From Scientific American:
More people survive cancer than ever before. With early detection, for example, women stricken with breast cancer are often successfully treated and go on to live long lives. But concomitant with this cheering rise in cancer survival is a worrying increase in complaints about cognitive impairment as life goes on. Some cancer survivors have trouble with concentration or fatigue. New research shows this is not just in their minds but, in fact, in their brains.
Daniel H. Silverman of the University of California, Los Angeles and a cross-disciplinary group of doctors, including UCLA oncologist Patricia Ganz, used scans to try to identify the brain basis for this intellectual deficit. Using positron emission tomography (PET) the researchers tracked both blood flow in the brain as well as the presence of a glucose analogue to examine brain metabolism. The researchers examined 40 regions of the brain as the women performed a word-pairing memory task six times to see how the woman–and their brains–differed. The chemotherapy patients showed a significant jump in blood flow to the frontal cortex and cerebellum compared with the controls. “They had to work harder to carry out the same cognitive tasks”.