New onset of isolated adrenocorticotropin deficiency associated with encephalopathy following coronavirus disease 2019 in a healthy elderly man

Coronavirus disease 2019 (COVID-19) due to a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection can include various systemic organ disorders including endocrinopathies and neurological manifestations. We report the case of a 65-year-old Japanese man who developed isolated adrenocorticotropic hormone (ACTH) deficiency and encephalopathy following SARS-CoV-2 infection. Two weeks after his COVID-19 diagnosis, he was emergently admitted to our hospital because of subacute-onset delirium. On admission, he presented hyponatremia (128 mEq/L) and secondary adrenal insufficiency (ACTH