Neonatal neurobehavioral abnormalities and MRI brain injury in encephalopathic newborns treated with hypothermia

Background: Neonatal Encephalopathy (NE) is a prominent cause of infant mortality and neurodevelopmental disability. Hypothermia is an effective neuroprotective therapy for newborns with encephalopathy. Post-hypothermia functional-anatomical correlation between neonatal neurobehavioral abnormalities and brain injury findings on MRI in encephalopathic newborns has not been previously described.

Aim: To evaluate the relationship between neonatal neurobehavioral abnormalities and brain injury on magnetic resonance imaging (MRI) in encephalopathic newborns treated with therapeutic hypothermia.

Study design: Neonates with hypoxic ischemic encephalopathy (HIE) referred for therapeutic hypothermia were prospectively enrolled in this observational study. Neurobehavioral functioning was assessed with the NICU network neurobehavioral scale (NNNS) performed at target age 14 days. Brain injury was assessed by MRI at target age 7-10 days. NNNS scores were compared between infants with and without severe MRI injury.

Subjects & outcome measures: Sixty-eight term newborns (62% males) with moderate to severe encephalopathy underwent MRI at median 8 days (range 5-16) and NNNS at median 12 days of life (range 5-20). Fifteen (22%) had severe injury on MRI.

Results: Overall Total Motor Abnormality Score and individual summary scores for Non-optimal Reflexes and Asymmetry were higher, while Total NNNS Z-score across cognitive/behavioral domains was lower (reflecting poorer performance) in infants with severe MRI injury compared to those without (p < 0.05).

Conclusions: Neonatal neurobehavioral abnormalities identified by the NNNS are associated with MRI brain injury in encephalopathic newborns post-hypothermia. The NNNS can provide an early functional assessment of structural brain injury in newborns, which may guide rehabilitative therapies in infants after perinatal brain injury.