CNTNAP2 and Encephalopathy: Antistreptolysin O 45 IU/mL (0-530).Nonreactive HIV-1 and HIV-2 antibodies.Serum Autoimmune Encephalopathy panel negative for AchR Ganglionic Neuronal Ab, AMPA-R Ab, Amphiphysin Ab, AGNA-1, ANNA-1, ANNA-2, ANNA-3, CASPR2-IgG, CRMP-5-IgG, DPPX Ab, GABA-B-R AB, GAD65 Ab, GFAP, IgLON5, LGI1-IgG, mGluR1 Ab, NIF, NMDA-R Ab, N-Type Calcium Channel Ab, P/Q-Type Calcium Channel Ab, PCA-1, PCA-2, PCA-Tr.