July 27, 2017 – Momentum is growing rapidly in research on stimulating the spinal cord to restore function after spinal cord injury. This is based on a recent report that an independent site (Mayo Clinic) has repeated findings at the University of Louisville and their collaborators at the University of California, Los Angeles. The Neilsen Foundation, along with other funders, has contributed support to these efforts.
While people often refer to the spinal cord as being “severed,” that is rarely the case. It has long been known that some nerves survive around the edges of the injury site after even the most serious injuries. There was no evidence, however, that these nerves conveyed useful information to the otherwise intact spinal circuits below the site of injury. That all changed in 2011, when researchers stimulated the surface of a person’s spinal cord below the injury with a commercial “epidural” stimulator commonly used to treat pain syndromes. They were attempting to improve the spinal cord’s ability to coordinate stepping but found that, with the stimulator on, the research volunteers could move their feet and legs on command. As these studies progressed, hints emerged that, in some cases, stimulation might also benefit functions such as bladder, circulation and breathing.
Today, these and other laboratories are addressing the many questions raised by these observations. Among the multiple research directions yet to be explored, the first question is: what is going on? That is, how is the stimulation having these effects and can stimulators that aren’t surgically implanted also work? These answers will come from a combination of animal studies and more clinical testing. The important clinical question is: how reliable (and how safe) is this? That is, will it move from being a laboratory observation to being a bona fide treatment strategy? We need to know much more about where and in what patterns to effectively apply stimulation, how variable it is for different people, and whether stimulation actually modifies how the spinal cord itself functions over the long-term.
That is where researchers at Louisville, UCLA and Mayo as well as other centers (e.g., the University of Minnesota) continue to do what are still relatively early-stage explorations with research volunteers. Meanwhile, laboratory researchers are trying to understand, at the level of spinal cord nerve fibers, how these Rip Van Winkle connections can be awakened and how best to recruit them to restore reliable function.