What chemo brain is, who gets it and how it might affect you.
What chemo brain is
After cancer treatment, some people notice changes in their memory, concentration and the way they think. Women with breast cancer were the first to report these problems, which they linked to their chemotherapy treatment. So they called the changes chemo brain. Another name people use is chemo fog.
It's not clear exactly what causes these memory and concentration changes in people with cancer. So calling them chemo brain may not be accurate. Mild cognitive impairment (MCI) is a more accurate description used by doctors. Another name is cognitive dysfunction.
People use the word cognitive or cognition in different ways. It basically means thinking. In psychology, it means the way you process information or understand the world and how it works.
Most people who have cognitive changes are able to do everyday things. But they may notice they aren’t able to do some things quite as well as before they had cancer. Symptoms can include:
- memory loss – forgetting things that you normally remember
- difficulty thinking of the right word for a particular object
- difficulty following the flow of a conversation
- trouble concentrating or focusing on one thing
- difficulty doing more than one thing at a time (multi tasking)
- more difficulty doing things you used to do easily, such as adding up in your head
- fatigue (tiredness and lack of energy)
- mental fogginess
The changes are often mild and very subtle. But if you have them they can reduce your quality of life. Doctors now know that people with different types of cancer may have these problems. So it’s not just breast cancer – and it may not just be chemotherapy that causes the problems.
Who gets chemo brain
It's not certain how many people have mild cognitive impairment after cancer. A review looked at women with breast cancer and suggested the number of women with cognitive impairment is somewhere between 17 out of every 100 (17%) and 50 out of every 100 (50%). We need more research to confirm how many women with breast cancer have these problems.
A review of studies in 2008 showed that some men having prostate cancer treatment to lower testosterone levels had cognitive impairment. Between about half and about two thirds of the men in these studies had these types of changes. The men showed difficulty in coping with problems that involved mentally rotating objects in space (spatial ability) and problems with multi tasking.
We need larger, more thorough studies that include brain scans so we can understand more about how prostate cancer treatment affects thought processes. We also need more research to find out how many people with other types of cancer are affected.
How chemo brain might affect you
The symptoms of cognitive impairment can come and go. How much you notice them seems to depend on what you're doing. For example, if you need to juggle a number of things as part of your normal day, you might notice it more than someone who doesn’t. People often notice it more when they go back to work. Tiredness usually makes the symptoms worse.
For most people, the symptoms have either gone or really improved within a year of ending treatment. But for some people the symptoms can be long term and may continue for years after treatment has finished.
Research suggests that people who have mild cognitive impairment are also more likely to have depression, anxiety, and fatigue. We don’t know whether the causes of these are the same as the causes of cognitive impairment, or whether one leads to the other.
One of the problems with testing for these changes is that current psychological tests are not always sensitive enough to pick up the sort of problems that people have after cancer. So people who say they are having problems tend to come out of the tests with results that the researchers would describe as a normal score.