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Updated: Jan 4, 2026
Early Pathological and Magnetic Resonance Detection of Cerebral Injury Using a Rat Model of Neonatal Hypoxic Ischemic Encephalopathy
Published on: October 28, 2022
Signal Change in the Mammillary Bodies after Perinatal Asphyxia
M Molavi1, S D Vann2, L S de Vries1
1From the Departments of Radiology and Neonatology (M.M., L.S.d.V., F.G., M.L.), Wilhelmina Children's Hospital, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands.
Background And Purpose:
Research into memory deficits associated with hypoxic-ischemic encephalopathy has typically focused on the hippocampus, but there is emerging evidence that the medial diencephalon may also be compromised. We hypothesized that mammillary body damage occurs in perinatal asphyxia, potentially resulting in mammillary body atrophy and subsequent memory impairment.
Materials And Methods:
We retrospectively reviewed brain MRIs of 235 clinically confirmed full-term patients with hypoxic-ischemic encephalopathy acquired at a single center during 2004-2017. MRIs were performed within 10 days of birth (median, 6; interquartile range, 2). Two radiologists independently assessed the mammillary bodies for abnormal signal on T2-weighted and DWI sequences. Follow-up MRIs were available for 9 patients; these were examined for evidence of mammillary body and hippocampal atrophy.
Results:
In 31 neonates (13.2%), abnormal high mammillary body signal was seen on T2-weighted sequences, 4 with mild, 25 with moderate, and 2 with severe hypoxic-ischemic encephalopathy. In addition, restricted diffusion was seen in 6 neonates who had MR imaging between days 5 and 7. For these 31 neonates, the most common MR imaging pattern (41.9%) was abnormal signal restricted to the mammillary bodies with the rest of the brain appearing normal. Follow-up MRIs were available for 9 patients: 8 acquired between 3 and 19 months and 1 acquired at 7.5 years. There was mammillary body atrophy in 8 of the 9 follow-up MRIs.
Conclusions:
Approximately 13% of full-term infants with hypoxic-ischemic encephalopathy showed abnormal high mammillary body signal on T2-weighted images during the acute phase, which progressed to mammillary body atrophy in all but 1 of the infants who had follow-up MR imaging. This mammillary body involvement does not appear to be related to the severity of encephalopathy, MR imaging patterns of hypoxic-ischemic encephalopathy, or pathology elsewhere in the brain.
Insights
Hypoxic-ischemic encephalopathy in newborns can damage the mammillary bodies, a key memory area. This damage, seen on MRI, often leads to mammillary body atrophy and potential memory issues.
Area of Science:
- Neuroscience
- Pediatric Neurology
- Radiology
Background:
- Hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal brain injury.
- Memory deficits in HIE are typically linked to hippocampal damage.
- Emerging evidence suggests the medial diencephalon, including the mammillary bodies, may also be affected.
Purpose of the Study:
- To investigate mammillary body damage in term infants with HIE.
- To determine if perinatal asphyxia leads to mammillary body atrophy.
- To explore the link between mammillary body atrophy and memory impairment.
Main Methods:
- Retrospective review of brain MRIs from 235 term infants with HIE.
- MRIs assessed for abnormal mammillary body signal on T2-weighted and DWI sequences.
- Follow-up MRIs analyzed for mammillary body and hippocampal atrophy.
Main Results:
- Abnormal mammillary body signal observed in 13.2% of HIE infants.
- Mammillary body atrophy occurred in 8 of 9 infants with follow-up MRIs.
- Mammillary body involvement was independent of HIE severity or other brain pathology.
Conclusions:
- Mammillary body damage is a significant finding in HIE.
- Acute mammillary body signal changes on MRI can predict subsequent atrophy.
- This atrophy may contribute to memory deficits in survivors of HIE.
