Changes in Mental Function - Chemo Brain or Cancer Fog
Does chemotherapy disturb mental functioning?
Some people experience changes in higher mental function during the course of their chemotherapy, and sometimes for some months afterwards. Technically, this is sometimes referred to in the medical literature as "cognitive dysfunction".
These changes include:
Many of you will recognize these as symptoms you had before you even thought about having chemotherapy! After all, how many of us can program the microwave or a mobile phone with the agility of our teenage children?
However, careful testing has revealed that, on average, people experiencing many forms of chemotherapy perform less well at complex mental tasks than do control subjects.
There could be many reasons for this besides the actual effects of the anti-cancer drugs on the brain. Brain cells, which do not divide, are not known to be particularly sensitive to chemotherapy. The anti-nausea drugs like Stemetil and Ativan are sedatives and these may transiently contribute to mental dysfunction. People having chemotherapy are generally anxious about their illness and stressed by the knowledge of it and by unknowns about their future medical care, relationships with family and employers, and often financial and business concerns. All may contribute to make concentration on complex tasks a big ask at this time.
Most of these changes occur during the chemotherapy program, and disappear shortly after it ceases.
I have never known them to be sufficiently concerning to make special advice about driving or operating machinery at work. Of course, you should not do either of these things under the influence of sedative anti-nausea medications like Stemetil or Serenace, sedatives like Ativan, or strong codeine or morphine-containing pain killers.
Are there any permanent effects on mental function?
Several psychological studies have reported slight permanent changes in higher mental function in women who have received adjuvant chemotherapy for early breast cancer when compared to matched control women who have not. These changes are slight and certainly not universal. They are probably equivalent to the same slight changes that are measurable in people who have had a long general anaesthetic, for example, for open heart surgery. It is unknown in my experience for women to be aware of them or to be troubled by them.
Because of a number of problems with the way these studies were designed, including the fact that they have not taken hormonal changes into account, the effect of chemotherapy on long-term mental function remains uncertain and controversial.
Tips for managing altered mental function
The cancer council has recently added a page on their website dedicated to cancer-related cognitive impairment. You can check it out here. They have also published a printable leaflet which you can download here.
Some people experience changes in higher mental function during the course of their chemotherapy, and sometimes for some months afterwards. Technically, this is sometimes referred to in the medical literature as "cognitive dysfunction".
These changes include:
- Difficulty concentrating
- Deficiencies in memory (for example, forgetting names, and telephone numbers)
- Episodes of slight confusion (for example, suddenly not knowing your way home from the supermarket)
- Less ability to learn new facts easily
- Getting muddled with complex equipment or electronic gadgets
Many of you will recognize these as symptoms you had before you even thought about having chemotherapy! After all, how many of us can program the microwave or a mobile phone with the agility of our teenage children?
However, careful testing has revealed that, on average, people experiencing many forms of chemotherapy perform less well at complex mental tasks than do control subjects.
There could be many reasons for this besides the actual effects of the anti-cancer drugs on the brain. Brain cells, which do not divide, are not known to be particularly sensitive to chemotherapy. The anti-nausea drugs like Stemetil and Ativan are sedatives and these may transiently contribute to mental dysfunction. People having chemotherapy are generally anxious about their illness and stressed by the knowledge of it and by unknowns about their future medical care, relationships with family and employers, and often financial and business concerns. All may contribute to make concentration on complex tasks a big ask at this time.
Most of these changes occur during the chemotherapy program, and disappear shortly after it ceases.
I have never known them to be sufficiently concerning to make special advice about driving or operating machinery at work. Of course, you should not do either of these things under the influence of sedative anti-nausea medications like Stemetil or Serenace, sedatives like Ativan, or strong codeine or morphine-containing pain killers.
Are there any permanent effects on mental function?
Several psychological studies have reported slight permanent changes in higher mental function in women who have received adjuvant chemotherapy for early breast cancer when compared to matched control women who have not. These changes are slight and certainly not universal. They are probably equivalent to the same slight changes that are measurable in people who have had a long general anaesthetic, for example, for open heart surgery. It is unknown in my experience for women to be aware of them or to be troubled by them.
Because of a number of problems with the way these studies were designed, including the fact that they have not taken hormonal changes into account, the effect of chemotherapy on long-term mental function remains uncertain and controversial.
Tips for managing altered mental function
- Laugh at yourself if you can, and your carers, family and friends will laugh with you; this breaks the tension that can only compound the problem and make it worse.
- Remember that things will normalise when your treatment is over. You’re not losing it!
- Don’t passively accept the problem. Get organized. Use written reminders, notes, a personal organizer (if you’re computer-inclined), and a portable diary. There could be a positive spin-off from this: you might emerge a much more efficient and organized person than ever!
- Keep a routine. Try to stick fairly closely to regular sleeping/waking times, and an ordered, repeated routine to your week. You have a license to be boring during all this!
- Relax and don’t test yourself with challenging mental tasks like crossword puzzles or complex reading. Be gentle on yourself, indulge yourself with light reading, the movies, and the chat of close and valued friends..
The cancer council has recently added a page on their website dedicated to cancer-related cognitive impairment. You can check it out here. They have also published a printable leaflet which you can download here.