12/2/22 · Health

"The cognitive impairments that COVID-19 causes are mild, but their social and economic impact is very significant"

Photo: Maite Garolera (C3-CST)

Photo: Maite Garolera (C3-CST)

Maite Garolera , head of the Neuropsychology Unit and the director of the Brain, Cognition and Behaviour Research Group at the Hospital de Terrassa-Consorci Sanitari de Terrassa

 

The COVID-19 pandemic has given rise to a great many cases of what has been called long COVID-19: people who manifest symptoms without any apparent ill effects, which continue long after they have recovered from the acute phase of the infection. A large proportion of these symptoms are related to cognitive impairments, arising from the possible direct or indirect impact of the virus on the brain.

On 12 November, the Faculty of Health Sciences of the Universitat Oberta de Catalunya (UOC) organized an event on neurological effects and neuropsychologicalimpairments due to COVID-19. Various experts met at the event to share the results of their research, which seeks to obtain a better understanding of these sequelae and to make progress towards tools to identify and treat them. One of those experts was Maite Garolera, who is head of the Neuropsychology Unit and the director of the Brain, Cognition and Behaviour Research Group at the Hospital de Terrassa-Consorci Sanitari de Terrassa. Garolera is in charge of the Nautilus project, a multicentre initiative that seeks to understand, characterize and alleviate the cognitive effects caused by COVID-19. We talked to her about how the virus affects the brain, about the importance of long COVID-19, as well as about undoubtedly false alarms, possible therapies and the initial results of her project.

 

The COVID-19 pandemic has given rise to a great many cases of what has been called long COVID-19: people who manifest symptoms without any apparent ill effects, which continue long after they have recovered from the acute phase of the infection. A large proportion of these symptoms are related to cognitive impairments, arising from the possible direct or indirect impact of the virus on the brain.

On 12 November, the Faculty of Health Sciences of the Universitat Oberta de Catalunya (UOC) organized an event on neurological effects and neuropsychologicalimpairments due to COVID-19. Various experts met at the event to share the results of their research, which seeks to obtain a better understanding of these sequelae and to make progress towards tools to identify and treat them. One of those experts was Maite Garolera, who is head of the Neuropsychology Unit and the director of the Brain, Cognition and Behaviour Research Group at the Hospital de Terrassa-Consorci Sanitari de Terrassa. Garolera is in charge of the Nautilus project, a multicentre initiative that seeks to understand, characterize and alleviate the cognitive effects caused by COVID-19. We talked to her about how the virus affects the brain, about the importance of long COVID-19, as well as about undoubtedly false alarms, possible therapies and the initial results of her project.

There have been many studies to estimate the number of people with long COVID-19, but a lot of them of them have been of poor quality, with no clear definition of the symptoms... Do we now have any reliable data on the cognitive effects that COVID-19 can have?

Well, if you look at the databases, there are more than 1,000 articles on cognitive impairment after COVID-19. But it's true that there's a mixture of studies which use very varied methodologies, and it's difficult to reach any conclusions. In overall terms, the literature says that between 10% and 15% of COVID-19 survivors suffer from long COVID-19, and approximately 70% of those have cognitive problems. But even those figures vary depending on what's being considered. What we do know is that many people present this type of problems.

Many hypotheses have also been put forward about the mechanisms by which the virus could act on the brain: due to direct invasion, or the inflammation it causes, etc. Have any conclusions been reached?

We're still in the realms of hypothesis, but there are probably some shared mechanisms, and others which are specific to the individual. In one of our studies, we tried to see if there were any differences in cognitive performance depending on the severity of COVID-19. We presented the results at the event, although they haven't been published yet, and what we can see is that there are differences depending on whether the patients have been in intensive care, in a hospital ward, or if they've had a mild form of COVID-19. Those in the latter category, who are more likely to experience depressive symptoms, have more difficulties with memory and learning tasks. Their ill effects are undoubtedly related to the invasion of the virus through the olfactory tract, and in particular to the inflammation it causes. But their situation isn't the same as people who've been in intensive care, where hypoxia may generally have had a major effect on their brain, and who predominantly suffer from poor executive functions and problems with processing information. In any event, it's all subject to hypothesis at the moment.

Other viruses can also affect the nervous system. Is SARS-CoV-2 a special virus?

Well, we know that other viruses can affect the brain. Herpes-type viruses can sometimes cause encephalitis, and HIV can lead to cognitive changes. What's special about this particular virus is that it can cause a strong inflammatory response, which can also lead to clots and ischaemic strokes. And the brain has receptors for the virus. It's not unique, and nor is it by any means the most dangerous virus, but it's real, and it's had a major impact due to the large numbers of people who've been infected.

The changes are generally minor, but they have major consequences. Most people who experience them are women between the ages of 30 and 50 who are active and need to be functioning at their highest level, but they're unable to do things in the way they used to. This has very important social and economic repercussions. In our study, we found that 40% of people with long COVID-19 have experienced a deterioration in their employment situation. The percentage among people that had not had long COVID-19 was 8%.

During the pandemic, we often saw messages warning of the risk that the virus could contribute to the development of dementia such as Alzheimer's. Are those warnings justified?

We don't have enough data to say one way or another because we don't have enough records - not enough time has passed. It's something that we have to take into account, and we have to study it, but there's no reason to create alarm among the public, and it makes no sense to do so. What we do know is that long COVID-19 is real, and that it has an impact on many people's lives. Does it make people more vulnerable to a neurodegenerative disease? There are as yet no data to support this theory, even though it may increase the risk in elderly and predisposed individuals, like many other factors.

What is the Nautilus project that you're leading?

The Nautilus project has received funding from the La Marató telethon, and it began a year ago, with 24 hospitals participating. It includes patients with long COVID-19 and people who hadn't been infected when the study began. We study their cognitive and emotional state, as well as their functional capacity. We collect blood and microbiota samples, brain images, compile sociodemographic determinants and the symptoms caused by COVID-19 for all of them. We use artificial intelligence tools to try to predict which people are at most risk of experiencing cognitive impairment, and to understand why.

Some of the data were presented at the meeting. What have you found so far?

The project lasts four years, and so far we've only analysed a few initial areas to try to answer some questions. One was whether there were any differences in cognitive impairment depending on the severity of COVID-19, as I explained earlier. Something else we've seen is that people with long COVID-19 may or may not have cognitive issues, but the group with no issues also presents impairments compared to the control group which hasn't had the disease. This suggests that there may be more people who have cognitive changes, even if they haven't reported them.

You are also trialling a type of therapy.

Yes, it's a pilot study in which we've included 24 people with long COVID-19. Thirteen of them have undergone an immersive virtual therapy with images that surround them in a room, which means we can develop a multimodal programme that we've designed, which includes mindfulness and cognitive and physical stimulation. The cognitive and physical exercise programme has also been carefully designed for people who suffer from these particular problems. We saw significant and considerable improvements, especially for memory, after two months. These are just a few patients, but I've been doing trials for many years and results like these are difficult to find. It's not a cure, but it can be effective. We've just received funding from the Spanish Ministry of Science and Innovation to carry out a much larger clinical trial, which will give us better answers.

We're now at a very different stage in the pandemic. What message would you like to send to people?

My message would be that people should get vaccinated, and protect themselves. And also that we need to investigate, care for and treat people with long COVID-19. We must understand that these people need evaluation and treatment.

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