To assess the effects of neonatal
seizures on the hypothalamus and to test clinical use of
prolactin as a neonatal seizure marker, we studied postictal and recovery baseline serum
prolactin levels in 19 neonates whose
seizures were classified according to their clinical and EEG features. Postictal
prolactin levels were obtained 30 min after the seizure, and recovery levels were ascertained 2-4 days later. The ratio of postictal
prolactin level to recovery baseline level (
prolactin ratio) was used as an
indicator of postictal
prolactin increase. The specificity and sensitivity of a
prolactin ratio of > 2 was compared with the current standard of diagnosis (seizure discharges recorded by ictal EEG). Infants with electroclinical
seizures had significantly higher
prolactin ratios than control infants or infants with
seizures without EEG correlation. Marked
prolactin increases were noted only in infants with
focal tonic seizures and temporal
electrode involvement. A
prolactin ratio of > 2 had a specificity of 100% and a sensitivity of 40%. We conclude that neonatal
seizures have variable effects on the hypothalamus and that the low sensitivity and the need to await recovery levels limit the clinical value of
prolactin ratio as a neonatal seizure marker.