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NeuroVoices: Francois Bethoux, MD, on Innovating MS Rehabilitation With the EksoNR Exoskeleton
Author(s):
The chair of Cleveland Clinic’s Department of Physical Medicine discussed a new rehabilitative approach using a robotic exoskeleton to improve fatigue and gait in patients with multiple sclerosis.
Francois Bethoux, MD
After first receiving approval for rehabilitation of patients with stroke and traumatic brain injury in 2016, and later gaining greenlight for those with acquired brain injury in 2020, the EksoNR robotic exoskeleton once again made history in mid-June 2022, as it became the first FDA-approved device for rehabilitative efforts in patients with multiple sclerosis (MS).1 Approved for use in Europe as well, the robotic device that attaches to a patient’s body is designed to help improve the ability to walk.
Following a small pilot study published in 2017, researchers at Cleveland Clinic, including Francois Bethoux, MD, began conducting a new study budling on those findings. The aim of the trial was to gauge the feasibility and safety of the technology for gait training in those with relapsing or progressive MS who experience severe mobility limitations through at least 3 sessions. Presented at the 2022 Consortium of Multiple Sclerosis Centers (CMSC) Annual Meeting, June 1-4, in National Harbor, Maryland, the study showed that use of the robotic exoskeleton statistically significantly increased in walk time (P = .008), number of steps (P = .011), and programmed step length (P <.001).2
Within-group analysis showed no significant change on the Timed 25 Foot Walk, with 20% (3 of 15) of patients exhibiting a greater than 20% increase in walking speed. Additionally, there was a statistically significant increase in the time to complete the Timed Up and Go (P = .029), and the exoskeleton showed good safety as well, with 1 adverse event reported in 5 patients.
On a new iteration of NeuroVoices, Bethoux, chair of Cleveland Clinic’s Department of Physical Medicine discussed the functions of the exoskeleton, advantages it brings, and how it can be used in real-world clinic setting. He also touched on the study was conducted, the major take-home points for clinicians, and the need to further analyze large sets of data to understand optimal patient populations for the device.
NeurologyLive®: Can you first provide detail about this exoskeleton and some of its capabilities, how it functions and operates?
Francois Bethoux, MD: There are some features that are common to all exoskeletons—there’s a bracing element that is basically goes from the hip down under the feet. It’s what we call a long leg brace, and it involves the pelvis as well. There are the robotic components, including monitors, especially in the hip and knee joint, and a software that can initiate the steps and be programmed by clinicians to adjust the parameters of the steps over time. Basically, we’re looking at the exoskeleton and its ability to provide variable assistance. This particular exoskeleton has that capacity, and others do as well. That was very important to us, the reason being that we all know with people with MS, there’s two elements [at play].
One, there is a fatigue or fatiguability that can hit quickly as people do some physical training. The difference between fatigue and fatiguability can be debated, but generally, we tend to say fatigue is the sensation of being exhausted whereas fatiguability is a decrease in performance over time. That’s what you can observe when someone is walking, and their steps get slower and slower and maybe shorter and shorter over time. And so, if the device can then provide some assistance to make the steps longer and increase the number of steps per minute, you can continue the training even though the body was starting to lose steam.
Performance will vary day to day or morning to afternoon with MS. Again, the ability to provide variable resistance would allow to account or compensate for that. Finally, as our patients improve through the training and they’re walking better, we can dial down the assistance provided by the device and they can be more of the ones initiating the steps and providing some of the movement.
How did you go about this study and how does it build on the previous, smaller trial?
It’s a body of knowledge we’re trying to expand upon, and we’re thrilled that now there’s a specific indication for MS, which recognizes the importance of using technology in rehabilitation for people with MS. We are nowhere near having enough evidence to fully understand who the best candidates are, who’s more likely to benefit, or even the treatment parameters such as how many sessions are optimal, what’s the optimal duration of training sessions, etc. All this knowledge will be built in two ways. First, we had a small, safety and feasibility study where we had a few patients with MS go through a few weeks of training with the exoskeleton and we looked at adverse effects, whether people came back for all the sessions—interestingly enough, everybody attended 100% of the training sessions, which is fairly rare. We also looked at how they were doing over time.
With such a small study it wasn’t possible to understand who was more likely to benefit. The next step would be building the pilot study. At the same time, after this small pilot study, we started using the exoskeleton in the clinic. This was an off-label use at the time but backed by our experience with the first pilot study. Now, what we recently presented at the Consortium of MS Center’s Annual Meeting, is the outcome data from observation in the clinic of people who had at least 3 training sessions with the exoskeleton. With that, we could see the characteristics of the patients, but also what king of changes were noted on examination in a clinical setting.
Research data and clinical data complement each other because in research, we are more restrictive about who we allow in a study and monitor things very closely in regular intervals whereas in the clinic, its more open. The downside to that is the number of sessions may vary, the intervals between assessments may vary, and it’s not always felt to be as rigorous in terms of evaluation, but more real-world. You need both sets of data to better understand. The next pilot study would build on both of these data sets and have two components. One, a comparison. Comparing the use of this device to a more traditional form of gait training therapy. Second, to use the outcome measures that seem to be the most sensitive to the effects of the exoskeleton found in our data sets.
Again, [we need to] have enough of a sample size that would be able to see some positive signals. For example, a question that we’ve had is will it benefit more in people who are struggling to walk short distances in their home? Anecdotally, some of our patients who could only walk from the living room to the bathroom or the bedroom to the bathroom after training, we’re able to walk around their home and maybe venture a few steps outside [following the training]. That’s a huge difference. That’s one example. On the flip side, people who are already walking around their home in their area with or without the device, like a walker or cane, could they derive a great benefit from it? If you can go from just walking down your driveway to walking through a grocery store, that changes your perspective and changes your activities in a great way. That’s the kind of questions we’re going to try to tackle.
Transcript edited for clarity. Click here for more NeuroVoices.
