Perinatal events and early magnetic resonance imaging in therapeutic hypothermia

Objective: To compare the association between perinatal events and the pattern and extent of brain injury on early magnetic resonance imaging in newborn infants with and without therapeutic hypothermia for hypoxic-ischemic encephalopathy.

Study design: We performed a cohort study of 35 treated and 25 nontreated neonates who underwent magnetic resonance imaging. The injury patterns were defined a priori as: normal, watershed, or basal ganglia/thalamus-predominant, as well as a dichotomous outcome of moderate-to-severe versus mild-no injury.

Results: Neonates with hypothermia had less extensive watershed and basal ganglia/thalamus injuries and a greater proportion had normal imaging. Therapeutic hypothermia was associated with a decreased risk of both basal ganglia/thalamus injury (relative risk, 0.29; 95% CI, 0.10 to 0.81, P = .01) and moderate-severe injury. Neonates with sentinel events showed a decrease in basal ganglia/thalamus-predominant injury and an increase in normal imaging. All neonates with decreased fetal movements had injury, predominantly watershed, regardless of therapeutic hypothermia.

Conclusions: These results validate reports of reduced brain injury after therapeutic hypothermia and suggest that perinatal factors are important indicators of response to treatment.