Chemotherapy: Out of the Fog

Cancer patient blogs and chat rooms are filled with personal stories about minds that get foggy soon after chemotherapy begins.

Up to 61 percent of cancer patients taking chemo lose cognitive function during treatment. They have trouble concentrating and multitasking, and short-term memory suffers. Five years after diagnosis, survivors continue to have higher rates of so-called “chemo brain” than cancer patients who never received chemo, says Janette Vardy, MD, of the International Cognition and Cancer Task Force.

As long as it’s been around, no one has figured out the reason for chemo brain.

“There’s no question that chemo brain exists. The question is: What is it?” says Halle Moore, MD, a staff physician in Cleveland Clinic’s solid tumor oncology unit. She intends to find out.

Dr. Moore is comparing eight early-stage breast cancer patients — a group in which chemo brain has long been noticed — with eight healthy women. The patients will receive cognitive tests and electroencephalograms (EEGs) to record brain activity before, during and after chemotherapy (the healthy volunteers are tested at the same intervals).

“There are many things that are worth investigating as potential treatments,” she says. Among those are exercise, crossword puzzles and attention-boosting medications, such as methylphenidate (Ritalin®). But understanding the condition must come first, Dr. Moore says.