Paralysed men regain movement after spinal implant, study finds
Electrical device a ‘milestone’ in spinal cord injury research
Kent Stephenson lies down during voluntary training while Katelyn Gurley (not seen) tracks his level of muscle activity and force at the Human Locomotion Research Center laboratory, Frazier Rehab Institute, as part of the University of Louisville’s Kentucky Spinal Cord Injury Research Center in Louisville, Kentucky. Photograph: University of Louisville/Handout via Reuters
Four men who had each been paralysed from the chest down for more than two years and had been told their situation was hopeless regained the ability to voluntarily move their legs and feet - though not to walk - after an electrical device was implanted in their spines, researchers reported today.
The success, albeit in a small number of patients, offers hope that a fundamentally new treatment can help many of the millions of paralysed people.Even those whose cases are deemed so hopeless they are not offered further rehabilitation might benefit, scientists say.
The results also cast doubt on a key assumption about spinal cord injury: that treatment requires damaged neurons to regrow or be replaced with, for instance, stem cells. Both approaches have proved fiendishly difficult and, in the case of stem cells, controversial.
“The big message here is that people with spinal cord injury of the type these men had no longer need to think they have a lifelong sentence of paralysis,” Dr Roderic Pettigrew, director of the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health, said in an interview.
“They can achieve some level of voluntary function,” which he called “a milestone” in spinal cord injury research. His institute partly funded the study, which was published in the journal Brain.
The partial recovery achieved by “hopeless” patients suggests that physicians and rehabilitation therapists may be giving up on millions of paralysed people. That’s because physical therapy can mimic some aspects of the electrical stimulation that the device provided, said Susan Harkema, a specialist in neurological rehab at the University of Louisville’s Kentucky Spinal Cord Injury Research Center (KSCIRC), who led the new study.
“One of the things this research shows is that there is more potential for spinal cord injury patients to recover even without this electrical stimulation,” she said in an interview. “Today, patients are not given rehab because they are not considered ‘good investments.’ We should rethink what they’re offered, because rehabilitation can drive recovery for many more than are receiving it.”
The research built on the case of a single paralysed patient that Ms Harkema’s team reported in 2011. College baseball star Rob Summers had been injured in a hit-and-run accident in 2006, paralysing him below the neck.
In late 2009, Summers received the epidural implant just below the damaged area. The 72-gramme device began emitting electrical current at varying frequencies and intensities, stimulating dense bundles of neurons in the spinal cord. Three days later he stood on his own. In 2010 he took his first tentative steps.
His partial recovery became a media sensation, but even the Louisville team thought that epidural stimulation could benefit only spinal cord patients who had some sensation in their paralysed limbs, as Mr Summers did. “We assumed that the surviving sensory pathways were crucial for this recovery,” Harkema said.
She and her team had little hope for two of their next patients. Neither had sensation in their paralysed legs.
One was Kent Stephenson, who had been paralysed in a 2009 motocross crash when he was 21. After months of rehab in Colorado, “they said I would never move my legs again, and there was no hope,” he said.
Eleven days after he began receiving the deck-of-cards-size restore advanced stimulator, which is made by Medtronic and used for pain control, Mr Stephenson moved his “paralysed” left leg while lying on his back.