About 273,000 Americans have a spinal cord injury or disorder (SCI/D) that significantly affects their lives, and the Department of Veterans Affairs (VA) estimates that more than 45,000 of these are eligible for VA health care. That’s a lot of people, many of them in a lot of pain – but statistically, it’s a small percentage of the 6.6 million veterans who used VA health care in 2014.
… the VA has established the largest single network of spinal cord injury or disorder care in the nation, a hub-and-spoke system extending from 24 regional centers to 134 primary care teams at local VA medical centers.
According to Dr. Robert Jaeger, the VA’s director of deployment health research, SCI/D is sometimes referred to as an “orphan” condition in the medical research community: “The population of individuals who have a spinal cord injury, and the incidence of spinal cord injury,” he said, “is small compared to some other health conditions.” For example, the Centers for Disease Control and Prevention found that there are around 67 million Americans who suffer from high blood pressure, and nearly 9 million of them are veterans, according to the National Institutes of Health. This disparity often limits the incentive of private industry to create a market for drugs, therapies, or assistive technologies for SCI/D patients, or to engage in the expensive pursuit of a “cure” for SCI – a cure that is beginning to seem, through the efforts of VA researchers and their partners, increasingly plausible.
The VA’s mandate is to care for all veterans, and those with SCI/D suffer many life-threatening and chronically debilitating health consequences in addition to the resulting loss of mobility and sensation. To address these consequences, the VA has established the largest single network of SCI/D care in the nation, a hub-and-spoke system extending from 24 regional centers to 134 primary care teams at local VA medical centers.
The VA’s ambitious research portfolio supports this system of care by exploring the complex medical and social issues associated with spinal cord injury, and by investigating ways in which an injured spinal cord might repair itself and restore neuromotor function. VA spinal cord research addresses the challenges confronting individual patients, as well as the issues involved in caring for veterans with SCI/D.
VA researchers have made strides in restoring some degree of strength, balance, and motor function to SCI/D patients through technologies – Functional Electrical Stimulation (FES), Functional Neuromuscular Stimulation (FNS), and now neuroprosthetics – that apply electric stimulation to motor neurons. Researchers at the Cleveland FES Center – a consortium involving the Cleveland VA Medical Center (VAMC), the National Institutes of Health, Case Western Reserve University, and Cleveland’s MetroHealth System – are currently wrapping up a 10-year evaluation of a surgically-implanted electrical system that stimulates the muscles of the trunk and legs to allow for standing, improved balance, and exercise.
One of the most intriguing questions being pursued by researchers is how damage to the spinal cord might be repaired and function restored. In 2010, the VA and several of the nation’s leading academic researchers established a consortium – now known as the Gordon Mansfield SCI Consortium – to pursue the high-risk, high-return ideas that otherwise would be unlikely candidates for funding.
Healing an injured spinal cord has proved more complicated than healing other tissues. The scarring caused by injury releases compounds that interfere with the neurochemical processes required for regenerating axons, the slender projections of nerve cells extending out from the cells’ main bodies. In addition to this scarring, a cavity forms on the inside of the injured spinal cord, leaving an empty space that had been packed with active neurons.
This is brand-new territory. If we do get this to work in a more chronic model, this opens up the possibility of regeneration for people who have had spinal cord injuries for a year or so. We may be able to perform transplants that could help them.”
In the past few years, a corps of investigators led by Dr. Mark Tuszynski, a San Diego VAMC physician and director of the Center for Neural Repair at the University of California-San Diego, has achieved several milestones in neural regeneration. In one of these studies, reported in 2012, a team led by Dr. Paul Lu transplanted human neuroprogenitor cells (an intermediate cell type, between a stem cell and a neuron) into a rodent spinal cord that had been completely severed. Researchers then applied a carefully engineered combination of factors – biological substrates, and growth-enabling proteins – that allowed the transplanted cells to extend axons over a distance of several inches, bridging the scar tissue and forming functional connections that allowed for the recovery of some hind-limb function.
“This is actually a very seminal study,” said Dr. Audrey Kusiak, scientific program manager for VA’s spinal cord research. “It’s the first demonstration of human neuroprogenitor cells surviving and forming connections in the rodent spinal cord.”