Case records of the Massachusetts General Hospital. Case 22-2010. An 87-year-old woman with dementia and a seizure

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We present clinical and neuroradiological observations in seven unpublished CAA-RI cases, including neuropathological findings in two definite cases.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

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.

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.

Amylin, Aβ42, and Amyloid in Varicella Zoster Virus Vasculopathy Cerebrospinal Fluid and Infected Vascular Cells

BACKGROUND

Varicella zoster virus (VZV) vasculopathy is characterized by persistent arterial inflammation leading to stroke. Studies show that VZV induces amyloid formation that may aggravate vasculitis. Thus, we determined if VZV central nervous system infection produces amyloid.

METHODS

Aβ peptides, amylin, and amyloid were measured in cerebrospinal fluid (CSF) from 16 VZV vasculopathy subjects and 36 stroke controls. To determine if infection induced amyloid deposition, mock- and VZV-infected quiescent primary human perineurial cells (qHPNCs), present in vasculature, were analyzed for intracellular amyloidogenic transcripts/proteins and amyloid. Supernatants were assayed for amyloidogenic peptides and ability to induce amyloid formation. To determine amylin's function during infection, amylin was knocked down with small interfering RNA and viral complementary DNA (cDNA) was quantitated.

RESULTS

Compared to controls, VZV vasculopathy CSF had increased amyloid that positively correlated with amylin and anti-VZV antibody levels; Aβ40 was reduced and Aβ42 unchanged. Intracellular amylin, Aβ42, and amyloid were seen only in VZV-infected qHPNCs. VZV-infected supernatant formed amyloid fibrils following addition of amyloidogenic peptides. Amylin knockdown decreased viral cDNA.

CONCLUSIONS

VZV infection increased levels of amyloidogenic peptides and amyloid in CSF and qHPNCs, indicating that VZV-induced amyloid deposition may contribute to persistent arterial inflammation in VZV vasculopathy. In addition, we identified a novel proviral function of amylin.

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.

Amyloid-related imaging abnormalities in amyloid-modifying therapeutic trials: recommendations from the Alzheimer's Association Research Roundtable Workgroup

Amyloid imaging related abnormalities (ARIA) have now been reported in clinical trials with multiple therapeutic avenues to lower amyloid-β burden in Alzheimer's disease (AD). In response to concerns raised by the Food and Drug Administration, the Alzheimer's Association Research Roundtable convened a working group to review the publicly available trial data, attempts at developing animal models, and the literature on the natural history and pathology of related conditions. The spectrum of ARIA includes signal hyperintensities on fluid attenuation inversion recoverysequences thought to represent "vasogenic edema" and/or sulcal effusion (ARIA-E), as well as signal hypointensities on GRE/T2* thought to represent hemosiderin deposits (ARIA-H), including microhemorrhage and superficial siderosis. The etiology of ARIA remains unclear but the prevailing data support vascular amyloid as a common pathophysiological mechanism leading to increased vascular permeability. The workgroup proposes recommendations for the detection and monitoring of ARIA in ongoing AD clinical trials, as well as directions for future research.

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.