Expansion of Intact Sensory-motor Territories in Proximal Neuraxial Lesions using Peripheral Nerve-muscle Weeding Interventions

Following complete peripheral nerve injury, collateral sprouting (CS) by adjacent nerves causes concentric shrinkage of the insensate area. Such take-over of insensate territory is unknown in proximal lesions such as stroke, spinal cord injury, and cauda equina syndrome, as peripheral nerves supplying insensate territories still maintain continuity from the cell body in the dorsal root ganglion (DRG) to the skin innervation territory. This preserved distal continuity opposes territory take-over by the expansion of adjacent sensate territories; sectioning peripheral nerves in insensate territories distal to DRGs disconnects nerve cell bodies from their skin territory, thus facilitating sensate territory expansion of adjacent nerves. Similar motor system applications in paralyzed territories include lower motor neurone lesioning and fasciectomies, facilitating motor territory expansion of adjacent nerves through CS. A search for evidence of previous conception of these hypotheses was conducted in the literature, using a combination of relevant terms from three categories (proximal neuraxial lesions, nerve-muscle interventions, collateral sprouting); however, this yielded no pertinent results, suggesting that these concepts are novel. Observations from the literature on peripheral nerve injury indicate a sound scientific basis for these hypotheses. Therefore, the suggested "weeding" interventions are likely to succeed in minimizing neurological deficits and improving patients' quality of life. Various interventions to expand sensory/motor territories are considered; these include nerve lesioning distal to DRGs and removing fascial barriers between innervated and paralyzed muscles. Experience from such interventions will help expand our understanding of the speed and extent of CS-mediated neurological recovery as well as brain's plastic abilities in reorienting after such procedures.