To report a case of Miller Fisher syndrome in a pediatric patient with gastroenteritis associated with seroconversion of Campylobacter jejuni titer during the development of neurological symptoms and positive anti-GQ1b IgG.

An 8-year-old male patient visited our clinic with bilateral ophthalmoplegia, diplopia, and ptosis of the right upper lid. He had experienced gastroenteritis one week previous, and antibodies to Campylobacter jejuni were detected in his plasma. Ophthalmic examination revealed a corrected visual acuity of 20/20 in both eyes. Ocular motor examination revealed limitations in all positions of gaze. Neurologic examination demonstrated areflexia and ataxia. The serologic anti-GQ1b IgG test was positive. Intravenous immunoglobulin and steroid pulse therapy were started. Extraocular movement, ptosis, and ataxia gradually improved after one month of treatment.

We confirmed a case of Miller Fisher syndrome in a pediatric patient with bilateral ophthalmoplegia, ptosis, and a positive anti-GQ1b antibody test.