[Activation of motor pathways in neonates at term by percutaneous stimulation of the motor cortex and spinal cord].

The percutaneous stimulation of both the motor cortex and the spinal cord have been used to study the central motor pathways of 19 healthy full-term newborns and of 5 infants (17 months to 4 years). The responses of lower limb muscles to cortical stimulation were more difficult to obtain than those of upper limb muscles. Conduction velocities of central motor fibres along the spinal cord (between C7 to L4) were around 10 m/s in full-term newborns and 38 m/s at the age of 4 years old. These values are considerably less than those published in adult man (48 to 60 m/s).