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

Abstract

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 (18F-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 18F-FDG-PET imaging in probable seronegative AIE.

Case Report: Anti-NMDAR Encephalitis Presenting With Catatonic Symptoms in an Adolescent Female Patient With a History of Traumatic Exposure

“…Furthermore, there is reluctance in the usage of nuclear imaging in pediatric patients due to the perception of the radiation burden associated with this technique, so cases should be carefully selected (29). It has been suggested that 8F-FDG PET might have a diagnostic role in autoantibody-negative encephalitis and that it might play a role in monitoring of the immunosuppressive response (27,30), even in pediatric population (31), but further studies are needed.…”

Neuroinflammatory syndromes in children

“…They concluded that brain 18F-FDG PET should be included in future diagnostic autoimmune encephalitis recommendations (brain 18F-FDG PET has a high detection sensitivity and should be included in future diagnostic autoimmune encephalitis recommendations) [63]. Finally, a specific NavigaƟng neuroinflammatory disorders in children and adolescents: Diagnosis interest of PET scan for patients with seronegative autoimmune encephalitis or probable autoimmune encephalitis (normal MRI and no specific CSF antibodies) has been raised with challenging paediatric case successfully presumptively treated with immunosuppressive treatments after a positive PET scan [64][65][66][67].…”