P3.K216: The Impact of Pediatric Traumatic Brain Injury on Amygdala and Hippocampal Volume as Related to Anxiety

Background: Traumatic brain injury (TBI) is one of the leading causes of childhood disability and death and children who experience TBIs are at a significantly increased risk for a broad array of psychological health difficulties, related in part to changes in structure and function of brain regions, such as the amygdala and hippocampus. This study examined 1) the relation between amygdala and hippocampal volumes and anxiety in children with TBI relative to healthy controls, and 2) evaluated whether the relation of amygdala and hippocampal volumes with anxiety differed in children with TBI versus healthy children and varied with time since injury.

Methods: Structural MRIs were obtained on children ages 8-15 years who experienced TBI in a vehicle accident (n=51) and age matched healthy controls (n = 36) at 7 weeks (Time 1) and 14 months (Time 2). The Screen for Child Anxiety Related Emotional Disorders (SCARED) was administered at both time points. General linear models examined group differences in anxiety and amygdala and hippocampal volumes. Generalized linear models were used to evaluate the relationship between SCARED scores and amygdala and hippocampal volumes (corrected for total gray matter), group (TBI, healthy comparison), time of scan, and their interactions. Pubertal status at Time 1 and sex were included as covariates.

Results: The Group x Volume x Time interaction was significant bilaterally for both the Amygdala (p < 0.01) and the Hippocampus (p < 0.0001). In the Amygdala, from Time 1 to Time 2 the HC’s relationship between volume and SCARED became less negative, in contrast the TBI group which initially demonstrated a positive relationship between volume and SCARED, the opposite to the HCs, showed a reversal of this relationship by Time 2. In the Hippocampus, from time 1 to time 2, the HCs maintained the same positive relationship between volume and SCARED, while the TBI group demonstrated a reversal of this pattern by time 2. Finally, there was a significant main effect of sex on SCARED score for the bilateral Amygdala and Hippocampus; girls demonstrated higher SCARED scores than boys.

Conclusion: TBI significantly impacts the relationship between Amygdala and Hippocampal values and anxiety scores in children. Additionally, these relationships between amygdala and hippocampal volumes and anxiety scores varied over time with TBI disrupting normal patterns of brain development as compared to the HCs. TBI not only impacts the neuropsychiatric development of children, but these effects may be delayed over time.