CASPR2 autoimmunity was the second most common type of anti-neuronal surface antibody autoimmunity in our cohort, which occupied 3.2% of known neuronal surface antibodies associated neurological disease and second only to anti-NMDAR encephalitis, similar to another two pediatric studies [1, 9].However, whether CASPR2 autoimmunity might be the second most common known anti-neuronal surface antibodies associated neurological disease in children warrants larger scale multi-center cohort study. The gene discussed is CNTNAP2; the disease is viral encephalitis.