[Pathophysiology of Ataxia in Fisher Syndrome].

Fisher syndrome is regarded as a peculiar inflammatory neuropathy associated with ophthalmoplegia, ataxia, and areflexia. The disorder is associated with preceding infection, cerebrospinal fluid albumino-cytological dissociation, and spontaneous recovery, and regarded as a variant of Guillain-Barré syndrome. The discovery of anti-GQ1b IgG antibodies led to dramatic advances in understanding the pathophysiology of Fisher syndrome. The lesions in Fisher syndrome are determined by expression of ganglioside GQ1b in the human nervous system. This review article focuses on the pathophysiology of ataxia in Fisher syndrome. Current evidence suggests that antibody attack on Group Ia neurons in the dorsal root ganglia is mainly responsible for the sensory ataxia. Involvement of the muscle spindles might also contribute to the development of ataxia.