Neuroimaging study of hippocampus in cancer survivors with posttraumatic stress disorder

Abstract

This review focused on our neuroimaging studies about posttraumatic stress disorder (PTSD) and intrusive symptoms in cancer patients. At the beginning, we reported smaller left hippocampi and amygdalae in breast cancer survivors with intrusive symptoms at 3 years or more after surgery. In order to approach the causality, we investigated the effect of hippocampal volume on enhanced emotional memory in healthy women. Left hippocampal volume showed a significant inverse correlation with enhanced emotional memory. These findings support that smaller left hippocampus in cancer survivors with intrusive symptoms represent a pre-existing vulnerability factor rather than the neurotoxic effect of persistent intrusive symptoms. As the frequency of large cavum septi pellucidi was not associated with intrusive symptoms, the possibility of neurodevelopmental anomaly was not accepted. Cancer-related PTSD was not associated with either hippocampal or amygdala volume at 1 year after surgery, but we found an inverse association between intrusive symptoms and hippocampal volume. Furthermore, the gray matter volume of the right orbitofrontal cortex, estimated by voxel-based morphometry, was significantly smaller in cancer survivors with PTSD than in those without PTSD or healthy subjects. Although neuroimaging data don’t contribute clinical assessment or psychological care, understanding of hippocampal involvement in intrusive symptoms may be likely to provide initiating new intervention strategy.