title: Neuropsychological and FDG-PET profiles in VGKC autoimmune limbic encephalitis.
abstract: Limbic encephalitis (LE) is characterized by an acute or subacute onset with memory impairments, confusional state, behavioral disorders, variably associated with seizures and dystonic movements. It is due to inflammatory processes that selectively affect the medial temporal lobe structures. Voltage-gate potassium channel (VGKC) autoantibodies are frequently observed. In this study, we assessed at the individual level FDG-PET brain metabolic dysfunctions and neuropsychological profiles in three autoimmune LE cases seropositive for neuronal VGKC-complex autoantibodies.
  
  
  
  LGI1 and CASPR2 potassium channel complex autoantibody subtyping was performed. Cognitive abilities were evaluated with an in-depth neuropsychological battery focused on episodic memory and affective recognition/processing skills. FDG-PET data were analyzed at single-subject level according to a standardized and validated voxel-based Statistical Parametric Mapping (SPM) method.
  
  
  
  Patients showed severe episodic memory and fear recognition deficits at the neuropsychological assessment. No disorder of mentalizing processing was present. Variable patterns of increases and decreases of brain glucose metabolism emerged in the limbic structures, highlighting the pathology-driven selective vulnerability of this system. Additional involvement of cortical and subcortical regions, particularly in the sensorimotor system and basal ganglia, was found.
  
  
  
  Episodic memory and fear recognition deficits characterize the cognitive profile of LE. Commonalities and differences may occur in the brain metabolic patterns. Single-subject voxel-based analysis of FDG-PET imaging could be useful in the early detection of the metabolic correlates of cognitive and non-cognitive deficits characterizing LE condition.
authors: Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy. Electronic address: dodich.alessandra@hsr.it.
authors: Alessandra
authors: A
authors: Dodich
authors: Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; Department of Clinical Neurosciences, San Raffaele Hospital, Milan, Italy.
authors: Chiara
authors: C
authors: Cerami
authors: Department of Clinical Neurosciences, San Raffaele Hospital, Milan, Italy.
authors: Sandro
authors: S
authors: Iannaccone
authors: Department of Clinical Neurosciences, San Raffaele Hospital, Milan, Italy.
authors: Alessandra
authors: A
authors: Marcone
authors: Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
authors: Pierpaolo
authors: P
authors: Alongi
authors: Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.
authors: Chiara
authors: C
authors: Crespi
authors: Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; NeTS Center - IUSS, Pavia, Italy.
authors: Nicola
authors: N
authors: Canessa
authors: Neurology IV, Neurological Institute C. Besta, Milan, Italy.
authors: Francesca
authors: F
authors: Andreetta
authors: Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; Neuroradiology - CERMAC, San Raffaele Scientific Institute, Milan, Italy.
authors: Andrea
authors: A
authors: Falini
authors: Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; NeTS Center - IUSS, Pavia, Italy.
authors: Stefano F
authors: SF
authors: Cappa
authors: Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
authors: Daniela
authors: D
authors: Perani
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D005239:Fear / Q000502:physiology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D020363:Limbic Encephalitis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D061212:Memory, Episodic; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods*; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology*; D019275:Radiopharmaceuticals; D021641:Recognition, Psychology / Q000502:physiology
chemical_list: D001323:Autoantibodies; D024642:Potassium Channels, Voltage-Gated; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Autoimmune limbic encephalitis; Episodic memory impairment; FDG-PET imaging; Fear recognition; VGKC-complex autoantibodies