The authors report the case of a 16 year-old girl with the following features: clinically, a progressive bulbar paralysis, a weakness and wasting of muscles predominantly in the upper limbs; pathologically, a severe neuronal loss in the motor nuclei of the VIIth, IXth, XIIth cranial nerves and in the anterior horns of the cervical and thoracic spinal cord, a demyelinisation of the corticospinal tracts. A classification of progressive bulbar paralysies in infants and children is proposed. In the first group, the peripheral motoneuron is the only involved. Such cases are often called Fazio-Londe disease and can be related to those cases of infantile spinal amyotrophy either of the Werdnig-Hoffmann type or, most often, of the Wolfhardt-Kugelberg type. In the second group, the corticospinal tract is also involved. Some of these cases can be included in the spinocerebellar degenerations but others, such as the case reported here, are strongly reminiscent of the adult amyotrophic lateral sclerosis.