[Morphological studies of peripheral nerves for a better understanding of Charcot-Marie-Tooth atrophy and Roussy-Lévy hereditary areflexic dysstasia].

The author beings with preliminary remarks concerning the role played by the electron microscope in the correct interpretation of onion bulb formations which are, when observed in sufficient number, characteristics of hypertrophic neuritis. As a result of such studies, certain entities initially considered as closely related to spinocerebellar degenerations are now attributed to this type of peripheral nerve pathology. Discussed first is Charcot-Marie-Tooth atrophy, mainly characterized by its topography and considered to be of neurogenic origin. However, there is disagreement concerning the site of the primary lesions thus bringing into question the individually of this entity. It has now been demonstrated that this disease belongs, at least partly, to the large group of disorders defined as familial or primary hypertrophic neuritis. The same conclusion may be applied to the Roussy-Lévy disease since it has been recently demonstrated that the original family upon whom the description was based is suffering from hypertrophic neuritis. Thus, there exists a relationship between these two disorders which may be additionally linked by the present of a tremor. Finally, as a result of pathological nerve studies, the field of disorders due to hypertrophic neuritis has enlarged at the expense of spinocerebellar degenerations. This nosological reappraisal should provide better direction for future research.