Every year about 11,000 people in the US suffer spinal cord injuries that will likely change their lives forever. More than half of these people are younger than 30. Today’s treatments can’t completely help the 250,000-400,000 people currently living with spinal cord injuries, but researchers at KU Medical Center’s Hoglund Brain Imaging Center are working to change that.
“Spinal cord injury is a major health and socio-economic problem,” said Mehmet Bilgen, PhD, director of high field magnetic resonance imaging research at the Hoglund Brain Imaging Center.
Bilgen, who is also associate professor of molecular and integrative physiology at the KU School of Medicine, serves as principal investigator on two current research projects. He recently received two National Institutes of Health grants totaling nearly $730,000 to study the progression of spinal cord injuries in longitudinal animal studies.
“Research on the neural fibers and vascular systems of animal spinal cords holds great potential for better understanding of spinal cord injuries and, ultimately, for better clinical treatment,” Bilgen said. The other investigators in these projects are Barry W. Festoff, MD; Randy Nudo, PhD; Paul Arnold, MD; Baraa Al-Hafez, MD; Yong Yue He, MD; Charles Little, PhD and Sandra Hall, PhD.
Methods of Discovery
While all spinal cord injuries recover to a limited extent, severe injuries can cause life-long paralysis and almost insurmountable disabilities related to pain, bladder control and upper extremity functions. The brain communicates with the body through neural fibers in the spinal cord, so the outcome of an injury is determined by how much damage is done to the neural fibers. If the spinal cord is completely severed, paralysis below the point of injury occurs. If only some of the neural fibers are damaged, sensory and Motor function may only be impaired.
Part of Bilgen’s research focuses on identifying viable neural fibers after an injury using manganese-enhanced magnetic resonance imaging (MRI). Manganese serves both as an MRI contrast agent and in vivo neuroal tract tracer. Researchers can follow manganese via MRI as it is uploaded and transported down the undamaged fibers to the point of injury.
Some of the manganese travels across the injury to the fibers below it. This suggests neural tissue bridging across the injury, possibly because it survived the injury or was restored afterward. “This should form a basis for testing new therapies for promoting fiber connectivity, understanding spinal cord Plasticity and improving Functional recovery from spinal cord injury,” Bilgen said.
Survival of some fibers within these tracts may promote recovery, repair and/or Regeneration of other fibers. This process is known as “endogenous plasticity” and the group lead by Barry W. Festoff, MD, professor of neurology and pharmacology and director, Neurobiology Research Laboratory at the Kansas City VA Medical Center, focuses on means to enhance this built-in ability of the body to promote healing and recovery. “The ability to detect these fibers by Dr. Bilgen’s techniques could lead to new treatments and paradigm shifts that restore some or even most of the lost functionality in spinal cord injured patients,” Festoff said.
Bilgen and his team are also using magnetic resonance angiography to study how blood vessels change and repair after a spinal cord injury. When blood vessels are damaged in the injury, blood supply to the spinal cord becomes disrupted. In response to the injury, new vessels are formed.
Understanding the way the vascular system changes after an injury could improve treatment and the eventual physical outcome for the patient.
“This will be a large step forward in understanding the recovery mechanisms. In the long term, it will provide objective assessment of potential new therapies with the power to manipulate the spinal cord vasculature to improve the neurofunctional outcome,” Bilgen says.
Bringing It All into Focus
While the human spinal cord may be as wide as your finger, the spinal cord of a rat or mouse is only as wide as the tip of its tail, with a vascular system even smaller. Previous imaging techniques were too low-resolution to view the tiny elements of rat and mouse physiology. Researchers in the past had to use many animals and dissect them at each stage of injury.
With new MRI techniques, researchers can follow the injury in one animal and take images at each stage. This allows them to use fewer animal subjects and to track the injury in a natural Environment.
At the Hoglund Brain Imaging Center, Bilgen uses a technique he developed called inductively- overcoupled coil technology. It uses a small implanted radio frequency coil and a larger tunable external coil. The combined coils act as a transformer to allow for high quality and high resolution MRIs.
“You won’t be able to believe how beautiful these images are to me,” Bilgen says of the high resolution MRIs.
Hope for the Future
There may be no cure for severe spinal cord injuries and their life-altering effects today, but researchers are working to get closer and closer. The work being done at Bilgen’s laboratory offers hope of continually improving treatment for those living with spinal cord injuries.