Everything You Want to Know about Chemobrain
Perhaps this should be titled More than Everything You Want to Know about Chemobrain. I know that I have written before about this problem that troubles many of us, but this is the most complete article I have seen.
From Cancer Network comes this very thorough overview of the issue. Ignore it or skim it or read every word if this is an issue for you. You will learn something (or you will learn a lot).
An Overview of Chemotherapy-Related Cognitive Dysfunction, or ‘Chemobrain’
By Halle C. F. Moore, MD 
This review will focus largely on the effects of systemic cytotoxic treatment on cognitive function,
reflecting what has been most extensively studied in the literature.
Chemotherapy-associated cognitive dysfunction, often referred to as
“chemobrain,” includes subjectively reported and objectively measured
problems with cognition following chemotherapy. The American Cancer
Society estimates there will be close to 14.5 million cancer survivors in
the United States by 2015. Increasingly, individuals with cancer are
experiencing long-term survival following initial treatment, leading to an
ever greater need to understand, manage, and prevent lasting adverse
effects of cancer treatment. Reflecting this need, the American Society
of Clinical Oncology has recently issued a set of new Survivorship
Guidelines addressing fatigue, mood disorders, and peripheral neuropathy. Currently there are
no clear guidelines for the clinical assessment and management of chemobrain.
The recognition that a variety of factors other than chemotherapy may contribute to cognitive
decline in cancer patients has led to use of the broader term, “cancer treatment–related cognitive
impairment.” This review, however, will focus largely on the effects of systemic cytotoxic
treatment on cognitive function, reflecting what has been most extensively studied in the
literature. It should also be noted that much of the research on this topic has been conducted in
breast cancer patients, as they represent the largest group of long-term cancer survivors who
have had frequent exposure to chemotherapy. This review does not address cognitive effects of
central nervous system (CNS) malignancies or CNS-directed treatments.
In a sampling of participants in the National Health and Nutrition Examination Survey, individuals
with and without a history of cancer were surveyed about whether they felt they were limited by
difficulty with memory or periods of confusion. Approximately 14% of cancer survivors reported
memory problems, compared with 8% of participants without a prior cancer diagnosis,
representing an approximately 40% increase in the likelihood of cancer survivors reporting
cognitive concerns. Similarly, studies assessing cognitive function with objective cognitive
tests have suggested a higher likelihood of impairment among individuals who have received
chemotherapy. In one study of breast cancer survivors who had, on average, completed
treatment with adjuvant cyclophosphamide, methotrexane, and fluorouracil (CMF) chemotherapy
more than 20 years prior to enrollment, cognitive deficits were observed compared with a control
group who underwent the same neuropsychological tests as part of a population-based