When cancer patients undergo chemotherapy, they notice changes in their memory, concentration and the way they think. Women with breast cancer (in particular) were the first to report these problems, which they linked to their chemotherapy treatment. Hence, they called the changes chemo brain also known as chemo fog.
For the first time, researchers have been able to demonstrate that chemo brain is a genuine effect. The study, published in the journal Clinical Neurophysiology, found that people who reported chemo brain lack the ability for sustained focused thought.
A healthy brain spends some time wandering and some time engaged. We found that chemo brain is a chronically wandering brain, they’re essentially stuck in a shut out mode,” said Todd Handy, one of the researchers and a professor of psychology at the University of British Columbia.
The researchers found that those with chemo brain tend to stay in disengaged state. That is the reason why 50% of patients who are thought to be affected feel the need to constantly write things down and keep tasks as simple as possible.
In the latest study from the Moffitt Cancer Center in Florida, a team analysed previous studies at the effect of chemotherapy on breast cancer patients. They used an encephalogram (EEG), a device that detects electrical activity in the brain, to monitor the brain activity of breast cancer patients while they completed a series of tasks. They found that the women on average had mild impairments in verbal abilities (such as difficulty choosing words) and visuospatial abilities (such as getting lost more easily).
More so, they discovered that the breast cancer survivors were “less likely to maintain sustained attention” compared to healthy individuals—this was true even up to three years after treatment.
What was even more worrying was that when the women thought they were concentrating, the EEG showed that large parts of their brains were actually turned off and that their minds were wandering. The study also showed that when these patients were asked to relax, their brains were more active than healthy women.
The study noted that the results varied across survivors, with some reporting no problems whilst others had more severe deficits. According to co-author Paul Jacobsen,
Our analysis indicated that patients previously treated with chemotherapy performed significantly worse on tests of verbal ability than individuals without cancer. In addition, patients treated with chemotherapy performed significantly worse on tests of visuospatial ability than patients who had not had chemotherapy.
Breast cancer patients treated with chemotherapy who have subsequent cognitive deficits should be referred to a neuropsychologist for evaluation and management of the deficits. Management usually involves developing an awareness of the situations in which their cognitive difficulties are likely to arise so that they can come up with strategies to compensate. Research shows that such strategies can make a big difference in daily life when cognitive difficulties do arise,” Colleague Dr Heather Jim, added.
Other factors that may play a part include anxiety, old age and depression.