Marc-Hector Landouzy (1812-1864) was one of the first to describe facial paralysis in newborn, through a series of case studies. By examining these four cases in the context of Landouzy's life, publications and professional circumstances, this study shows how case studies were an important part of the scientific revolution within medicine in the 19th century. Landouzy, soon followed by others, used the growing clinical populations of Parisian hospitals, patho-anatomy and cutting-edge physiologic techniques to help describe a previously ignored disease among newborns. His case studies, in particular, are a valuable example of the emerging interest in children as a clinical population and of early interest in child neurology.