Herein, we present a 12-month history of an adult patient presenting with seizures, a unilateral cortical MRI lesion at the left parietal lobe, CSF pleocytosis and elevated protein, anti-MOG and anti-GFAP IgG antibodies, as well as a focal neurological deficit (Gerstmann syndrome) attributable to the cortical lesion, indicating the diagnosis of autoimmune encephalitis. The gene discussed is MOG; the disease is Gerstmann syndrome.