Hyperammonaemic coma in ureterosigmoid urinary diversion.

We report on a patient with ureterosigmoid anastomosis, who presented with recurrent episodes of confusion, agitation and aggressive behaviour, culminating in coma. Investigations revealed profound hyperammonaemia, which responded to treatment with sodium benzoate and sodium phenylacetate. No definite cause was found for the abnormality, apart from possible urinary tract infection. The patient remains well on a protein restricted diet with mildly elevated levels of plasma ammonia.