Amyloid β-related angiitis of the central nervous system occurring after COVID-19 vaccination: A case report

Severe cerebral amyloid angiopathy related inflammation (CAA-ri) associated with vaccination: Case report and literature review

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rapid but reversible autoimmune encephalopathy where spontaneous autoantibody reaction against amyloid beta deposited in cerebral blood vessels produces characteristic neuroinflammatory changes such as vasogenic edema and microhemorrhages on MRI. The term amyloid-related imaging abnormalities (ARIA) is sometimes used to describe these changes but are more often reserved for similar MRI signal abnormalities seen after administration of anti-amyloid immunotherapy, using treatment exposure as an antecedent. It is unclear if there is any biological basis for this dichotomized distinction. We report a case of severe CAA-ri after exposure to SARS-CoV-2 vaccine and performed a literature review of CAA-ri related to vaccination. CAA-ri precipitated by immunogenic triggers other than anti-amyloid therapy would lend support to the hypothesis that ARIA seen on MRI may represent the same disease underpinned by a shared anti-Aβ autoantibody response irrespective of etiology. A thorough history should be taken before labelling CAA-ri as spontaneous.

Post-COVID-19 Vaccination CNS Magnetic Resonance Imaging Findings: A Systematic Review

Objective

This systematic review aims to synthesize and analyze the available literature on central nervous system (CNS) magnetic resonance imaging (MRI) findings in individuals who have received COVID-19 vaccinations. Our objective is to enhance understanding of potential neurological side effects, inform clinical practice, and guide future research on the neurological implications of COVID-19 vaccination.

Methods

In this systematic review, we conducted a comprehensive search in PubMed, Scopus, and Web of Science from January 2020 to April 2023, using terms related to COVID-19 vaccination and CNS MRI findings. We evaluated the quality of the study, extracted relevant data, and included 89 eligible studies that covered various vaccines, demographics of patients, symptoms, and MRI findings to provide a thorough understanding of SARS-CoV-2 vaccination-related CNS problems.

Results

We investigated CNS MRI findings following COVID-19 vaccination across various vaccine types. Common diseases associated with post-vaccination CNS MRI findings included cerebral venous sinus thrombosis (CVST), vaccine-induced immune thrombotic thrombocytopenia (VITT), acute disseminated encephalomyelitis (ADEM), acute myelitis, autoimmune encephalitis (AE), and others. Patients presented with diverse onset symptoms and neurological manifestations. Abnormalities identified in CNS MRI findings included white matter (WM) hyperintensity. Our analysis offers a comprehensive overview of the current literature on post-vaccination CNS MRI findings. Discussion. We highlight a range of post-COVID-19 vaccination CNS MRI findings, including CVST, with a higher incidence in individuals receiving the ChAdOx1 (AstraZeneca) vaccine. Other notable observations include cases of ADEM, myelitis or transverse myelitis (TM), Guillain-Barré syndrome (GBS), and acute encephalopathy following COVID-19 vaccination. The incidence of these neurological complications is extremely rare, and the benefits of vaccination outweigh the risks. The reviewed studies were primarily case reports or case series, and thus large-scale epidemiological studies and controlled clinical trials are needed to better understand the underlying mechanisms and risk factors associated with these neurological complications following COVID-19 vaccination.

The Vascular-Immune Hypothesis of Alzheimer's Disease

Alzheimer's disease (AD) is a devastating and irreversible neurodegenerative disorder with unknown etiology. While its cause is unclear, a number of theories have been proposed to explain the pathogenesis of AD. In large part, these have centered around potential causes for intracerebral accumulation of beta-amyloid (βA) and tau aggregates. Yet, persons with AD dementia often exhibit autopsy evidence of mixed brain pathologies including a myriad of vascular changes, vascular brain injuries, complex brain inflammation, and mixed protein inclusions in addition to hallmark neuropathologic lesions of AD, namely insoluble βA plaques and neurofibrillary tangles (NFTs). Epidemiological data demonstrate that overlapping lesions diminish the βA plaque and NFT threshold necessary to precipitate clinical dementia. Moreover, a subset of persons who exhibit AD pathology remain resilient to disease while other persons with clinically-defined AD dementia do not exhibit AD-defining neuropathologic lesions. It is increasingly recognized that AD is a pathologically heterogeneous and biologically multifactorial disease with uncharacterized biologic phenomena involved in its genesis and progression. Here, we review the literature with regard to neuropathologic criteria and incipient AD changes, and discuss converging concepts regarding vascular and immune factors in AD.