Foot Drop – Denmark Research Prize
The 2010 Danish Research Result of the Year prize has been awarded to Professor Ole Kaeseler Anderson, of the Center for Sensory-Motor Interaction. Anderson and his team has developed a method that uses a stroke patient’s residual spinal reflex reaction to aid in rehabilitation and treatment of foot-drop.
Foot Drop is the inability, or reduced ability, to move the ankle and toes upward (called dorsiflexion). It is usually the result of stroke or other disease of the nervous system. Sufferers often compensate with an exaggerated lift or “swagger” of the leg during walking, or with the help of an ankle-foot orthosis (AFO) that locks the foot in a neutral position. Two FES (Functional Electrical Stimulation) systems have hit the market recently: the Bioness L300 and the Innovative Neurotronics Walkaide. These, and other systems like them, can be very beneficial to suitable patients. Below is a video of the before and after of a patient using the Walkaide system.
Andersen’s research takes advantage of a reflex (controlled by the spinal cord, and not the brain) response to sudden pain. The “nociceptive withdrawal reflex” causes the foot to flex back in response to sudden pain.
“We have developed a method of using electrical stimulation of the withdrawal reflex in a way that can help in patients’ rehabilitation,” says Andersen. “The electrical impulse triggers a natural reflex such that the leg is pulled up and the foot moves, so the patient is helped to move their leg even though he or she was partially paralyzed after a stroke.”
Anderson is not the first to exploit this reflex – in 1993, Granat et al. attempted to improve hip flexion for the wing phase of gait with only limited success. The group cited the following issues:
- a decrease in the magnitude of the hip flexion to repeated stimuli (habituation)
- long latency in response
- inhibition of the response when stimulated bilaterally
Source: Granat MH, Heller BW, Nicol DJ, Baxendale RH, and Andrews BJ. Improving limb flexion in FES gait using the flexion withdrawal response for the spinal cord injured person. Journal of Biomedical Engineering 15: 51-56, 1993.
Stroke Therapy Study
News of a second stroke rehabilitation study in Southampton was released today (click here for news about another recent stroke rehabilitation study in Southampton). This new study, lead by Dr. Jane Burridge, will combine transcranial Direct Current Stimulation (tDCS) with robotic training for the hand and arm.
tDCS uses a low constant current delivered to the part of the brain of interest using small electrodes. It has been discovered that such a current can result in cortical modulations (modified brain activity) that lasts longer than the current itself. Currently, tDCS is primarily used in applications involving psychological disorders, like anxiety and depression, and is used experimentally in motor rehabilitation.
tDCS is readily compared to Transcranial Magnetic Stimulation (TMS), which uses high voltage pulses of electricity through coils located close to the head to induce a small electrical charge in a desired region of the brain.
The £80,000 (approximately $126,000USD) study, funded by Wessex Medical Trust, will enroll stroke patients in the following treatment regime:
- 20 minutes of electrical stimulation to increase the “excitability” of the brain cells, which send the messages to the muscles in the arm.
- three 20-minute sessions with the robotic arms to build strength and get the arm and hand moving again.
The research team hopes that the combination treatment will speed up recovery by increasing activity of the damaged portion of the brain using tDCS, better preparing it to create new connections during the course of robotic therapy.
If successful, the team hopes to create a version of the tDCS machine for use in home-based stroke therapy.
Another similar clinical trial is wrapping up in Israel, although it uses conventional occupational therapy instead of a robotic system:
The purpose of this study is to determine whether a non-painful, non-invasive, brain-stimulation technique called transcranial direct current stimulation (tDCS) combined with occupational therapy (OT) will improve motor function in patients with chronic stroke.
This study is scheduled to be completed this month (December, 2010).
Hand/Arm Stimulator Trial in the UK
Dr. Jane Burridge, Professor of restorative neuroscience at Southampton University in the UK, is part of a team building a new hand and arm electrical stimulation system for people who have suffered a stroke. Functional Electrical Stimulation (FES) is commonly used as a rehabilitation tool to help retrain a patient’s nervous system by stimulating nerves that control movement. The Bioness H200 is an example of a commercially available stimulator used for hand rehabilitation. Here’s a video of a stroke patient using the H200:
The new UK stimulation system will help patients with hand and arm movements, providing just enough muscle stimulation to help patients complete a set of movements, like reaching out and grasping a tea cup. The researchers hope that training with such a device will help stroke patients regain use of their arms and hands faster, and more effectively.
The project received £464,231 (approximately $722,000) in funding from the EPSRC (Engineering and Physical Science Research Council), and is designed to complement existing hand arm and shoulder rehabilitation training using virtual reality rehabilitation games.
‘We’re going to be stimulating a number of different muscles to open the hand, as well as to reach the arm forward. And, instead of doing it on a pre-determined, very tightly controlled trajectory, we’re actually going to do it with a free movement, with just minimal support from a sling.’ – Dr. Jane Burridge
The experimental work, starting in March 2011 and scheduled to run for three years, will include an eight-week clinical trial involving up to eight stroke patients.
Robot-Assisted Therapy in New Jersey
During his presentation at Neuroscience 2010, Dr. Sergei V. Adamovich’s suggested that stroke rehabilitation involving video-gaming in combination with a robotic system could improve a patient’s abilities.
“In virtual environments, individuals with arm and hand impairment practiced tasks such as reaching and touching virtual objects. They took a cup from a shelf and put it on a table, hammered a nail, and even played a virtual piano.” – Dr. Adamovich, New Jersey Institute of Technology
The study’s 24 subjects, who had suffered a stroke at least six months prior to therapy, played with the video game system for about 22 hours over a two-week period. The subjects were helped by a robotic arm, and were challenged to perform increasingly difficult tasks.
“Our preliminary data suggest that, indeed, robot-assisted training in virtual reality may be beneficial for functional recovery after chronic stroke. Furthermore, our data imply that this recovery may be particularly due to increased functional connections between different brain regions.” – Dr. Adamovich
The following is a video of Dr. Adamovich’s robotic system.
Sources: Science Daily, RAVR Lab
Rick Hansen and SCI Research in Vancouver
Below is a link to a recent news story about spinal cord injury research currently underway at ICORD and UBC in Vancouver. In addition to a brief profile of ReJoyce, the story showcases some additional research:
Peter Cripton - Experimental helmet to prevent spinal cord injury
Dr. Brian Kwon – Stem cell therapy
Click on the image below to watch the whole video:
ReJoyce at the Rick Hansen Institute
New EMG-Controlled Hand Rehabilitation Robot
Tommy Chan at Deltason, a Hong Kong medical devices distributor with an impressive array of rehabilitation products, has recently added the “Hand Of Hope” to his company’s line.
Hand Of Hope
Developed at the Hong Kong Polytechnic University, the Hand Of Hope combines non-invasive EMG sensors with a robotic exo-skeleton to help the patients perform tasks related to rehabilitation. The device is controlled by non-invasive EMG pickup electrodes that detect patients’ attempts to move their hands. Once an attempted movement is detected, linear actuators are used to drive each finger. The system is used to increase performance of hand grasp (palmar grasp and pinch) and hand opening. The range of motion of each finger actuator can be customized for each patient.
Hand Of Hope - Prototype
Hand Of Hope - Prototype
Here are some pictures of the device:
Large Portion of Post-Stroke Therapy Not Based On Clinical Studies
An alarming study published in Implementation Science in October 2010 suggests that the rate of reliance on the research literature in clinical decision making among physical therapists is low. Simply put, a large portion (more than 50%) of physical therapists surveyed in the study rarely base their post-stroke treatment programs on evidence-based research studies.
The study identified organizational, research, and practitioner characteristics associated with research use among physical therapists involved in post-stroke rehabilitation services. Of 263 physical therapists surveyed, more than a third hardly used evidence-based research at all (no more than once per month), with more than 50% only referring to evidence-based research 2-5 times per month.
The author summarizes the need important of evidence-based medicine in the following paragraph:
Evidence-based medicine has been described as ‘the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. Numerous perceived benefits of evidence-based practice (EBP), including improvement to the work environment, increased professional accountability, ensuring the future of the profession, improved efficiency of service delivery, and compliance with regulatory agencies or quality assurance initiatives in the workplace, may lead healthcare professionals to incorporate research evidence into clinical practice. A patient-centered motivation for appropriately applying findings from rigorously conducted research in clinical decision making is to improve the quality of healthcare services and patient outcomes. There is empirical evidence to support these latter benefits in post-acute stroke rehabilitation, wherein the degree of compliance with a clinical practice guideline has been associated with not only physical recovery but also patient satisfaction.
The authors’ study was primarily based on data collected in Canada, but cited the following statistics gathered from similar studies conducted in other parts of the world:
| Location | PTs Surveyed | 0-1 times/month | 2-5 times/month |
| USA | 488 | 25% | 49% |
| Australia | 124 | 43.9% | unknown |
| Canada (this study) | 263 | 33.8% | 52.9% |
Brain Plasticity After Stroke
A University of South Carolina study using neuroimaging of stroke patients struggling to regain their communication skills has found that brain cells outside the damaged area can take on new roles.
Julius Fridriksson, a researcher at the USC’s Arnold School of Public Health, said the findings offer hope to patients of “chronic stroke,” characterized by the death of cells in a specific area of the brain. The damage results in long-term or permanent disability.
“For years, we heard little about stroke recovery because it was believed that very little could be done,” Fridriksson said. “But this study shows that the adult brain is quite capable of changing, and we are able to see those images now. This will substantially change the treatment for chronic-stroke patients.”
The study, reported in the Sept. 15 issue of the Journal of Neuroscience, involved 26 patients with aphasia, a communication disorder caused by damage to the language regions in the brain’s left hemisphere. Aphasia impairs a person’s ability to process language and formulate speech.
About 35% of stroke patients have speech and/or communication problems. While many patients with aphasia regain some language function in the days and weeks after a stroke, scientists have long thought that recovery is limited after this initial phase.
Fridriksson’s study shows that the brain can recover and that a patient’s ability to communicate can improve.
Stroke patients underwent a functional magnetic resonance imaging test. They also received multiple MRI sessions before and after undergoing 30 hours of traditional speech therapy used to improve communication function in patients with aphasia.
By using fMRI — an imaging technique more improved and widely used in the past decade — Fridriksson was able to see the healthy areas of the brain that “take over” the functions of the areas damaged as a result of a stroke.
“The areas that are immediately around the section of the brain that was damaged become more ‘plastic,’” Fridriksson said. “This ‘plasticity,’ so to speak, increases around the brain lesions and supports recovery. In patients who responded well with the treatment for anomia [difficulty in recalling words and names], their fMRI showed evidence that areas of the brain took over the function of the damaged cells.”
The study found that patients who did not experience these changes did not recover as much, he said.
Efficacy of Stroke Rehabilitation Devices
Here’s an interesting article about the Myomo, a robotic device developed at MIT and sold by Myomo Inc. Part of the article addresses the lack of scientific evidence demonstrating efficacy of the device. Here’s an excerpt:
But there is no rigorous scientific evidence demonstrating how well it works. And the $7,000 device casts a spotlight on the hard-to-navigate world of rehabilitation devices — in which patients who are often desperate face a growing number of products whose effectiveness is still being determined.
“While there’s some suggestive, tiny studies — that are really pilot studies — that it might be useful, there’s no proof of efficacy using the usual criteria,’’ said Dr. Joel Stein, chairman of the rehabilitation and regenerative medicine department at Columbia University. He is also on Myomo’s scientific advisory board.
“I’ve worked with many stroke patients through the years, and I’m careful to not be too paternalistic deciding for them. . . . They feel like the medical system has given up on them, and there’s a fine line between not over-promising and saying we have nothing shown to be helpful, therefore you should just give up.’’
Technology in Rehabilitation
I posted a link to this seminar series a few months ago. Since then, the seminar has been posted on YouTube. You can watch the video here:
This is part of a seminar series put on by the Cleveland FES Center. The next series of lectures is scheduled to begin in September 2010.