Raymond Daniel was paralyzed from the waist down four years ago in a traumatic injury, but three times a week he gets up out of his wheelchair and walks.
He doesn’t do it by himself-a team of engineers, armed with electrical stimulators, a treadmill and a harness, force his legs to move and get him to walk. But the hope is that someday, after enough treatment, practice and repetition, he will be able to get up out of his wheelchair by himself.
Daniel is a subject in a study being conducted by a team of biomedical engineers from U of T and Toronto Rehab. They help people regain the ability to move muscles that became paralyzed, either from a stroke or a spinal cord injury. This might involve taking a stroke victim and helping them to move an immobile arm again, or getting a car crash victim to move their legs again.
The study is still in it’s early stages “but so far the results are surprising,” says Dr. Milos Popovic, head of the two labs where the research is being done. One is located in the Rosebrugh Building at U of T, and one is at Toronto Rehab’s Lyndhurst Centre near Sunnybrook Hospital.
“If you define ‘success rate’ by the number of people that have improved function after going through our study, we have a 100 per cent success rate.”
What Dr. Popovic and his colleagues perform is called “functional electrical stimulation.” They apply small electric shocks to the surface of a patient’s skin, causing their muscles to contract, mimicking what normally happens when a person with an intact nervous system moves.
When you decide to lift your arm or kick your foot, your brain sends a signal down through your spinal cord, which acts like a highway, to activate the nerves that run to the muscle you’re trying to move. A small electrical impulse goes running down your nerve. When it reaches the muscle, the muscle contracts, in the wave of a hand or the swing of a bat.
But in people with spinal cord injuries, the spinal cord, the message route has been cut. The muscles and accompanying nerves are all still intact, but no signals can reach them. By applying electric shocks to the surface of a patient’s skin, you can hopefully get that impulse to reach the nerve you’re targeting. This then triggers a impulse to go down the nerve fiber and replicate what happens in a normal contraction. If you sequence a group of muscles to contract in a specific order, you can create a useful movement, like the clenching of a fist or the gait of a leg.
This technology isn’t new-people have been using functional electrical stimulation for about 40 years. Many researchers in fact have implanted wires into the muscles of paralyzed people to create movement in their otherwise motionless limbs. Often however, after 20 years patients wanted the wires removed because they migrated around their body or even broke, and were no longer of any use in replicating motion.
But for about the past five years, many scientists all over the world have made the same startling discovery: without surgery, with only suface stimuation, some patients can actually regain voluntary control of those muscles , after just a few months of treatment.
Ten years ago, nobody thought this was possible. If you had a spinal cord injury or you had a stroke, there was nothing modern science could do for you. Even worse, 50 years ago, if you had a paralyzing injury you weren’t expected to live even a year. This was mainly due to a lack of bowel and bladder control that led to severe infections, because handicapped patients then simply did not receive adequate care and attention.
Yet today labs all over the world, including several others in Canada, are reporting the same thing: paralyzed muscles can in fact be reawakened.
There are other labs that perform this same basic procedure, but Dr. Popovic and his associates add another layer to the treatment: they ask their study subjects to do a certain task, for example, picking up a pen, when they apply treatment. The subject has to imagine what it would feel like to make the motion, and they have to strain themselves. The electric shock is then applied, and the muscles contract. The idea is that if the brain is giving output to the hand to move, and the muscles actually contract, the brain will get feedback about what has happened in the system and will in a sense “relearn” how to move those muscles. “The brain has a certain amount of plasticity, so you can retrain it,” says Dr. Popovic.
One of the most remarkable things about this study however is that nobody knows how, or why it works. It may be that damaged nerves get regrown, or that preexisting nerves get rewired to perform different tasks. Nobody knows for sure. But one thing is certain: the treatment works.
It hasn’t worked for all patients, thus far, but it has for many. Christopher Reeves used a similar method to regain the use of one of his fingers after four months of treatment. “But for us that’s very little improvement,” says Dr. Popovic. “You spend too much time and energy just to move one finger, it’s a waste of time.”
The electrical shocks are certainly not pleasant, says Dr. Popovic. “But it doesn’t damage the tissue, it doesn’t cause any side effects, you just have to get used to it. It’s like a bad-tasting medicine that is good for you.”
The attitude around the lab does feel a bit like “tough love”-Dr. Popovic can be quite firm with squeamish subjects. He often resorts to stimulating his own arm to demonstrate that it is safe.
Dr. Popovic mainly conducts studies on grasping-trying to help people regain the ability to pick up and manipulate objects. Dr. Adam Thrasher, a Canadian Paraplegic Association of Ontario post-doctoral fellow, is in charge of something even more ambitious: the locomotion study. He is helping people in wheelchairs walk again.
Until recently, Dr. Thrasher has only been able to help about 10 to 15 per cent of the population of people with spinal cord injuries. Every spinal cord injury is different, and there are varying degrees of paralysis, from total body, to just below the waist, to just one side of the body. Some people are unable to move their legs at all and are completely confined to their wheelchairs. Others however are able to get up out of their chair and stand, hobble around a bit, or even walk very short distances. They usually do so with help or with assisting devices, like rollers, leg braces, and canes. It is only these people, called “partial ambulators,” that Dr. Thrasher has been able to treat, because they are able to stand up and try out various walking exercises. After three or four months of repeated stimulation of their leg muscles, Dr. Thrasher has been able to get some patients to walk faster, and with fewer assisting devices. “I firmly believe from our pilot studies so far that we can make them walk better,” says Dr. Thrasher.
The most dramatic example he cited was a man that came in walking at only 0.2 meters per second, who after the study could walk at 0.6 meters per second (normal walking speed is about 1.0 meters per second). This may not sound like a huge difference, but it means that now this man can cross the street before the light changes to red. “I mean, that just opened up a whole new world for him,” he says.
But now, with a shiny new piece of equipment called a body weight support treadmill, Dr. Thrasher can expand his treatment to a possible 50 per cent of the spinal cord injury population. “A lot of my subjects are calling it the ’50 Cent machine,’ after the rapper’s music video, so I’ve started calling it that because it means a lot more to them than ‘body weight support treadmill.'”
With harnesses and counterweights to take the load off a patient’s feet, a running treadmill, the right sequence of electric shocks, and sometimes even a pair of hands to help move their feet, Dr. Thrasher can take people who cannot walk at all and get them to cruise along the treadmill, their chair sitting unused in the corner. “They’re walking with a lot of assistance, but you know, it’s walking,” said Dr. Thrasher.
Daniel is one such patient. He is paralyzed from the waist down, but because he still has some sensation in his legs and relatively strong muscles compared to many other handicapped individuals, Dr. Thrasher thinks he may be able to help him regain the ability to stand and move about a bit on his own. “If we can help them restore some of their walking functions so they can do more than they could, it’s a huge jump in independence and it’s a huge increase in their quality of life as well, and that’s the bottom line for us. We just want to make their lives better.”
Daniel’s treatment is particularly exciting, because textbook knowledge states that the only way to help people with a spinal cord injury or a stroke is immediately after their accident-wait a few years and the window of opportunity is lost. But Dr. Popovic and Dr. Thrasher have already cast doubt on this, having helped several people years after their injury.
Dr. Thrasher is modest about what he hopes to achieve with his subjects. The science is still very new. But his patients seem more optimistic about his ability to help them. “He’s the man,” says Daniel.
Dr. Popovic’s patients show similar enthusiasm. “I was thrilled to death right off the bat to be one of the lucky ones to be included in the electric chair program,” jokes Ivaan Kotulsky, who lost the use of his right arm after his second stroke in December of 2002. He began treatment with Dr. Popovic in January of 2003, stopped in February, and then started again in August. He can now freely move his arm about the shoulder joint, and can pick up objects easily. “I can open a can, I can cut a bagel now,” says Kotulsky. He isn’t however ready to quit the treatment. Kotulsky, a jeweler, used to own a store on Queen St. West called The Lord of the Rings where he sold his own handcrafted jewelry. “That’s why I want my hand back. I don’t care if I hobble, but I want to impress the hell out of everybody by showing them the bracelets and rings I can still make,” he says.
Dr. Mark Tonack is an anthropologist with Toronto Rehab, who is conducting an independent survey of Dr. Popovic’s patients to assess how much the treatment has really helped them, to see if the lab is all it’s cracked up to be. “Even I’m quite surprised that everybody that I have talked to has very positive feedback on the treatment,” he says. “There were clients that came in that couldn’t even open or close their fingers, or grasp objects, and after participating in the treatment regime they were able to open their hand, move their fingers and grasp objects. It may not sound remarkable if you’re not familiar with people with spinal cord injuries, but for a quadriplegic it means the difference between being able to hold a pen, being able to drive their wheelchair themselves, being able to shave themselves.”
Subjects in the study do not have to pay for the treatment, nor does OHIP pick up the bill. Research money pays for treatment given to study subjects, but both Thrasher and Popovic provide treatment free of cost to other people as well. Neither feel the clinic is adequately funded-the waiting list is quite long with people desiring treatment that there just isn’t the time or money for yet. Their intention is to establish a stable funding source that would allow them to treat any patient desiring it. They also stress that more student volunteers would help them considerably.
Nevertheless, improvements in treatment for paralyzed people are not likely to stop here. A great deal of research is investigating the potential to regrow damaged nervous tissue, one of the goals of stem-cell research. “If stem cell research can truly start regrowing central nervous system cells [the cells of the brain and spinal cord], that’s great, because that’s something that we didn’t use to think was possible a long time ago,” says Dr. Thrasher.
But, stress both Dr. Thrasher and Dr. Popovic, even if you successfully regrow such tissue, that doesn’t mean that a patient with a new set of nerves will be able to walk-the nerves and the spinal cord will still have to be “taught” how to work in the right way to create an action as complex as walking, and functional electrical stimulation is clearly one way to accomplish this. “A very simple example is that of the Russian astronauts sitting on MIR for 300 days straight-you bring them back, they have complete nervous systems, but they can’t walk,” says Dr. Popovic. “You have to train them for months, literally, to teach them again how to walk.”
They might only be truly walking around a controlled lab environment now, but considering that 10 years ago they had no hope at all, the future is clearly bright for people who never thought they would get out of their wheelchairs again.