Relations of hippocampal and ventricle volumes to Memory Outcomes in the Management of Myelomeningocele Study (MOMS) prenatal surgery clinical trial.

Abstract

Objective: Many individuals with spina bifida myelomeningocele perform poorly on memory tasks, with hippocampal damage a possible mechanism. This study analyzed quantitative hippocampal, amygdala, and ventricular volumes to determine if prenatal surgery reduced the effects of hydrocephalus as a potential mechanism for improved memory performance in relation to hydrocephalus status.

Method: We collected magnetic resonance imaging data from 110 children enrolled in the Management of Myelomeningocele Study (n = 55 per prenatal and postnatal groups). Volumes of the hippocampus, amygdala, and lateral ventricles were quantified using FreeSurfer. Memory was assessed with the California Verbal Learning Test-Children and Children's Memory Scale.

Results: Children who received prenatal surgery did not differ from children who received postnatal surgery on memory performance. However, within the prenatal group, children who did not meet clinical criteria for hydrocephalus or had ventricular dilation but did not require shunting showed better verbal and nonverbal memory performance than those who required shunting. The magnetic resonance imaging findings indicated larger hippocampi in the prenatal group than in the postnatal group. Similarly, within the prenatal groups, children who had no hydrocephalus showed larger hippocampal volumes than children with ventricular dilation and no shunt, and these groups had larger hippocampal volumes than children with prenatal surgery and shunted hydrocephalus. There were no significant differences in amygdala volumes. Larger hippocampi were associated with better memory performance, but there was no mediating effect of ventricular volumes.

Conclusions: Prenatal surgery is associated with larger hippocampi and better memory performance in those children who did not require shunting. (PsycInfo Database Record (c) 2025 APA, all rights reserved).