[Contribution of Hoffmann's reflex, evoked on the soleus muscle, to the study of nerve conduction velocity from birth to age 5].

Abstract

We tried to appreciate the maturation of the peripheric nervous system, in children from two days to five years old, by electrophysiological technics. Hoffmann's monosynaptic reflex is recorded on the soleus muscle and conduction velocity is calculated on the motor tibial nerve. So, we can follow the conduction velocities on the proximal and distal part of this nerve, from birth to five years of life. The conduction velocities develop in a parallel and approximately exponential way. The proximal conduction velocity remains always faster than the distal one but their difference decreases during the first 18 months of life and then remains constant. The evolution of the proximal conduction velocity explains that the conduction time slightly but significantly decreases during the first year of life in contrast to the increase of the nerve length. So, during the first year of life, nervous system maturation gets on very quickly and anticipates the skeletal growth.