Chemotherapy patients commonly report cognitive deficits after treatment. Known as “chemo brain,” the condition generally entails loss of memory, trouble with attention, reduced ability to multitask, and difficulties handling everyday activities. In addition, patients often find it difficult to find words. Chemo brain is reported to affect as many as 30 percent of patients receiving chemotherapy. However, one study, in 2006, of 595 patients found that 488 of them, or more than 82 percent, reported memory and concentration difficulties. It is almost always found in patients with breast cancer—in whom it was first observed—and cancers of the reproductive system.
The exact nature of chemo brain is difficult to pin down, though there is a technical name for the condition, the duly scientific-sounding “post-chemotherapy cognitive impairment.” Nonetheless, it is proving elusive to study. Part of the difficulty the the lack of a consistent definition for chemo brain. Assessment of memory loss and other cognitive difficulties is done in a variety of ways, and different researchers may choose different ways to measure the problems under study. Brain scans, including MRI, have shown changes in the parts of the brain associated with memory and concentration after chemo, but the exact details of the link are inconclusive.
Nonetheless, a number of possible factors have been suggested as causing or exacerbating chemo brain:
- Cancer itself
- Other drug regimes
- Low blood counts
- Hormonal changes or hormone treatments
- Opportunistic illness
- Malnutrition or malabsorption
Regardless of the cause, the condition has almost always been observed to gradually improve after the treatment has stopped. So while the mechanism is unknown, there is hope on the horizon.