Progressive encephalopathy with edema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a rare neurodegenerative syndrome first reported in 1991. Most patients described are of Finnish descent and very few patients have been reported in other countries. We report the first Swiss patient who fulfils the criteria of the PEHO syndrome. The course of the epilepsy is less severe than previously reported. Our patient developed a severe dystonic state after a febrile gastrointestinal infection, with a hypotonic state that may have been a dysregulation of brainstem origin. The diagnosis was made because of marked cerebellar atrophy in the repeated MRI. In patients with infantile spasms and severe developmental delay PEHO syndrome should be considered; it is not confined to Finnish heritage. Optic atrophy should be looked for and repeat MRI is indicated.