麻豆影视

Skip to main content

COVID-19 could serve as a 'Trojan horse' for dementia and Alzheimer's, experts say

Share
TORONTO -

Experts are warning that the COVID-19 pandemic could usher in a wave of increased dementia and Alzheimer鈥檚 worldwide through the 鈥楾rojan horse鈥 of neurological symptoms associated with long COVID, also known as long-haul COVID-19.

Alzheimer鈥檚 Disease International (ADI), which represents more than 100 Alzheimer鈥檚 and dementia associations, is calling on the World Health Organization and governments across the globe to invest funding into more research on the link between long COVID cases and dementia.

In a press release, ADI explained that even before COVID-19, it was predicted that dementia cases would rise from 55 million to 78 million by 2030, and associated health-care costs could rise to $3.5 trillion annually.

Now, experts believe millions more than that could face an accelerated risk of dementia due to COVID-19鈥檚 impact on the brain.

鈥淢any dementia experts around the globe are seriously concerned by the link between dementia and the neurological symptoms of COVID-19,鈥 Paola Barbarino, CEO of ADI, said in the release.

鈥淲e urge the WHO, governments and research institutions across the globe to prioritise and commit more funding to research and establish resources in this space, to avoid being further overwhelmed by the oncoming pandemic of dementia.鈥

Dementia is a general term describing symptoms that affect memory and executive functioning. A person with dementia may struggle to remember things, process thoughts and make decisions in a way that interferes with day-to-day activity. Alzheimer鈥檚 disease is the most common type of dementia. According to Alzheimer鈥檚 Association, more than 747,000 Canadians live with dementia.

Dr. Alireza Atri, a leading expert in dementia, and part of a working group of scientists looking to study this issue, told CTVNews.ca over email that he first started to notice the problem last fall, when several patients in their 50s showed fast deterioration of their cognitive functions.

鈥淎ll had been ill with COVID 鈥 mostly with mild illness, though one had been in the hospital for four days 鈥 a few months prior to the steep decline in their cognitive functions,鈥 he said. "None of the patients or their family members had thought to link COVID with their mental decline.鈥 

Since the COVID-19 pandemic began, many of those who survive the virus have reported lasting cognitive impairment. A June survey looking at 1,000 Canadians who previously tested positive for COVID-19 found that more than 80 per cent of respondents had cognitive symptoms last for at least three months, while almost half said that their symptoms had lasted 11 months or longer.

Other studies have found that those hospitalized with COVID-19 experienced neurological symptoms, with one study across 13 countries finding that 82 per cent reported neurological issues.

And new research revealed at the recent Alzheimer鈥檚 Association International Conference found specific biomarkers associated with dementia and Alzheimer鈥檚 in patients hospitalized with COVID-19.

In the study, which looked at plasma samples from 310 COVID-19 patients admitted to New York University Langone Health, researchers observed that biomarkers of neuronal injury, neuroinflammation and Alzheimer鈥檚 disease were found at higher levels in COVID-19 patients who had reported neurological symptoms.

Atri said that with the combination of studies showing neurological symptoms in COVID-19 patients, as well as autopsy results showing that the brain was affected, he and his colleagues started to realize the extent of the impact.

鈥淚t dawned on us that COVID was likely causing a massive acceleration in cognitive decline in individuals who were harboring Alzheimer鈥檚 disease (AD) in their brains, but who, up to that point, were mostly combating it and showing very little symptoms,鈥 he said. 鈥淐OVID likely set fire to the Alzheimer鈥檚 kindling and fanned small flames that were already there, thus tipping their mental function over the edge.鈥

In the release, he outlined the neurological symptoms of long COVID that are worrisome, such as loss of taste and smell, brain fog and difficulties with memory, concentration and language.

鈥淐OVID-19 can cause damage and clotting in the brain鈥檚 micro vessels, immune dysfunction and hyperactivation, inflammation, and, last but not least, direct viral brain invasion through the olfactory pathways,鈥 he said in the release.

鈥淪imply put, if you have a fortress and an enemy puts holes in your walls, you鈥檙e less likely to be able to withstand current and future attacks. COVID-19 opens the gates in the same way that the Greek soldiers hiding in the wooden horse did. It gives easier access to things that can harm your brain.鈥

He told CTVNews.ca that the decline that leads to Alzheimer鈥檚 generally starts 15-25 years before symptoms show up, and that diagnosis takes a couple years after that in most cases.

The processes that lead to dementia 鈥渋nvolve the clumping of toxic proteins in the brain that ultimately overcome the brain鈥檚 defense mechanisms,鈥 he said.

鈥淲ith the spreading of these 鈥榝ires鈥, including inflammation, there is disruption of energy use and destruction of brain connections and cells.鈥

Although it鈥檚 not yet fully understood how COVID-19 impacts the brain, 鈥渁nything that diminishes cognitive resilience allows the impact of neurodegenerative processes to accelerate.鈥

So a person who may be vulnerable to developing dementia, or may have presented with it later in life, could start showing symptoms earlier, experts believe.

鈥淏y taking a COVID-19 hit to the brain, it can be like pouring fuel or starting new fires in the brain 鈥 and thus add to a person鈥檚 risk or accelerate their trajectory of decline,鈥 he said.

In the short term, experts expect to see a temporary dip in dementia levels worldwide, simply because a large majority of those suffering from dementia are older, and COVID-19 has killed so many of the elderly. But they expect that we will see dementia impacting more and more people moving forward.

How soon we will see these increases in dementia levels depends on how quickly we can gather the resources to study it properly, Atri said.

鈥淏ut first, we need to let people know that this is a likelihood,鈥 he said.

More research into the issue is important in order to make a plan for how to address a coming increase in dementia patients, Barbarino said.

鈥淧eople at risk of developing dementia need to know about the potential impact of long COVID on their brain health,鈥 says Barbarino. 鈥淲e need people to be aware of the possible link between long COVID and dementia, so they know to self-monitor for symptoms and catch it in its tracks. Measures must be put in place to protect them.鈥

For those who are concerned about dementia,

Atri suggested that in addition to investing in research, we should be investing in clinical care for those with dementia, as well as those with long COVID. But awareness is the first step to diagnosis 鈥 and it seems this is something we need to be watching out for during this pandemic.

CTVNews.ca Top Stories

Why brain aging can vary dramatically between people

Researchers are uncovering deeper insights into how the human brain ages and what factors may be tied to healthier cognitive aging, including exercising, avoiding tobacco, speaking a second language or even playing a musical instrument.

The union representing some 1,200 dockworkers at the Port of Montreal has overwhelmingly rejected a deal with their employers association.

A man who was critically injured in a police-involved shooting in Hamilton late Sunday afternoon has died in hospital, says the province鈥檚 police watchdog.

opinion

opinion How to transition from renting to owning a home in Canada

In his column for CTVNews.ca, personal finance contributor Christopher Liew offers a step-by-step guide on how to make the shift from renting to becoming a homeowner, and what you can start doing today to help the process go smoother.

Local Spotlight

For the second year in a row, the 鈥楪ift-a-Family鈥 campaign is hoping to make the holidays happier for children and families in need throughout Barrie.

Some of the most prolific photographers behind CTV Skywatch Pics of the Day use the medium for fun, therapy, and connection.

A young family from Codroy Valley, N.L., is happy to be on land and resting with their newborn daughter, Miley, after an overwhelming, yet exciting experience at sea.

As Connor Nijsse prepared to remove some old drywall during his garage renovation, he feared the worst.

A group of women in Chester, N.S., has been busy on the weekends making quilts 鈥 not for themselves, but for those in need.

A Vancouver artist whose streetside singing led to a chance encounter with one of the world's biggest musicians is encouraging aspiring performers to try their hand at busking.

Ten-thousand hand-knit poppies were taken from the Sanctuary Arts Centre and displayed on the fence surrounding the Dartmouth Cenotaph on Monday.

A Vancouver man is saying goodbye to his nine-to-five and embarking on a road trip from the Canadian Arctic to Antarctica.

Stay Connected