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.
While a new study that was done around this was done in mice, it helps 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, brain fog implies that there is a problem with your thinking. 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 (studies show up to 32%) 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) looked at experiments in mice 🐭 🐭 🐭 to better understand what is happening to the brain. And what they found seems to shed some light on why specific things like memory are affected.
1️ 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.
2️ 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.
3️ 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 Co-V2 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.
🧑🏾🤝🧑🏾 So how does this translate to humans?
Well, it doesn’t just yet. It is exciting to see what the possible mechanisms are and definitely 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 to understand 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 in large groups of people with different severity of COVID-19 disease and with different characteristics to learn even more.
So 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 DP post.)
The Bottom Line:
We are learning more about brain fog. It is not in someone’s head, but is caused by immune and cell changes in the brain. 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
New Study by Dr. Monje and Dr. Iwasaki in Cell
The Secrets of Brain Fog are Starting to Lift
Brain fog and similarity to Chemo-Brain
COVID brain fog and search for treatments