Background: Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis causes substantial neurological disability. Autoantibodies causing encephalitis directed against the neuronal cell surface or synapse are of diagnostic importance giving the possibility of successful immunotherapy.
Objective: In this study, we aim to provide supporting evidence that brain 18F-FDG-PET may be helpful in identifying likely patterns of regional brain glucose metabolism.
Methods: Thirty-three patients (18 men and 15 women; age range of 17-55 y) with positive NMDA receptor antibody encephalitis that underwent an 18F-FDG-PET imaging examination were prospectively selected and compared with a reference group of 14 brain 18F-FDG-PET scans from healthy volunteers using voxel-based statistical analysis. Clusters of hyper- and hypo-metabolism were reported for the whole sample of patients (FWE-corrected P < 0.05), and uncorrected at P < 0.005 for a group of relapsed patients.
Results: Mixed metabolic patterns (focal/bilateral hypermetabolism in the temporal lobe, insula, and cerebellum; associated with severe bilateral hypometabolism in the occipital and parietal lobes) were found.
Conclusions: Our findings suggest that 18F-FDG-PET should be included as an imaging tool when assessing affected patients in the clinical workup to rule out anti-NMDA encephalitis and help determine the most effective treatment.
Keywords: FDG; acute disorder; encephalitis; neuropsychiatry; positron emission tomography.
Copyright © 2019 Academy of Consultation-Liaison Psychiatry. Published by Elsevier Inc. All rights reserved.