I added some information to my section "How to Find Medical and Scientific Information." The addition consisted of a new link, http://librarysearch.org, which tells you about intra-library loans and some service packed such as EBSCO (which I have separately discussed) and Illiad (which is the main interlibrary loan service). There is also some other information of general interest to those who want or need to do library research.  I also corrected a few typographical errors and reworked a few of the paragraphs in an effort to make my presentation more clear.

Limbic encephalitis is a poorly understood inflammation of the hippocampus and other parts of the limbic system that causes a subacute confusión, memory loss, seizures and, sometimes, a permanent dementia and/or death.  In many cases it seems  to be due to an autoimmune response to cancer, in which case it would  be called paraneoplastic (limbic) encephalitis.  In other cases it appears to be an idiopathic (of no known cause) autoimmune response.  A number of antigens have been identified in the autoimmune  cases including  a number of synaptic proteins such as N-methyl-d-aspartate (NMDA), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and gamma amino butyric acid (GABA) receptors.  A whole subgroup of limbic encephalitis has been thought to be due to antibodies not to a synaptic protein but, rather, to voltage gated potassium channels.

The authors of the Lancet Neurology article listed below challenged this connection.  They identified 57 patients who had the syndrome of limbic encephalitis and who, according to the conventional tests, had antibodies to the voltage gated K channels.  But they used definitive methods of identifying the antibodies and found that the antibodies were all directed toward LGl1, a protein secreted at the synapse which appears to facilitate synaptic function by promoting or modulating interactions between the pre synaptic and post synaptic parts of the synapse.  Thus, this category of limbic encephalitis is actually related to a synaptic protein similar to cases involving NMDA, AMPA and GABA receptors.  But it is also different from these in that LGl1 is a secreted protein, not a receptor.

http://www.thelancet.com/journals/laneur/issue/current

Investigation of LGI1 as the antigen in limbic encephalitis previously attributed to potassium channels: a case series Meizan Lai, Maartje GM Huijbers, Eric Lancaster, Francesc Graus, Luis Bataller, Rita Balice-Gordon, John K Cowell, Josep Dalmau

Lancet Neurol 2010; 9: 776–85

Lancet Neurol 2010; 9: 776–85