Hyperammonemia-Associated Delirium Mimics Dementia: A Case Report.

Ammonia is considered to be a neurotoxin that affects various physiological pathways, including energy metabolism, mitochondria function, and inflammatory response. Dysfunctions of these pathways contribute to the development of cognitive and executive function impairments. A case of a 67-year-old female patient who presented with unusual features of delirium after spine surgery was reported in this study. The patient initially developed acute hepatitis, and 3 weeks later, liver functions gradually improved. However, the acute onset of cognitive impairment and mild hyperammonemia was found. The patient mainly presented with cognitive deficits and impairment of executive functions without a fluctuating course. Her cognitive impairment was resolved when the serum ammonia level returned to the normal range. Consequently, we considered the diagnosis for this patient was delirium rather than a major neurocognitive disorder (dementia). Thus, the clinical diagnosis for delirium and etiologies are discussed.