Yes, Virginia, Chemo Brain is Real

Abstract

Introduction Twenty years ago, while interviewing a newly assigned patient on our hospital’s oncology unit, she apologized to me for “being stupid.” Startled at this self-deprecating response to a medical history question I had just asked, I put down my pen and met her eyes. “What makes you think you’re stupid?” Embarrassed, she blushed with her answer. “Ever since getting chemo, I feel like I’m forgetting everything. I never used to be like that. Now I can’t remember names of people or things. At work I can’t find the right words or write the drafts I’ve been doing for years . or spell or type. I’m sure I (appear) as though I’m not educated.” This was my first introduction to “chemo brain,” also described as “brain fog.” What we know currently is that this phenomenon is a toxicity of the nervous system causing cognitive impairment in verbal ability, visuospatial ability, problem solving, and affecting concentration and memory. Until around 1995, medical practitioners referred a patients’ concern with these symptoms to the commonly known chemotherapy side effects such as anemia, fatigue, depression, and hormonal changes. Primarily it was breast cancer patients who voiced concerns: studies during early acknowledgment of this phenomenon were noted only as a supplement to pharmaceutical clinical study and not specifically addressed. However, research now indicates that men with prostate cancer and subsequent treatment with hormonal therapy, such as leuprolide and goserelin, can be at risk for cognitive side effects, particularly memory maintenance. Tamoxifen, an oral drug long used to inhibit estrogen in hormone receptorpositive breast cancer, might cause neurological function changes such as concentration and planning ability. Besides chemotherapy and radiation, immunotherapy (interleukin-1 and interleukin-6) can generate increased inflammation and fatigue, both thought to contribute to cognitive dysfunction.