Post-acute COVID-19 syndrome with severe sexually deviant behavior.

The neurological symptoms of the coronavirus disease 2019 (COVID-19) can be prolonged or intensified. Many patients experience "brain fog" after recovery, termed as post-acute COVID-19 syndrome (PACS) or long COVID. Here, we describe the case of a male patient with post-COVID-19 encephalopathy and psychotic symptoms. He developed delirium and behavioral abnormalities associated with PACS after the COVID-19 infection resolved. He was admitted for sexually inappropriate behavior and catatonia symptoms. His cerebrospinal fluid tested positive for severe acute respiratory syndrome coronavirus 2 on polymerase chain reaction testing. Brain magnetic resonance imaging showed no abnormalities; however, single-photon emission computed tomography showed increased uptake in the bilateral thalamus, septal regions, and posterior cingulate gyrus. In our patient's case, the course of events led to the diagnosis of PACS with psychosis related to post-acute COVID-19 encephalopathy. Surprisingly, COVID-19 encephalitis is not caused solely by direct brain injuries; autoimmune paraneoplastic or post-infectious encephalitis can occur after viral clearance. PACS is known to cause delirium, brain fog, and depression within 4-12 weeks of the onset of COVID-19. COVID-19 is frequently associated with delirium. However, encephalopathy is overlooked owing to the lack of testing. Missed encephalopathy may progress to PACS.