Brainstem hypoxic-ischemic lesions on MRI in infants treated with therapeutic cooling: effects on the length of stay and mortality.

Objective: To test the hypothesis that brainstem hypoxic-ischemic injury on magnetic resonance imaging (MRI) would be independently associated with short-term outcomes in cooled asphyxiated infants.

Methods: A total of 90 consecutively cooled asphyxiated infants who survived to have brain MRI were reviewed. A neuroradiologist who was masked to outcomes evaluated MRI images for brainstem involvement. Outcomes were mortality and length of stay.

Results: Brainstem lesions were present on post-cooling brain MRI in 20 of the 90 infants (22%). Overall, four infants died before discharge, and all four had brainstem involvement. The infants with brainstem involvement had longer hospital stay (29 days, IQR 20-47 versus 16 days, IQR 10-26; P = 0.0001), compared to infants without brainstem lesions (n = 70); and upon multivariate analysis, brainstem involvement remained independently associated with prolonged hospital stay (β = 12.4, P = 0.001).

Conclusion: This study demonstrates the importance of recognizing brainstem injury for the prediction of short-term outcomes in cooled asphyxiated infants.