Should neurologists be thinking of Influenza H1N1?

Every now and then neurologists come across patients with what appears to be ‘straightforward’ viral encephalitis but who do not respond to conventional treatment. These treatments are usually according to established guidelines such as the ABN/BIAN guidelines, the IDS Guidelines. What to do when the patient isn’t responding is however very challenging.

Journal of Neuroinfectious Diseases (ssshh…the JNNP declined it) has just published our case report of such a patient who turned out to have H1N1 influenza encephalopathy. This experience suggests we should consider an autoimmune cause in such cases, especially if the spinal fluid does not show any viruses.

3D model of influenza virus
3D model of influenza virus


It’s only a single patient but with an excellent outcome and valuable insights (I would say so wouldn’t I!). It was rather fortuitous as her treatment with IVIg was on the assumption she had anti NMDA antibody encephalitis. Its not always in the science as the viral serology subsequently showed!

Is your interest piqued enough? OK, here is the link (and its open access):

H1N1 Associated Encephalopathy in an Adult: Response to Intravenous Immunoglobulin Supporting an Autoimmune Pathogenesis