Post-infectious demyelinating disorders are uncommon. In the Hospital Pediatrico de la Misericordia de Santafé de Bogotá there were 14 cases in three years. The commonest age group was the new born, as is found in the literature. The infections involved in these neurological changes are probably viral, since at the time the patient is seen most symptoms have cleared up spontaneously. According to several authors, the viruses are most often found to be those of measles or mumps. Between the infection and the development of