A More Rigorous Approach to Stroke Rehab

More rigorous scientific study, along with advanced technologies, has been transforming stroke rehab in recent years. In this MossRehab Conversation, Joel Stein, MD, explores some of the latest advances. Dr. Stein is Simon Baruch Professor of Physical Medicine & Rehabilitation at the Columbia University College of Physicians and Surgeons, professor of Rehabilitation and Regenerative Medicine at Weill Cornell Medical College and chair of the Department of Rehabilitation and Regenerative Medicine at New York-Presbyterian Hospital. 

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Welcome to a MossRehab Conversation, part of a continuing series of discussions with pioneers in physical medicine and rehabilitation from one of America's top US news-ranked rehab facilities. In this episode, we chat with Joel Stein, MD, the Simon Baruch, professor of Physical Medicine and Rehabilitation at Columbia University College of Physicians and Surgeons, professor of Rehabilitation and Regenerative Medicine at Weill Cornell Medical College and chair of the Department of Rehabilitation and Regenerative Medicine at New York-Presbyterian Hospital. In addition to his very impressive credentials, Dr Stein has authored and edited several papers and books on rehabilitation after stroke, which of course is one of the more devastating things that can happen in a person's lifetime. 

Dr. Stein: At the same time, I come in as it were the next day to try and help them put their lives back together and from that point forward it's a time of improvement and rehabilitation and hopefully recovery. It can be extremely satisfying work to work with people who have had this devastating thing happened, but help them figure how to get back as much as they can towards where they work to begin with. There's a tremendous opportunity, I think, to do good in this population. 

What are some of the recent advances in stroke rehab you're especially excited about? 

Dr. Stein: I would say broadly, the most exciting thing in the field of stroke rehabilitation is the increasing scientific rigor that's being brought to the issue. The number of substantial clinical trials that are rigorously testing hypotheses had been growing and I think that's a trend that's going to continue and will result ultimately in a number of advances for the specialty. One of the particular areas of interest that I have and I think in general is of interest to the field, is the use of technologies to advance the rehabilitation care that we provide. Much of what we do in rehabilitation hasn't really changed in terms of delivery of care very much since the 20th century when these first techniques were developed, but the fact is that we have new tools that we can bring to bear  - robots, virtual reality, some of these will speak about later - that can hopefully make this a more efficient and effective process, and I think that's very exciting. 

Well, you mentioned robotics. You've done work with the use of robotics and upper limb rehab following stroke. Please tell us about some of that work, what you're researching and why it's important. 

Dr. Stein: Strokes are frequently affects the upper limb more severely than the lower limb. Most people who have a stroke or able to resume walking perhaps with a cane or a brace, but there's a large percentage of the affected population that never regain substantial use of their arms. Some of them regain minimal use of their arms. So it's been a particularly pressing issue in terms of finding more effective therapy. At the same time, the arm seems to benefit from intensive and repetitive exercise and the use of robotics and other tools to provide that is inherently very appealing. The other piece of this is that there are other technologies and treatments that are being developed. For example, noninvasive brain stimulation which we'll touch on later, which may be most effective when combined with some form of exercise therapy. The use of medications is being explored as well to enhance recovery. But all of these treatments are believed to be most effective when combined with some form of exercise therapy. And robotics, in fact, is a way of providing exercise therapy in a more controlled and reproducible fashion. So that's really why I am so focused on upper arm robotics. 

I suppose that control is one of the advantages of robotic exercises and training. What are some of the other pluses, and are there possible disadvantages? 

Dr. Stein: I think there are some challenges with robotic therapy, which is cost and complexity. Right now these devices remain relatively expensive and some of them are quite large and they are certainly complex. On the other hand, I think those are issues that are going to improve over time. Certainly the complexity issues, the ease of use, I think we're already seeing advances in that. What robots can do in a way that really no other device can, is provide a reliable and reproducible form of exercise that can be pre-programmed in advance. When someone is receiving robotic therapy, you know exactly what kind of treatment they receive, we know how many repetitions of each exercise and that's something that will be consistent from individual to individual. That's very important as we try and determine the most effective algorithms for treatment. The other potential advantage of robots in the long run is the potential for labor savings. Labor costs of course continue to rise and a skilled therapists are always in short supply. If we can provide more therapy to our patients without requiring additional resources in terms of personnel, then I think we'll be able to be more effective. I do see it as an important extender for therapists to be able to provide more therapy without necessarily needing more personnel. 

One project you've been working on is a wearable powered brace for the hand. Can you tell us more about that? 

Dr. Stein: This device, which we've named the "My Hand," is a robotic device. It is a wearable power hand orthosis. This is a project that's been funded by the National Robotics Initiative through the National Science Foundation. I've been partnered with Matei Ciocarlie, PhD, who is the engineer who's been developing this, and, of course, has a team of graduate students and others working with him. The goal here is to have a practical, relatively lightweight wearable device that can be worn on the hand that assists with hand opening. Many stroke survivors have the ability to close their fingers and to grasp an object, but for complex neurologic reasons have difficulty in the opposite motion in extending the fingers or opening their hand, which makes it very difficult for them to do any exercise with the hand and certainly difficult to use it in a functional context. So our goal has been to develop a device that assists them with that opening movement, while allowing them to use their own abilities to a close the hand and to grasp objects. We believe that combining that with other forms of training for the other portions of the arm to the shoulder and elbow will provide really an optimal combination of exercise therapies. We have a working prototype, and we are engaging in a small pilot clinical trial that is just getting started. We're quite optimistic about this device. 

Among the areas you've been researching is the use of cortical electrical stimulation to facilitate motor recovery. What can you tell us about this technique?

Dr. Stein: It's been known for some time that you can modulate the ability of the brain to form new connections - new synapses as they're known - through electrical stimulation of the brain. There are two primary ways that are being explored to provide that to the brain. One is the use of transcranial direct current stimulation where a small electrical current, you can imagine thinking of a nine volt battery if you will, kind of attached to leads and a small electrical current going through the skull and a little bit of that actually gets to the brain. It doesn't cause any visible effects, but it does prime the brain, if you will, to take advantage of the signals provided by exercise activities. So that's one technique. The other technique is transcranial magnetic stimulation where a powerful magnetic pulse is provided externally and that induces through the magic of physics an electrical current within the brain. 

And that again is believed to potentially help modulate the recovery process. Actually you can see visible effects with that when you deliver the pulse, the limb, the arm or the leg, depending where you stimulate may jump a little bit. That has been combined in a clinical trial that I was involved in looking at the effects of motor recovery. And that was a follow on trial that is still in progress. And a number of other laboratories and centers are researching both of these techniques. The jury is still out. These are not yet established therapeutic techniques, but I do believe there is substantial promise. And I would be personally surprised if we don't ultimately see some form of non-invasive brain stimulation become a standard part of a rehabilitation for stroke. 

What's your estimate of the timeframe for that? 

Dr. Stein: I think we're talking within the next five years. I don't think this is a distant goal. The technologies are there. There is not a need to develop some new device. What's really needed here is more rigorous clinical testing and figuring out the right paradigm. Who are the right people, where do you stimulate, for how long, at what stage of recovery after stroke, what are the stimulation parameters you can stimulate more or less intensively or greater or lower frequency. So there's a number of parameters that hasn't really been fully worked out to basically get the most bang for your buck. But the technologies are here. It's really not one of these situations where we're waiting for something to be developed. It's really refining how to use them and verifying that they're truly useful. 

Please share some of your ideas, Dr. Stein, on therapeutic interventions using force guided systems for impaired balance and gait. If you could in a few words describe the system and your preliminary findings. 

Dr. Stein: There are a variety of different ways to try and facilitate gait and balance training in stroke survivors. One particularly interesting technique has been using cable driven systems and the tethered pelvic assist device that Professor Sunil Agrawal has developed is a very good example of that. The idea here is that the basic system is a belt applied around the user's waste that is connected to cables to wires that are controlled by a computer and move and pull the user in different directions. So you could imagine that these tethers could provide a force on the individual's waste, on their pelvis, to move them to the left, to the right, up or down, forwards or backwards or some combination thereof. And the idea here is [to avoid] encasing the individual in a large, heavy, bulky robotics system. From the user's perspective, this is a very lightweight and it's not a very intrusive system, so it allows the user to exercise in a relatively normal way to walk on a treadmill and we can be very selective in the forces we apply. 

A significant problem in stroke survivors is that their gate tends to be very asymmetric. They don't put as much weight on their weak side. They tend to limp, if you will, and their balances impaired. We believe that this kind of approach can allow us to test several different strategies to improve balance in these individuals. One strategy would be an "assist if needed strategy" to basically try and help the person get into a more midline sitting position and that is something that has traditionally been a commonly used physical therapy technique. But there are other strategies such as pushing them in the opposite direction. Actually pushing them away from where you want them so that they push back. Then when you take away forces you're applying, they continue to push back in the direction that you'd like them to. That's called adaptation. That's a little bit hard to explain without visualizing it, but imagine someone keeps pushing your arm to the right, keeps pushing it to the right. Eventually you figure out that you need to push back to the left a little bit to stay in the middle, and then when someone stops pushing on your arm to the right, you're going to actually overcompensate and have a little bit to the left. And it's the same idea with gait training. 

Virtual reality technology has become a very popular consumer item. You mentioned earlier that there's also a place for that in stroke rehabilitation. 

Dr. Stein: Absolutely. It's a very appealing idea to incorporate various forms of virtual reality and I would expand that to gaming into rehabilitation. The idea of using gaming, first of all, is very appealing because it takes what can otherwise be a hideous activity - imagine during an hour's worth of exercise for your arm or your leg. It's a very tedious thing. You can turn that instead into a game that can be fun and engaging for the individual and improve motivation and if you are blasting aliens or hunting for fish or whatever the particular game might be  - navigating an airplane. These are all very engaging visual activities that are not technically virtual reality, but I think have the potential to enhance people's participation in rehabilitation. In terms of more formal virtual reality that comes in sort of two versions. One is a two dimensional version where you essentially look at a computer screen rather than having an immersive head-mounted goggle system. This is not usually what people think of as virtual reality, but it is in fact a simple version of that. That's been the most commonly used virtual reality for stroke survivors, in part because the technology is inexpensive and widely available. There have been concerns about using more immersive systems such as the Oculus Rift with stroke survivors because many of them are elderly and there's been concerns that those systems may be overwhelming for them. So that form of computer screen-based virtual reality has been tested and continues to be explored. It has not been shown to be superior to conventional therapies yet, but it's certainly intriguing. Lastly are the head-mounted displays. The Oculus Rift being one that's been widely discussed in the media. There are several other companies that have developed similar systems. I think that these are very appealing because they can truly control your visual environment completely. So there is a gaming aspect of it, but also you could create distortions that are therapeutically intended, so someone who has visual spacial difficulties, they have what's called hemi-spatial neglect where they have trouble seeing things on the left side and paying attention to them. You can in fact distort the environment that they see visually through these head-mounted displays to actually have a therapeutic purpose of trying to help them pay attention to things on the left side. That's one potential application. Certainly not the only one. So I think virtual reality has a lot of appeal. It also could be combined with robotics. I don't think these two fields really are competing in any sense, but in fact might be complementary in the end. 

Finally, as you look to the future in stroke rehab, what are you most optimistic about? 

Dr. Stein: I believe that there's a lot of energy and enthusiasm among researchers in the field to try and find more effective therapies and, as I mentioned earlier, a flourishing of more rigorous clinical trials to test out hypotheses. In the past, unfortunately, we didn't have better design files and really reliable data, much of what happened in rehabilitation was based on what people thought would work. Now we can actually know what works and often when you do clinical trials, you are surprised. Things that you thought would work don't work or things that you didn't expect to work proved to be more useful. There's no substitute for empiric data. I think that really we are entering finally the era of empiric data that's reliable for stroke rehabilitation. So I think that's very encouraging. There are exciting opportunities in modulating the process of recovery through the use of non-invasive brain stimulation. Perhaps for the use of medications. There's some evidence that some medications that are commonly used such as fluoxetine or Prozac may be useful in facilitating recovery. The combination of those treatments helped with the use of robotic devices or virtual reality training systems hopefully can get us to a new level of recovery and that's really the focus on I think what makes me optimistic about stroke rehabilitation. 

Well, thank you for taking the time to talk with Dr Stein and for helping MossRehab educate the physical medicine and rehabilitation community. Joel Stein, is the Simon Baruch professor of Physical Medicine and Rehabilitation at Columbia University College of Physicians and Surgeons, professor of Rehabilitation and Regenerative medicine at Weill Cornell Medical College and chair of the Department of Rehabilitation and Regenerative Medicine at New York-Presbyterian Hospital.  

Look for more conversations to come on our website at MossRehab.com/conversations. I'm Bill Fantini. Thanks for listening.