LGI1 and viral encephalitis: Liu X et al. [18] and Xinyue Zhang et al. [42] found involvement of the limbic system in the anti-GABAB group on 18F-FDG PET and MRI, which was more common in the poor prognosis group than in the favourable prognosis group, contrary to the viewpoint of Qian Zhao et al. [43] in LGI1 encephalitis.