Approximately 300,000 Americans in the United States live with some form of spinal cord injury (SCI), with about 20,000 new cases each year. Vehicular accidents are the leading cause of SCIs, followed by incidences of falls, violent behaviors and mishaps during recreational activities. Depending on the severity of the SCI, these injuries may lead to paralysis in various areas of the body.
The spinal cord is approximately 18 inches long and is housed in a structure known as the vertebral column — commonly known as the backbone. The backbone, along with the meninges and cerebrospinal fluid, protects the spinal cord from injuries.
The meninges consists of three membranes that encase the spinal cord and the brain. The cerebrospinal fluid that flows through the middle of the spinal cord protects the neurons.
The spinal cord is a major relay center between the brain, the body and the outside world. Information from the external environment is picked up through the sensory system, and these sensory impulses travel to the brain, via the spinal cord, for interpretation. On the other side, motor impulses from the brain are sent out, via the spinal cord, to different parts of the body for proper functioning.
With 31 pairs of nerves that exit from the spinal cord to innervate various parts to the body, damage to any part of the spinal cord can vastly compromise various voluntary and involuntary functions. The inability to move a part of the body is known as paralysis, which can be temporary or permanent, depending on the severity of the trauma.
Salvatore Insinga, chief of Neurosurgery at Southside Hospital in New York, further explained how SCIs affect nerves.
“Spinal cord injury is basically any trauma to the spinal cord that interrupts the flow of [electrical] information from the brain to wherever the nerves are going,” Insinga said, according to Live Science.
SCIs are classified based on location and severity, where severity is categorized as “complete” loss of movement and sensation or “incomplete” — indicating that some movement and sensation remains functional. SCI can result in paralysis of all four limbs, known as quadriplegia, or paralysis in the lower limbs, known as paraplegia.
In a recent study published in the Journal of Neurotrauma, David Darrow, a senior neurosurgery resident at Hennepin Healthcare and the University of Minnesota Medical Center, showed that epidural stimulation may be able to restore function in patients with complete paralysis due to SCI.
In the study, two female subjects both suffering from complete paralysis in the lower limbs were treated with epidural spinal cord stimulation (ESCS) in accordance with an extensive rehabilitation routine. The two female participants, age 48 and 52 with SCIs for five and 10 years, respectively, were able to immediately experience voluntary movement and sensation after ESCS. These two patients did not have any significant rehab prior to the treatments.
A participant with cardiovascular dysautonomia — a condition affecting the autonomic nervous system — was treated with ESCS and cardiovascular function was restored. One patient with trouble controlling their bowel and bladder from a SCI was treated with ESCS and their ability to voluntarily urinate was restored.
“We believe that we are studying a population that is much closer to the general population of patients with spinal cord injury,” Darrow said in a press release. “We have opened the doors to so many more patients with traumatic spinal cord injury.”
Investigation is still underway at the University of Minnesota to develop more strategies to maximize recovery in all patients with permanent SCI-related paralysis.