What is Long COVID?
Long COVID is a term used to describe a group of symptoms that continue for at least three months after someone has had COVID-19. These symptoms can include things like extreme tiredness (fatigue), problems with thinking or memory (brain fog), dizziness when standing up (orthostatic intolerance), and feeling worse after doing any physical or mental activity (post-exertional malaise).
It’s hard to know exactly how many people around the world have long COVID because there aren’t consistent systems in place to track it. However, experts estimate that by the end of 2023, around 400 million people worldwide could have experienced it. This is a huge number, and it’s concerning because long COVID can seriously affect people’s daily lives and overall well-being.
A report from the UK in 2023 found that 74.7% of people with long COVID said their symptoms made it hard to do everyday tasks, like work or taking care of themselves. Around 8.2% of people also said they had memory problems because of long COVID.
Long COVID is still not fully understood, and doctors are working to figure out exactly what causes it and how best to treat it. Right now, the focus is mostly on managing the symptoms and helping people feel better, but it’s clear that long COVID is having a big impact on people around the world.
Key takeaway: Long COVID is a complex condition affecting millions worldwide, often impacting their ability to carry out daily tasks and maintain quality of life.
Smell Loss and Long COVID
Smell loss is often one of the earliest symptoms of COVID-19. While many people recover their sense of smell within weeks, some experience long-lasting issues. Scientists think the lingering symptoms might be linked to inflammation in the brain’s olfactory bulb, the area responsible for processing smell.
Key takeaway: Smell loss, a common symptom of COVID-19, can persist in long COVID due to inflammation in the brain’s smell-processing area.
Cognitive problems
Cognitive difficulties, often called “brain fog,” are common symptoms of long COVID. These can include problems with paying attention, remembering things for a short time, and thinking clearly. While the term “brain fog” is used a lot, it doesn’t always show how much these problems can affect a person’s daily life and ability to function. A recent study found that these cognitive problems are some of the most common and debilitating symptoms of Long COVID. Interestingly, these issues can occur even if someone had only mild symptoms during their initial infection.
Standard tests might not always catch smaller cognitive problems or show how they come and go. A person might seem fine when doing tasks they’re used to, like at home, but could struggle with more complicated tasks, such as at work or in a new place, like a hospital. People with long COVID might also have trouble explaining their cognitive difficulties, which can make doctors underestimate how much these issues affect their lives. Sometimes, people might save their energy for doctor’s appointments, so they seem fine during these visits, but they could have real challenges outside of those times. Another problem is that cognitive issues in long COVID can come and go, often getting worse after doing too much (this is called post-exertional malaise or PEM).
Because of this, many people with cognitive problems may not get the help they need. They might be misunderstood as lazy or not trying hard enough. Health professionals, including occupational therapists, need to think about cognitive problems when assessing people with long COVID, even if the problems seem mild, because they can still affect daily life a lot.
Cognitive difficulties can make it hard to work, and many people with long COVID either can’t work at all or need to reduce their hours. Studies show that these cognitive problems affect many areas of life, like completing everyday tasks, having fun, driving, and even spending time with family and friends. One study from Sweden found that cognitive issues were some of the most common and serious symptoms of long COVID, even for those who were not hospitalised. The study also found that people with long COVID have similar challenges to those with other chronic conditions, like chronic fatigue syndrome.
Key takeaway: Cognitive challenges like brain fog are among the most disabling symptoms of long COVID, often misunderstood and underestimated by healthcare providers.
What Causes Cognitive Issues in Long COVID?
Scientists are uncovering several possible causes for these cognitive challenges, and it seems multiple factors may be at play.
Neuroinflammation: Long-lasting brain inflammation has been found in some individuals with long COVID. This inflammation may persist even after the virus is no longer detectable in the body.
Viral Persistence: Studies suggest the virus may linger in “reservoirs” within the body, such as the brain or gut, causing ongoing immune responses.
Reduced Blood Flow to the Brain: Conditions like postural orthostatic tachycardia syndrome (POTS) can reduce oxygen and blood flow to the brain, leading to dizziness and cognitive difficulties and may explain some of the mental fogginess people with Long COVID experience.
Key takeaway: Cognitive problems in long COVID may stem from a combination of brain inflammation, lingering virus, and reduced blood flow to the brain.
How Can Long COVID Be Managed?
There is no clear way forward yet. Since the cognitive problems seen in long COVID are similar to those in other neurological conditions, like concussion, brain injury, and multiple sclerosis, some experts believe that rehabilitation methods used for these conditions could help people with long COVID too. These approaches might focus on improving memory, attention, and thinking skills, just as they do for people recovering from brain injuries or other neurological issues.
The idea that traditional physical rehabilitation methods, like gradually increasing exercise, would help people with ME (myalgic encephalomyelitis) has been strongly rejected by many experts. Studies have shown that this approach can make symptoms worse rather than improve them.
Surveys and studies have shown that people with long COVID experience similar problems with mental energy and recovery after using their brain, just like they do after physical activity. This is known as post-exertional malaise (PEM) or post-exertional symptom exacerbation (PESE).
When doctors try to help with cognitive problems, they often use a method that focuses on repeating tasks to help the brain grow and improve (called neuroplasticity). However, health professionals need to be careful not to overdo this with cognitive “exercise,” even if their intentions are good. Pushing people too hard mentally can lead to more exhaustion and worsen symptoms, just like it can with physical activity.
Cognitive problems often get worse during post-exertional malaise (PEM) or post-exertional symptom exacerbation (PESE) for many people with long COVID. One of the best ways to manage these cognitive issues might be to identify what triggers them and reduce the post-exertional symptoms. This can be done by using energy management techniques, like pacing. Pacing is the practice of balancing activities with rest to avoid pushing yourself too hard, which can help reduce the frequency and severity of PEM/PESE.
Key takeaway: Effective management of long COVID’s cognitive challenges requires careful pacing and tailored strategies to avoid worsening symptoms.
Conclusion
Cognitive problems are common for people with long COVID and can have a big impact on their daily lives. The causes of cognitive dysfunction in long COVID may include brain inflammation (neuroinflammation), the virus lingering in the body, damage to blood vessels, and reduced blood flow to the brain. These factors are likely connected in some way. Another important factor to consider is post-exertional malaise (PEM) or post-exertional symptom exacerbation (PESE), where symptoms get worse after physical or mental exertion. It’s crucial not to ignore mental effort in this context.
Healthcare professionals need to be aware of PEM/PESE to help people with long COVID safely manage their condition. One self-management strategy is cognitive pacing, which involves balancing rest with mental activity. However, cognitive pacing is more than just alternating rest with activity—it requires careful attention to other factors. Right now, there are gaps in research on the details of cognitive pacing as an intervention.
In the absence of clear guidelines, we suggest that occupational therapists and other healthcare professionals can make the biggest difference by working with people with long COVID to create individualised and flexible pacing plans. These plans should be based on a thorough understanding of the person’s needs, the factors behind their cognitive changes, and the challenges of living with a condition that limits energy. More research is needed to better understand cognitive pacing and test how well it works.
Key takeaway: Collaborative, individualised pacing plans and further research are key to helping people with long COVID manage their cognitive symptoms effectively.
