Hippocampal Volume and its Association with Verbal Memory in Adult Survivors of Pediatric Brain Tumor

Verbal memory (VM) has been shown to be impacted in brain tumor (BT) survivors, but the nature of VM problems and underlying neuropathology are poorly understood and a longterm outlook is lacking. Our study examined hippocampus volume (HV) and VM in adult survivors of pediatric BT (n=32) and controls (n=48). Results indicate that disruption to a maturing brain in childhood is detectable 17 years (mean) after diagnosis, as HV is significantly lower in survivors compared to controls. Analysis of the VM scores shows that survivors have significantly lower overall immediate recall compared to controls, but learning slope, retention, and recognition are not different across the groups. Survivors’ memory profile indicates that auditory attention and retrieval difficulties could be contributing to their lower immediate recall. For survivors, HV is significantly correlated with delayed free recall but not with other VM indices. Implications of these findings are discussed. INDEX WORDS: Hippocampus, Verbal memory, Pediatric brain tumor, Survivorship, Long-term outcomes, Neuroimaging HIPPOCAMPAL VOLUME AND ITS ASSOCIATION WITH VERBAL MEMORY IN ADULT SURVIVORS OF PEDIATRIC BRAIN TUMOR