Abnormalities of neuromuscular transmission in patients with Miller-Fisher syndrome.

The mechanism of motor weakness in patients with Miller-Fisher syndrome (MFS) remains to be fully elucidated. We performed stimulated single fibre electromyography (sSFEMG) in a clinically weak frontalis muscle in a patient with MFS. Stimulate single fiber EMG revealed increased jitter in over 50% of the apparent single fibre action potentials from the frontalis muscle in addition to increased mean jitter. The findings in the present study suggest dysfunction of neuromuscular transmission in patients with MFS.