Partial return of motor function in paralyzed legs after surgical bypass of the lesion site by nerve autografts three years after spinal cord injury

Spinal cord injuries often result in irreversible loss of motor and somatosensory functions below the lesion level. Treatment is limited to physiotherapy aimed at compensating disability. We previously showed that re-establishment of tissue continuity can be achieved in animal models through nerve autografts implanted between the rostral spinal ventral horn and the caudal ventral roots. Rostral motor neuron axons could thus reach peripheral targets, leading to some return of motor function. We used a similar approach in a paraplegic patient with stabilized clinical states three years after spinal cord traumatic damage at the T9 level. Three segments from autologous sural nerves were implanted into the right and left antero-lateral quadrant of the cord at T7-8 levels, then connected to homolateral L2-4 lumbar ventral roots, respectively. Eight months after surgery, voluntary contractions of bilateral adductors and of the left quadriceps were observed. Muscular activity was confirmed by motor unit potentials in response to attempted muscle contraction. Motor-evoked potentials from these muscles were recorded by transcranial magnetic stimulation. These data support the hypothesis that muscles have been re-connected to supra-spinal centers through motor neurons located in the rostral stump of the damaged cord. They suggest that delayed surgical reconstruction of motor pathways may contribute to partial functional recovery.