Radiation impedes children’s ability to recall memories

Researchers from Baylor University in Waco, Texas, found that pediatrics patients with brain tumors who undergo radiation treatment are less likely to remember detailed events they’ve experienced after treatment, according to research published online Aug. 20 in Neuroscience.  

Radiotherapy or chemotherapy used to treat medulloblastoma was associated with reduced volume of the hippocampus in the children. Such treatments also decreased development of new cells in the nervous system, wrote lead author Melanie Sekeres, PhD, assistant professor of phycology and neuroscience director of Sekeres Memory Laboratory at Baylor University, and colleagues.  

“We know that these new cells play crucial roles in regulating memory and spatial learning, which is required to navigate,” Sekeres said in a prepared statement. “These treatments limit the brain’s ability to produce these new cells, which, in turn, limits the ability to form new memories.”  

For the study, the team focused on “autobiographical memory," which is responsible for the recollection of emotional and perceptual details that allows a person to re-experience an event. The study included 13 children between the ages of 7 and 18 who survived brain tumors and received radiation treatment one year prior and 28 healthy controls. All children completed a standard memory test and underwent brain MRI, according to the researchers. 

The children were then individually asked to recall memories of personal events, including an old memory that occurred before their radiation treatment (or an equally old memory for the control group) and a memory from within the past month.  

Though the interview allowed the children to freely recall memories, the children with brain tumors struggled forming new, detailed memories about certain personal events, according to the researchers.  

“Such specific details might seem trivial, but these are precisely the kinds of details that allow us to vividly replay important events in our lives,” Sekeres said. “For most events, though, even healthy people forget a lot of specific details over time because we typically don’t need to retain all that incidental information.”  

The research highlights how radiation treatment can inadvertently impact quality of life of pediatric patients with brain tumors, which could help physicians and their patient’s families better explore treatment options.  

The study was conducted with the Brain Tumor Program and the Program in Neurosciences and Mental Health at the Hospital for Sick Children in Toronto. It was funded by the Canadian Institutes of Health Research.