Neuroimaging of executive function in survivors of pediatric brain tumors and healthy controls.

OBJECTIVE Research on the long-term sequelae of treatment for pediatric brain tumors has identified significant neurocognitive deficits experienced by many survivors. Despite indications of deficits based on cognitive assessment, the identification of specific neurobiological mechanisms of these deficits using neuroimaging techniques has yet to be considered. METHOD This study used norm-referenced standardized assessment and functional MRI (fMRI) to examine attention and executive functioning deficits of survivors of pediatric brain tumors, as compared with healthy children. RESULTS Survivors of pediatric brain tumors performed more poorly than healthy children on measures of overall cognitive ability, attention, and executive function during testing, as well as on a working memory task during fMRI. Survivors showed lower blood-oxygen level dependent (BOLD) signal in bilateral frontal regions associated with sustained attention (BA6/8) and greater BOLD signal in left cingulate regions associated with complex problem-solving and performance monitoring (BA32) during working memory task completion. Both group and brain activation accounted for significant variance in neurocognitive functioning. CONCLUSIONS Survivors of pediatric brain tumor and healthy children differed in brain activation during completion of a working memory task, and brain activation was associated with deficits noted in testing. These findings may improve understanding of mechanisms of cognitive deficits and avenues for intervention for children with brain tumors.