Reduced hippocampal subfield volumes and memory performance in preterm children with and without germinal matrix-intraventricular hemorrhage

Abstract

Preterm newborns with germinal matrix-intraventricular hemorrhage (GM-IVH) are at a higher risk of evidencing neurodevelopmental alterations. Present study aimed to explore the long-term effects that GM-IVH have on hippocampal subfields, and their correlates with memory. The sample consisted of 58 participants, including 36 preterm-born (16 with GM-IVH and 20 without neonatal brain injury), and 22 full-term children aged between 6 and 15 years old. All participants underwent a cognitive assessment and magnetic resonance imaging study. GM-IVH children evidenced lower scores in Full Intelligence Quotient and memory measures compared to their low-risk preterm and full-term peers. High-risk preterm children with GM-IVH evidenced significantly lower total hippocampal volumes bilaterally and hippocampal subfield volumes compared to both low-risk preterm and full-term groups. Finally, significant positive correlations between memory and hippocampal subfield volumes were only found in preterm participants together; memory and the right CA-field correlation remained significant after Bonferroni correction was applied (p = .002). In conclusion, memory alterations and both global and regional volumetric reductions in the hippocampus were found to be specifically related to a preterm sample with GM-IVH. Nevertheless, results also suggest that prematurity per se has a long-lasting impact on the association between the right CA-field volume and memory during childhood.

Figure 1

Correlation between the right CA-field and memory performance in preterm-born children. Note: mm³: cubic millimeter. Details of Pearson correlation coefficient (r) and p-corrected value are provided. Significant results were obtained between the right CA-field volume and memory performance after Bonferroni correction for multiple comparisons was applied (p = .006). Unstandardized residuals were calculated and used for display purposes (adjusted according to age and eTIV).

Figure 2

Right and left hippocampus and hippocampal subfield volumes. Coronal (a,b) and sagittal (c) views showing volumetric segmentation among groups in right and left hippocampus and hippocampal subfields. In accordance with radiological convention, the left side is shown on the right of the image for each view. CA: Cornu Ammonis, GC–DG: granule cell layer of dentate gyrus, HATA: hippocampal-amygdalar transition area; HP: hippocampus; and GM-IVH: germinal matrix-intraventricular hemorrhage. Coronal coordinate (a,b): x: -205.43, y: -11.00, z: -127.00; and sagittal coordinate (c): x: 2.50, y: 140.00, z: -50.05.