Hyperammonemic Encephalopathy due to Underlying Ornithine Transcarbamylase Deficiency

Valproate-induced hyperammonemia with encephalopathy is a rare adverse effect.Polytherapy with risperidone or haloperidol further increases the risk.Encephalopathy may be mistaken for psychosis or worsening of mania especially as the liver function tests (LFTs) may be normal. [1]Hyperammonemic encephalopathy (HE) leads to astrocyte edema via glutamate uptake inhibition, and leads to cerebral edema and neuronal injury.HE is usually characterized by confusion, lethargy,