Chemotherapy not only causes the phenomenon called “chemobrain,” there now is evidence of subtle changes in specific brain regions explaining why some patients can’t remember where they’ve placed their keys or lose their way along well traveled routes.

Despite a few past studies suggesting that chemobrain – a feeling reported by cancer patients of forgetfulness, confusion and disorientation – was more imagined than real, a team of medical investigators in Japan found the condition indeed is genuine and substantially affects cognition. Reported in the current issue of Cancer, the analysis provides concrete evidence that chemotherapy affects regions involved in thinking, reasoning and remembering.