Therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy: magnetic resonance imaging findings and neurological outcomes in a Brazilian cohort

Abstract

Objective: To determine the neurodevelopment outcomes after therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy (HIE) and identify the neonatal magnetic resonance imaging (MRI) findings associated with neurological outcome in a middle-income country.

Study design: All infants born after 35 completed weeks’ gestation with signs of moderate to severe encephalopathy and evidence of perinatal asphyxia before 6 hours of life were submitted to whole-body hypothermia and were imaged at 18 ± 8.4 days of life (range 7–33 days) after birth. Surviving infants had the neurodevelopment outcome assessed at 12 to 18 months of age by trained professional masked to MRI findings.

Results: Forty-eight infants included, MRI scans were obtained from 34 infants; 14 (29.1%) patients died during hospitalization before MRI was performed. Nine (64.3%) of 14 patients were classified as severe encephalopathy presented Posterior Limb Internal Capsule (PLIC) sign at the MRI, 10 (71.4%) thalamus and basal ganglia (TBG) lesion, 9 (64.3%) white matter (WM) lesion, and 7 (50.0%) cortical lesion. Severe encephalopathy was associated with the motor delay at 12–18 months by Bayley III, Alberta Infant Motor Scale (AIMS), and Gross Motor Function Classification System (GMFCS) scores (p = .020, p = .048, p = .033, respectively), but not for the cognitive (p = .167) or language skills (p = .309). Lower BSID-III motor, cognitive, and language composite scores were associated with PLIC sign (p = .047; p = .006 and p = .003, respectively). TBG lesion (p = .051) and cortical lesion (p = .030) were associated with lower language composite score. Motor delay by AIMS and the presence of PLIC sign, TBG lesion, WM lesion, and Cortical lesion on MRI were observed (p < .001; p = .002; p = .001 and p = .027, respectively); as well as higher GMFCS score were associated with the presence of PLIC sign, TBG lesion, WM lesion, and Cortical lesion on MRI (p < .001; p = .001; p = .001, and p = .011, respectively).

Conclusions: Brain MRI in neonates with HIE after therapeutic hypothermia is a valuable tool for diagnosis of encephalopathy cerebral abnormalities and is an early predictor of outcome in infants treated with whole body hypothermia for HIE in the Brazilian experience.

Keywords:

• Neonates
• hypoxic-ischemic encephalopathy
• therapeutic hypothermia
• magnetic resonance imaging
• neurodevelopmental outcome

Acknowledgements

We thank Luciano Santos Pinto Guimarães for his assistance in data analysis, and the follow up clinic multidisciplinary team for their assistance with neurological outcomes evaluations.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.