Autoimmune cerebellar ataxia associated with anti-leucine-rich glioma-inactivated protein 1 antibodies: Two pediatric cases

Objectives: To report two pediatric cases of autoimmune cerebellar ataxia associated with the anti-Leucine-rich glioma-inactivated protein 1 (LGI1)antibodies.Methods: The clinical features of the two patients were described retrospectively. The indirect immunofluores-cence using transfected cells (cell-based assay, CBA) and the rat cerebellum (tissue-based assay, TBA) with the multi-antigen co-plate biochip mosaic techniques were used to detect the antibodies. Clinical and laboratory characteristics were described.Results: Two males were included. The onset ages were 2.7y and 4y, respectively. Patient 1 manifested as isolated acute cerebellar ataxia. Patient 2 had extra-cerebellar symptoms, including seizures, encephalopathy, faciobra-chial dystonic seizures(FBDs), and significant cerebellar ataxia. The hyponatremia and tumors were not found. Both of them responded well to the immunotherapy.Conclusions: The autoimmune cerebellar ataxia might be a new phenotype of LGI1-Abs autoimmunity in children.