A case of anti-GA1 antibody-positive Fisher syndrome with elevated tau protein in cerebrospinal fluid.

We describe a boy with Fisher syndrome. He presented the typical symptoms of Fisher syndrome, including external ophthalmoplegia, abnormality of convergence, and areflexia, after an episode of Campylobacter enterocolitis. Atypically, however, anti-GA1 antibody was detected in his serum, though anti-GQ1b and anti-GT1a antibodies were not. In addition, the tau protein level in his cerebrospinal fluid was elevated. Generally, Fisher syndrome is a self-limiting disease and has a good prognosis. In our patient, however, mild diplopia and areflexia persisted 6 months after their onset. Here, we report on the first Fisher syndrome patient with anti-GA1 antibody in the serum and elevated tau protein in the cerebrospinal fluid.