[Autoimmune Encephalitis/Meningitis].

Less than half of the cases of autoimmune encephalitis have brain MRI abnormalities; however, some patterns of MRI findings help diagnosis. Usually, DWI and FLAIR images reveal hyperintensity lesions in the cortical or subcortical regions or the cerebellum and/or the brainstem. Hyperintensity lesions in the limbic cortex on DWI suggest NMDAR encephalitis. RA or polychondritis-related meningitis show bright dot or linear signals on the convexities on DWI. Area postrema syndrome is a typical form of neuromyelitis optica. These conditions need to be diagnosed promptly for effective treatment.