Truths and Myths About COVID-19 and Alzheimer Disease: Joanna Hellmuth, MD, MS

WATCH TIME: 4 minutes

"I’m not going to say [COVID-19 is] not going to cause it [Alzheimer disease], because for some people it might. But my hypothesis would be that for most people who develop COVID-associated cognitive changes, that this is not likely to set them up for an incipient neurodegenerative disease in the future."

Cognitive post-acute sequelae (PASC) of SARS-CoV-2 can occur after mild COVID-19 infection, although the reasons why this happens is unknown. A recently published analysis compared clinical characterizations of those who did and did not develop cognitive changes after infection.1 Delayed onset of cognitive PASC occurred in 43% of the cohort and was associated with younger age. Additionally, patients who showed cognitive changes a higher number of preexisting cognitive risk factors and higher proportion of abnormal cerebrospinal fluid findings versus controls.

The post-COVID cognitive changes, commonly referred to as “COVID fog” have become more wildly reported, causing concern that infection may lead to neurocognitive disorders such as Alzheimer disease (AD), or other predementia disorders such as mild cognitive impairment. It is also unclear what changes are directly caused by COVID-19, or whether they are exacerbated by an underlying condition. When conducting the study, senior author Joanna Hellmuth, MD, MS, noticed that the clinical characterizations of patients with PASC resembled those of HIV-associated neurocognitive disorders.

Although patients with HIV-associated neurocognitive disorders have not been linked to an increased risk of AD, it may be too early to make same assumptions for COVID-19, Hellmuth said. Hellmuth, who is a cognitive neurologist at the University of California, San Francisco, sat down for an interview with NeurologyLive® to discuss how PASC could develop into mild cognitive impairment or AD. She provided insight on what has been previously observed, the pathogenesis of COVID-19, and the data’s comparisons with other viral infections, such as HIV.

REFERENCE
1. Apple AC, Oddi A, Peluso MJ, et al. Risk factors and abnormal cerebrospinal fluid associate with cognitive symptoms after mild COVID-19. Ann Clin Transl Neurol. Published online January 19, 2022. doi:10.1002/can3.51498