The investigators will conduct a randomized, double-blind, controlled, dose escalation study of BTN as add-on therapy to treat refractory seizures caused by HIE, focal or multi-focal stroke, intracranial hemorrhage, CNS infection, genetic syndrome, focal or diffuse brain malformation, idiopathic or presumed genetic etiology of seizures, or metabolic disorder other than electrolyte disturbances or those caused by renal failure not controlled by an initial loading dose of PB. The trial will test the feasibility of early enrollment of newborns with HIE, rapid application of a full montage EEG, and continuous review of EEG data to detect refractory seizures as soon as they occur following an initial loading dose of PB. When an EEG-proven seizure occurs at least 30 minutes following a loading dose of PB, the newborn will be randomized to receive either BTN or placebo in conjunction with a loading dose of PB. Clinical, laboratory and continuous EEG monitoring data obtained after BTN administration will be analyzed to determine the pharmacokinetics and safety of BTN by comparing data from treatment and standard therapy groups. This study addresses important challenges in trial design and sets the stage for trials to improve treatment of neonatal seizures. Data from this pilot study will be used to guide design of a planned Phase III multicenter trial to test the efficacy of BTN to control refractory neonatal seizures.