Electroencephalographic findings in ornithine transcarbamylase deficiency

A 3-day-old infant presented with anorexia, irritability, hypotonia, and se izures. Blood ammonia was 2115 mu mol/L and amino and organic acid analyses were consistent with ornithine transcarbamylase deficiency. Liver biopsy c onfirmed only 1% enzyme activity. The patient was treated with hemodialysis . An electroencephalogram (EEG) revealed multifocal independent spike-and-s harp-wave discharges. After initial stabilization he was placed on a low-pr otein diet with citrulline and phenylbutyrate. Conjugating agents (arginine , sodium benzoate, and sodium phenylacetate) have been added during periods of metabolic decompensation. Although developmentally delayed, the patient has shown signs of clinical improvement and EEG activity has Likewise impr oved with only mild background slowing and no evidence of epileptogenic act ivity at 4 years of age. A second infant presented at 3 days of age with a similar history, blood ammonia of 1382 mu mol/L, and metabolic studies indi cative of ornithine transcarbamylase deficiency. EEG showed multifocal inde pendent ictal and interictal discharges. Electrographic abnormalities persi sted despite lowering of blood ammonia with hemodialysis and conjugating ag ents. The patient continued to decline clinically and died on the 7th hospi tal day. EEG changes parallel the clinical course of ornithine transcarbamy lase deficiency and may serve as an objective marker of the effectiveness o f therapeutic interventions.