Association of cerebral activity with MRI scans in infants with neonatal encephalopathy undergoing therapeutic hypothermia.

We aimed to correlate amplitude-integrated EEG (aEEG) in neonatal hypoxic ischemic encephalopathy (HIE) with early magnetic resonance imaging (MRI). In this retrospective study, 32 neonates over 35 weeks' gestation with moderate/severe HIE who were treated with hypothermia were included. Early MRI scans and daily aEEG background were categorized to mild/normal, moderate, and severely abnormal. Time to sleep cycling was noted on aEEG. Mantel-Haenszel test for trends was used to explore associations between aEEG and MRI and outcome. LOESS regression was used for exploring the association of cycling with MRI scores. MRI was normal/mildly abnormal in 20 (63%) infants; in 9 (28%), moderately abnormal; and in 3 (9%), severely abnormal. Twenty-seven (84%) infants s urvived. MRI severity score was significantly associated with aEEG background score on the third and fourth days of life (p < 0.01). An increase in the MRI severity score was noted if sleep cycling appeared after the fifth day of life.

Conclusions

Depressed aEEG at the third and fourth days of life and appearance of cycling beyond the fifth day of life are associated with cerebral MRI abnormalities and may be associated with increased risk of abnormal outcome. What is known: • Since therapeutic hypothermia has been shown to change long-term outcome, amplitude-integrated EEG in infants with hypoxic ischemic neonatal encephalopathy soon after birth have a limited predictive power for long-term outcome in treated infants. • Brain MRI after therapeutic hypothermia in the above infants has a significant predictive value for long-term outcome What is new: • Background amplitude-integrated EEG activity depression at the age of 3 and 4 days and delay of appearance of cycling activity are associated with worse MRI scores and may be predictive of worse long-term outcome.