A case of atypical Miller Fisher syndrome with negative anti-GQ1b immunoglobulin G and importance of H reflex.

Miller Fisher syndrome (MFS) is characterized by ophthalmoplegia, ataxia and areflexia1. The disease is strongly associated with antiGQ1b immunoglobulin (Ig)G antibodies2. The clinical diseases associated with anti-GQ1b IgG antibodies are diverse. Anti-GQ1b IgG antibodies have been found in cases with acute ophthalmoplegia without ataxia as well, and these patients have been designated as having atypical MFS3. Electrophysiological abnormalities in MFS include selectively or globally abnormal motor nerve conduction velocity, sensory nerve conduction velocity, F waves, and H reflex4. In some patients, absence of H reflex may be the sole abnormality in MFS5. Here, we report a patient with negative anti-GQ1b IgG antibodies who presented with diplopia. He also had areflexia despite no signs of weakness, and absence of H reflex was the sole electrophysiological abnormality.