Acute ophthalmoplegia, ataxia, and areflexia (Fisher syndrome) in childhood

A previously healthy 3 1/2-year-old white boy had total external ophthalmoplegia, ataxia, and areflexia occurring 1 week after an upper respiratory infection. The relationship between Fisher syndrome and Guillain-Barre syndrome is explored and the differential diagnosis discussed. The relationship of mononucleosis to these entities is reviewed. The invariably benign nature of Fisher syndrome as opposed to the possibly lethal nature of the Guillain-Barre syndrome is stressed. The possible sites for involvement are described and the need to consider infectious mononucleosis in any acute neurologic illnes of childhood is stressed.