Extensive microbiological findings, including CSF PCR for herpes simplex virus (HSV) and varicella-zoster virus (VZV) and CSF cultures, as well as a comprehensive autoimmune encephalitis panel in serum and CSF (anti-NMDA, anti-AMPA, anti-GABA, anti-LGI1, anti-CASPR2, anti-DPPX), were all negative. Here, CNTNAP2 is linked to autoimmune encephalitis.