Hippocampal sclerosis (HS), on magnetic resonance imaging (MRI), developed in patients with antibodies against LGI1 (LGI1-2, -4, -5, -6, -7, -9, -11; 64%), GAD65 (GAD65-4, -7, -9, -13; 31%), and CASPR2 (CASPR2-4; 20%), but not with NMDAR antibodies. This evidence concerns the gene LGI1 and histiocytic sarcoma.