November 2011

Paraplegic Regains Voluntary Movement, Stands and Takes Steps

Paraplegic Rob Summers Regains Voluntary Movement

A paraplegic man can stand up to four minutes at a time or longer with assistance, walk on treadmill with assistance, and move his hips, knees, ankles and toes on command thanks to a remarkable breakthrough by researchers from the California Institute of Technology and the University of Louisville, UCLA. The unprecedented results were achieved by continual direct epidural electrical stimulation of his spinal cord, a treatment that follows 30 years of studies on clinical therapies for paralysis. The study was recently published in The Lancet.

Rob Summers, 25, was the volunteer for this experiment. Summers was left paralyzed from the chest down after a hit-and-run accident in 2006. He underwent the experiment at the Frazier Rehab Institute.

Paraplegic Rob Summers Regains Voluntary Movement

The 11-member research team was led by two prominent neuroscientists: Susan Harkema, Ph.D. of the University of Louisville’s Department of Neurosurgery, Kentucky Spinal Cord Research Center, and Frazier Rehab Institute, and V. Reggie Edgerton, Ph.D. of the Division of Life Sciences and David Geffen School of Medicine at UCLA. Also part of the research team was Joel W. Burdick, Ph.D., Professor of Mechanical Engineering and Bioengineering at Caltech. Burdick developed new computer algorithms and electromechanical technologies that promote locomotive recovery in patients with spinal cord injuries.

The procedure involved applying direct epidural electrical stimulation to the lower spinal cord and mimicking brain signals normally transmitted to induce movement. Once the signal is transmitted, the spinal cord’s neural network, combined with the sensory input from the legs to the spinal cord, can direct muscle and joint movements required to stand and takes steps on a treadmill with assistance.

Epidural stimulation is the application of continuous electrical current, at varying intensities and frequencies to specific locations on the lumbosacral (lower) spinal cord corresponding to the dense neural bundles that largely control movement of the hips, knees, ankles and toes. The electrodes required for this stimulation were implanted at the University of Louisville Hospital by Dr. Jonathan Hodes, chairman of the Department of Neurosurgery at the University of Louisville.

The other component of the experiment involved extensive Locomotor Training during electrical stimulation while the subject was suspended over the treadmill. With assistance from rehabilitation specialists, the neural networks of the spinal cord were retrained to produce muscle movements necessary to stand and take assisted steps.

The research was funded by the National Institutes of Health and the Christopher & Dana Reeve Foundation. Dr. Edgerton is on the Reeve Foundation’s Science Advisory Council and its International Research Consortium on Spinal Cord Injury. Dr. Harkema is Director of the Reeve Foundation’s NeuroRecovery Network.

Drs. Harkema and Edgerton have worked closely together since Harkema began her career as a post-grad student in Dr. Edgerton’s UCLA laboratory, where he pioneered the field of locomotion with extensive animal studies. Dr. Harkema is now the Professor of Neurological Surgery at the University of Louisville and oversees its human research program. Both doctors envision a day when individuals with complete lower-body paralysis will be able to use portable stimulation units or use walkers to stand, maintain balance and take steps. The treatment could also result in more significant relief from complications related to complete spinal injury-related paralysis, such as loss of sexual response or loss of sphincter and bladder control.

“The spinal cord is smart,” notes Dr. Edgerton. “The neural networks in the lumbosacral spinal cord are capable of initiating full weight bearing and relatively coordinated stepping without any input from the brain. This is possible, in part, due to information that is sent back from the legs directly to the spinal cord.”

“This is a breakthrough. It opens up a huge opportunity to improve the daily functioning of these individuals,” concludes Dr. Harkema, lead author of today’s Lancet article. “But we have a long road ahead.”

“While these results are obviously encouraging,” concurs Dr. Edgerton, “we need to be cautious. There is much work to be done.”

The reason for Edgerton’s and Harkema’s cautiousness is the fact that the experiment was conducted on only one human subject to date–Summers. Furthermore, Summers was in exceptional physical condition prior to his injury. In addition, the subject in this case retained some feeling. It is not known how well the experiment will work on patients with entirely no sensation. Another consideration is that earlier experiments on animals involved the use of drug compounds that increased sensitivity and function of the spinal cord’s neural network–drugs not approved for humans. Five new human subjects have been authorized by the Food and Drug Administration to be enrolled in the study.

“Today’s announcement clearly demonstrates proof of concept,” said Susan Howley, Executive Vice President for Research at the Christopher & Dana Reeve Foundation. “It’s an exciting development. Where it leads to from here is fundamentally a matter of time and money.”

Paraplegic Rob Summers Regains Voluntary Movement

Adds research volunteer Rob Summers, “This procedure has completely changed my life. For someone who for four years was unable to even move a toe, to have the freedom and ability to stand on my own is the most amazing feeling. To be able to pick up my foot and step down again was unbelievable, but beyond all of that my sense of well-being has changed. My physique and muscle tone has improved greatly, so much that most people don’t even believe I am paralyzed. I believe that epidural stimulation will get me out of this chair.”


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Study Finds Link Between Stress and Neurodegenerative Disease

Stress and Brain Aging

A team of researchers from the Hull York Medical School, the University of York, and the Peninsula College of Medicine and Dentistry have discovered a link between the growth rate of neuronal connections and stressful conditions as the human brain ages. These findings may provide a better understanding of the development of neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease. The researchers detailed their findings in the Proceedings of the National Academy of Sciences (PNAS) journal.

The researchers studied stress responses in synapses in fruit flies. Synapses are structures that allow neurons to transmit signals to other cells in the brain. The researchers found that stressful conditions such as neurodegeneration resulted in a high-energy form of damaging oxygen that caused an excessive growth of synapses, which potentially contributed to dysfunction. These stresses typically occur during diseases such as Alzheimer’s and Parkinson’s, according to the researchers.

The Drosophila fruit fly was used as a model for the study, however, the researchers stated that similar pathways exist in humans. The researchers also used a model of lysosomal storage disease, a hereditary incurable neurodegenerative disease in which enlarged synapses were observed, but how that growth affects disease progression and brain function remains unclear.

“The findings have strong implications for neuronal function as brains age, and will add significantly to our understanding of neurodegenerative disease such as Alzheimer’s and Parkinson’s disease,” said study co-author Dr. Sean Sweeney of the Department of Biology at the University of York.

“Our work sheds light on how our brain becomes less able to make these changes in neuronal contacts as we age and helps explain the loss of neuronal contacts seen in several neurodegenerative diseases,” said co-researcher Dr. Iain Robinson of the Peninsula College of Medicine and Dentistry. Dr. Robinson also stated that neuronal contacts in the brain constantly change, which enables us to form short- or long-term memories.

Previously, researchers have conducted similar studies on stress and aging of the brain in mice, as seen in the video below.


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Toyota to Offer Health-aid Robots for Paralysis Patients by 2013

Toyota Independent Walk Assist Robot

Toyota Motor Corp. has brought healthcare to high tech, and the result is a new line of assistive robots designed to help people with physical disabilities. The auto giant recently announced plans to offer the Toyota Partner Robot series, a line of health-aid robots designed to lift and carry patients and help injured or paralyzed persons walk.

One of the robotic devices is the Independent Walk Assist, a mechanical exoskeleton for a person’s legs. The device enables a person with paralysis or other ailment to walk by utilizing computer sensors. The robots are expected to be available for purchase by 2013.

Toyota Patient Transfer Assist Robot

[Toyota] endeavors to provide the freedom of mobility to all people, and understands from its tie-ups with the Toyota Memorial Hospital and other medical facilities that there is a strong need for robots in the field of nursing and healthcare,” the company said. “We aim to support independent living for people incapacitated through sickness or injury, while also assisting in their return to health and reducing the physical burden on caregivers.”

Toyota Patient Transfer Assist Robot

Researchers at the University of California developed a robotic exoskeleton similar to the Walk Assist, which enabled a student with paralysis to walk across the stage like his classmates and receive his diploma in the spring of 2010. In 2000, after receiving backing from the US military, university researchers designed wearable robots to assist soldiers in carrying heavy loads. Toyota plans to make its version–called the Independent Walk Assist–available to Japanese paralysis patients by 2013.

Toyota Patient Transfer Assist Robot

The Independent Walk Assist is only one of several health-aid robots that Toyota recently revealed. Another model is the Patient Transfer Assist, a machine designed for use by patients and caregivers. The machine uses weight-bearing arms, a mobile platform, and robotic controls to move and carry patients.

Toyota Independent Walk Assist Robot

Each robot incorporates the latest in advanced technologies developed by [Toyota], including high-speed, high-precision motor control technology, highly stable walking-control technology advanced through development of two-legged robots, and sensor technology that detects the user’s posture as well as their grasping and holding strength,” Toyota reported.

According to MIT economists who recently spoke at a robotic symposium in Massachusetts, computers and robots will increasingly become more commonplace in the workplace in the years to come. Robots may even replace human workers in positions such such as call-center and clerical jobs. As a result, the economy will change and workers will have to be retrained.

The use of robotic exoskeletons has been extensively researched during the last decade. Two years ago, Japan-based Cyberdyne, Inc. designed a robotic exoskeleton named Robot Suit HAL. The device is worn like a suit and helps persons who suffered a stroke or debilitating accident regain their mobility.

Kudos to Toyota for considering assistive technology and accessibility in the design and implementation of new products for all people to use, regardless of ability.


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