When Shakespeare meets neurology: Hamlet, Ophelia and autoimmune encephalitis

Neurology can’t seem to get away from autoimmune disorders of the central nervous system. This blog has visited this topic several times before such as with the posts titled What are the dreadful autoimmune disorders that plague neurology? and What’s evolving at the cutting-edge of autoimmune neurology? The attraction of autoimmune neurological diseases lies in part in the ever-expanding spectrum of the antibodies and the challenging symptoms and syndromes they produce.

By Gentaur – Gentaur, Public Domain, Link

The fairly well-recognised ‘conventional’ antibodies are those against VGKC (Caspr 2 and LGI1), NMDA, and AMPA. There is however an almost endless list of less familiar antibodies such as those against glycine, adenylate kinase 5, thyroid, GABA-A receptors, α-enolase, neurexin-3α, dipeptidyl-peptidase-like protein 6 (DPPX), and myelin oligodendrocyte glycoprotein (MOG). I am however fascinated by the group of disorders caused by antibodies to metabotropic receptors. The main antibody in this group targets the metabotropic glutamate receptor 5 (mGluR5). The clinical picture with this antibody is a form of encephalitis which may manifest with prosopagnosia (difficulty recognising faces), and with the curious Ophelia syndrome.

By Benjamin WestOwn work, Public Domain, Link

Yes, you read it correctly. Ophelia syndrome is named after Shakespeare’s unfortunate Danish maiden, and it was first described by Dr. Ian Carr whose daughter, at the age of 15, developed progressive loss of memory, depression, hallucinations, and bizarre behaviour. These symptoms aptly describe Ophelia’s deluded and obsessional attraction to the equally deluded and murderous Hamlet. Ophelia syndrome is almost always associated with Hodgkins lymphoma and affects young people.

By V from Coventry, UK – Hamlet, CC BY 2.0, Link

Thankfully Ophelia syndrome is a relatively mild disease without the Shakespearean tragic ending because it has a good outcome if recognised and treated.

Why not explore all the autoimmune neurological disorders on neurochecklists.

What’s evolving at the cutting-edge of autoimmune neurology?

This is a follow up to my previous blog titled What are the dreadful autoimmune disorders that plague neurology. Autoimmune neurology is a rapidly evolving field; blink and you will miss important developments. So what’s evolving in autoimmune neurology? Below are my top 4.

 

1. Insignificance of isolated VGKC positivity

By The original uploader was Iantresman at English Wikipedia - Transferred from en.wikipedia to Commons., CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1821346
By The original uploader was Iantresman at English Wikipedia – Transferred from en.wikipedia to Commons., CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1821346

Anti VGKC antibody encephalitis is caused by two different antibodies called LGI1 and Caspr2. The immunology laboratory would however only test for these two if the ‘generic’ VGKC test is positive. Neurologists are understandably left scratching their heads when both tests turn out to be negative. Not any more, going by a report in Neurology titled The relevance of VGKC positivity in the absence of LGI1 and Caspr2 antibodies. The judgment is out: a positive VGCK antibody test is not significant if both LGI1 and Caspr2 are negative. What a relief.

2. IgG4-mediated autoimmune disorders

By Swharden - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4752456
By SwhardenOwn work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4752456

This is a fairly new group of autoimmune disorders consisting of at least 13 different types. They are bad news because they cause many neurological disorders and also ravage other organs. I have previously discussed IgG4 peripheral neuropathy in my post titled What’s looming at the frontline of peripheral neuropathy. The other neurological diseases associated with IgG4 include, surprisingly, myasthenia gravis (MG), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and neuromyotonia. Less familiar IgG4 disorders are encephalopathyhypertrophic pachymeningitis and  sleep disorders with antibody to Iglon5. Trust the researchers to keep the clinicians ever on their toes.

3. GRIN-1 NMDA receptor encephalitis

DNA strand. Mehmet Pinarci on Flikr. https://www.flickr.com/photos/99843102@N05/14002600832
DNA strand. Mehmet Pinarci on Flikr. https://www.flickr.com/photos/99843102@N05/14002600832

Many acquired neurological disorders have a way of dragging genetics into their fold. Such is the case it seems with anti NMDA receptor encephalitis. This is the case with the GRIN-1 gene which codes for an NMDA receptor subunit. Mutations in this gene results in visual impairmentintellectual disability, and eye movement disorders. This is reported in Neurology by Josep Dalmau and colleagues in a paper titled Delineating the GRIN1 phenotypic spectrum. It is appropriate that the authors call this the genetic sibling of NMDA receptor encephalitis.

4. ECT for anti-NMDA receptor encephalitis 

Medcraft B-24 MarkII ECT. Niall Williams on Flikr. https://www.flickr.com/photos/niftyniall/17654690751
Medcraft B-24 MarkII ECT. Niall Williams on Flikr. https://www.flickr.com/photos/niftyniall/17654690751

The typical treatment of autoimmune encephalitis revolves around steroids, intravenous immunoglobulins (IVIg), and plasma exchange. Neurologists, when pushed to the wall, may use heavy duty agents such as Rituximab and Cyclophosphamide. Because anti-NMDA receptor encephalitis may be associated with ovarian teratomas, neurologists may make the difficult trip across the border to consult their gynaecology colleagues. I thought these were all the treatment options for anti NMDA receptor encephalitis until I read this case report, again in Neurology, which reported an excellent response to Electroconvulsive therapy in anti-NMDA receptor encephalitis. A no-brainer then if you see neurologists exchanging pleasantries with psychiatrists: they are the ECT experts. It is just a case report for now, but well-worth thinking about when all else fails.

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You may check out The Anti NMDA Receptor Encephalitis Foundation which is raising awareness of autoimmune encephalitis.

And here is a recent practical and comprehensive review of anti NMDA encephalitis by Eric Lancaster in the Journal of Clinical Neurology

And indulge me to make another shameless pitch here for neurochecklists which, after all, covers   autoimmune neurology comprehensively!