Prognostic value of electroencephalograms in asphyxiated newborns treated with hypothermia

Previous studies described how early electroencephalogram patterns in neonatal hypoxic-ischemic encephalopathy seem to correlate with the severity of the clinical picture and provide prognostic information. This study evaluated whether electroencephalograms of newborns with severe perinatal hypoxic-ischemic encephalopathy, treated with hypothermia, provide information on clinical outcomes. Twenty-three newborns treated with hypothermia underwent electroencephalogram monitoring within 48 hours of age, and were enrolled in a follow-up with sequential electroencephalogram and neurologic controls (at ages 1 week, 1 month, 3-6 months, and 1 year). An inactive electroencephalogram pattern in the first 48 hours of age was associated with death or major neurologic sequelae. At age 1 week, a low-voltage, continuous pattern indicated a worse prognostic value when compared with other patterns. The persistence of electroencephalogram abnormalities at age 1 month was associated with a higher risk of neurologic sequelae. Background electroencephalogram abnormalities, detected in the first days of life after hypoxic-ischemic encephalopathy, can provide prognostic information, even in patients treated with hypothermia. After 1 month of age, the information on clinical outcomes provided by electroencephalograms usually decreases because of the natural trend toward electroencephalogram normalization.