Failure of PET scan: A case of psychiatric catatonia mistaken for encephalitis

Abstract

Catatonia is a neuropsychiatric syndrome that can mimic or accompany a variety of psychiatric and medical conditions. An etiology is often elusive, especially when patients present with a history with multiple confounding features. Workup for rapidly progressive illnesses such as N-methyl- D -aspartate receptor (NMDAR) encephalitis can involve multiple laboratory tests and brain imaging, such as [ 18 F]fluorodeoxyglucose-positron emission tomography (FDG-PET). However, some catatonic behaviors may confound FDG-PET results and delay appropriate treatment. This case highlights the diagnostic and therapeutic challenges in catatonia and the potential danger of overreliance on imaging before proceeding with symptomatic treatment.