title: Uncommon 18F-FDG-PET/CT findings in patients affected by limbic encephalitis: hyper-hypometabolic pattern with double antibody positivity and migrating foci of hypermetabolism.
abstract: Autoimmune limbic encephalitis (LE) is a rare disorder; its diagnosis can be challenging. We report two uncommon cases of LE evaluated by brain 2-deoxy-2-[18F]fluoro-d-glucose ((18)F-FDG) positron emission tomography/computed tomography describing the metabolic imaging patterns, which were different from those observed in previous studies: the first one presented an unprecedented (18)F-FDG brain mixed pattern, involving also the midbrain, despite negative magnetic resonance imaging exams; the second one showed migrating foci of hypermetabolism, one of which turned into hypometabolism at a later examination.
authors.affiliation: Positron Emission Tomography Centre IRMET S.p.A., Euromedic Inc., Turin, Italy; PET Pediatric AIMN InterGroup, Turin, Italy; Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy. Electronic address: a.cistaro@irmet.com.
authors.forename: Angelina
authors.initials: A
authors.lastname: Cistaro
authors.affiliation: Department of Nuclear Medicine, Fondazione Poliambulanza, Brescia, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Caobelli
authors.affiliation: Nuclear Medicine Unit, Department of Biomedical Sciences and of Morphological and Functional Images, University of Messina, Italy.
authors.forename: Natale
authors.initials: N
authors.lastname: Quartuccio
authors.affiliation: PET Pediatric AIMN InterGroup, Turin, Italy.
authors.forename: Piercarlo
authors.initials: P
authors.lastname: Fania
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy; Department of Nuclear Medicine, Karolinska University Hospital, Solna, Stockholm, Sweden.
authors.forename: Marco
authors.initials: M
authors.lastname: Pagani
mesh_terms: D000906:Antibodies / Q000032:analysis; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism*; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D020363:Limbic Encephalitis / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D000906:Antibodies; D019788:Fluorodeoxyglucose F18
keywords: (18)F-FDG PET/CT; Autoimmune limbic encephalitis; GAD; MRI; NMDAR