Primary angiitis of the central nervous system associated with cerebral amyloid angiopathy: report of two cases and review of the literature

Cerebral amyloid angiopathy and the immune system

Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of amyloid protein in the walls of cerebral blood vessels. This deposition of amyloid causes damage to the cerebral vasculature, resulting in blood-brain barrier disruption, cerebral hemorrhage, cognitive decline, and dementia. The role of the immune system in CAA is complex and not fully understood. While the immune system has a clear role in the rare inflammatory variants of CAA (CAA related inflammation and Abeta related angiitis), the more common variants of CAA also have immune system involvement. In a protective role, immune cells may facilitate the clearance of beta-amyloid from the cerebral vasculature. The immune system can also contribute to CAA pathology, promoting vascular injury, blood-brain barrier breakdown, inflammation, and progression of CAA. In this review, we summarize the role of the immune system in CAA, including the potential of immune based treatment strategies to slow vascular disease in CAA and associated cognitive impairment, white matter disease progression, and reduce the risk of cerebral hemorrhage. HIGHLIGHTS: The immune system has a role in cerebral amyloid angiopathy (CAA) which is summarized in this review. There is an inflammatory response to beta-amyloid that may contribute to brain injury and cognitive impairment. Immune cells may facilitate the clearance of beta-amyloid from the cerebral vasculature. Improved understanding of the immune system in CAA may afford novel treatment to improve outcomes in patients with 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We present clinical and neuroradiological observations in seven unpublished CAA-RI cases, including neuropathological findings in two definite cases.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.

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.

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.

Amyloid-β related angiitis presenting as eosinophilic meningitis: a case report

BACKGROUND

Eosinophilic meningitis is uncommon and often attributed to infectious causes.

CASE PRESENTATION

We describe a case of a 72-year-old man who presented with subacute onset eosinophilic meningitis, vasculitis, and intracranial hypertension with progressive and severe neurologic symptoms. Brain MRI demonstrated multifocal strokes and co-localized right temporo-parieto-occipital vasogenic edema, cortical superficial siderosis, and diffuse leptomeningeal enhancement. He ultimately underwent brain biopsy with immunohistochemical stains for amyloid-β and Congo red that were extensively positive in the blood vessel walls and in numerous diffuse and neuritic parenchymal confirming a diagnosis of amyloid-β related angiitis. He was treated with immunosuppression with clinical stabilization.

CONCLUSIONS

Amyloid-β related angiitis is an underrecognized cause of eosinophilic meningitis that can present fulminantly and is typically responsive to immunosuppression. The presence of eosinophils may provide additional clues to the underlying pathophysiology of amyloid-β related angiitis.

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.

Association Between Immunosuppressive Treatment and Outcomes of Cerebral Amyloid Angiopathy-Related Inflammation

IMPORTANCE

Cerebral amyloid angiopathy-related inflammation (CAA-ri), a distinct subtype of cerebral amyloid angiopathy, is characterized by an autoimmune reaction to cerebrovascular β-amyloid deposits. Outcomes and response to immunosuppressive therapy for CAA-ri are poorly understood.

OBJECTIVE

To identify clinical, neuroimaging, laboratory, pathologic, or treatment-related associations with outcomes after an episode of CAA-ri.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study of prospectively identified individuals who presented from July 3, 1998, to November 27, 2017, with a median follow-up of 2.7 years (interquartile range, 1.0-5.5 years). The study included 48 consecutive patients with CAA-ri meeting diagnostic criteria who had at least 1 disease episode and subsequent outcome data. No patients refused or were excluded.

EXPOSURES

Prespecified candidate variables were immunosuppressive therapies, cerebrospinal fluid pleocytosis, magnetic resonance imaging findings of recent infarcts or contrast enhancement, and histopathologic evidence of vessel wall inflammation.

MAIN OUTCOMES AND MEASURES

Clinical improvement and worsening were defined by persistent changes in signs or symptoms, radiographic improvement by decreased subcortical foci of T2 hyperintensity or T1 enhancement, and radiographic worsening by increased subcortical T2 hyperintensity, T1 enhancement, or infarcts. Disease recurrence was defined as new-onset clinical symptoms associated with new imaging findings.

RESULTS

The 48 individuals in the study included 29 women and had a mean (SD) age of 68.9 (9.9) years. Results of presenting magnetic resonance imaging revealed that 10 of 29 patients with CAA-ri (34%) had T1 contrast enhancement, 30 of 32 (94%) had subcortical T2 hyperintensity (22 of 30 [73%] asymmetric), 7 of 32 (22%) had acute or subacute punctate infarcts, and 27 of 31 (87%) had microbleeds. Immunosuppressive treatments after first episodes included corticosteroids (33 [69%]), cyclophosphamide (6 [13%]), and mycophenolate (2 [4%]); 14 patients (29%) received no treatment. Clinical improvement and radiographic improvement were each more likely in individuals treated with an immunosuppressive agent than with no treatment (clinical improvement: 32 of 34 [94%] vs 7 of 14 [50%]; odds ratio, 16.0; 95% CI, 2.72-94.1; radiographic improvement: 24 of 28 [86%] vs 4 of 14 [29%]; odds ratio, 15.0; 95% CI, 3.12-72.1). Recurrence was less likely if CAA-ri was treated with any immunosuppressant agent than not (9 of 34 [26%] vs 10 of 14 [71%]; hazard ratio, 0.19; 95% CI, 0.07-0.48). When controlling for treatment, no variables were associated with outcomes aside from an association between APOE ɛ4 and radiographic improvement (odds ratio, 4.49; 95% CI, 1.11-18.2).

CONCLUSIONS AND RELEVANCE

These results from a relatively large series of patients with CAA-ri support the effectiveness of immunosuppressive treatment and suggest that early treatment may both improve the initial disease course and reduce the likelihood of recurrence. These results raise the possibility that early blunting of CAA-ri and the autoimmune response may have long-term benefits for the subsequent disease course.

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.

"Idiopathic Eosinophilic Vasculitis": Another Side of Hypereosinophilic Syndrome? A Comprehensive Analysis of 117 Cases in Asthma-Free Patients

BACKGROUND

The absence of asthma may rule out a diagnosis of eosinophilic granulomatosis with polyangiitis in patients with hypereosinophilic syndrome (HES) and features of vasculitis.

OBJECTIVE

To describe eosinophilic vasculitis (EoV) as a possible manifestation of HES in asthma-free patients.

METHODS

We screened our hospital database and the literature for patients with HES who met the following 4 criteria: (1) histopathological or clinical features of EoV (biopsy-proven vasculitis with predominant eosinophilic infiltration of the vessel wall and/or features of vasculitis with tissue and/or blood hypereosinophilia [absolute eosinophil count >1.5 G/L]); (2) no other obvious causes of reactive eosinophilia, organ damage, and vasculitis; (3) the absence of antineutrophil cytoplasmic antibodies; and (4) the absence of current asthma.

RESULTS

Ten of our 83 (12%) asthma-free patients with HES and 107 additional cases in the literature met the criteria for EoV. After a critical analysis of the patients' clinical and laboratory characteristics and outcomes, we identified 41 cases of single-organ EoV (coronary arteritis, n = 29; temporal arteritis, n = 8; cerebral vasculitis, n = 4). Of the remaining 76 patients with EoV, the most frequent manifestations (>10%) were cutaneous vasculitis (56%), peripheral neuropathy (24%), thromboangiitis obliterans-like disease (16%), fever (13%), central nervous system involvement (13%), deep venous thrombosis (12%), and nonasthma lung manifestations (12%). Blood hypereosinophilia more than 1.5 G/L was observed in 79% of patients, and necrotizing vasculitis was observed in 44%.

CONCLUSIONS

Our results suggest that idiopathic EoV (HES-associated vasculitis) can be classified as an eosinophilic-rich, necrotizing, systemic form of vasculitis that affects vessels of various sizes in asthma-free patients.

Rapid Cognitive Decline and Recurrent Falls in a 71 Year-Old Man Due to Cerebral Amyloidangiopathy-Related Inflammation (CAA-RI)

Cognitive decline and falls in the elderly are common and are often accepted as natural and inevitable by relatives and health care professionals, but frequently there are specific and treatable diseases that should be revealed. In our case, cerebral amyloid angiopathy-related inflammation (CAA-RI) was causative for neuro-psychiatric symptoms and worsening of gait in a 71 year-old man with recurrent falls and decline of gait and cognition. Cerebral amyloidangiopathy (CAA) is an important cause of cerebrovascular disorders in the elderly, characterized by leukoencephalopathy combined with lobar or small cortical hemorrhage due to amyloid deposition in cortical and leptomeningeal vessels. In several conditions, amyloid deposition can provoke inflammation or edema that lead to -normally reversible- encephalopathy. CAA-RI is then characterized by subacute neurobehavioral symptoms, headache, seizures or stroke-like signs. The first therapeutic option after confirming the diagnosis is treatment with glucocorticoids. Despite treatment with prednisolone, our patient could not regain his unrestricted mobility and self-help competence. Our report aims to sharpen awareness for CAA and its inflammatory form (CAA-RI) in healthcare professionals involved in medical care of the elderly and provide a short summary of this disease.

Pearls & Oy-sters: The critical role of histopathology in diagnosing cancer-associated necrotizing CNS vasculitis

OBJECTIVE

To highlight the importance of a broad differential and histopathologic confirmation in patients with newly diagnosed cancer with brain lesions atypical for CNS metastasis.

METHODS

We report 2 cases of biopsy-proven CNS vasculitis in patients undergoing treatment for a newly diagnosed nonmetastatic cancer. Comprehensive medical record review was performed to identify the clinical presentation, representative neuroimaging, histopathologic features, and response to treatment.

RESULTS

Patient 1 presented 1 month into induction therapy of malignant vaginal squamous cell carcinoma (stage 3, T2N1M0) with acute episodic left-sided hemiparesis due to seizure activity progressing to severe encephalopathy. Imaging revealed a right frontoparietal lesion while systemic workup was unrevealing. Biopsy demonstrated necrotizing vasculitis. Patient 2 presented 6 months after diagnosis of right breast invasive ductal carcinoma (stage IIa, T2N0M0, estrogen receptor-positive, progesterone receptor-positive, human epidermal growth factor receptor-2 positive) with subacute bifrontal headaches with associated phonophobia. Imaging showed hyperintense lesions involving the right temporoparietal region and systemic workup was unrevealing. Brain biopsy showed a necrotizing vasculitis. Patient 1 was treated with methyprednisolone and plasmapheresis and patient 2 was treated with prednisone. Both patients showed complete resolution of symptoms shortly after treatment and improvement on imaging.

CONCLUSIONS

These cases highlight the importance of comprehensive evaluation of new brain lesions in patients with nonmetastatic solid tumors. Characteristics of new brain lesions in patients with cancer that should raise suspicion of diagnoses other than brain metastasis include (1) primary malignancy without regional or distant metastasis, (2) imaging without discrete mass-like enhancement, and (3) cortically based location of lesions not at the gray-white matter junction.

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.

Status epilepticus caused by cerebral amyloid angiopathy-related inflammation

This report discusses a case of nonconvulsive status epilepticus, caused by cerebral amyloid angiopathy-related inflammation. Brain biopsy demonstrated cerebral amyloid angiopathy, with clinical and radiographic features indicative of a fluctuating inflammatory process. Immunomodulatory treatment with pulse steroids resulted in rapid and dramatic clinical and radiographic improvement. Cerebral amyloid angiopathy-related inflammation should be considered in the differential diagnosis of new-onset seizures after the age of 40, when associated with fluctuating multifocal T2 hyperintensities and petechial hemorrhages on gradient echo (GRE) or susceptibility-weighted (SWI) MRI sequences.

Pseudotumoral presentation of cerebral amyloid angiopathy-related inflammation

OBJECTIVE

To identify the clinical and radiologic features that should raise suspicion for the pseudotumoral presentation of cerebral amyloid angiopathy-related inflammation (CAA-I).

METHODS

We retrospectively reviewed the characteristics of 5 newly diagnosed and 23 previously reported patients in whom the CAA-I imaging findings were initially interpreted as CNS neoplasms.

RESULTS

Most cases (85%) occurred in patients >60 years old. The clinical characteristics at presentation included subacute cognitive decline (50%), confusion (32%), focal deficits (32%), seizures (25%), and headaches (21%). Brain MRI demonstrated infiltrative white matter lesions that exhibited a loco-regional mass effect without parenchymal enhancement (93%). In general, these findings were interpreted as low-grade glioma or lymphoma. Eighteen patients (64%) underwent a biopsy, which was nondiagnostic in 4 patients (14%), and 6 patients (21%) underwent a surgical resection. The primary reason for the misinterpretation of the imaging findings was the absence of T2*-weighted gradient recalled echo (T2*-GRE) sequences on initial imaging (89%). When subsequently performed (39%), the T2*-GRE sequences demonstrated multiple characteristic cortical and subcortical microhemorrhages in all cases. Perfusion MRI and magnetic resonance spectroscopy (MRS), which were performed on a subset of patients, indicated markedly reduced relative cerebral blood flow and a normal metabolic ratio.

CONCLUSION

The identification of one or several nonenhancing space-occupying lesions, especially in elderly patients presenting with cognitive impairment, should raise suspicion for the pseudotumoral presentation of CAA-I and lead to T2*-GRE sequences. Perfusion MRI and MRS appear to be useful techniques for the differential diagnosis of this entity.

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

INTRODUCTION

Cerebral amyloid angiopathy associated with inflammatory process (CAA-I) is a rare potentially treatable encephalopathy, characterized by an inflammatory response to vascular deposits of β-amyloid. We aimed to describe 3 clinical cases and perform a systematic review of all neuropathologically proved CAA-I case reports to describe its clinical and pathologic features and outcome under different treatments.

METHODS

We searched PubMed and Cochrane Library and screened references of included studies and review articles for additional citations. Outcome was classified at the last available follow-up by the modified Rankin Scale (mRS).

RESULTS

A total of 67 publications, reporting on 155 patients, were included. Mean age was 66.9 years, and 53.5% were men. The most common clinical presentation was cognitive dysfunction (48.0%) followed by headaches (38.7%), seizures (36.7%), and pyramidal signs (20.0%). Perivascular and vasculitic inflammation with granuloma was the most common pathologic pattern (27.5%). Eighty-six percent were treated with corticosteroids and 33.9% with cyclophosphamide. Forty-two percent regained independence (mRS score 0-2), whereas 20.5% were left with a severe handicap (mRS score 3-5) and 37.5% died. There were no statistically significant differences in outcome between patients treated with therapy with corticosteroids alone comparing with those treated with combination corticosteroids with cytostatic agents.

CONCLUSIONS

The most common clinical manifestation of CAA-I was cognitive dysfunction. The functional outcome was unfavorable in the majority of the patients, with death or severe disability in almost two third of the cases, despite treatment. No differences in outcome could be detected between patients treated with corticosteroids versus patients treated with cytostatics, combined with corticosteroids.

Amyloid β-Related Central Nervous System Angiitis Presenting With an Isolated Seizure

Amyloid beta-related angiitis (ABRA) of the central nervous system (CNS) is a very rare inflammatory disorder that causes destruction of CNS arteries and subsequent neuronal injury. Most patients with ABRA are old and present with cognitive dysfunction and stroke; however, some patients may present atypically. In this article, we report a 44-year-old man who presented with a first-time seizure but was otherwise neurologically intact and denied any headache. Brain MRI showed right hemispheric and bilateral medial frontal lobe hyperintensities and microhemorrhages that were most suspicious for a mass lesion. An extensive diagnostic evaluation including CSF analysis and catheter angiography was unremarkable. A brain biopsy with specific stains for amyloid surprisingly demonstrated ABRA and led to immunosuppressive treatment. The patient has remained neurologically intact and seizure-free 1 year after presentation. This case demonstrates that ABRA can occur in young patients without headache or neurologic deficits, and should be considered in patients with new-onset seizures and mass lesions. It also reinforces the need to consider a brain biopsy in patients with idiopathic brain lesions and negative non-invasive testing, as it is virtually impossible to confirm the diagnosis of ABRA otherwise.

[A case report of cerebral amyloid angiopathy-related inflammation treated with cyclophosphamide]

A 78-year-old woman was admitted to another hospital with progressive cognitive dysfunction and right hemiparesis. Magnetic resonance imaging (MRI) of the brain revealed a high-intensity area in bilateral frontal lobes on T2-weighted imaging (T2WI) and fluid-attenuated inversion recovery (FLAIR). Brain biopsy revealed no significant findings. She was transferred to our hospital for further examination. Although the etiology of the white matter lesion was not specified, the lesion and symptoms improved with steroid pulse therapy. Three months later, disturbance of consciousness and right hemiparesis worsened again, and the white matter lesion was expanded on MRI. Steroid pulse therapy was again performed, but her condition gradually deteriorated and akinetic mutism developed. T2-based imaging showed microbleeds and analysis of the apolipoprotein E (ApoE) genotype showed ε4/ε4; therefore, cerebral amyloid angiopathy-related inflammation was diagnosed. Two cycles of cyclophosphamide pulse therapy were performed, resulting in improvement of the white matter lesion, disorder of consciousness, and hemiparesis after the first cycle. The patient was discharged from our hospital in an ambulatory state. Steroid therapy for cerebral amyloid angiopathy-related inflammation is relatively well-known in Japan, but cyclophosphamide therapy appears useful for steroid-resistant amyloid angiopathy-related inflammation in the early stage of the disease.

Aβ-related angiitis: comparison with CAA without inflammation and primary CNS vasculitis

OBJECTIVE

To analyze the clinical findings, response to therapy, and outcomes of patients with cerebral vascular amyloid-β (Aβ) deposition with and without inflammatory vascular infiltration.

METHODS

We report 78 consecutive patients with cerebral vascular Aβ deposition examined at Mayo Clinic Rochester over 25 years (1987 through 2011). Specimens reviewed by a neuropathologist showed 40 with vascular Aβ peptide without inflammation (cerebral amyloid angiopathy [CAA]), 28 with granulomatous vasculitis (Aβ-related angiitis or ABRA), and 10 with perivascular CAA-related inflammation. We also matched findings in 118 consecutive patients with primary CNS vasculitis (PCNSV) without Aβ seen over 25 years (1983 through 2007).

RESULTS

Compared to the 40 with CAA, the 28 with ABRA were younger at diagnosis (p = 0.05), had less altered cognition (p = 0.02), fewer neurologic deficits (p = 0.02), and fewer intracranial hemorrhages (<0.001), but increased gadolinium leptomeningeal enhancement (p = 0.01) at presentation, and less mortality and disability at last follow-up (p < 0.001). Compared with PCNSV, the 28 patients with ABRA were older at diagnosis (p < 0.001), had a higher frequency of altered cognition (p = 0.05), seizures/spells (p = 0.006), gadolinium leptomeningeal enhancement (p < 0.001), and intracerebral hemorrhage (p = 0.02), lower frequency of hemiparesis (p = 0.01), visual symptoms (p = 0.04), and MRI evidence of cerebral infarction (p = 0.003), but higher CSF protein levels (p = 0.03). Results of treatment and outcomes in ABRA and PCNSV were similar.

CONCLUSIONS

ABRA appears to represent a distinct subset of PCNSV.

Immune activation in amyloid-β-related angiitis correlates with decreased parenchymal amyloid-β plaque load

BACKGROUND

Primary angiitis of the central nervous system (PACNS) is a rare but serious condition. A fraction of patients suffering from PACNS concurrently exhibit pronounced cerebral amyloid angiopathy (CAA) which is characterized by deposits of amyloid-β (Aβ) in and around the walls of small and medium-sized arteries of the brain. PACNS with CAA has been identified as a distinct disease entity, termed Aβ-related angiitis (ABRA). Evidence points to an immune reaction to vessel wall Aβ as the trigger of vasculitis.

OBJECTIVE

To investigate whether the inflammatory response to Aβ has (1) any effect on the status of immune activation in the brain parenchyma and (2) leads to clearance of Aβ from brain parenchyma.

METHODS

We studied immune activation and Aβ load by quantitative immunohistochemical analysis in brain parenchyma adjacent to affected vessels in 11 ABRA patients and 10 matched CAA controls.

RESULTS

ABRA patients showed significantly increased immune activation and decreased Aβ loads in the brain parenchyma adjacent to affected vessels.

CONCLUSION

Our results are in line with the hypothesis of ABRA being the result of an excessive immune response to Aβ and show that this can lead to enhanced clearance of Aβ from the brain parenchyma by immune-mediated mechanisms.

Cerebral amyloid angiopathy-associated intracerebral hemorrhage: pathology and management

Amyloid angiopathy-associated intracerebral hemorrhage (ICH) comprises 12%-15% of lobar ICH in the elderly. This growing population has an increasing incidence of thrombolysis-related hemorrhages, causing the management of hemorrhages associated with cerebral amyloid angiopathy (CAA) to take center stage. A concise reference assimilating the pathology and management of this clinical entity does not exist. Amyloid angiopathy-associated hemorrhages are most often solitary, but the natural history often progresses to include multifocal and recurrent hemorrhages. Compared with other causes of ICH, patients with CAA-associated hemorrhages have a lower mortality rate but an increased risk of recurrence. Unlike hypertensive arteriolar hemorrhages that occur in penetrating subcortical vessels, CAA-associated hemorrhages are superficial in location due to preferential involvement of vessels in the cerebral cortex and meninges. This feature makes CAA-associated hemorrhages easier to access surgically. In this paper, the authors discuss 3 postulates regarding the pathogenesis of amyloid hemorrhages, as well as the established clinicopathological classification of amyloid angiopathy and CAA-associated ICH. Common inheritance patterns of familial CAA with hemorrhagic strokes are discussed along with the role of genetic screening in relatives of patients with CAA. The radiological characteristics of CAA are described with specific attention to CAA-associated microhemorrhages. The detection of these microhemorrhages may have important clinical implications on the administration of anticoagulation and antiplatelet therapy in patients with probable CAA. Poor patient outcome in CAA-associated ICH is associated with dementia, increasing age, hematoma volume and location, initial Glasgow Coma Scale score, and intraventricular extension. The surgical management strategies for amyloid hemorrhages are discussed with a review of published surgical case series and their outcomes with a special attention to postoperative hemorrhage.

Advances in our Understanding of the Pathophysiology, Detection and Management of Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is pathologically defined as the deposition of amyloid protein, most commonly the amyloid β peptide (Aβ), primarily within the media and adventitia of small and medium-sized arteries of the leptomeninges, cerebral and cerebellar cortex. This deposition likely reflects an imbalance between Aβ production and clearance within the brain and leads to weakening of the overall structure of brain small vessels, predisposing patients tolobar intracerebral haemorrhage (ICH), brain ischaemia and cognitive decline. CAA is associated with markers of small vessel disease, like lobar microbleeds and white matter hyperintensities on magnetic resonance imaging. Therefore, it can be now be diagnosed during life with reasonable accuracy by clinical and neuroimaging criteria. Despite the lack of a specific treatment for this condition, the detection of CAA may help in the management of patients, regarding the prevention of major haemorrhagic complications and genetic counselling. This review discusses recent advances in our understanding of the pathophysiology, detection and management of CAA.

Cerebral amyloid angiopathy-related inflammation presenting with steroid-responsive higher brain dysfunction: case report and review of the literature

A 56-year-old man noticed discomfort in his left lower limb, followed by convulsion and numbness in the same area. Magnetic resonance imaging (MRI) showed white matter lesions in the right parietal lobe accompanied by leptomeningeal or leptomeningeal and cortical post-contrast enhancement along the parietal sulci. The patient also exhibited higher brain dysfunction corresponding with the lesions on MRI. Histological pathology disclosed β-amyloid in the blood vessels and perivascular inflammation, which highlights the diagnosis of cerebral amyloid angiopathy (CAA)-related inflammation. Pulse steroid therapy was so effective that clinical and radiological findings immediately improved.CAA-related inflammation is a rare disease, defined by the deposition of amyloid proteins within the leptomeningeal and cortical arteries associated with vasculitis or perivasculitis. Here we report a patient with CAA-related inflammation who showed higher brain dysfunction that improved with steroid therapy. In cases with atypical radiological lesions like our case, cerebral biopsy with histological confirmation remains necessary for an accurate diagnosis.

Eosinophilic vasculitis of the spinal cord associated with Churg-Strauss syndrome

Eosinophilic vasculitis has been described as part of Churg-Strauss syndrome (CSS), but it also affects the central nervous system in <10% of cases. However, spinal cord involvement in CSS has not been reported. We report a patient with myelopathic symptoms, with a two-year history of asthma. Laboratory tests revealed leukocytosis, with 31.7% eosinophils. A chest computed tomographic scan and radiography showed patchy bilateral areas of consolidation, predominantly involving the peripheral regions of the lower lobes. Spinal cord magnetic resonance imaging (MRI) revealed high-signal-intensity lesions at the C3-C5 and T1-T4 spinal levels on T2-weighted images. A microscopic evaluation revealed an eosinophil-rich inflammatory infiltrate with fibroid necrosis of a vessel wall, and granuloma formation in the small veins was not clearly visible. To the best of our knowledge, this is the first case of eosinophilic vasculitis of the spinal cord associated with CSS, and the patient responded well to steroids.

Steroid responsive encephalopathy in cerebral amyloid angiopathy: a case report and review of evidence for immunosuppressive treatment

Cerebral amyloid angiopathy (CAA) is a common but often asymptomatic disease, characterized by deposition of amyloid in cerebral blood vessels. We describe the successful treatment of CAA encephalopathy with dexamethasone in a patient with CAA-related inflammation causing subacute progressive encephalopathy and seizures, which is an increasingly recognized subtype of CAA. The two pathological subtypes of CAA-related inflammation are described and a review of the literature is performed concerning immunosuppressive treatment of CAA-related inflammation with special attention to its pathological subtypes. Immunosuppressive therapy appears to be an appropriate treatment for CAA encephalopathy.

Association of angiitis of central nervous system, cerebral amyloid angiopathy, and Alzheimer's disease: report of an autopsy case

The association of angiitis of central nervous system (ACNS) with cerebral amyloid angiopathy (CAA) suggests a physiopathological relationship between these two affections. Few cases are reported in patients with Alzheimer's disease (AD). We describe here a clinicopathological case associating ACNS, CAA, and AD. We discuss the aetiology of ACNS and its relationship with cerebral deposition of beta A4 amyloid protein (betaA4).

Eosinophilic vasculitis in an isolated central nervous system distribution

Eosinophilic vasculitis has been described as part of the Churg-Strauss syndrome, but affects the central nervous system (CNS) in <10% of cases. A 39-year-old woman with a history of migraine without aura presented to an institution in an acute confusional state with concurrent headache and left-sided weakness. Laboratory evaluation showed an increased cerebrospinal fluid (CSF) protein level, but otherwise unremarkable serologies. Magnetic resonance imaging showed bifrontal polar gyral-enhancing brain lesions. Her symptoms resolved over two weeks without residual deficits. Eighteen months later the patient presented with similar symptoms and neuroradiological findings showed involvement of territories different from those in her first episode. Brain biopsy showed transmural, predominantly eosinophilic, inflammatory infiltrates and fibrinoid necrosis without granulomas. She improved when treated with corticosteroids. To our knowledge, this is the first case of non-granulomatous eosinophilic vasculitis isolated to the CNS. No aetiology for this patient's primary CNS eosinophilic vasculitis has yet been identified.

Primary central nervous system vasculitis: comparison of patients with and without cerebral amyloid angiopathy

OBJECTIVES

To describe the clinical features and outcomes of patients with primary central nervous system vasculitis (PCNSV) and cerebral amyloid angiopathy (CAA) from a large cohort of consecutive patients with PCNSV treated at a single institution.

METHODS

We identified 101 consecutive patients with PCNSV admitted between January 1983 and December 2003. PCNSV diagnoses were based on findings from a central nervous system (CNS) biopsy (n = 31) and conventional angiography (n = 70). CNS tissue specimens from 49 cases were examined histologically, and 49 were stained for amyloid deposits. Those with vascular amyloid deposits (CAA) were compared with those without histological evidence of amyloid deposition.

RESULTS

Eight cases (26%) with CNS biopsy specimens positive for PCNSV also showed findings of CAA. Compared with patients with PCNSV only, these patients were older at diagnosis, predominantly male, had a more acute onset, a higher frequency of cognitive dysfunction and showed prominent gadolinium-enhanced leptomeningeal lesions with MRI. Histologically, all had a granulomatous vascular inflammatory pattern. Six patients responded promptly to therapy. Outcomes at last follow-up were similar in the two groups.

CONCLUSIONS

PCNSV with CAA appears to form a clinical subset of PCNSV. The vasculitis influences the clinical findings to a greater degree than the presence of amyloid deposits in the vessels.

Eosinophilic vasculitis in an isolated central nervous system distribution

BACKGROUND

Eosinophilic vasculitis has been described as part of the Churg-Strauss syndrome, but affects the central nervous system (CNS) in <10% of cases; presentation in an isolated CNS distribution is rare. We present a case of eosinophilic vasculitis isolated to the CNS.

CASE REPORT

A 39-year-old woman with a history of migraine without aura presented to an institution (located in the borough of Queens, New York, USA; no academic affiliation) in an acute confusional state with concurrent headache and left-sided weakness and numbness. Laboratory evaluation showed increased cerebrospinal fluid (CSF) protein level, but an otherwise unremarkable serological investigation. Magnetic resonance imaging showed bifrontal polar gyral-enhancing brain lesions. Her symptoms resolved over 2 weeks without residual deficit. After 18 months, later the patient presented with similar symptoms and neuroradiological findings involving territories different from those in her first episode. Again, the CSF protein level was high. She had a raised C reactive protein level and erythrocyte sedimentation rate. Brain biopsy showed transmural, predominantly eosinophilic, inflammatory infiltrates of medium-sized leptomeningeal arteries without granulomas. She improved, without recurrence, when treated with a prolonged course of corticosteroids.

CONCLUSIONS

To our knowledge, this is the first case of non-granulomatous eosinophilic vasculitis isolated to the CNS. No aetiology for this patient's primary CNS eosinophilic vasculitis has yet been identified. Spontaneous resolution and recurrence of her syndrome is an unusual feature of the typical CNS vasculitis and may suggest an environmental epitope with immune reaction as the cause.

Regression stage senile plaques in the natural course of Alzheimer's disease

Resolution process of cerebroparenchymal amyloid beta-protein (Abeta) deposition has become of increasing interest in the light of recent advance in the Abeta-vaccination therapy for Alzheimer's disease (AD). However, the neuropathological features of degraded and disappearing senile plaque remain poorly characterized, especially in the natural course of the disease. To clarify the natural removal processes of Abeta burden in the brain with AD, we devised a triple-step staining method: Bodian for dystrophic neurites, anti-glial fibrillary acidic protein for astrocytes, and anti-Abeta. We thus examined 24 autopsied AD brains. A novel form of senile plaques, termed 'remnant plaques', was identified. Remnant plaques were characterized by mesh-like astroglial fibrils within the entire plaque part, Abeta deposit debris exhibiting weak Abeta immunoreactivity, and only a few slender dystrophic neurites. In remnant plaques, amyloid burden was apparently decreased. The density of remnant plaques increased significantly with disease duration. Dual-labelling immunohistochemistry revealed many Abeta-immunoreactive granules in astrocytes and a modest number in microglia, both of which accumulated in senile plaques. We consider amyloid deposits of diffuse and neuritic plaques to be shredded by astrocytic processes from the marginal zone of plaques, and to gradually disintegrate into smaller compartments. Cerebroparenchymal Abeta deposits undergo degradation. After a long-standing resolution process, diffuse and neuritic plaques may finally proceed to remnant plaques. Astrocytes are actively engaged in the natural Abeta clearance mechanism in advanced stage AD brains, which may provide clues for developing new therapeutic strategies for AD.

The cerebral beta-amyloid angiopathies: hereditary and sporadic

We review the clinical, radiologic, and neuropathologic features of the hereditary and sporadic forms of cerebral amyloid angiopathy (CAA) associated with vascular deposition of the beta-amyloid peptide. Amino acid substitutions at 4 sites in the beta-amyloid precursor protein, all situated within the beta-amyloid peptide sequence itself, have been shown to cause heritable forms of CAA. The vascular diseases caused by these mutations are associated primarily with cerebral hemorrhages, white matter lesions, and cognitive impairment, and only variable extents of the plaque and neurofibrillary pathologies characteristic of Alzheimer disease. Sporadic CAA typically presents 20 or more years later than hereditary CAA, but is otherwise characterized by a comparable constellation of recurrent cerebral hemorrhages, white matter lesions, and cognitive impairment. The clinical, radiologic and pathologic similarities between hereditary and sporadic CAA suggest that important lessons for this common age-related process can be learned from the mechanisms by which mutation makes beta-amyloid tropic or toxic to vessels.

Paraneoplastic chorea with leukoencephalopathy presenting with obsessive-compulsive and behavioral disorder

Chorea is a rare manifestation of paraneoplastic disease and is associated with CV2/CRMP-5 antibodies. Obsessive-compulsive disorder and large-scale white matter abnormalities on MRI have not been previously reported in association with these antibodies. We report on a case of CV2 paraneoplastic syndrome with obsessive-compulsive behavior preceding the motor manifestations of chorea with associated leukoencephalopathy on MRI. The literature on paraneoplastic chorea is reviewed.

Cerebral amyloid angiopathy presenting with vasculitic pathology

We present an elderly patient with an unusual extensive multifocal central nervous system mass lesion, with dramatic imaging changes but only minor disturbance of cerebral function. Cerebral biopsy revealed an unexpected finding of severe cerebral amyloid angiopathy with secondary florid vasculitic appearances, which is a very rare but recognised association. Immunosuppression has produced significant sustained clinical and radiological remission.

Cerebral amyloid angiopathy and thrombolysis-related intracerebral haemorrhage

Intracerebral haemorrhage is a complication of thrombolytic therapy for acute myocardial infarction, pulmonary embolism, and ischaemic stroke. There is increasing evidence that cerebral amyloid angiopathy (CAA), which itself can cause haemorrhage (CAAH), may be a risk factor for thrombolysis-related intracerebral haemorrhage. CAAH and thrombolysis-related intracerebral haemorrhage share some clinical features, such as predisposition to lobar or superficial regions of the brain, multiple haemorrhages, increasing frequency with age, and an association with dementia. In vitro work showed that accumulation of amyloid-beta peptide causes degeneration of cells in the walls of blood vessels, affects vasoactivity, and improves proteolytic mechanisms, such as fibrinolysis, anticoagulation, and degradation of the extracellular matrix. In a mouse model of CAA there is a low haemorrhagic threshold after thrombolytic therapy compared with that in wild-type mice. To date only a small number of anecdotal clinicopathological relations have been reported; neuroimaging advances and further study of the frequency and role of CAA in patients with thrombolysis-related intracerebral haemorrhage are required.

Primary central nervous system angiitis, amyloid angiopathy, and alzheimer's pathology presenting with balint's syndrome

We report a patient who presented with Balint's syndrome as a manifestation of primary central nervous system angiitis. Clinical findings included simultanagnosia, optic ataxia, and optic apraxia. Pathologic evaluation demonstrated amyloid angiopathy and Alzheimer's plaques. The presence of primary central nervous system angiitis along with amyloid angiopathy and Alzheimer's plaques may not be coincidental. Angiitis may be a foreign body reaction to A4 amyloid deposition.

Rapidly reversible dementia in cerebral amyloid inflammatory vasculopathy

This report discusses a biopsy proven case of cerebral amyloid angiopathy, with additional prominent vascular inflammatory features, characterized by a rapidly progressive dementia and leukoencephalopathy, where the clinical and radiological abnormalities resolved rapidly with minimal therapeutic intervention. We propose the term cerebral amyloid inflammatory vasculopathy (CAIV) to describe this condition.

Clinical manifestations of cerebral amyloid angiopathy-related inflammation

To explore the clinical effects of inflammation associated with vascular deposits of the amyloid beta peptide (A beta), we analyzed 42 consecutive patients with pathologically diagnosed cerebral amyloid angiopathy (CAA) for evidence of an inflammatory response. Inflammation with giant-cell reaction surrounding amyloid-laden vessels was identified in 7 of the 42 cases. The clinical symptoms in each of the seven were subacute cognitive decline or seizure rather than hemorrhagic stroke, the primary clinical presentation in 33 of 35 patients with noninflammatory CAA (p < 0.001). Inflammatory CAA also was associated with radiographic white matter abnormalities, significantly younger age at presentation, and a marked overrepresentation of the apolipoprotein E epsilon 4/epsilon 4 genotype (71% vs 4%, p < 0.001). Of the six inflammatory CAA patients with available follow-up information, five demonstrated clinical and radiographic improvement after immunosuppressive treatment. The syndrome of CAA-related perivascular inflammation appears to represent a subset of CAA with clinically distinct symptoms that may respond to immunosuppressive treatment. These data add to evidence that inflammation against A beta can cause vascular dysfunction, a potential mechanism for the toxic response recently observed in clinical trials of A beta immunization.