Spinal cord stimulation for restoration of locomotion

Intraspinal microstimulation (ISMS) may provide a means for improving motor function in people with spinal cord injury, head trauma or stroke. The goal of this study was to determine whether ISMS of the lumbosacral cord after a semi-chronic thoracic injury could generate locomotor-like stepping in the paralyzed legs. Under isoflurane anesthesia, microwires were implanted bilaterally in the lumbar enlargement of adult cats completely spinalized at the low-thoracic level 2 to 3 weeks earlier. The cats were subsequently decerebrated and anesthesia was terminated. Patterned stimulation through the intraspinal microwires generated unilateral and bilateral stepping of the legs. Foot clearance during swing and weight support during stance were achieved. The stepping movements did not decay over time. These results indicate that ISMS may be a viable neuroprosthetic approach for improving or restoring limb movements after spinal cord injury. It may also be used in conjunction with other rehabilitation approaches such as regeneration, locomotor training and neuropharmacology to enhance the functional benefits after injury.