Alessandra Dodich1, Chiara Cerami2, Sandro Iannaccone3, Alessandra Marcone3, Pierpaolo Alongi4, Chiara Crespi5, Nicola Canessa6, Francesca Andreetta7, Andrea Falini8, Stefano F Cappa6, Daniela Perani9. 1. Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy. Electronic address: dodich.alessandra@hsr.it. 2. 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. 3. Department of Clinical Neurosciences, San Raffaele Hospital, Milan, Italy. 4. Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy. 5. Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy. 6. Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; NeTS Center - IUSS, Pavia, Italy. 7. Neurology IV, Neurological Institute C. Besta, Milan, Italy. 8. Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; Neuroradiology - CERMAC, San Raffaele Scientific Institute, Milan, Italy. 9. Università Vita-Salute San Raffaele, Milan, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
Abstract
BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
BACKGROUND: 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. MATERIALS AND METHODS: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. RESULTS: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. CONCLUSIONS: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: Nicolas De Leiris; Berangère Ruel; Jean Vervandier; José Boucraut; Stephan Grimaldi; Tatiana Horowitz; Jean Pelletier; Frederique Fluchere; Jacques-Yves Campion; Elsa Kaphan; Eric Guedj Journal: Eur J Nucl Med Mol Imaging Date: 2021-08-31 Impact factor: 9.236
Authors: Christoph Mueller; Lisa Langenbruch; Johanna M H Rau; Tobias Brix; Christine Strippel; Andre Dik; Kristin S Golombeck; Constanze Mönig; Andreas Johnen; Saskia Räuber; Heinz Wiendl; Sven G Meuth; Jens Bölte; Stjepana Kovac; Nico Melzer Journal: Arch Clin Neuropsychol Date: 2022-05-16 Impact factor: 3.448