The Application of Neurodiagnostic Studies to Inform the Acute Management of a Newborn Presenting With Carbamoyl Phosphate Synthetase 1 Deficiency

Neonatal-onset urea cycle disorders (UCDs) may result in hyperammonemic (HA) encephalopathy presenting with several neurologic sequelae including seizures, coma, and death. However, no recommendations are given in how and when neurodiagnostic studies should be used to screen or assess for these neurologic complications. We present a case of carbamoyl phosphate synthetase 1 (CPS1) deficiency in a newborn female in which electroencephalogram monitoring to assess encephalopathy and seizures, and magnetic resonance imaging measurements of brain metabolites were used to guide care during her hyperammonemic crisis. Her neurologic course and response to treatment characterizes the significant neurologic impact of HA encephalopathy. Our group herein proposes a clinical neurodiagnostic pathway for managing acute HA encephalopathy.