Ten cases of Miller Fisher syndrome. Electrophysiological study.

The association of ophthalmoplegia, ataxia and areflexia was described by M iller Fisher in 1956. it is postulated as a variant of the Guillain Barre s yndrome. We report 10 Miller Fisher syndrome patients admitted in an intens ive care unit between June 1990 and February 1999 who were selected accordi ng to clinical criteria of Ropper and Wijdicks. All patients had motor and sensory nerve conduction studies and electromyography, nine had visual and brainstem auditory evoked potentials and two had short latency somatosensor y evoked potentials. Peripheral neuropathy was found in all patients. AN had sensory nerve chang es and some were severe. Motor nerve conduction abnormalities were observed in 7 only cases with moderate increase of F latency in 3 cases and compoun d muscle action potential reduction in 3 other cases. in the last case, mot or conduction abnormalities was more severe, caracterized by conduction vel ocity slowing in both distal and proximal sites and by temporal dispersion of action potentials. All brainstem auditory evoked studies were normal. In 4 patients, MRI studi es were normal. These data support that brainstem is preserved in MFS. Only one patient had visual evoked potential abnormalities. Optic neuropathy is debated in Miller Fisher and in Guillain Barre syndrome. As a conclusion, in MFS peripheral neuropathy is always present with severe sensitive changes and moderate motor changes (This is different as compare d to Guillain Barre syndrome according to electrophysiological data). We di d not find involvement of brainstem in our patients with Miller Fisher synd rome.