Neurologic outcome after electroencephalographically proven neonatal seizures.

Infants in whom neonatal seizures were confirmed by randomly recorded ictal electroencephalographic (EEG) tracings were retrospectively examined to determine their global neurologic outcome and the specific frequency of epilepsy, development delay, and cerebral palsy. Perinatal and postnatal clinical and EEG variables were also examined for their relevance to the neurologic outcome. Forty infants with EEG documented seizures of diverse etiologies were studied. The 27 survivors were followed up at a mean of 31 months. The outcome was unfavorable in 70%. The rate of epilepsy was 56%, of developmental delay 67%, and of cerebral palsy 63%. The etiology of seizures was an important factor influencing the outcome. Other clinical factors that showed a significant relationship with global or specific aspects of the neurologic outcome included the age at the onset of seizures, birth weight, and neurologic examination results. The EEG parameters that significantly predicted the neurologic outcome were interictal EEG background, increased seizure frequency, and decreased seizure duration.