Miller Fisher syndrome with presynaptic neuromuscular transmission disorder.

Miller Fisher syndrome is defined by a triad of symptoms, namely areflexia, ataxia, and ophthalmoparesis. The ophthalmoparesis is mostly severe, undulating weakness of eye movements with ptosis and increased fatigability resembling a neuromuscular transmission disorder. We present a 52-year-old man with severe Miller Fisher syndrome with a high level of anti-GQ1b antibodies and a presynaptic type of neuromuscular transmission disorder. The diagnosis was confirmed by stimulated single-fiber electromyography with the use of a concentric needle electrode and various stimulation rates.