DIRECT CONNECTION OF THE CENTRAL NERVOUS SYSTEM WITH MUSCLES IN PARAPLEGIC PATIENTS

Abstract

Purpose: Spinal cord injury is definitive because the advancement of axon regeneration from cortical cells is blocked.

Material and methods: Research in the field began in 1980 with peripheral nerve grafts positioned between the stumps of the sectioned cord. Regenerated axons entered the grafts but were blocked when they reached the cord. We therefore developed the concept of connecting the fibres of the descending corticospinal cord directly to the nerves of selected muscles. Research was conducted over 22 years, first with rats then with monkeys. Mortality was high due to insufficient intensive care. For the surviving animals, muscles connected to the cord were trophic, moved, and responded to electrical stimulation of the nerve or the cord and presented histological features comparable to those of sutured peripheral nerves.

Results: After obtaining the approval of the national ethics commission, we performed the procedure in a young woman who was fully informed of the risks and volunteered for the operation. Before operating other patients, we decided to wait for the first clinical results. The operation consisted in connecting the corticospinal cord with the glutemus maximus and medius muscles and the quadriceps muscles (bilaterally). We expected to wait two years or more due to the distance between T10 and the innervated muscles. The patient moved and walked earlier than expected. At the present time, she is able to walk 10 to 15 minutes with a walking aid. In the pool, she is even able to climb a few steps. Her improvement continues.

Discussion: Since the innervation arises from the glutamatergic central motoneuron and the normal motor plaque is a cholinergic junction, research is continuing in rats to search for the genes which code for the receptors of the innervated muscle to learn whether the central motoneuron changes its transmittor or the muscle changes its receptors. Curarisation in these rats paralyses the normal muscles while the denervated muscles re-innervated with central motoneurons are not.

Conclusion: Apparently, the receptors of the motor plaque change. Further confirmation is needed.