The objective of this contract is the establishment of one of two clinical research centers will: a) work to establish uniform, reproducible, and objective methodologies for data collection and identification and diagnosis of neonatal seizures; b) determine etiology and pathophysiology of neonatal seizures, to study natural history, and to determine factors predictive of outcome; and c) contribute to clinical understanding regarding which infants neonatal seizures require treatment and what treatment might be the safest and most effective. This contract will be awarded for a period of four (4) years. This organization is one of two centers to be awarded contracts for the purpose stated . These centers shall collaborate on common "core" studies as well as pursue investigations unique to their center. The core studies include a prospective controlled clinical study of the natural history of neonatal seizures on all inborn infants less than 1500 grams and a clinical study of neonatal seizures in infants greater than 1500 grams. Followup to at least age 2 years is planned as a part of both studies. In addition, this center will conduct a controlled double-blind clinical trial of allopurinol to prevent encephalopathy and seizures in neonates undergoing deep hypothermia during cardiac surgery. Other studies will involve nuclear magnetic resonance (NMR) spectroscopy and near infrared (NIR) spectroscopy in neonatal seizures.