The authors report the clinical criteria for the diagnosis of progressive myoclonus epilepsies on the basis of their experience following 34 cases (2 with sialidosis, 2 with MERRF, 4 with Lafora disease, 24 with Unverricht-Lundborg type, 4 with ataxic myoclonus). 3 rare forms of PME are also reported: a case of lipoma and PME, a family with dentato-rubro-pallido-luysian atrophy and a family of myoclonus epilepsy, Hartung type. The autonomy of Ramsay Hunt syndrome is discussed on the light of recent molecular genetic data.