Serial 18F-FDG PET/CT Findings in a Patient With IgLON5 Encephalopathy.

We presented the serial FDG PET/CT brain scans of a 64-year-old woman with IgLON5 encephalopathy, which is a novel syndrome in association with antibodies to a neuronal cell adhesion protein named IgLON5, and FDG PET findings have not been characterized previously. For our case, the relatively hypermetabolism in primary sensorimotor cortices, basal ganglia, and cerebrum comparing to other cortical regions on the pretreatment FDG PET/CT was partially recovered on the follow-up FDG PET/CT scan after immunotherapy, corresponding with the alleviation of clinical syndromes. The metabolic change pattern was not similar as other types of autoimmune encephalitis.