[Fisher Syndrome and Bickerstaff Brainstem Encephalitis].

Fisher syndrome has been regarded as a peculiar inflammatory neuropathy with ophthalmoplegia, ataxia, and areflexia, whereas Bickerstaff brainstem encephalitis has been considered a pure central nervous system disease characterized by ophthalmoplegia, ataxia, and consciousness disturbance. Both disorders share common features including preceding infection, albumin-cytological dissociation, and association with Guillain-Barré syndrome. The discovery of anti-GQ1b IgG antibodies further supports the view that the two disorders represent a single disease spectrum. The lesions in Fisher syndrome and Bickerstaff brainstem encephalitis are presumably determined by the expression of ganglioside GQ1b in the human peripheral and central nervous systems. Bickerstaff brainstem encephalitis is likely to represent a variant of Fisher syndrome with central nervous system involvement.