Voltage-Gated Potassium Channel (VGKC) antibodies (predominately Anti-LGI1 and Anti-CASPR2) are associated with paraneoplastic neurological syndromes and limbic encephalitis.

Autoimmune encephalitis is a debilitating inflammatory disorder of the brain causing various neurological signs and symptoms. VGKCs are proteins consisting of Leucine-rich glioma inactivated protein 1(LGI1) & Contactin-associated protein 2 (CASPR2), responsible for controlling the cell membrane potential; development of antibodies against these proteins can cause Morvan syndrome, epilepsy and limbic encephalitis (short memory loss, psychiatric symptoms). These antibodies may also be associated with certain types of tumours.

This blood test helps in diagnosis of autoimmune encephalitis. It is also useful in managing patients on immunotherapy and/or plasmapheresis. The test is done to diagnose peripheral nervous system disease and central nervous system diseases in certain types of tumours.