November 29, 2011 | by City of Hope Staff
Evidence is growing that the foggy-headed feeling patients get after going through chemotherapy is real and is based on changes in the brain — but scientists are still unsure what causes those changes.
A study in the November issue of the Archives of Neurology showed that areas of the brain critical to working memory, attention and executive function were less active in women who’d undergone chemotherapy for breast cancer than in women who hadn’t undergone chemotherapy.
The research shines light on what many patients call “chemo brain” or, as scientists refer to it, cancer-related cognitive dysfunction. It's the experience of undergoing a change in your cognitive ability linked to the diagnosis of cancer and its treatment, explains Sunita K. Patel, Ph.D., clinical neuropsychologist and assistant professor at City of Hope, who studies the phenomenon. Common problems include memory issues and difficulty concentrating, paying attention or reacting quickly.
Researchers in New York performed functional magnetic resonance imaging, or fMRI, scans on women as the women sorted cards, a task that tested their problem-solving abilities. Women either had breast cancer and had undergone chemotherapy, had breast cancer and didn’t undergo chemotherapy or were cancer-free.
The scientists found that women with breast cancer — regardless of whether they’d had treatment — had less activity in the prefrontal cortex area of the brain. But only the women who’d undergone chemotherapy actually had impaired performance on the card-sorting test.
No one knows why chemotherapy might affect the brain; it may affect neural stem cells or it might increase inflammation or damage the inner workings of certain cells. But for now, Patel underscores the good news: Symptoms generally disappear over time.
Patel suggests a variety of practical coping strategies to deal with memory and cognitive struggles during and after treatment, and the American Cancer Society offers a helpful factsheet. If patients continue to have difficulties after several months to a year following the end of their cancer treatments, she recommends they consult their doctor about getting a comprehensive neuropsychological evaluation.