Developments in autoimmune channelopathies.

Autoimmune forms of encephalopathy have become a hot topic in neurology. These conditions are now known to be associated with antibodies to neuronal or glial cell surface proteins, such as ion channels, receptors or associated proteins. The most common conditions are a form of limbic encephalitis associated with antibodies to voltage-gated potassium channel complex proteins, and a more complex encephalopathy with antibodies to the NR1 subunit of the N-methyl-D aspartate receptor, a class of glutamate receptor. In addition, a very inflammatory disease of the nervous system, neuromyelitis optica, associated with blindness as well as spinal cord damage, can be distinguished by the presence of antibodies to aquaporin-4, a water channel. Many other antibodies are now being identified, but their frequencies are less clear. Most importantly, these new antibody-mediated diseases are being identified in patients of all ages, and in the majority of cases, the patients improve substantially with immunotherapies.