiopathy. Two main patterns of this inflammatory response have been identified to date: one involving a perivascular inflammatory cell infiltrate (cerebral amyloid angiopathy-related inflammation); the other a transmural vasculitic process (A-beta related angiitis). Unlike cerebral amyloid angiopathy itself, which predisposes to intracerebral hemorrhage and has no known treatment, cerebral amyloid angiopathy associated with inflammation typically presents in diverse ways and diagnosis may be challenging and delayed.

Aims

We sought to summarize the clinical features, imaging appearances and available data on outcome and treatment responses, using information derived from a systematic review of pathologically proven cases of cerebral amyloid angiopathy associated with inflammation.

Summary of review

We identified 213 distinct pathologically proven cases of cerebral amyloid angiopathy-related inflammation/A-beta related angiitis, from 104 publications. The clinical presentation, imaging features, pathology, treatment, and outcomes of cerebral amyloid angiopathy associated with inflammation are described.

Conclusions

Cerebral amyloid angiopathy associated with inflammation is an important and increasingly recognized clinical condition, which affects the older patient population and presents most commonly with cognitive decline, seizures, and headaches. Future research is required to develop and validate diagnostic criteria and determine optimum treatment strategies.

Relapsing cerebral amyloid angiopathy-related inflammation: the wax and the wane

Cerebral amyloid angiopathy-related inflammation (CAA-I) is a rare variant of cerebral amyloid angiopathy (CAA). Its precise pathophysiology remains uncertain and we currently have limited evidence on which immunosuppressive agents are the most effective in its treatment. The disease course of CAA-I disorders can vary from an isolated clinical event to recurrent episodes. We present a case of biopsy-confirmed CAA-I that gives insight into its potential relapsing nature and the challenges of its long-term management.

Multimodality Review of Amyloid-related Diseases of the Central Nervous System

Amyloid-β (Aβ) is ubiquitous in the central nervous system (CNS), but pathologic accumulation of Aβ results in four distinct neurologic disorders that affect middle-aged and elderly adults, with diverse clinical presentations ranging from chronic debilitating dementia to acute life-threatening intracranial hemorrhage. The characteristic imaging patterns of Aβ-related CNS diseases reflect the pathophysiology of Aβ deposition in the CNS. Aβ is recognized as a key component in the neuronal damage that characterizes the pathophysiology of Alzheimer disease, the most common form of dementia. Targeted molecular imaging shows pathologic accumulation of Aβ and tau protein, and fluorine 18 fluorodeoxyglucose positron emission tomography and anatomic imaging allow differentiation of typical patterns of neuronal dysfunction and loss in patients with Alzheimer disease from those seen in patients with other types of dementia. Cerebral amyloid angiopathy (CAA) is an important cause of cognitive impairment and spontaneous intracerebral hemorrhage in the elderly. Hemorrhage and white matter injury seen at imaging reflect vascular damage caused by the accumulation of Aβ in vessel walls. The rare forms of inflammatory angiopathy attributed to Aβ, Aβ-related angiitis and CAA-related inflammation, cause debilitating neurologic symptoms that improve with corticosteroid therapy. Imaging shows marked subcortical and cortical inflammation due to perivascular inflammation, which is incited by vascular Aβ accumulation. In the rarest of the four disorders, cerebral amyloidoma, the macroscopic accumulation of Aβ mimics the imaging appearance of tumors. Knowledge of the imaging patterns and pathophysiology is essential for accurate diagnosis of Aβ-related diseases of the CNS. (©)RSNA, 2016.

Oxidative stress and inflammation in cerebral cavernous malformation disease pathogenesis: Two sides of the same coin

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CCM proteins play pleiotropic roles in various redox-sensitive signaling pathways.

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CCM proteins modulate the crosstalk between redox signaling and autophagy that govern cell homeostasis and stress responses.

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Oxidative stress and inflammation are emerging as key focal determinants of CCM lesion formation, progression and severity.

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The pleiotropic functions of CCM proteins may prevent vascular dysfunctions triggered by local oxidative stress and inflammatory events.

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The distinct therapeutic compounds proposed so far for CCM disease share the ability to modulate redox signaling and autophagy.

Cerebral Cavernous Malformation (CCM) is a vascular disease of proven genetic origin, which may arise sporadically or is inherited as an autosomal dominant condition with incomplete penetrance and highly variable expressivity. CCM lesions exhibit a range of different phenotypes, including wide inter-individual differences in lesion number, size, and susceptibility to intracerebral hemorrhage (ICH). Lesions may remain asymptomatic or result in pathological conditions of various type and severity at any age, with symptoms ranging from recurrent headaches to severe neurological deficits, seizures, and stroke. To date there are no direct therapeutic approaches for CCM disease besides the surgical removal of accessible lesions. Novel pharmacological strategies are particularly needed to limit disease progression and severity and prevent de novo formation of CCM lesions in susceptible individuals.

Useful insights into innovative approaches for CCM disease prevention and treatment are emerging from a growing understanding of the biological functions of the three known CCM proteins, CCM1/KRIT1, CCM2 and CCM3/PDCD10. In particular, accumulating evidence indicates that these proteins play major roles in distinct signaling pathways, including those involved in cellular responses to oxidative stress, inflammation and angiogenesis, pointing to pathophysiological mechanisms whereby the function of CCM proteins may be relevant in preventing vascular dysfunctions triggered by these events. Indeed, emerging findings demonstrate that the pleiotropic roles of CCM proteins reflect their critical capacity to modulate the fine-tuned crosstalk between redox signaling and autophagy that govern cell homeostasis and stress responses, providing a novel mechanistic scenario that reconciles both the multiple signaling pathways linked to CCM proteins and the distinct therapeutic approaches proposed so far. In addition, recent studies in CCM patient cohorts suggest that genetic susceptibility factors related to differences in vascular sensitivity to oxidative stress and inflammation contribute to inter-individual differences in CCM disease susceptibility and severity.

This review discusses recent progress into the understanding of the molecular basis and mechanisms of CCM disease pathogenesis, with specific emphasis on the potential contribution of altered cell responses to oxidative stress and inflammatory events occurring locally in the microvascular environment, and consequent implications for the development of novel, safe, and effective preventive and therapeutic strategies.

Statin Therapy and the Development of Cerebral Amyloid Angiopathy--A Rodent in Vivo Approach

Background: Cerebral amyloid angiopathy (CAA) is characterized by vascular deposition of amyloid β (Aβ) with a higher incidence of cerebral microbleeds (cMBs) and spontaneous hemorrhage. Since statins are known for their benefit in vascular disease we tested for the effect on CAA. Methods: APP23-transgenic mice received atorvastatin-supplemented food starting at the age of eight months (n = 13), 12 months (n = 7), and 16 months (n = 6), respectively. Controls (n = 16) received standard food only. At 24 months of age cMBs were determined with T2*-weighted 9.4T magnetic resonance imaging and graded by size. Results: Control mice displayed an average of 35 ± 18.5 cMBs (mean ± standard deviation), compared to 29.3 ± 9.8 in mice with eight months (p = 0.49), 24.9 ± 21.3 with 12 months (p = 0.26), and 27.8 ± 15.4 with 16 months of atorvastatin treatment (p = 0.27). In combined analysis treated mice showed lower absolute numbers (27.4 ± 15.6, p = 0.16) compared to controls and also after adjustment for cMB size (p = 0.13). Conclusion: Despite to a non-significant trend towards fewer cMBs our results failed to provide evidence for beneficial effects of long-term atorvastatin treatment in the APP23-transgenic mouse model of CAA. A higher risk for bleeding complications was not observed.

Anti-Aβ Autoantibodies in Amyloid Related Imaging Abnormalities (ARIA): Candidate Biomarker for Immunotherapy in Alzheimer's Disease and Cerebral Amyloid Angiopathy

Amyloid-related imaging abnormalities (ARIA) represent the major severe side effect of amyloid-beta (Aβ) immunotherapy for Alzheimer’s disease (AD). Early biomarkers of ARIA represent an important challenge to ensure safe and beneficial effects of immunotherapies, given that different promising clinical trials in prodromal and subjects at risk for AD are underway. The recent demonstration that cerebrospinal fluid (CSF) anti-Aβ autoantibodies play a key role in the development of the ARIA-like events characterizing cerebral amyloid angiopathy-related inflammation generated great interest in the field of immunotherapy. Herein, we critically review the growing body of evidence supporting the monitoring of CSF anti-Aβ autoantibody as a promising candidate biomarker for ARIA in clinical trials.