Chemotherapy Causes "Brain Cloud"?

If you've seen Joe vs. The Volcano (and if you haven't, you should), you remember that Joe is dubiously diagnosed with a "brain cloud" which is, of couse, terminal. This prompts his willingness to jump into the volcano to appease the Waponi Wu (aka, the Big Wu). I always thought that the idea of a brain cloud was rather funny, until I stumbled upon this diconcerting Yahoo news piece on the long-term effects of chemotherapy on brain metabolism and function.

Chemotherapy causes changes in the brain's metabolism and blood flow that can last as long as 10 years, a discovery that may explain the mental fog and confusion that affect many cancer survivors, researchers said on Thursday.

The researchers, from the University of California, Los Angeles, found that women who had undergone chemotherapy five to 10 years earlier had lower metabolism in a key region of the frontal cortex. Experts estimate at least 25 percent of chemotherapy patients are affected by symptoms of confusion, so-called chemo brain, and a recent study by the University of Minnesota reported an 82 percent rate, the statement said.

"People with 'chemo brain' often can't focus, remember things or multitask the way they did before chemotherapy," Silverman said. "Our study demonstrates for the first time that patients suffering from these cognitive symptoms have specific alterations in brain metabolism."

This study was recently published in Breast Cancer Research and Treatment, and specifically tested breast cancer survivors who had, and had not, received chemotherapy. The researchers used PET scanning (which measures blood flow to a particular brain region by way of a radioactive tracer) to compare brain function between these two groups, as well as normal controls, as they performed a short-term memory task.