Neurologic Disorders and Neurodevelopment
Time-sensitive brain injury
Hypoxic-ischemic encephalopathy is staged by clinical exam, cord gases, and EEG. Therapeutic hypothermia improves outcomes for infants at least 36 weeks’ gestation with moderate-to-severe encephalopathy and should begin within six hours of birth, targeting 33.5–34.5°C for 72 hours. Seizures in newborns are often subtle and require EEG confirmation; phenobarbital is first-line. Germinal matrix hemorrhage and periventricular leukomalacia are major preterm complications, linked to hemodynamic instability and inflammation. Hypoglycemia can cause seizures and long-term disability. Developmental follow-up is essential because early deficits may not be apparent at discharge.
Traps: cooling an infant outside eligibility criteria; missing seizures because they are subtle; attributing hypotonia solely to prematurity; and forgetting that bilirubin encephalopathy can present with lethargy and poor feeding before obvious jaundice.
Worked example: a term infant has a cord pH of 6.8, needs resuscitation, and at 3 hours has lethargy and abnormal tone. Amplitude-integrated EEG shows suppression. Cooling is started within the window, and seizures are treated with phenobarbital.
Rule of thumb: “Cool within six hours if the infant is at least 36 weeks and has moderate-to-severe encephalopathy; treat seizures promptly.”