In addition to the T2-weighted imaging/fluid-attenuated inversion recovery (T2WI/FLAIR) hyperintensities on MRI scans, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is a potential marker for anti-LGI1 encephalitis (6, 7), In some cases, MRI may not detect abnormalities in patients with anti-LGI1 encephalitis, particularly in the early stages of the disease. This evidence concerns the gene LGI1 and encephalitis.