- Email: [email protected]
Paralysed man stands unaided after electrode treatment
Paralysed man stands unaided Breakthrough suggests the spinal cord is able to recover function years after severe damage Helen Thomson, New Orleans
PARALYSIS may no longer mean life in a wheelchair. A man who is paralysed from the trunk down has recovered the ability to stand and move his legs unaided thanks to training with an electrical implant. Andrew Meas of Louisville, Kentucky, says it has changed his life (see “I suddenly noticed I can move my pinkie”, below). The stimulus provided by the implant is thought to have either strengthened persistent “silent” connections across his damaged spinal cord or even created new ones, allowing him to move even when the implant is switched off. The results are potentially
revolutionary, as they indicate that the spinal cord is able to recover its function years after becoming damaged. Previous studies in animals with lower limb paralysis have shown that continuous electrical stimulation of the spinal cord below the area of damage allows an animal to stand and perform locomotion-like movements. That’s because the stimulation allows information about proprioception – the perception of body position and muscle effort – to be received from the lower limbs by the spinal cord. The spinal cord, in turn, allows lower limb muscles to react and support the body without any information being received from
“I suddenly noticed I could move my pinkie” “I WAS cruising towards the highway when this old guy tried to cross the 4-lane road really fast. He hit me and I ejected over to the opposite lane. Luckily someone found me before the traffic got to me.” On 6 September 2007, Andrew Meas of Louisville, Kentucky, suffered a spinal injury to an area near his neck. This resulted in full paralysis of his trunk and lower limbs. “I took part in 80 sessions of supported standing and locomotor training and nothing happened.” Then Meas had a 16-lead electrode implanted into the lower segments of his spinal cord. This provides constant electrical stimulation to his lower limbs (see main story). “When it was turned on there was this jolt in my muscles,” he says. He was able to stand and support his body weight.
6 | NewScientist | 27 October 2012
“It was awesome,” Meas says. Blood pressure, vision and bladder problems have all cleared up. But there were more surprises. Three months after stimulation training started, he was sitting on a mat trying to move different parts of his body when the implant was turned off. “I suddenly noticed that I could move my pinkie toe. I wiggled it.” Now the voluntary movement is starting to work its way around his body. “I can feel more muscle contraction in the bottom of my left foot and I’m working hard to strengthen that. I can kick my foot out and lift up my knees.” “When it happened for the first time we were all really excited about it,” he says. “It was amazing – the most normal feeling I’d felt since my injury.”
the brain (Journal of Neuroscience, doi.org/czq67d). Last year, Susan Harkema and Claudia Angeli at the Frazier Rehab Institute and University of Louisville in Kentucky and colleagues tested what had been learned on animals in a man who was paralysed after being hit by a car in 2006. He was diagnosed with a “motor complete” spinal lesion in his neck, which means that no motor activity can be recorded below the lesion. First, the man had extensive training in which his legs were moved by physiotherapists while his weight was supported by a harness. During this time no
Simone Becchetti/getty
THIS WEEK
“Even when the implant was switched off one man was able to continue moving his lower limbs” improvement was observed. He then had a 16-electrode array implanted into the lower region of his spinal cord, which stimulated spinal nerves with continuous electrical activity. When the implant was switched on he succeeded on standing on his first attempt. Then something unexpected happened. Seven months into training on how to stand using the implant, he tried to move his toe while the stimulation was on. “He just started trying to move his toe,” says Angeli. “He was like, ‘look it’s wiggling!’ Further testing showed that he was able to move his leg and ankle, too – showing that voluntary signals from the brain were crossing the lesion. Over time, the volunteer also gained increased bladder control and sexual function, and had better temperature regulation (The Lancet, doi.org/b3spxp). All of these abilities involve input from the brain, confirming information could now be sent across the damaged area of the spine, as long as the stimulation was on. Reggie Edgerton of the University of California, Los Angeles, who also worked on the
study, says that their initial reason for doing the experiment was to utilise proprioception to tell the spinal cord what to do to allow someone to stand. “We had no idea that the stimulation would be working upwards as well, doing something to the connections between the spinal cord and the brain,” he says. One possible explanation is that new connections grew across the spinal lesion. But since this response to stimulation has never
In this section n Dinosaurs: sexy, flighty and always hungry, page 8 n How to preserve Arctic ice, page 10 n Robots navigate like primates, page 17
months of training, the amount of stimulation needed to create the same amount of movement fell. However, there was a final surprise in store. At the conference, Angeli showed how, after three months, Meas was able to stand and move his lower limbs without the aid of stimulation. “One day he was training with the stimulation and we shut it off and he was still able to move,” she says. “We didn’t expect to see it happen so quickly.” We now need to learn how to push these silent connections above their threshold, says Edgerton. He thinks it may simply be a case of improving the implants. “We’re using an implant that was build three decades ago and designed to suppress pain. We thought it would be good enough to show proof of principle, but our volunteers are going crazy because they know what they need to do but the stimulation device isn’t good enough yet to allow them to do it.” For now, none of the volunteers can walk without support. “We have a feeling that it’s a question of the technology restricting us, that
“The implant’s stimulus may have strengthened ‘silent’ connections across the damaged spinal cord” being able to control stimulation to the left and right legs separately might help,” says Angeli. Brian Noga, who works on –Nerve signals may still get through– spinal damage research at the University of Miami Health been shown in animals, a more Another suggestion is that the may have been able to do it System in Florida, says the work likely explanation is that the sensory fibres that allowed this straight away too, but just never clearly demonstrates that even stimulation pushed the activity particular patient to retain some tried,” says Angeli, who presented people with the most severe of damaged connections over a feeling in his legs may have been the results at the Society for spinal injuries may have some threshold needed for them to used in motor control. To rule Neuroscience Conference in remaining connections. send information from the brain this out, Angeli and her colleagues New Orleans last week. “It really makes us open our to the limbs. “There may be ‘silent’ recruited Meas and another Over time, all three of the mind to very new possibilities,” connections that can’t be seen by volunteer who had complete volunteers were able to carry out says Edgerton. “All those current imaging techniques, and motor and sensory paralysis. a variety of movements ranging individuals that are considered are too damaged to work by From the first session with the from whole leg flexion to toe completely paralysed and know themselves, which can be boosted electrical implant, both were extension. Their coordination about this experiment, you know into crossing a threshold of able to move their lower limbs also improved and they could they are thinking ‘am I one of activation by the stimulation,” when the stimulation was on. generate more force from each those that can do this?’ We just says Edgerton. “We think that the first volunteer movement. And after four don’t know.” n 27 October 2012 | NewScientist | 7
PARALYSIS may no longer mean life in a wheelchair. A man who is paralysed from the trunk down has recovered the ability to stand and move his legs unaided thanks to training with an electrical implant. Andrew Meas of Louisville, Kentucky, says it has changed his life (see “I suddenly noticed I can move my pinkie”, below). The stimulus provided by the implant is thought to have either strengthened persistent “silent” connections across his damaged spinal cord or even created new ones, allowing him to move even when the implant is switched off. The results are potentially
revolutionary, as they indicate that the spinal cord is able to recover its function years after becoming damaged. Previous studies in animals with lower limb paralysis have shown that continuous electrical stimulation of the spinal cord below the area of damage allows an animal to stand and perform locomotion-like movements. That’s because the stimulation allows information about proprioception – the perception of body position and muscle effort – to be received from the lower limbs by the spinal cord. The spinal cord, in turn, allows lower limb muscles to react and support the body without any information being received from
“I suddenly noticed I could move my pinkie” “I WAS cruising towards the highway when this old guy tried to cross the 4-lane road really fast. He hit me and I ejected over to the opposite lane. Luckily someone found me before the traffic got to me.” On 6 September 2007, Andrew Meas of Louisville, Kentucky, suffered a spinal injury to an area near his neck. This resulted in full paralysis of his trunk and lower limbs. “I took part in 80 sessions of supported standing and locomotor training and nothing happened.” Then Meas had a 16-lead electrode implanted into the lower segments of his spinal cord. This provides constant electrical stimulation to his lower limbs (see main story). “When it was turned on there was this jolt in my muscles,” he says. He was able to stand and support his body weight.
6 | NewScientist | 27 October 2012
“It was awesome,” Meas says. Blood pressure, vision and bladder problems have all cleared up. But there were more surprises. Three months after stimulation training started, he was sitting on a mat trying to move different parts of his body when the implant was turned off. “I suddenly noticed that I could move my pinkie toe. I wiggled it.” Now the voluntary movement is starting to work its way around his body. “I can feel more muscle contraction in the bottom of my left foot and I’m working hard to strengthen that. I can kick my foot out and lift up my knees.” “When it happened for the first time we were all really excited about it,” he says. “It was amazing – the most normal feeling I’d felt since my injury.”
the brain (Journal of Neuroscience, doi.org/czq67d). Last year, Susan Harkema and Claudia Angeli at the Frazier Rehab Institute and University of Louisville in Kentucky and colleagues tested what had been learned on animals in a man who was paralysed after being hit by a car in 2006. He was diagnosed with a “motor complete” spinal lesion in his neck, which means that no motor activity can be recorded below the lesion. First, the man had extensive training in which his legs were moved by physiotherapists while his weight was supported by a harness. During this time no
Simone Becchetti/getty
THIS WEEK
“Even when the implant was switched off one man was able to continue moving his lower limbs” improvement was observed. He then had a 16-electrode array implanted into the lower region of his spinal cord, which stimulated spinal nerves with continuous electrical activity. When the implant was switched on he succeeded on standing on his first attempt. Then something unexpected happened. Seven months into training on how to stand using the implant, he tried to move his toe while the stimulation was on. “He just started trying to move his toe,” says Angeli. “He was like, ‘look it’s wiggling!’ Further testing showed that he was able to move his leg and ankle, too – showing that voluntary signals from the brain were crossing the lesion. Over time, the volunteer also gained increased bladder control and sexual function, and had better temperature regulation (The Lancet, doi.org/b3spxp). All of these abilities involve input from the brain, confirming information could now be sent across the damaged area of the spine, as long as the stimulation was on. Reggie Edgerton of the University of California, Los Angeles, who also worked on the
study, says that their initial reason for doing the experiment was to utilise proprioception to tell the spinal cord what to do to allow someone to stand. “We had no idea that the stimulation would be working upwards as well, doing something to the connections between the spinal cord and the brain,” he says. One possible explanation is that new connections grew across the spinal lesion. But since this response to stimulation has never
In this section n Dinosaurs: sexy, flighty and always hungry, page 8 n How to preserve Arctic ice, page 10 n Robots navigate like primates, page 17
months of training, the amount of stimulation needed to create the same amount of movement fell. However, there was a final surprise in store. At the conference, Angeli showed how, after three months, Meas was able to stand and move his lower limbs without the aid of stimulation. “One day he was training with the stimulation and we shut it off and he was still able to move,” she says. “We didn’t expect to see it happen so quickly.” We now need to learn how to push these silent connections above their threshold, says Edgerton. He thinks it may simply be a case of improving the implants. “We’re using an implant that was build three decades ago and designed to suppress pain. We thought it would be good enough to show proof of principle, but our volunteers are going crazy because they know what they need to do but the stimulation device isn’t good enough yet to allow them to do it.” For now, none of the volunteers can walk without support. “We have a feeling that it’s a question of the technology restricting us, that
“The implant’s stimulus may have strengthened ‘silent’ connections across the damaged spinal cord” being able to control stimulation to the left and right legs separately might help,” says Angeli. Brian Noga, who works on –Nerve signals may still get through– spinal damage research at the University of Miami Health been shown in animals, a more Another suggestion is that the may have been able to do it System in Florida, says the work likely explanation is that the sensory fibres that allowed this straight away too, but just never clearly demonstrates that even stimulation pushed the activity particular patient to retain some tried,” says Angeli, who presented people with the most severe of damaged connections over a feeling in his legs may have been the results at the Society for spinal injuries may have some threshold needed for them to used in motor control. To rule Neuroscience Conference in remaining connections. send information from the brain this out, Angeli and her colleagues New Orleans last week. “It really makes us open our to the limbs. “There may be ‘silent’ recruited Meas and another Over time, all three of the mind to very new possibilities,” connections that can’t be seen by volunteer who had complete volunteers were able to carry out says Edgerton. “All those current imaging techniques, and motor and sensory paralysis. a variety of movements ranging individuals that are considered are too damaged to work by From the first session with the from whole leg flexion to toe completely paralysed and know themselves, which can be boosted electrical implant, both were extension. Their coordination about this experiment, you know into crossing a threshold of able to move their lower limbs also improved and they could they are thinking ‘am I one of activation by the stimulation,” when the stimulation was on. generate more force from each those that can do this?’ We just says Edgerton. “We think that the first volunteer movement. And after four don’t know.” n 27 October 2012 | NewScientist | 7