Doctors in Poland and scientists from England have restored some feeling and function to a 38-year-old man who had suffered a grievous spinal cord injury. The injury, the result of a knife attack in 2010, severed the man’s spinal cord at the level of the ninth thoracic vertebra and left the man paralyzed from the chest down.
About two years later, the patient had one of his olfactory bulbs removed and used to derive a culture containing olfactory ensheathing cells (OECs) and olfactory nerve fibroblasts (ONFs). The patient had glial scar tissue removed, and the cultured cells were transplanted into his spinal cord stumps above and below the injury site, where an 8 mm gap was bridged by four strips of autologous sural nerve.
Nineteen months of follow-up, which included intense physical therapy, has now culminated in a study, published October 21 in Cell Transplantation, which describes the man’s progress.
“The patient improved from ASIA A to ASIA C,” the study reads. “There was improved trunk stability, partial recovery of the voluntary movements of the lower extremities, and an increase of the muscle mass in the left thigh, as well as partial recovery of superficial and deep sensation. There was also some indication of improved visceral sensation and improved vascular autoregulation in the left lower limb.”
In the ASIA Impairment Scale, which is promulgated by the American Spinal Injury Association, “A” indicates a complete spinal cord injury where no motor or sensory function is preserved in the sacral segments S4-S5. “C” indicates an incomplete spinal cord injury where motor function is preserved below the neurological level and fewer than half of the key muscles below the neurological level have a muscle grade of 3 or more.
Reports provided by popular news services including the BBC emphasize that the man, named Darek Fidyka, is now able to walk provided he uses a frame.
“Prior to the transplantation, we estimated that without this treatment, our patient's recovery chances were less than one percent,” said Pawel Tabakow, M.D., Ph.D., of the Department of Neurosurgery at the Wroclaw Medical University in Wroclaw, Poland. “However, we observed a gradual recovery of both sensory and motor function that began four months after the surgery.”
Dr. Tabakow is the first author of the Cell Transplantation article, which asserts that the man’s pattern of recovery suggests functional regeneration of both efferent and afferent long-distance fibers: “Imaging confirmed that the grafts had bridged the left side of the spinal cord, where the majority of the nerve grafts were implanted, and neurophysiological examinations confirmed the restitution of the integrity of the corticospinal tracts and the voluntary character of recorded muscle contractions.”
These results offer encouragement to researchers who have been experimenting with olfactory cells for years. OECs, for example, reside in both the peripheral and central nervous system. Together with ONFs, they make bundles of nerve fibers that run from the nasal mucosa to the olfactory bulb. Most interesting, these cells enable nerve fibers in the olfactory system to be continually renewed.
Prior studies with animals had suggested that OECs from the olfactory bulb had greater regeneration powers than OECs from the nasal mucosa. The technique of bridging the sectional spinal cord using autologous sural nerve grafts has been used in animal studies for three decades, but never in combination with OECs, commented the doctors.
“The OECs and the ONFs appeared to work together, but the mechanism between their interaction is still unclear,” said Geoffrey Raisman, M.D., Ph.D., Professor at the Spinal Repair Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London. Dr. Raisman, the study’s second author and leader of the U.K. science team, has spent more than four decades studying how to repair the spinal cord.
The doctors noted that further laboratory studies would be needed to better understand the interactive properties between the human OECs and ONFs within the nerve bridge.
“Our results in treating the first patient with a complete spinal cord injury with transplanted bulbar OECs and ONFs and the reconstruction of the spinal cord gap with nerve implants are very encouraging,” concluded the medical team. “However, our results need to be confirmed in a larger group of patients with a similar injury. In the meantime, we are investigating surgical techniques for more minimally invasive access to the olfactory bulb.”