Innovative Stroke Rehabilitation
By David Yeager
New stroke rehabilitation technologies can help patients to achieve recovery goals while limiting the extent of disability.
Improved acute care following stroke, along with patient education on stroke prevention, has positively influenced the stroke death rate, which dropped by about one-third from 1999 to 2007.1 But despite its move in the past year from the third-leading to the fourth-leading cause of death in the United States, stroke still accounted for nearly 1 million hospitalizations in 2009, two-thirds of which were among people aged 65 and older.2
In 2010, the number of stroke-related hospitalizations climbed slighty.3 Not surprisingly, the hospitalization rate among people aged 85 and older was significantly higher than the rate for people under the age of 65. Men under the age of 65 were hospitalized for stroke at a rate of 14.7 per 10,000 people, while men aged 85 and over were hospitalized at a rate of 285.7 per 10,000. For women, the rates were 11.6 per 10,000 for the group under the age of 65 and 277.4 per 10,000 for the group over the age of 85.3
By 2030, when the last of the baby boomers have reached the age of 65, people aged 65 and older will number approximately 72 million, roughly 21% of the US population, according to US Census Bureau data. As the boomer generation continues its march toward retirement age, it’s reasonable to wonder whether the US healthcare system will have the capacity to handle this influx of older people who proportionally suffer more strokes. It’s likely that stroke rehabilitation’s importance will continue to increase.
The Long View
Since the source of these impairments is neurological, retraining the brain is necessary to help patients regain at least some of their lost function. It was once thought that patients regained function only during the 90-day poststroke window, but that view has evolved.
While the greatest amount of recovery takes place in the first 30 days after a stroke and tapers off after 90 days, Larry B. Goldstein, MD, FAAN, FAHA, a neurology professor and director of the Duke University Stroke Center, says patients can continue to recover lost function for much longer periods of time, even years poststroke, albeit at a much slower pace. Rehabilitative strategies that incorporate a high number of task-specific repetitions can increase a patient’s ability to recover by helping him or her rewire neural pathways or develop new ones that can compensate for those damaged by stroke.
“A lot of the interventions that have been studied recently that seem to improve recovery compared to standard therapy are really ways of trying to further intensify the amount of practice,” Goldstein says. “More intensive physiotherapeutic interventions—the training component—seem to me to be one of the things associated with better improvement.”
Some experimental data suggest that starting therapy too soon after stroke might exacerbate the injury, but Goldstein says at this point it’s best to begin therapy as soon as the patient can safely tolerate it. Although patients are typically in an inpatient setting during this time, they may be eligible for a broader range of services than most physicians realize.
“Oftentimes, patients are referred to a skilled level of care from acute care when they have the potential to benefit from the intensity of an acute rehabilitation program, where often [more advanced] technologies and an expert clinical staff and specialized services are available to the patient,” says Amy Goldman, PT, DPT, stroke program manager for Madonna Rehabilitation Hospital in Lincoln, Nebraska. “We need to better identify patients in need of specialized stroke rehabilitation services during the period where they are most likely to benefit from intense rehabilitation services and refer them to the appropriate facilities where these services are available.”
“This is not a cure by any stretch of the imagination, but an improvement of 10% can represent a tremendous difference in the quality of life of the patient,” Krebs says. “For example, somebody who cannot put on a jacket by themselves in the winter and therefore doesn’t feel comfortable leaving home may now be able to dress themselves without assistance from anybody. Somebody who is a little bit on the more moderate side may be able to do other things like push a cart with the impaired limb.”
While they are mainly considered experimental, newer types of therapy attempt to enhance brain plasticity. Some, such as transcranial magnetic stimulation and direct current stimulation, are used as adjuncts to therapy. These noninvasive therapies use magnetic or electric impulses, respectively, to stimulate cortical activity in the brain while patients perform repetitive functional tasks. The patients don’t feel the impulses, but functional MRI shows that the impulses increase the brain activity that correlates to the bodily function. Madonna Rehabilitation Hospital is currently studying the use of transcranial direct current stimulation for aphasic patients, with the possibility of using it for motor recovery in the future.
The goal of rehabilitation is to help patients regain their highest level of independence as soon as possible. Constraint-induced therapy is a method of rehabilitation used when one of a patient’s limbs is weakened. Use of the functional limb is restricted, forcing the patient to use the damaged limb to perform repetitive functional upper extremity tasks, such as picking up a fork or grasping a soda can.
The idea behind the therapy is that patients will preferentially use their functional limb unless they make a deliberate effort not to. A multisite trial of constraint-induced therapy for patients with stroke-related hand damage, conducted 50 weeks after therapy completion, found a 52% reduction in time to complete tasks vs. patients who received standard therapy, a 76% increase in quantity of use (vs. 43%) and a 77% increase in quality of use (vs. 41%).5
Robotic therapy offers another way to help patients increase the number of task repetitions. To be effective, robotic therapy requires patients to have some level of motor function in their limbs. Although many types of robotic therapy are considered experimental, they are increasingly being put to practical use because mounting evidence indicates that such therapies aid stroke rehabilitation. The use of upper extremity robotic therapy, for example, was recommended by the American Heart Association (AHA) in its overview of nursing and interdisciplinary rehabilitation care.6 The AHA assigned its highest level of evidence to upper extremity robotic therapy and recommended its use in outpatient and chronic care settings while deeming it reasonable for use in inpatient settings.6
The AHA found that in addition to reducing the number of therapists needed to assist a patient, robot-assisted therapy provides accurate sensory feedback.6 For upper extremity robotic therapy, a portable robot with an artificial arm guides patients through a series of either voluntary or motor-guided repetitive reaching exercises. Clinicians can specify and monitor variables such as speed, direction, rate of movement, and joint coordination.
Robotic therapy can be paired with a virtual reality environment that simulates the real world. For example, a patient may use a robotic device while viewing a computer screen that shows a hand picking up a piece of fruit or an egg. If the patient squeezes the robotic hand too tightly, the virtual egg will crack. The opportunity to repeatedly perform such real-world tasks, which can’t always be simulated in a rehab environment, aids in patient recovery.
Rehabbing Lower Extremities
Many treadmill systems consist of a harness suspended over a treadmill. Software regulates the speed of the treadmill and the percentage of body weight that’s supported. Therapists sit on either side of the patient and manually guide the patient’s legs through the walking cycle. An alternate treatment approach is Hocoma’s Lokomat robotic gait training system. It allows earlier initiation of walking recovery and longer, more intense training sessions than traditional treadmill training, which has the potential to speed up the patient’s recovery process. The Lokomat adjusts the patient’s gait speed and the force needed to retrain the gait, relieving some of the physical strain on therapists.
“Through the use of robotics, patients get so many more repetitions than a physical therapist or an occupational therapist can provide manually,” Goldman says. “For example, when we perform over-ground gait training, patients may walk 50 feet with two people required to assist them. If we train them in the Lokomat, they can walk up to 20 or 30 minutes with continuous repetitive stepping, and that just enhances the number of repetitions that are required to make cortical changes in the brain.”
One significant drawback of the Lokomat is expense. Because it costs roughly 3.5 times as much as other treadmill systems, there are only about 96 in the United States, mostly at large rehabilitation hospitals and VA facilities.
As a more affordable alternative, Madonna Rehabilitation Hospital’s Institute for Rehabilitation Science and Engineering recently developed the intelligently controlled assistive rehabilitation elliptical (ICARE). ICARE was developed to address barriers associated with manual body weight-supported and robotic-assisted gait training devices while providing the repetition that patients require to regain walking function and facilitate motor recovery. The motor-assisted elliptical trainer adjusts resistance depending on a patient’s needs and can be used in smaller rehabilitation facilities, assisted-living units, and potentially in home and community settings.
The advantage of having systems such as the Lokomat and ICARE along with other robotic treadmill systems is that patients can begin rehab sooner on the more advanced systems and transition to the other treadmills as they progress. This is important because patients, on average, spend only three weeks in acute rehabilitation before they transition to the next level of care. Goldman says the goal is to simulate the home environment and transition the patient to real-world walking as soon as possible.
As patients progress in their rehabilitation, they may transition to wearable functional electrical stimulation devices. The purpose of these devices is to replace or assist voluntary muscle contractions during functional tasks. They are used by acute and chronic stroke patients in conjunction with repetitive task training to increase function, strength, and movement and decrease pain and muscle spasticity.
The devices are custom-fit over the affected limb and use surface electrodes to stimulate and activate muscles of the hand, forearm, or leg to promote sensorimotor recovery, often on an outpatient basis. Bioness Inc makes the H200 device for hand paralysis, the L300 for foot drop, and the L300 Plus for thigh weakness. Walk Aide also produces devices to combat foot drop.
Points to Ponder
There also have been limited attempts to use drug therapy to enhance patients’ recovery but to date, there are few drugs that have shown any clinical benefit. Krebs believes that getting drugs into the pipeline potentially would be of great benefit, but pharmaceutical companies currently see no value in stroke drugs. Goldstein says clinical trials are still trying to determine the effects of drug therapy, and some drugs used when patients become agitated may actually impair the recovery process. For this reason, he advises a careful approach to pharmacology.
“Even if we can’t, at this point, necessarily improve their recovery with these drugs, at least we can try to avoid drugs that have the potential to impair their recovery,” Goldstein says.
Some of the most exciting new research is in the realm of brain-computer interfaces. In a recent study described in the Journal of Neural Engineering, researchers isolated the same-side brain signals of hemiplegic stroke patients and channeled the signals to perform a computerized task.7 This is significant because signals from a brain hemisphere typically control actions on the opposite side of the body. By isolating the same-side signals in the uninjured hemisphere, the researchers were able to channel those signals to a computer interface, and the patients could control a computer cursor that served as a stand-in for their same-side limb. This provides evidence that brain-computer interfaces can be used by patients to control the movement of the ipsilateral limb on the uninjured side of the brain.
Eric C. Leuthardt, MD, an associate professor of neurosurgery, biomedical engineering, and neurobiology; director of the Center for Innovation in Neuroscience and Technology at Washington University School of Medicine in St Louis; and one of the study’s authors, says this may open the door to new rehabilitative approaches or even brain-controlled orthotic devices that allow patients to regain the use of a limb. In the future, he and his team may conduct research on how these findings apply to the lower extremities but for now, they are focusing mainly on the hands. Leuthardt believes this research has the potential to lead to significant advances in stroke care.
“If this works and it helps people in a reliable way, I think it could be completely game changing,” Leuthardt says. “If you can use your hand again so that you can do the activities of daily living, that’s a huge, huge advance. It really reduces the burden of that person on social systems; it enables that person. I think it substantially helps both the individual and the social suffering due to stroke.”
As the population ages, technology that reduces patients’ reliance on the healthcare system will become increasingly important. Long term care is costly, and facilities will increasingly be forced to find ways to provide the same level of care with fewer resources, which means there are likely to be fewer clinicians caring for more patients. Robotic technologies may help fill the gaps in care.
“We might need to create robotics as assistive technology to cover the gap that is missing,” Krebs says. “But our goal on the rehab robotic side is to try to bring the patient back so close to where they were that we would not need so much assistive technology. That’s the ideal.”
“The importance of understanding aging with a stroke is huge,” Goldman says. “It is so important for the physician and the rehab team to keep in touch with the patient and help them address those changes that they’re facing throughout the course of their recovery. As part of our stroke follow-up process, we contact our patients at six to 12 months postdischarge and then yearly thereafter in order to help them maintain their functional gains while reducing their risk for rehospitalization.”
— David Yeager is a freelance writer and editor based in Royersford, Pennsylvania.
Considerations for Stroke Care
• Patient education is key. Stroke mortality declined by one-third between 1999 and 2007. Teaching patients how to prevent stroke is the best treatment of all.
• Begin therapy as soon as safely possible. Starting rehabilitation too soon can be detrimental to a patient, but the greatest degree of recovery occurs within the first 90 days poststroke. Starting rehabilitation as soon as possible helps patients take advantage of that window.
• Age is not a barrier. Although aging affects people in general, stroke patients of all ages benefit from intensive therapy. Older patients should participate to the greatest degree possible to derive the greatest possible benefit.
• Consider more intensive options. Don’t assume that patients won’t benefit from a more intensive rehab setting. It can take thousands of repetitions for a patient to relearn a task. Intensive rehabilitation at a rehabilitation hospital can provide patients with access to state-of-the-art equipment and expert staff that smaller facilities don’t have, which can speed the process of resuming the activities of daily living.
• Develop a long-term plan. Patients continue to recover for months or years after a stroke, but aging presents challenges as patients proceed through recovery. Monitor progress and keep in mind that additional rehabilitation may become necessary.
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