Posts tagged rehabilitation

Posts tagged rehabilitation
(Image caption: The EyeCane: (A) A flow chart depicting the use of the device and an illustration of a user. Note the two sensor beams, one pointing directly ahead, and one pointing towards the ground for obstacle detection. (B) Photo of the “EyeCane.”)
User-Friendly Electronic “EyeCane” Enhances Navigational Abilities for the Blind
White Canes provide low-tech assistance to the visually impaired, but some blind people object to their use because they are cumbersome, fail to detect elevated obstacles, or require long training periods to master. Electronic travel aids (ETAs) have the potential to improve navigation for the blind, but early versions had disadvantages that limited widespread adoption. A new ETA, the “EyeCane,” developed by a team of researchers at The Hebrew University of Jerusalem, expands the world of its users, allowing them to better estimate distance, navigate their environment, and avoid obstacles, according to a new study published in Restorative Neurology and Neuroscience.
“The EyeCane was designed to augment, or possibly in the more distant future, replace the traditional White Cane by adding information at greater distances (5 meters) and more angles, and most importantly by eliminating the need for contacts between the cane and the user’s surroundings [which makes its use difficult] in cluttered or indoor environments,” says Amir Amedi, PhD, Associate Professor of Medical Neurobiology at The Israel-Canada Institute for Medical Research, The Hebrew University of Jerusalem.
The EyeCane translates point-distance information into auditory and tactile cues. The device is able to provide the user with distance information simultaneously from two different directions: directly ahead for long distance perception and detection of waist-height obstacles and pointing downward at a 45° angle for ground-level assessment. The user scans a target with the device, the device emits a narrow beam with high spatial resolution toward the target, the beam hits the target and is returned to the device, and the device calculates the distance and translates it for the user interface. The user learns intuitively within a few minutes to decode the distance to the object via sound frequencies and/or vibration amplitudes.
Recent improvements have streamlined the device so its size is 4 x 6 x 12 centimeters with a weight of less than 100 grams. “This enables it to be easily held and pointed at different targets, while increasing battery life,” says Prof. Amedi.
The authors conducted a series of experiments to evaluate the usefulness of the device for both blind and blindfolded sighted individuals. The aim of the first experiment was to see if the device could help in distance estimation. After less than five minutes of training, both blind and blindfolded individuals were able to estimate distance successfully almost 70% of the time, and the success rate surpassed 80% for two of the three blind participants. “It was amazing seeing how this additional distance changed their perception of their environment,” notes Shachar Maidenbaum, one of the researchers on Prof. Amedi’s team. “One user described it as if her hand was suddenly on the far side of the room, expanding her world.”
A second experiment looked at whether the EyeCane could help individuals navigate an unfamiliar corridor by measuring the number of contacts with the walls. Those using a White Cane made an average of 28.2 contacts with the wall, compared to three contacts with the EyeCane – a statistically significant tenfold reduction. A third experiment demonstrated that the EyeCane also helped users avoid chairs and other naturally occurring obstacles placed randomly in the surroundings.
“One of the key results we show here is that even after less than five minutes of training, participants were able to complete the tasks successfully,” says Prof. Amedi. “This short training requirement is very significant, as it make the device much more user friendly. Every one of our blind users wanted to take the device home with them after the experiment, and felt they could immediately contribute to their everyday lives,” adds Maidenbaum.
The Amedi lab is also involved in other projects for helping people who are blind. In another recent publication in Restorative Neurology and Neuroscience they introduced the EyeMusic, which offers much more information, but requires more intensive training. “We see the two technologies as complementar,y” says Prof. Amedi. “You would use the EyeMusic to recognize landmarks or an object and use the EyeCane to get to it safely while avoiding collisions.”
A video demonstration of the EyeCane is available at http://www.youtube.com/watch?v=rpbGaPxUKb4
Kessler stroke researchers and colleagues have identified an association between over-optimistic estimation of one’s own ability to take medications accurately, and memory loss among stroke survivors. Results indicate that assessing patients for their ability to estimate medication skills accurately may predict memory disorder. The article, “Stroke survivors over-estimate their medication self-administration ability (MSA), predicting memory loss,” was epublished ahead of print on May 28 by Brain Injury. The authors are AM Barrett, MD, and J Masmela of Kessler Foundation, Elizabeth E Galletta of Hunter College, Jun Zhang of St. Charles Hospital, Port Jefferson, NY, and Uri Adler, MD, of Kessler Institute for Rehabilitation.

Researchers compared 24 stroke survivors with 17 controls, using the Hopkins Medication Schedule to assess MSA, the Geriatric Depression Scale to assess mood, and the Hopkins Verbal Test and Mini-Mental State Examination to assess memory. Results showed that stroke survivors over-estimated their MSA in comparison to controls. Over-estimation of MSA correlated strongly with verbal memory deficit.
Strategies that enhance adherence to medication are a public health priority. “Few studies, however, have looked at cognitive factors that may interfere with MSA,” commented Dr. Barrett. “While some stroke survivors have obvious cognitive deficits, many people are not aware that stroke survivors can be intelligent and high functioning, but still have trouble with thinking that can cause errors in medication self-management. These individuals may not realize their own deficits, a condition called cognitive anosognosia. Screening stroke survivors for MSA may be a useful approach to identifying memory deficits that hinder rehabilitation and community participation and contribute to poor outcomes.”
Larger studies of left and right stroke survivors need to be conducted in the community and rehabilitation settings in order to determine the underlying mechanisms for both over-estimation and under-estimation of self-performance.
(Source: kesslerfoundation.org)
With the right rehabilitation, paralyzed rats learn to grip again
After a large stroke, motor skills barely improve, even with rehabilitation. An experiment conducted on rats demonstrates that a course of therapy combining the stimulation of nerve fiber growth with drugs and motor training can be successful. The key, however, is the correct sequence: Paralyzed animals only make an almost complete recovery if the training is delayed until after the growth promoting drugs have been administered, as researchers from the University of Zurich, ETH Zurich and the University of Heidelberg reveal.
Only if the timing, dosage and kind of rehabilitation are right can motor functions make an almost full recovery after a large stroke. Rats that were paralyzed down one side by a stroke almost managed to regain their motor functions fully if they were given the ideal combination of rehabilitative training and substances that boosted the growth of nerve fibers. Anatomical studies confirmed the importance of the right rehabilitation schedule: Depending on the therapeutic design, different patterns of new nerve fibers that sprouted into the cervical spinal cord from the healthy part of the brain and thus aid functional recovery to varying degrees were apparent. The study conducted by an interdisciplinary team headed by Professor Martin Schwab from the Brain Research Institute at the University of Zurich and ETH Zurich’s Neuroscience Center is another milestone in research on the repair of brain and spinal cord injuries.
“This new rehabilitative approach at least triggered an astonishing recovery of the motor skills in rats, which may become important for the treatment of stroke patients in the future,” says first author Anna-Sophia Wahl. At present, patients have to deal with often severe motor-function, language and vision problems, and their quality of life is often heavily affected.
Allow nerves to grow first, then train
On the one hand, the treatment of rats after a stroke involves specific immune therapy, where so-called Nogo proteins are blocked with antibodies. These proteins in the tissue around the nerve fibers inhibit nerve-fiber growth. If they are blocked, nerve fibers begin to sprout in the injured sections of the brain and spinal cord and relay nerve impulses again. On the other hand, the stroke animals, whose front legs were paralyzed, underwent physical training – namely, gripping food pellets. All the rats received antibody treatment first to boost nerve-fiber growth and – either at the same time or only afterwards – motor training. The results are surprising: The animals that began their training later regained a remarkable 85 percent of their original motor skills. For the rats that were trained straight after the stroke in parallel with the growth-enhancing antibodies, however, it was a different story: At 15 percent, their physical performance in the grip test remained very low.
On the one hand, the treatment of rats after a stroke involves specific immune therapy, where so-called Nogo proteins are blocked with antibodies. These proteins in the tissue around the nerve fibers inhibit nerve-fiber growth. If they are blocked, nerve fibers begin to sprout in the injured sections of the brain and spinal cord and relay nerve impulses again. On the other hand, the stroke animals, whose front legs were paralyzed, underwent physical training – namely, gripping food pellets. All the rats received antibody treatment first to boost nerve-fiber growth and – either at the same time or only afterwards – motor training. The results are surprising: The animals that began their training later regained a remarkable 85 percent of their original motor skills. For the rats that were trained straight after the stroke in parallel with the growth-enhancing antibodies, however, it was a different story: At 15 percent, their physical performance in the grip test remained very low.
Meticulous design very promising
The researchers consider timing a crucial factor for the success of the rehabilitation: An early application of growth stimulators – such as antibodies against the protein Nogo-A – triggers an increased sprouting and growth of nerve fibers. The subsequent training is essential to sift out and stabilize the key neural circuits for the recovery of the motor functions. For instance, an automatic, computer-based analysis of the anatomical data from the imaging revealed that new fibers in the spinal cord sprouted in another pattern depending on the course of treatment. By reversibly deactivating the new nerve fibers that grow, the neurobiologists were ultimately able to demonstrate for the first time that a group of these fibers is essential for the recovery of the motor function observed: Nerve fibers that grew into the spinal cord from the intact front half of the brain – changing sides – can reconnect the spinal cord circuits of the rats’ paralyzed limbs to the brain, enabling the animals to grip again.
“Our study reveals how important a meticulous therapeutic design is for the most successful rehabilitation possible,” sums up study head Martin Schwab. “The brain has enormous potential for the reorganization and reestablishment of its functions. With the right therapies at the right time, this can be increased in a targeted fashion.
Literature:
Wahl, A.S., Omlor, W., Rubio, J.C., Chen, J.L., Zheng, H., Schröter, A., Gullo, M., Weinmann, O., Kobayashi, K., Helmchen, F., Ommer, B., Schwab, M.E. Asynchronous therapy restores motor control by rewiring of the rat corticospinal tract after stroke. Science, June 13, 2014.
MIT robot may accelerate trials for stroke medications
The development of drugs to treat acute stroke or aid in stroke recovery is a multibillion-dollar endeavor that only rarely pays off in the form of government-approved pharmaceuticals. Drug companies spend years testing safety and dosage in the clinic, only to find in Phase III clinical efficacy trials that target compounds have little to no benefit. The lengthy process is inefficient, costly, and discouraging, says Hermano Igo Krebs, a principal research scientist in MIT’s Department of Mechanical Engineering.
“Most drug studies failed and some companies are getting discouraged,” Krebs says. “Many have recently abandoned the neuro area [because] they have spent so much money on developing drugs that don’t work. They end up focusing somewhere else.”
Now a robot developed by Krebs and his colleagues may help speed up drug development, letting pharmaceutical companies know much earlier in the process whether a drug will ultimately work in stroke patients.
To receive approval from the Food and Drug Administration, a company typically has to enroll 800 patients to demonstrate that a drug is effective during a Phase III clinical trial; this sample size is determined, in part, by the accuracy of standard outcome measurements, which quantify a patient’s ability over time to, say, lift her arm past a certain point. A clinical trial can take several years to enroll appropriate patients, run tests, and perform analyses.
The study’s authors found that by using a robot’s measurements to gauge patient performance, companies might only have to test 240 patients to determine whether a drug works — a reduction of 70 percent that Krebs says would translate to a similar reduction in time and cost.
While pharmaceutical companies would still have to adhere to the FDA’s established guidelines and outcome measurements to receive final drug approval, Krebs says they could use the robot measurements to guide early decisions on whether to further pursue or abandon a certain drug. If, after 240 patients, a drug has no measurable effect, the company can pursue other therapeutic avenues. If, however, a drug improves performance in 240 robot-measured patients, the pharmaceutical company can continue investing in the trial with confidence that the drug will ultimately pass muster.
The researchers have published their results in the journal Stroke.
Creating a translator for stroke recovery
In their study, Krebs and his colleagues explored the robot MIT-Manus as a tool for evaluating patient improvement over time. The robot, developed by the team at MIT’s Newman Laboratory for Biomechanics and Human Rehabilitation, has mainly been used as a rehabilitation tool: Patients play a video game by maneuvering the robot’s arm, with the robot assisting as needed.
While the robot has mainly been used as a form of physical therapy, Krebs says it can also be employed as a measurement tool. As a patient moves the robot’s arm, the robot collects motion data, including the patient’s arm speed, movement smoothness, and aim. For the current study, the researchers collected such data from 208 patients who worked with the robot seven days after suffering a stroke, and continued to do so for three months.
The researchers created an artificial neural network map that relates a patient’s motion data to a score that correlates with a standard clinical outcome measurement.
The authors then selected a separate group of nearly 3,000 stroke patients who did not use the robot, but who went through standard clinical tests. In particular, the researchers calculated the “effect size” — the difference in patient performance from the beginning to the end of a trial, divided by the standard deviation, or variability, of improvement among these patients. To determine whether a drug works, the FDA will often look to a study’s effect size.
Using the robot-derived neural network map, the group calculated the effect size at twice the rate usually achieved with standard clinical outcome measurements, indicating that the robot scale demonstrated greater sensitivity in measuring patient recovery.
The study’s authors went one step further and performed a power analysis that determines the optimal sample size for a given technique, finding that the robot scale would require only 240 patients to determine a drug’s effectiveness — a reduction in sample size that would save a company up to 70 percent in time and cost.
“Such a savings would be fantastic,” says David Reinkensmeyer, a professor of physical medicine and rehabilitation at the University of California at Irvine. “Robotic measurements will help us identify promising treatments with smaller numbers of patients and provide better insight into the mechanisms of the treatments, so that we can target those mechanisms and improve the treatments.”
Currently, only a few stroke drugs are in the late stages of development. However, once a company reaches a Phase III clinical trial, Krebs says it may use the MIT-Manus robot as a more efficient way to evaluate the drug’s impact by employing the measurement techniques on a smaller group of patients.
Stroke rehabilitation researchers report improvement in spatial neglect with prism adaptation therapy. This new study supports behavioral classification of patients with spatial neglect as a valuable tool for assigning targeted, effective early rehabilitation. Results of the study, “Presence of motor-intentional aiming deficit predicts functional improvement of spatial neglect with prism adaptation” were published ahead of print in Neurorehabilitation and Neural Repair on December 27, 2013.

The article is authored by Kelly M. Goedert, PhD, of Seton Hall University, Peii Chen, PhD, of Kessler Foundation, Raymond C. Boston, PhD, of the University of Pennsylvania, Anne L. Foundas, MD, of the University of Missouri, and A.M. Barrett, MD, director of Stroke Rehabilitation Research at Kessler Foundation, and chief of Neurorehabilitation Program Innovation at Kessler Institute for Rehabilitation. Drs. Barrett and Chen have faculty appointments at Rutgers New Jersey Medical School.
Spatial neglect, an under-recognized but disabling disorder, often complicates recovery from right brain stroke,” noted Dr. Barrett. “Our study suggests we need to know what kind of neglect patients have in order to assign treatment.” The research team tested the hypothesis that classifying patients by their spatial neglect profile, i.e., by Where (perceptional-intentional) versus Aiming (motor-intentional) symptoms, would predict response to prism adaptation therapy. Moreover, they hypothesized that patients with Aiming bias would have better response to prism adaptation recovery than those with isolated Where bias.
The study involved 24 patients with right brain stroke who completed 2 weeks of prism adaptation treatment. Participants also completed the Behavioral Inattention Test and Catherine Bergego Scale (CBS) tests of neglect recovery weekly for 6 weeks. Results showed that those with only Aiming deficits improved on the CBS, whereas those with only Where deficits did not improve. Participants with both types of deficits demonstrated intermediate improvement. “These findings suggest that patients with spatial neglect and Aiming deficits may benefit the most from early intervention with prism adaptataion therapy,” said Dr. Barrett. “More broadly, classifying spatial deficits using modality-specific measures should be an important consideration of any stroke trial intending to obtain the most valid, applicable, and valuable results for recovery after right brain stroke.”
(Source: kesslerfoundation.org)
For patients recovering from a traumatic brain injury (TBI), the rehabilitation process – compensating for changes in functioning, adaptation and even community reintegration – can be challenging. Unfortunately, not all rehab programs are created equal, and with the differences comes a difference in outcomes, according to a first-of-its-kind study published in The Journal of Head Trauma Rehabilitation.

Collectively authored by Baylor researchers, the outcomes study (titled “Comparative Effectiveness of Traumatic Brain Injury Rehabilitation: Differential Outcomes Across TBI Model Systems Centers”), set out to identify if outcomes at the post-discharge and one-year points varied across 21 Traumatic Brain Injury Model System (TBIMS) centers. The Baylor Institute of Rehabilitation (BIR) was one of the centers studied.
At the study’s onset, researchers had an idea of what they might find, but their findings revealed the opposite.
“We expected that, after accounting for differences in patient characteristics and severity of injury, patient outcomes would be similar across centers,” said Marie Dahdah, PhD, investigator at the Baylor Institute for Rehabilitation. “They were not. There were significant variations, with a 25 percent to 45 percent difference between the best performing site and the site with the lowest outcomes at discharge.”
While differences in outcomes have long been reported in designated trauma centers (and for other specialties, including general and cardiac surgery, transplant and oncology), the study was the first piece of research to demonstrate that those differences exist in the rehabilitation context.
The team acknowledged that those variances could be attributed to institutional structures, resources and clinical practices, but that more research is needed to determine which of these factors is associated with optimum outcomes.
“In order to identify factors that contribute to variation in patient outcomes across centers, we are undertaking research that identifies different patient, injury and process-level factors associated with functional outcomes of patients,” Dr. Dahdah said. “Those factors can then be targeted to improve patient outcomes.”
In other phases of this study, these Baylor investigators (along with teams from three other TBIMS sites) are reviewing the quantity and frequency of various types of rehabilitation therapies used in inpatient TBI settings. The team will also study evidenced-based best practices for speech, occupational, physical and recreational therapy interventions, as well as neurocognitive and psychosocial interventions.
The results from those subsequent studies could help identify gaps between current practices and evidence-based best practices, with the aim of helping inform rehabilitation programs across the country and ensuring that all centers have the same opportunities for quality outcomes.
“I think I speak for my entire research team when I say that our involvement in this type of research comes out of our collective desire to improve quality of rehabilitation care, thereby enhancing outcomes following TBI,” Dr. Dahdah said. “My hope is that by synthesizing and disseminating what is known about effective evidence-based rehabilitation interventions, BIR as part of the North Texas TBIMS will be able to encourage changes necessary to help institutions, clinicians and therapists to provide the best quality TBI rehabilitation care to their patients.”
Of course, with the Baylor Institute of Rehabilitation being among the 21-center pool, one very obvious question remains. How did BIR’s outcomes compare with the other 20 centers?
“I cannot count for you the number of times I have been asked that question,” Dr. Dahdah said. “To ensure the integrity of our study, even our research team is blind to the identity of the centers.”
But despite how well even the strongest inpatient rehab centers perform in a comparative context, there is always room for improvement, especially with best-practice regimens.
“Our research has already started discussions within the TBI Model Systems research community,” Dr. Dahdah said. “We believe more research needs to be done to identify the key determinants of patient outcomes so that benchmarks for quality rehabilitation care can be derived for patients and their families.”
(Source: media.baylorhealth.com)

Novel Rehabilitation Device Improves Motor Skills after Stroke
Using a novel stroke rehabilitation device that converts an individual’s thoughts to electrical impulses to move upper extremities, stroke patients reported improvements in their motor function and ability to perform activities of daily living. Results of the study were presented today at the annual meeting of the Radiological Society of North America (RSNA).
"Each year, nearly 800,000 people suffer a new or recurrent stroke in the United States, and 50 percent of those have some degree of upper extremity disability," said Vivek Prabhakaran, M.D., Ph.D., director of functional neuroimaging in radiology at the University of Wisconsin-Madison. "Rehabilitation sessions with our device allow patients to achieve an additional level of recovery and a higher quality of life."
Dr. Prabhakaran, along with co-principal investigator Justin Williams, Ph.D., and a multidisciplinary team, built the new rehabilitation device by pairing a functional electrical stimulation (FES) system, which is currently used to help stroke patients recover limb function, and a brain control interface (BCI), which provides a direct communication pathway between the brain and this peripheral stimulation device.
In an FES system, electrical currents are used to activate nerves in paralyzed extremities. Using a computer and an electrode cap placed on the head, the new BCI-FES device (called the Closed-Loop Neural Activity-Triggered Stroke Rehabilitation Device) interprets electrical impulses from the brain and transmits the information to the FES.
"FES is a passive technique in that the electrical impulses move the patients’ extremities for them," Dr. Prabhakaran said. "When a patient using our device is asked to imagine or attempt to move his or her hand, the BCI translates that brain activity to a signal that triggers the FES. Our system adds an active component to the rehabilitation by linking brain activity to the peripheral stimulation device, which gives the patients direct control over their movement."
The Wisconsin team conducted a small clinical trial of their rehabilitation device, enlisting eight patients with one hand affected by stroke. The patients were also able to serve as a control group by using their normal, unaffected hand. Patients in the study represented a wide range of stroke severity and amount of time elapsed since the stroke occurred. Despite having received standard rehabilitative care, the patients had varying degrees of residual motor deficits in their upper extremities. Each underwent nine to 15 rehabilitation sessions of two to three hours with the new device over a period of three to six weeks.
The patients also underwent functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) before, at the mid-point of, at the end of, and one month following the rehabilitation period. fMRI is able to show which areas of the brain are activated while the patient performs a task, and DTI reveals the integrity of fibers within the white matter that connects the brain’s functional areas.
Patients who suffered a stroke of moderate severity realized the greatest improvements to motor function following the rehabilitation sessions. Patients diagnosed with mild and severe strokes reported improved ability to complete activities of daily living following rehabilitation.
Dr. Prabhakaran said the results captured throughout the rehabilitation process—specifically the ratio of hemispheric involvement of motor areas—related well to the behavioral changes observed in patients. A comparison of pre-rehabilitation and post-rehabilitation fMRI results revealed reorganization in the regions of the brain responsible for motor function. DTI results over the course of the rehabilitation period revealed a gradual strengthening of the integrity of the fiber tracts.
"Our hope is that this device not only shortens rehabilitation time for stroke patients, but also that it brings a higher level of recovery than is achievable with the current standard of care," Dr. Prabhakaran said. "We believe brain imaging will be helpful in both planning and tracking a stroke patient’s therapy, as well as learning more about neuroplastic changes during recovery."
Researchers Develop At-home 3D Video Game for Stroke Patients
Researchers at The Ohio State University Wexner Medical Center have developed a therapeutic at-home gaming program for stroke patients who experience motor weakness affecting 80 percent of survivors.
Hemiparesis affects 325,000 individuals each year, according to the National Stroke Association. It is defined as weakness or the inability to move one side of the body, and can be debilitating as it impacts everyday functions such as eating, dressing or grabbing objects.
Constraint-induced movement therapy (CI therapy) is an intense treatment recommended for stroke survivors, and improves motor function, as well as the use of impaired upper extremities. However, less than 1 percent of those affected by hemiparesis receives the beneficial therapy.
“Lack of access, transportation and cost are contributing barriers to receiving CI therapy. To address this disparity, our team developed a 3D gaming system to deliver CI therapy to patients in their homes,” said Lynne Gauthier, assistant professor of physical medicine and rehabilitation in Ohio State’s College of Medicine.
Gauthier, also principal investigator of the study and a neuroscientist, is collaborating with a multi-disciplinary team comprised of clinicians, computer scientists, an electrical engineer and a biomechanist to design an innovative video game incorporating effective ingredients CI therapy.
For a combined 30 hours over the course of two weeks, the patient-gamer is immersed in a river canyon environment, where he or she receives engaging high repetition motor practice targeting the affected hand and arm. Various game scenarios promote movements that challenge the stroke survivor and are beneficial to recovery. Some examples include: rowing and paddling down a river, swatting away bats inside a cave, grabbing bottles from the water, fishing, avoiding rocks in the rapids, catching parachutes containing supplies and steering to capture treasure chests. Throughout the intensive training schedule, the participant wears a padded mitt on the less affected hand for 10 hours daily, to promote the use of the more affected hand.
To ensure that motor gains made through the game carry over to daily life, the game encourages participants to reflect on their daily use of the weaker arm and engages the gamer in additional problem-solving ways of using the weaker arm for daily activities.
“This novel model of therapy has shown positive results for individuals who have played the game. Gains in motor speed, as measured by the Wolf Motor Function Test, rival those made through traditional CI therapy,” said Gauthier. “It provides intense high quality motor practice for patients, in their own homes. Patients have reported they have more motivation, time goes by quicker and the challenges are exciting and not so tedious.”
Gauthier said that, if this initial trial demonstrates sufficient evidence of efficacy in stroke survivors, future expansion of gaming CI therapy is possible for other patients with traumatic brain injury, cerebral palsy and multiple sclerosis.
Stroke Recovery Theories Challenged By New Studies Looking at Brain Lesions, Bionic Arms
Stroke survivors left weakened or partially paralyzed may be able to regain more arm and hand movement than their doctors realize, say experts at The Ohio State University Wexner Medical Center who have just published two new studies evaluating stroke outcomes.
One study analyzed the correlation between long-term arm impairment after stroke and the size of brain lesions caused by patients’ strokes – a visual measure often used by doctors to determine rehabilitation therapy type and duration. The other study compared the efficacy of a portable robotics-assisted therapy program with a traditional program to improve arm function in patients who had experienced a stroke as long as six years ago.
“These studies were looking at two entirely different aspects of a stroke, yet they both suggest that stroke patients can indeed regain function years and years after the initial event,” said Stephen Page, PhD, OTR/L, author of both studies and associate professor of Health and Rehabilitation Sciences in Ohio State’s College of Medicine. “Unfortunately, we know that this is not a message that many patients and especially their clinicians may be getting, so the patients may not be reaching their true potential for recovery.”
Size doesn’t matter
Clinicians frequently tell patients that the bigger the size of the area of their brains affected by their strokes, the worse that their outcomes will be. However, in a lead article in the Archives of Physical Medicine and Rehabilitation, Page’s research team found that there was no relationship between the size of stroke lesions and recovery of arm function in 139 stroke survivors. On average, study participants had experienced a stroke five years earlier.
“Historically, lesion size been thought to influence recovery, but we didn’t find that to be the case when looking at regaining arm and hand movement,” said Page, who also runs Ohio State’s B.R.A.I.N Lab, a research group dedicated to developing approaches to restore function after disabling injuries and diseases. “This has important implications because we know clinicians look closely at lesion volume and may make decisions about the type and duration of therapy, and that some may communicate likelihood for recovery to patients based on this size. Many people think the window for therapy is roughly six months, but we think it’s much longer.”
Page agrees that the first six months after a stroke may represent important healing time for the brain, but that “retraining” it with occupational therapy can potentially be helpful at any time after the stroke. He says that his findings support other theories that the health of remaining brain tissue influences recovery much more than lesion size.
Although there are many studies that have identified a relationship between stroke lesion size and overall neurological function, Page’s study is the first to specifically look at lesion size and upper extremity outcomes.
Robotic arm as good as traditional therapy
In the second study, Page’s team demonstrated that stroke survivors using a portable robotic-assisted arm to perform repetitive task training showed as much motor recovery as patients who performed similar tasks in a therapist-guided outpatient setting.
“Our results are exciting not just because we showed robotics-assisted therapy can offer equal benefit. We showed that both groups got better, even among patients who had suffered strokes as long as eight years ago,” noted Page.
For the study, which was published in the June 2013 issue of Clinical Rehabilitation, patients performed repetitive exercises that focused on everyday tasks while supervised by a therapist in an outpatient setting. Half of the group was randomly assigned to use the robotic arm, a portable device that is worn over the arm like a brace. When a person tries to move a weakened arm, the device senses the electrical impulses and helps the person carry out the movement. A second group performed the same tasks without the device for the same amount of time and in the same environment. The group training with the robotic arm performed tasks as well as their counterparts.
“Therapy can be tiring, expensive, and resource-intensive. This study is important because it shows us that in patients with moderate arm impairment, similar benefits can be derived from using a robotic device to aid with arm therapy as with manually based rehabilitative approaches,” said Page. “Study participants who trained with the robotic arm also reported feeling stronger and more positive about the rehabilitation process.”
Most of the estimated 80 million stroke survivors worldwide will continue to have upper body weakness for months after a stroke, preventing them from accomplishing everyday tasks like lifting a laundry basket or drinking from a cup. Page says that more research in stroke outcomes and rehabilitation is needed, and that he hopes families and healthcare practitioners dealing with stroke will keep the door to recovery open wider and longer.
“Loss of upper extremity movement remains one of the most common and devastating stroke-induced impairments. And the fact is that more stroke survivors are expected yet studies and pathways to optimize rehabilitative therapy for these millions are not always emphasized. In particular, we know active rehabilitation programs help people regain function, but we still don’t know who will benefit the most from these types of therapy,” said Page. “Both of these studies give us insights about patients who will respond best – and most importantly, that we have to give these patients every chance possible to get better, because they can keep getting better.”
The world’s first Brain Training Device has given a ray of new hope to the recovery of survivors after stroke. Developed by researchers of The Hong Kong Polytechnic University (PolyU)’s Interdisciplinary Division of Biomedical Engineering (BME), this novel device which can detect brainwave, and thereby control the movement of paralyzed limbs, or go even further to control a robotic hand based on its sophisticated algorithm.
The research was led by Prof. Raymond Tong Kai-yu, Professor of PolyU’s Interdisciplinary Division of Biomedical Engineering, who is also the Principal Investigator of the award-winning Exoskeleton Hand Robotic Training Device or the “Hand of Hope”. His team members include the BME research team (Newmen Ho, Xiaoling Hu, Ching-hang Fong, Xinxin Lou, Lawrence Chong and Nathan Lam) and the Industrial Centre team of PolyU (Robert Tam, Bun Yu, Shu-to Ng and Peter Pang).
The latest breakthrough “Brain Training Device” can be coupled with the use of the “Hand of Hope” to achieve higher degree of recovery for stroke patients. While effective motor recovery after stroke depends on early rehabilitation program and intensive voluntary practice of the paretic limbs, current rehabilitation products have not use brainwave to guide the stroke survivors to identify voluntary intention and to relearn how to reconnect to their paralyzed limb again.
Prof. Raymond Tong and his team therefore developed the Brain Training Device with a new coherence algorithm for hand function training. The new algorithm is based on frequency coherence on surface electroencephalography (EEG, brainwave) and electromyography (EMG, muscle activities) to identify voluntary intention and their connection.
"The Brain Training Device is able to guide the stroke patients to relearn the reconnection between the brain and the limb, with a new design on the EEG headset and the EMG forearm brace to transmit data for controlling a hand robotic system interfaced by a telecare software platform using iPad app." Prof. Raymond Tong explained.
The patented Brain Training System, which looks like a helmet for cyclist and can read brainwaves, also has new features to find the specific EEG electrode locations for each individual stroke patient and reduce the number of EEG electrodes, which can reduce the system cost and the preparation time for brain training, added by Prof. Tong.
To find a minimal set of electrodes to control the device with accuracy higher than 90%, five chronic stroke patients were recruited to be trained for 20 sessions in the study. The researchers found that, in general, 32 electrodes are needed to maintain accuracy higher than 90%.
The high accuracy and low number of channels needed means that the Brain Training Device is a viable tool for assistive aid and rehabilitation training. The futuristic system will be made portable and easy-to-use at hospital and home settings.
PolyU researchers have already filed patents for this Brain Training Device in both the United States and China. This project is funded by the HKSAR Government’s Innovation and Technology Fund (ITF). The findings of this brain control algorithm have been published as the cover story in top international journal IEEE Transactions on Neural Systems and Rehabilitation Engineering (2011.12).