CSF was collected from three patients with either LGI1 (n = 2) or CASPR2 (n = 1) antibody encephalitis at their disease presentation, 21 to 1,041 d after the onset of frequent focal seizures and memory disturbances typical of their disorders (8) (Fig. 1A and SI Appendix, Table S1). Here, LGI1 is linked to viral encephalitis.