Covid-19 linked to cognitive decline, acceleration of Alzheimer's-like symptoms, research finds

Covid-19 linked to cognitive decline, acceleration of Alzheimer's-like symptoms, research finds

Posted: Jul 29, 2021 3:50 PM
Updated: Jul 29, 2021 3:50 PM

Covid-19 may be associated with cognitive decline and acceleration of Alzheimer's-like symptoms, researchers reported Thursday.

Researchers with an international consortium looking to understand the long-term consequences of Covid-19 on the central nervous system are finding memory issues and biological markers similar to those seen in Alzheimer's disease patients. Both diseases have been marked by inflammation of the brain.

Dr. Gabriel de Erausquin, a professor of neurology at the University of Texas Health Science Center, and colleagues studied more than 200 adults 60 and older from Argentina who were infected with Covid-19.

Those who had a persistent loss of smell were more likely to experience cognitive issues, they told the Alzheimer's Association International Conference.

Three to six months after they were infected, more than half of the patients still struggled with forgetfulness and about a quarter experienced additional cognitive challenges. How sick a patient was with Covid-19 was not an indicator of whether they would experience cognitive decline.

"The severity of the initial disease does not predict who is going to get this," Erausquin told CNN. "In fact, many of them had minimal symptoms -- just a cold or loss of smell."

The cognitive issues --including persistent forgetfulness, difficulty sequencing tasks, and forgetting words and phrases -- are similar to those seen in Alzheimer's patients. Erausquin noted that the parts of the brain responsible for sense of smell overlap with those impacted by Alzheimer's disease.

He noted that the cognitive symptoms his team observed appear to be distinct from the "brain fog," associated with long-term symptoms of Covid-19, sometimes seen in younger patients.

"Brain fog in younger individuals has a different flavor, if you will," Erausquin said. "They have more attentional problems, more concentration problems, and frequently have more anxiety and depression."

It's too soon to tell whether the cognitive issues will worsen over time -- as they would in Alzheimer's patients -- or if these patients will recover, Erausquin said.

Biological Markers linked to Alzheimer's

In additional research presented at the conference, Dr. Thomas Wisniewski, a professor of neurology at New York University Grossman School of Medicine, and colleagues found that Covid-19 patients over the age of 60 had biological blood markers also found in Alzheimer's patients.

Among 310 Covid-19 patients admitted to New York University Langone Health, the team found that those with neurological symptoms had higher levels of biomarkers linked to Alzheimer's. Those biomarkers include a protein called tau that's been linked with Alzheimer's and other compounds known as neurofilament light -- an indicator of damage to nerve cells -- and others.

"These findings suggest that patients who had COVID-19 may have an acceleration of Alzheimer's-related symptoms and pathology," Wisniewski said in a statement.

Wisniewski said more research is needed to understand how those biomarkers affect long-term cognition in people who were infected with Covid-19.

"Those are the kinds of things that make you suspicious that indeed there may be an overlap with Alzheimer's disease, of some sort," Erausquin said. "But it's very early in the game. We need a lot more data."

Researchers have long been tuned in to the potential links between respiratory diseases and the brain, Heather Snyder, vice president of medical and scientific relations at the Alzheimer's Association, told CNN. She noted that similar changes in cognition and behavior, like increased anxiety and sleep disturbances, were observed in people infected during outbreaks of Severe Acute Respiratory Syndrome or SARS in 2003-2004 and Middle East Respiratory Syndrome or MERS.

Long-term questions

Snyder said researchers are working hard to understand the long-term consequences of these findings on Covid-19 and cognition.

"We also need to be really trying to understand the impact on the brain, overall, because we know that when our brains might be vulnerable for other reasons, it may also increase our risk of Alzheimer's," Snyder said.

Erausquin stressed that the research does not show that Covid-19 increases a person's risk for Alzheimer's, and there are some big questions that can only be answered with time.

"I'm trying to understand whether the virus accelerates a pre-existing condition, or if it causes a new Alzheimer's-like process to begin and then progress, or if it behaves as a fixed problem that will completely recover," he said. "We just don't know that yet."

What researchers do know is that older adults can take action to decrease their overall risk of cognitive impairment, like engaging in physical activity, staying socially connected and maintaining a healthy diet.

"I think that it's important to remember that regardless of the reason for the cognitive decline, the brain is plastic, and a lot of these interventions are likely to reduce the risk of impairment or the risk of progression," said Erausquin.

The-CNN-Wire
™ & © 2021 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.

Terre Haute
Clear
66° wxIcon
Hi: 68° Lo: 48°
Feels Like: 66°
Robinson
Partly Cloudy
66° wxIcon
Hi: 69° Lo: 45°
Feels Like: 66°
Indianapolis
Mostly Cloudy
61° wxIcon
Hi: 65° Lo: 53°
Feels Like: 61°
Rockville
Partly Cloudy
66° wxIcon
Hi: 67° Lo: 48°
Feels Like: 66°
Casey
Partly Cloudy
66° wxIcon
Hi: 68° Lo: 45°
Feels Like: 66°
Brazil
Partly Cloudy
66° wxIcon
Hi: 67° Lo: 48°
Feels Like: 66°
Marshall
Partly Cloudy
66° wxIcon
Hi: 68° Lo: 46°
Feels Like: 66°
Sunny and dry, but cool and breezy!
WTHI Planner
WTHI Temps
WTHI Radar

WTHI Events

 

Illinois Coronavirus Cases

(Widget updates once daily at 7 p.m. CT)

Cases: 1605320

Reported Deaths: 27132
CountyCasesDeaths
Cook61354910964
DuPage1039171357
Will873121089
Lake771121060
Kane65888850
Winnebago39007544
Madison38143576
St. Clair35003569
McHenry33032316
Peoria25972362
Champaign25862182
Sangamon24588271
McLean21879207
Tazewell19736326
Rock Island17806344
Kankakee16784234
Kendall15459106
LaSalle14496275
Macon14478240
Vermilion13234189
Adams12695148
DeKalb11667128
Williamson11419157
Whiteside7897176
Jackson769188
Boone760082
Coles7341112
Ogle713486
Grundy701281
Franklin686899
Clinton681498
Knox6651164
Marion6547138
Macoupin646399
Henry620474
Jefferson6060132
Effingham604382
Livingston571295
Woodford554291
Stephenson546289
Randolph529297
Monroe508199
Christian491780
Fulton487970
Morgan487296
Logan477474
Montgomery467476
Lee458156
Bureau427188
Perry415171
Saline409263
Fayette398956
Iroquois394673
McDonough354956
Jersey322253
Shelby311843
Douglas306636
Crawford304130
Lawrence301131
Union296747
Wayne274057
White265930
Richland262054
Hancock256334
Pike255956
Cass250928
Clark250738
Bond244024
Clay240047
Ford235256
Edgar234744
Carroll225437
Warren224960
Johnson213524
Moultrie211831
Jo Daviess206126
Washington206127
Wabash200915
Greene200739
Mason199351
Massac198144
De Witt195530
Piatt190814
Mercer190634
Cumberland178325
Menard158612
Jasper152418
Marshall134721
Hamilton128821
Brown10178
Pulaski98311
Schuyler9688
Edwards96315
Stark76827
Gallatin7435
Scott6975
Alexander67611
Henderson65114
Calhoun6442
Hardin56013
Putnam5444
Pope4815
Unassigned1882432
Out of IL40

Indiana Coronavirus Cases

(Widget updates once daily at 8 p.m. ET)

Cases: 941120

Reported Deaths: 15315
CountyCasesDeaths
Marion1282511983
Lake633041097
Allen53609758
Hamilton43827447
St. Joseph41906590
Elkhart33545490
Vanderburgh30383448
Tippecanoe26820249
Johnson23609417
Hendricks22250341
Porter21737346
Clark17409229
Madison17366384
Vigo16108281
Monroe14466191
LaPorte14311239
Delaware14070221
Howard13865272
Kosciusko11418135
Hancock10841165
Warrick10674177
Bartholomew10542168
Floyd10430205
Wayne9959226
Grant9130204
Morgan8865160
Boone8389111
Dubois7710123
Dearborn762289
Henry7608130
Noble7413101
Marshall7362128
Cass7176117
Lawrence6957153
Shelby6584111
Jackson656785
Gibson6156107
Harrison603786
Huntington600195
Montgomery5805105
DeKalb574291
Knox5494104
Miami542488
Putnam536768
Clinton533665
Whitley524953
Steuben497268
Wabash483592
Jasper479160
Jefferson470092
Ripley454277
Adams444068
Daviess4169108
Scott405865
White391857
Clay390857
Greene388392
Decatur385296
Wells384983
Fayette374278
Posey359941
Jennings353156
Washington332047
LaGrange321375
Spencer317835
Fountain316555
Randolph312888
Sullivan307449
Owen283863
Starke280064
Fulton277553
Orange275859
Jay254837
Perry251652
Carroll243729
Franklin239338
Rush234130
Vermillion233250
Parke219820
Tipton209655
Pike207639
Blackford168334
Pulaski163551
Crawford146018
Newton144345
Benton142516
Brown135346
Martin128217
Switzerland125810
Warren114616
Union96911
Ohio79711
Unassigned0479