Objective
To assess and contrast the incidence and severity of abnormalities on cerebral magnetic resonance imaging (MRI) between infants with mild, moderate, and severe neonatal encephalopathy who received therapeutic hypothermia.
Study design
This is a retrospective cohort study of infants with mild, moderate, and severe NE who received TH at a single tertiary neonatal intensive care unit (NICU) between 2013 and 2015. Two neuro-radiologists masked to the clinical condition evaluated brain MRIs for cerebral injury following TH using the Barkovich classification system. Additional abnormalities not included in this classification system were also noted. The rate, pattern, and severity of abnormalities/injury were compared across the grades of NE.
Results
Eighty-nine infants received TH and met study criteria – 48 with mild NE, 35 with moderate NE, and six with severe NE. Forty-eight infants (54%) had an abnormality on MRI. There was no difference in the rate of overall MRI abnormalities by grade of NE (mild NE 54%, moderate NE 54%, and severe NE 50%, p=0.89). Basal ganglia/thalamic injury was more common in those with severe NE (mild NE 4%; moderate NE 9%; severe NE 34%, p=0.03). In contrast, watershed injury did not differ between NE grades (mild NE 36%; moderate NE 32%; severe NE 50%, p=0.3)
Conclusion
Mild NE is commonly associated with MRI abnormalities after TH. The grade of NE during the first hours of life may not adequately discriminate between infants with and without cerebral injury noted by MRI after TH.