Relevance of Brain 18 F-FDG PET Imaging in Probable Seronegative Encephalitis With Catatonia: A Case Report.

Autoimmune encephalitis (AIE) is a rare, severe, and rapidly progressive encephalopathy, and its diagnosis is challenging, especially in adolescent populations when the presentation is mainly psychiatric. Currently, cerebral 18-fluorodeoxyglucose positron emission tomography ( ¹⁸ F-FDG-PET) imaging is not included in the diagnosis algorithm. We describe a 16-year-old patient with probable seronegative encephalitis with catatonia for which several cerebral PET scans were relevant and helpful for diagnosis, treatment decision making, and follow-up monitoring. The patient recovered after 2 years of treatment with etiologic treatment of AIE and treatment of catatonia. This case suggests a more systematic assessment of the clinical relevance of ¹⁸ F-FDG-PET imaging in probable seronegative AIE.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2021 Guetta, Kas, Aouidad, Soret, Allenbach, Bordonné, Oppetit, Raffin, Psimaras, Cohen and Consoli.)