What is brain fog then?
Brain fog describes a group of symptoms that are caused by the body. Researchers and clinicians are starting to think of it more like a neurological disease.
TL; DR: Brain fog is a general term used to describe many issues including poor attention, memory, and planning abilities. This can happen after an infection or injury. We are learning more about what causes it, but there do seem to be changes in the immune system and the way the cells work as a result after an infection. One study done in mice and another studying the brains of people who had COVID help us understand what is going on and ultimately how to help people who are dealing with this symptoms.
Read on for a longer explanation ⬇️⬇️⬇️
😶🌫️ HOW do we define brain fog?
The term “brain fog” can be used to describe a lot of different symptoms including poor memory, difficulty concentrating, fatigue, poor attention, difficulty completing complex tasks, or even confusion. In other words, we use the term brain fog to say that there is an issue with how the brain is helping you to think and function.
In COVID-19 patients, the main symptoms of brain fog seen are related to attention (focusing on one thing), memory (storing and using information later), and executive function (planning and doing complicated things).
Problems like this can often happen after an infection, like COVID-19. Some clinicians compare it to “chemotherapy brain” or “chemo fog,” when a person notices changes in their memory, thinking, and processing after receiving chemotherapy. But changes like this can also happen after head injury and even after a night of no sleep!
😔But WHY does this happen?
It isn’t clear, but it does seem to be happening for many people (some studies show up to one third of all people who have had COVID-19) after having had a COVID-19 infection, even if not a bad case. These symptoms can really impact someone’s ability to work, their relationships, and their mental health. It changes someone’s ability to live their daily life.
One recent study by researchers at Stanford and Yale (Drs. Monje and Iwasaki) in mice 🐭🐭🐭 helped to understand how the immune system might be involved with the brain symptoms seen in long COVID. In that study:
1. First, they infected mice with SARS CoV-2. Then they studied cytokine levels (markers or the immune system) in the fluid surrounding the brain and spinal cord as well as in the blood. The cytokines were high (meaning the immune system was really active) AND increased activity of the microglia (immune cells that hang around the nervous system and eat up the bad stuff, normally). In this case, the microglia were really reactive, which means that they were sensitive to anything going on around them and maybe even damaging normal and healthy brain cells. This can possibly impact the overall function of the brain.
2. Second, the researchers then looked at the type of cytokines (CCL11) hanging around and found that the specific ones that were high were related to making new brain cells, learning, and memories. This was especially noted around the hippocampus, an area in the brain responsible for several things, but especially memory.
3. Thirdly, the researchers looked at the cells that help make the myelin sheaths that coat the tracks between the brain cell bodies. These sheaths are cushions that help one cell communicate with another. When damaged, there can be problems with short term memory and attention. And in the SARS CoV-2 infected mice, there was a loss of nearly one third of the cells (oligodendrocytes) that do this.
These immune and cell changes were very similar to what is seen after chemotherapy.
A smaller study in humans last year (2022) 🧑🏾🤝🧑🏿 also looked at the cerebrospinal fluid of people who have had COVID-19. Results suggested that there could have been immune changes in people who had cognitive and neurological symptoms after having had COVID-19.
🧠Why does it matter if brain fog may be a neurological condition?
When researchers conduct studies to understand how these symptoms might be caused, it helps us to understand that brain fog is not just in someone’s mind, but is a NEUROLOGICAL condition as a result of the infection. The study in mice helps to explore some possible treatment options, including medications and therapies that may better help people to cope with brain fog and to help minimize and recover from symptoms. More research needs to be done in humans to understand what other characteristics people might have that influence how they develop brain fog and other long COVID symptoms, how these symptoms vary across time, what similarities there might be among other infections in how these symptoms develop, and perhaps most importantly, how to help people prevent triggers, like reinfection, for increased symptoms. Studies are needed in large groups of people with different severity of COVID-19 disease and with different characteristics to learn even more.
💁🏽 What can people struggling with brain fog do?
While we don’t have great ideas YET on how to treat brain fog, there are simple things that everyone can do that can help with overall wellness and maximize their ability to cope with brain fog. These include: ensuring enough sleep, eating and drinking properly, conserving energy and prioritizing one’s own health (See previous post here.) For most people, treating specific symptoms (like utilizing medications that help with attention and wakefulness or doing physical therapy) are helpful. A strategy called ”pacing” can also be very helpful (See link here.).
When clinicians recognize the group of symptoms and there is greater awareness, this can also help people feel more validated and know that they can bring their struggles up to get help. Finally, people struggling with any post-COVID symptoms can benefit from mental health support. Adapting to changes in level of activity, ability to work, and how one is able to be present in their family and home is not easy. It is completely OK and a positive thing to seek help in adjusting to a new normal.
The Bottom Line:
We are learning more about brain fog. It is not in someone’s head, but is caused by immune system changes and cell changes in the brain. Researchers are still understanding more about how exactly this happens. We don’t yet have treatments for it, but scientists are studying how it happens to better understand what we can do about it. We need to study more people to see what happens with brain fog over time and how it might be different in different groups.
🫶🏽 For those of you struggling with brain fog or other symptoms after COVID-19 or other infections, we see you and know that the symptoms you are experiencing are real. We are glad that there are steps being taken to better understand why it happens, and are hopeful for treatments and support for brain fog symptoms in the future.
Stay safe. Stay well.
Those Nerdy Girls
Relevant Links:
Mouse study by Dr. Monje and Dr. Iwasaki in Cell
Pacing information from the WaPo
Scientific American article on Long COVID as a neurological disease
