Of 1465 patients tested, 925 met inclusion criteria (median age 51 years, IQR 17-67; 53% female; Chinese 67.9%, Malay 13.1%, Indian 7.5%, others 11.5%). A total of 2168 neural antibody tests were performed: 1278 panels (1125 ENC, 153 PNEO), and 890 CBAs (performed locally or via separate referral for NMDAR, glycine receptor, AQP4, MOG); 513 of 751 panel-tested patients (68%) had paired serum and CSF. Ninety patients (9.7%) had clinically significant seropositivity, spanning nineteen distinct neural antibodies. The most frequent were NMDAR (n=29), VGCC P/Q-type (n=15), GFAP (n=8), GABA-B (n=7), LGI1 (n=7) and high titre GAD65 (n=6); rarer antibodies included mGluR1, IgLON5, AP3B2, and AMPAR. Seventeen patients (18.9%) had two or more coexisting antibodies. 

Comprehensive testing in this seven-year multi-ethnic Southeast Asian cohort identified a diverse neural antibody spectrum, including rarer antibodies undetectable by currently available commercial assays. These findings suggest the apparent rarity of certain antibody-mediated neurological disorders in this region may reflect limits of regional testing rather than true differences in disease frequency and support a broadened approach to antibody evaluation in patients with suspected autoimmune neurological disease.