Researchers at Georgia State University and Emory University report that adults who survived pediatric posterior fossa brain tumors performed significantly lower on standardized clinical tests of working memory performance than healthy adults in a control group.
More than half of all childhood brain tumors originate in the posterior fossa.
For the study, published in the Journal of the International Neuropsychological Society, researchers used functional magnetic resonance imaging (fMRI) and neuropsychological measures to study the working memory of 17 adults who survived childhood brain tumors and another 17 healthy adults.
During the fMRI, the participants completed a measure called the n-back task. They were asked to monitor a series of letters and respond “yes” or “no” with a finger on a button box if an item was presented “n” items before, ranging from one to three letters back. Accurately recalling a letter two or three letters back represented higher working memory capabilities, researchers explained.
The participants also completed other standardized clinical measures.
Whole-brain fMRI analyses found the survivors had significantly greater blood-oxygen level dependent (BOLD) activation in the left superior/middle frontal gyri and left parietal lobe of their brains during a verbal working memory task, demonstrating higher activation in these structures.
Analysis revealed higher levels of activations in prefrontal regions were associated with lower behavioral performance on higher-load working memory tasks, according to the researchers.
“Our goal was to identify the neural mechanisms underlying working memory difficulty in adult survivors of childhood brain tumors,” said Dr. Tricia King, associate professor of psychology and neuroscience at Georgia State.
“The results suggest that adult survivors of pediatric posterior fossa brain tumors recruited additional resources to control cognitive ability in the prefrontal lobe during increased demands for working memory. This increased prefrontal activation is associated with lower working memory performance.”
Adult survivors of childhood brain tumors are at risk for neurocognitive deficits, such as working memory impairment, that contribute to poor long-term outcomes, she noted.
While advances in diagnosis and treatment have led to improved outcomes and increases in the five-year survival rates of pediatric brain tumor patients, research has shown that long-term childhood brain tumor survivors suffer from adverse health, disrupted quality of life, and impaired cognitive and social outcomes.
Source: Georgia State University
Photo Credit: Georgia State University