PR90816

DENVER, July 30, 2021 /PRNewswire=KYODO JBN/ --

Much has been learned about SARS-CoV-2, the virus that causes the novel

coronavirus, since the beginning of the COVID-19 pandemic. However, questions

remain about the long-term impact of the virus on our bodies and brains. New

research reported at the Alzheimer's Association International Conference(R)

(AAIC(R)) 2021 (

https://c212.net/c/link/?t=0&l=en&o=3237010-1&h=636925912&u=https%3A%2F%2Fwww.alz.org%2Faaic&a=Alzheimer%27s+Association+International+Conference%C2%AE+(AAIC%C2%AE)+2021

), held virtually and in Denver found associations between COVID-19 and

persistent cognitive deficits, including the acceleration of Alzheimer's

disease pathology and symptoms.

Logo -

https://mma.prnewswire.com/media/1579813/Alzheimers_Association_International_Conference_2021_Logo.jpg

In addition to the respiratory and gastrointestinal symptoms that accompany

COVID-19, many people with the virus experience short- and/or long-term

neuropsychiatric symptoms, including loss of smell and taste, and cognitive and

attention deficits, known as "brain fog." For some, these neurological symptoms

persist, and researchers are working to understand the mechanisms by which this

brain dysfunction occurs, and what that means for cognitive health long term.

Scientific leaders, including the Alzheimer's Association and representatives

from nearly 40 countries -- with technical guidance from the World Health

Organization (WHO) -- are part of an international, multidisciplinary

consortium (

https://c212.net/c/link/?t=0&l=en&o=3237010-1&h=2803639794&u=https%3A%2F%2Fwww.alz.org%2Fresearch%2Ffor_researchers%2Fpartnerships%2Fsars-cov2-global-brain-study&a=consortium

) to collect and evaluate the long-term consequences of COVID-19 on the central

nervous system, as well as the differences across countries. Initial findings

from this consortium presented at AAIC 2021 from Greece and Argentina suggest

older adults frequently suffer persistent cognitive impairment, including

persistent lack of smell, after recovery from SARS-CoV-2 infection.

Other key results reported at AAIC 2021 include:

    - Biological markers of brain injury, neuroinflammation and Alzheimer's

      correlate strongly with the presence of neurological symptoms in

      COVID-19 patients.

    - Individuals experiencing cognitive decline post-COVID-19 infection

      were more likely to have low blood oxygen following brief physical

      exertion as well as poor overall physical condition.

"These new data point to disturbing trends showing COVID-19 infections leading

to lasting cognitive impairment and even Alzheimer's symptoms," said Heather M.

Snyder, Ph.D., Alzheimer's Association vice president of medical and scientific

relations. "With more than 190 million cases and nearly 4 million deaths

worldwide, COVID-19 has devastated the entire world. It is imperative that we

continue to study what this virus is doing to our bodies and brains. The

Alzheimer's Association and its partners are leading, but more research is

needed."

Cognitive Impairment Correlates with Persistent Loss of Smell in Recovered

COVID-19 Patients

Gabriel de Erausquin, M.D., Ph.D., M.Sc., of the University of Texas Health

Science Center at San Antonio Long School of Medicine, along with colleagues

from the Alzheimer's Association-led global SARS-CoV-2 consortium (

https://c212.net/c/link/?t=0&l=en&o=3237010-1&h=2803639794&u=https%3A%2F%2Fwww.alz.org%2Fresearch%2Ffor_researchers%2Fpartnerships%2Fsars-cov2-global-brain-study&a=consortium

), studied cognition and olfactory senses in a cohort of nearly 300 older adult

Amerindians from Argentina who had COVID-19.

Participants were studied between three and six months after COVID-19

infection. More than half showed persistent problems with forgetfulness, and

roughly one in four had additional problems with cognition including language

and executive dysfunction. These difficulties were associated with persistent

problems in smell function, but not with the severity of the original COVID-19

disease.

"We're starting to see clear connections between COVID-19 and problems with

cognition months after infection," said Erausquin. "It's imperative we continue

to study this population, and others around the world, for a longer period of

time to further understand the long-term neurological impacts of COVID-19."

COVID-19 Infection Associated with Uptick in Alzheimer's Biomarkers in the Blood

Certain biological markers in blood -- including total tau (t-tau),

neurofilament light (NfL), glial fibrillary acid protein (GFAP), ubiquitin

carboxyl-terminal hydrolase L1 (UCH-L1), and species of amyloid beta (AB40,

AB42) and phosphorylated tau (pTau-181) -- are indicators of injury in the

brain, neuroinflammation and Alzheimer's disease.

To study the presence of these blood biomarkers, neurodegeneration and

neuroinflammation in older patients who were hospitalized with COVID-19, Thomas

Wisniewski, M.D., a professor of neurology, pathology and psychiatry at New

York University Grossman School of Medicine, and colleagues took plasma samples

from 310 patients who were admitted to New York University Langone Health with

COVID-19. Of the patients, 158 were positive for SARS-CoV-2 with neurological

symptoms and 152 were positive for SARS-CoV-2 without neurologic symptoms. The

most common neurological symptom was confusion due to toxic-metabolic

encephalopathy (TME).

In patients who were initially cognitively normal with and without TME related

to COVID-19 infection, the researchers found higher levels of t-tau, NfL, GFAP,

pTau 181, and UCH-L1 in COVID-19 patients with TME compared to COVID-19

patients without TME. There were no significant differences with AB1-40, but

the pTau/AB42 ratio showed significant differences in patients with TME.

Additionally, t-tau, NfL, UCHL1, and GFAP significantly correlated with markers

of inflammation such as C-reactive peptide, which may suggest

inflammation-related blood-brain barrier disruption accompanying neuronal/glial

injury.

"These findings suggest that patients who had COVID-19 may have an acceleration

of Alzheimer's-related symptoms and pathology," said Wisniewski. "However, more

longitudinal research is needed to study how these biomarkers impact cognition

in individuals who had COVID-19 in the long term."

Individuals Recovered from COVID-19 Who Experience Cognitive Decline More

Likely to Have Poor Physical Condition, Low Oxygen Saturation

George Vavougios, M.D., Ph.D., postdoctoral researcher for the University of

Thessaly (UTH), and colleagues studied cognitive impairment and related health

measures in 32 previously hospitalized mild to moderate COVID-19 patients two

months after discharge from the hospital. Among them, 56.2% presented with

cognitive decline. Short-term memory impairments and multidomain impairment

without short-term memory deficits were the predominant patterns of cognitive

impairment.

Worse cognitive test scores correlated with higher age, waist circumference and

waist-to-hip ratio. After adjusting for age and sex, worse memory and thinking

scores were independently associated with lower levels of oxygen saturation

during the 6-minute walk test, which is commonly used to assess the functional

capacity of people with cardiopulmonary disease.

"A brain deprived of oxygen is not healthy, and persistent deprivation may very

well contribute to cognitive difficulties," said Vavougios. "These data suggest

some common biological mechanisms between COVID-19's dyscognitive spectrum and

post-COVID-19 fatigue that have been anecdotally reported over the last several

months."

This cohort is also part of the global SARS-CoV-2 consortium.

About the Alzheimer's Association International Conference (AAIC)

The Alzheimer's Association International Conference (AAIC) is the world's

largest gathering of researchers from around the world focused on Alzheimer's

and other dementias. As a part of the Alzheimer's Association's research

program, AAIC serves as a catalyst for generating new knowledge about dementia

and fostering a vital, collegial research community.

AAIC 2021 home page: www.alz.org/aaic/

AAIC 2021 newsroom: www.alz.org/aaic/pressroom.asp

AAIC 2021 hashtag: #AAIC21

About the Alzheimer's Association

The Alzheimer's Association is a worldwide voluntary health organization

dedicated to Alzheimer's care, support and research. Our mission is to lead  

the way to end Alzheimer's and all other dementia -- by accelerating global

research, driving risk reduction and early detection, and maximizing quality

care and support. Our vision is a world without Alzheimer's and all other

dementia(R). Visit: alz.org (

https://c212.net/c/link/?t=0&l=en&o=3237010-1&h=3961811081&u=https%3A%2F%2Fwww.alz.org%2F&a=alz.org

) or call +1-800.272.3900.

    - Gabriel de Erausquin, M.D., Ph.D., MSc., et al. Olfactory dysfunction

      and chronic cognitive impairment following SARS-CoV-2 infection in a

      sample of older adults from the Andes mountains of Argentina.

      (Funder(s): Alzheimer's Association; Fundacion de Lucha contra los

      Trastornos Neurol¨®gicos y Psiquiatricos en Minorias (FULTRA); Zachry

      Foundation Distinguished Chair of Alzheimer's Clinical Care and

      Research; Greehey Family Foundation Distinguished University Chair of  

      Alzheimer's Research)

    - Thomas Wisniewski, Ph.D., et al. Plasma Biomarkers of Neurodegeneration

      and Neuroinflammation in Hospitalized COVID-19 Patients with and

      without New Neurological Symptoms (Funder(s): National Institutes of

      Health/National Institute on Aging)

    - George Vavougios, MD, Ph.D., et al. Investigating the prevalence of

      cognitive impairment in mild and moderate COVID-19 patients two months

      post-discharge: associations with physical fitness and respiratory

      function. (Funder(s): 2020 National Strategic Reference Framework

      (NSRF) Scholarship)

SOURCE:  Alzheimer’s Association

CONTACT: Alzheimer's Association Media Line

         +1-312-335-4078

         media@alz.org

         AAIC 2021 Press Office

         aaicmedia@alz.org