ABSTRACT
Fluctuating confusion was detected in a 65-year-old woman who was suffering from alterations in consciousness and gait ataxia after high protein dietary intake. The blood level of ammonia was high and EEG showed slow-waves in delta frequency. Hyperammonemia and episodic neurological symptoms suggested a diagnosis of ornithine transcarbamylase deficiency (OTCD). Blood aminoacid profile showed increased tyrosine, and reduced valine-leucine-isoleucine levels. Treatment including protein restriction and administration of sodium benzoate yielded a full recovery. On literature research, she was found to have the most late-onset of OTCD. This case suggests the need to include OTCD in the differential diagnosis of episodic attacks and emphasizes the value of serial EEG recordings during the follow-up of the patient.