GRM5 and viral encephalitis: To date, a total of six cases of mGluR5 overlapping with other antibody encephalitis (Table 1) have been reported (7–11), with four cases demonstrating co-occurrence of NMDAR antibodies (8, 10, 11); among these, one case was positive for MOG, NMDAR, and mGluR5 antibodies (8), while another case showed positivity for NMDAR, AMPAR, and mGluR5 antibodies (10).