cognitive loss / chemo brain

Chemo Brain May Not be From Chemotherapy

PJ Hamel Health Guide April 27, 2008
  • “ ‘Chemofog’ effects on brain may be a myth-
    Two studies showed no memory impairments as a result of chemotherapy.”
    msnbc.com, April 17, 2008.


    Wait a minute. Are we going down that “chemobrain isn’t real” path—again?! Just reading that headline on the MSNBC Web site today got my hackles up. All of the issues so many of us experience post-chemo—the inability to remember names, concentrate, multitask, find your car keys (remember what your car keys are for), speak a simple sentence without getting lost… none of that is real?

    Of course it is. After simmering down I read the whole article, which said that new studies are showing that chemobrain might not be entirely due to chemotherapy drugs. It might also be the result of stress and anxiety women feel from the time of diagnosis right on through treatment.


    A recently concluded Australian study involving 60 subjects demonstrated that women who underwent chemotherapy didn’t perform any worse on a battery of cognitive tests than women who hadn’t done chemo. Those on chemo were tracked during treatment, and again 28 days after treatment had been concluded. And while both groups showed a noticeable level of “impairment in attention and learning” compared to a control group of non-cancer subjects, this impairment was across the board; it was no worse in chemo recipients than non-recipients.

    Another study, this one involving 58 women in Michigan, showed that women newly diagnosed with breast cancer performed more poorly on cognitive tests than breast cancer survivors who were a year past chemotherapy. The study concluded that the stress and other quality-of-life factors relating to cancer diagnosis, not chemotherapy, were responsible for “chemobrain.” 

    Past studies have shown a real, physical difference in brain activity—measured using sophisticated brain-imaging technology—between women who’ve had chemo, and those who haven’t. The chemicals used in chemotherapy do SOMETHING to your brain. But researchers have yet to build a conclusive link between that “something” that happens in your brain, and your inability to remember your mother’s name. Or your own phone number. To say nothing of how to make a door handle work.

    Dr. Tim Ahles, Ph.D., a cognitive psychologist at Memorial Sloan-Kettering Cancer Center in New York, is one of the pioneers of chemobrain research. (In fact, I was one of Dr. Ahles’ initial chemobrain study subjects, back when he was a researcher at the Dartmouth Medical School up here in New Hampshire.) Dr. Ahles, quoted recently in the Journal of the National Cancer Institute, noted that “One of the first things we ought to do is rename ‘chemobrain.’ ...For  most women with breast cancer, they also receive hormonal intervention like tamoxifen or aromatase inhibitors. There are issues like age, stress, anxiety, [and] depression that can factor in. If anything, it has become more complicated than we realized.”


  • Over the past 6 years, I’ve watched as chemobrain research has gone from “you’re imagining it” to “the drugs did it” to “we’re not quite sure what causes it.” This isn’t scientists running in circles. It’s called ongoing research. This is how the important discoveries that lead to better and more effective breast cancer treatment are nailed down. Lots of trials… lots of error. But that trial-and-error is a necessary foundation for what will eventually become real, proven knowledge. For what will, someday, be the conclusive evidence that the “chemobrain” suffered by up to 85% of chemo-treated breast cancer survivors is caused by a combination of drugs, stress, hormones, genetic predisposition, and “we’re not quite sure what else–but we’ll find out.”