[Subclinical forms of spinal disorders in discogenic lumbar radiculitis].

In patients with discogenic lumbar radiculitis with a unilateral affection of L5 or S1 root motor and central responses of the medial group of plantar muscles were recorded. In S1 root pathology the central response consisted in 25% of the cases in repeated antidromal discharges, which testified to an increased excitability of the corresponding alpha-motoneurons. In patients with L5-radiculitis a predominance of the reflex component in the response was typical. Since this phenomenon was lacking in combined L5 and S1 root lesions, it was interpreted as a sign of a decreasing function of the segmental inhibitory interneurons.