COVID-19 and Alzheimer's Disease: A Literature Review

Abstract

There are a number of potential implications for the field of Alzheimer's disease (AD) stemming from the global spread of "SARS-COV-2". Many studies that were conducted by Cleveland Clinic researchers identified a link between COVID-19 infection and brain abnormalities seen in people with AD. This article explains the association between COVID-19 and AD and how people with AD are affected by COVID-19, whether directly or indirectly. First, this article begins by explaining AD and its types, then giving an overview about COVID-19, its symptoms and the associated complications. Then, direct and indirect consequences of COVID-19 on people experiencing AD are discussed briefly. Some management strategies are recommended at the end of this article in addition to a future perspective on this topic. This article concludes by summarizing the main points mentioned about the association between COVID-19 and AD.

Keywords: Alzheimer’s disease; COVID-19; SARS-CoV-2; coronavirus infections; pandemics.

Figure 1

Potential Interactions Between “SARS-COV-2” and AD. Type 2 diabetes (T2D) acts as a predisposing factor for AD. Elevations in blood glucose resulting from T2D may exacerbate pathology in both AD and COVID-19, or comorbidity of the two, through increased activity of interferon regulatory factor 5 (IRF5). Type I interferons (IFN) mediate inflammation after viral infection and in response to nucleic acid containing amyloid fibrils, eventually leading to synaptic loss. Amyloid fibrils may entrap viral particles, leading to further enhancement of IFN response. Solid line arrows indicate proven mechanisms, dotted line arrows indicate theoretical mechanisms; from ref. [50] with authorization.