Chemotherapy 101: Chemobrain


The word instills terror, invokes images of hair loss, weakness, sickness. It can be an extraordinarily trying time, for patients and their caregivers. The literally hundreds of different drugs used in chemotherapy treatment can be daunting. In order to try and remove some of the terror and mystery of chemo, I'm going to use this blog to take an occasional look at different aspects of chemo—drugs, side effects, emotions, cognition—hoping to demystify it, even if only a little.

What is chemobrain?

Chemobrain is a phenomenon widely reported by cancer patients following treatment, one in which they feel like they're not operating with a clear mind; they feel mentally foggy and seem to have trouble with memory and planning.

It's not known how many cancer survivors suffer from chemobrain. Estimates vary from 20% up to 75%--a range that science surely finds unacceptably wide.

Although it's directly associated by name to chemotherapy, the actual causes of chemobrain are unknown and may or may not extend to any number of cancer treatments beyond chemo, or beyond them to the effects of cancer itself on the body prior to treatment.

Signs and Symptoms

Some of the signs and symptoms commonly reported, which can last for years following treatment, include:

  • Unusual difficulty concentrating, finding 'the right word', learning new tasks or multitasking
  • Unusual difficulty with verbal or visual memory
  • Unusual mental fatigue

Although some medications have been suggested as being effective in the treatment of chemobrain (such as Ritalin), in the US there are none that have received specific FDA approval.

The National Cancer Institute offers a helpful fact-sheet for patients on managing memory problems following cancer treatments.

Patients at Risk for Chemobrain

Experts at UCLA’s Jonsson Comprehensive Cancer Center are arguably at the forefront of current investigations into chemobrain. Led by Patricia Ganz MD, in April 2009 they published "Cognitive Changes after Cancer Treatment", which addressed a number of issues regarding chemobrain.

According to Dr. Ganz, patients at risk for chemobrain include children and adults treated for brain tumors or whole brain radiation, as well as leukemia and lymphoma survivors receiving certain intraspinal chemotherapy.

Some Things to Keep in Mind about Chemobrain

One deficiency in the available research data is that very few of the patients complaining of chemobrain had their cognitive functions tested before they were treated for cancer. This isn't to discount chemobrain or to minimize patient symptoms; it merely illustrates a lack of objectively in much of that data.

Additionally, people in general often complain about losing some cognitive abilities as they get older; it's possible that cancer, a cancer treatment, or both, are making the problem worse.

In sum, patients approaching chemotherapy or other cancer treatments ought to be concerned about chemobrain to the extent that they discuss the issue fully with their doctor(s) before treatment. Some patients may want to undertake doing crossword puzzles or other mental challenges if they're able to, and they might consider undergoing a cognitive test prior to treatment so that there is something to compare against afterwards. Either way, keep in mind that research into chemobrain is really relatively young, and the answers you receive may not be very satisfying, but they are probably all that are currently available.

--The Mayo Clinic's pages on Chemobrain
--Science Daily report on a 2006 UCLA study on chemobrain
--April 2009 article from the NCI Cancer Bulletin on chemobrain
--Patricia Ganz MD: "Cognitive Changes after Cancer Treatment" (Microsoft Powerpoint document)

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