September/October 2014

Stroke Rehabilitation: Strengthening Synapses to Achieve Optimal Outcomes
By Mosunmola Oyawusi, MD; Uri Adler, MD; and A.M. Barrett, MD
Today’s Geriatric Medicine
Vol. 7 No. 5 P. 12

Successful stroke rehabilitation requires individualized treatment focusing on reorganization in the recovering brain, a multidisciplinary rehabilitation approach, goal setting, and community therapy resources.

Stroke is one of the leading causes of death in industrialized countries, and complications arising from stroke present a major personal and economic burden. Studies show that up to 75% of stroke survivors have disabilities that ultimately affect their employability and livelihood.1 Every year more than 750,000 people in the United States suffer a stroke, and there are more than 6 million stroke survivors in the United States alone.2 As a result, millions of people in the United States are in need of rehabilitation to help them return to function, independence, social activities, and community participation.

Limitations on activity and participation3 can be classified as affecting activities of daily living (ADLs) or basic self-care activities such as dressing, bathing, or toileting.4 Such limitations may also affect functions or instrumental ADLs, such as housework, meal preparation, shopping, using the telephone, and other tasks that allow independent community living.5 It is important to understand that visible disabilities such as paralysis are not the only factors that limit people after stroke. Hidden disabilities such as depression, problems with cognition, memory, and communication; and functional vision problems such as visual-spatial deficits may also be disabling, even though they are not as easily identified on casual observation.

The recovery period following a stroke may range from weeks to months. Because recovery may frequently continue even after one year,6 it is very important at the time of stroke for all members of the medical team to introduce the rehabilitation process to stroke survivors and their families. Stroke survivors and their families benefit from support to prepare themselves for the care of both visible and hidden disabilities in a plan of care that transitions from the hospital to the home, outpatient rehabilitation, and beyond, with therapeutic options at each step.7

This article discusses several rehabilitation approaches, or therapies, that can be used following stroke to improve daily life function. The authors will outline the way in which each therapy is thought to work, which candidates may benefit, and the important characteristics of each technique. The article describes two categories of therapies: those intended to speed stroke recovery by generally enhancing brain activity, or stimulation-based approaches, and therapies intended to focus and target specific task practice. Clinicians may be unfamiliar with some of the newer therapies. The authors also touch on the advantages of using these approaches, as compared with more conventional or traditional techniques.

In discussing new treatments, the authors will also review critical components of successful stroke recovery: reorganization in the recovering brain, a multidisciplinary approach to rehabilitation, goal setting, and community therapy resources. Providing access to rehabilitation and encouraging stroke survivors and their families to take advantage of therapy will increase the odds of success in transitioning home after hospitalization. When health care providers inform the survivor and family about the rehabilitation process, it can help prepare the stroke survivor to take the steps necessary to return to former social and occupational roles.

Stimulation-Based Approaches
Neural plasticity refers to changes in the brain’s physiology during recovery from injury. These changes can be chemical, as this term was originally used.8 However, neurons can also change their physical, anatomic properties. Synapses can be strengthened and made more efficient through physical remodeling. A former misconception of neuronal growth is that neurons do not “sprout” after adulthood.

It is now known that neurons’ growth from neural progenitors does occur in some parts of the brain throughout life9 and that our functional brain circuitry remains capable of change after injury. As demonstrated in numerous studies since the classical work of Harlow and Harlow,10 rich environmental stimulation is needed to support healthy brain development, and the same kind of environmental resources are needed for poststroke recovery of brain networks supporting movement, communication, memory, and functional three-dimensional body movements.

Two emerging physiological brain stimulation approaches that have attracted considerable attention are noninvasive methods of applying electrical and magnetic energy directly to the cortex.11 Transcranial magnetic stimulation (TMS) uses electromagnetic technology to create an electrical current that can depolarize neurons. A brief, strong magnetic field created by a coil-circulated electrical current penetrates the skull when the stimulator applicator is held at the proper orientation near the head.

First introduced in 1985, TMS has been used for both diagnostic and therapeutic indications in a range of neurologic and psychiatric conditions.12 Repetitive application of electrical stimulation via TMS (rTMS) is approved as a clinical treatment for depression, when applied to the prefrontal cortex of the left brain. Because the excitatory or inhibitory effect of TMS on the cortex may persist with a repeated series of stimulation administered via rTMS, the hope is that clinical trials will indicate that poststroke hemiparesis and other neurological conditions may be treatable with this technique.

At this point, only adult candidates with major depressive disorder who have failed a prior trial of antidepressant medication are eligible for rTMS treatment. A history of epilepsy, stroke, tumors, or infectious lesions of the brain, sleep disorders, alcoholism, pregnancy, or severe heart disease, and other neurological disorders are contraindications. However, it is notable that some research studies report stroke recovery associated with TMS applied to the healthy hemisphere, where there is a decreased risk of treatment. Although TMS provides stimulation over a relatively large cerebral region, the region over which stimulation is applied differs depending on the indication being examined (eg, clinical trials examining rTMS for hemiparesis may stimulate motor cortex).

Transcranial direct current stimulation (tDCS) uses electrical stimulation to enhance cortical excitability. Saline-soaked pads placed on the scalp apply a very weak current (about two milliamperes) in 10- to 30-minute sessions to modify rather than generate neuronal activity in cortical neurons by generating an electrical field that fosters neural network interaction. Although tDCS is being investigated to improve paralysis, depression, and pain in neurological disorders,11 it is a research intervention only, without FDA-approved clinical indications. Further clinical trials are needed to determine the benefit of tDCS to the ADLs, and whether these benefits are short-lived or meaningful over longer time periods for recovery.

Therapies Based on Focused Intensive Practice
The Stroke Progress Review Group convened by the National Institute of Neurological Disorders and Stroke conducted a 10-year review of National Institutes of Health-funded stroke research. The working group for rehabilitation and recovery13 noted the increasing emphasis on activity-based therapies as opposed to general brain stimulation. In this approach, a desired behavior must be practiced intensively in order for the stroke survivor to experience beneficial performance improvement.

Perhaps the best example of intensive, experience-based, repetitive training is motor rehabilitation of a paretic limb in constraint-induced movement therapy (CIMT), first used in stroke survivors in the 1980s based on the observation of “learned nonuse” in monkeys with a deafferented limb but intact motor capability.14 Immobilizing the unaffected limb restored competent, symmetric movements in the deafferented limb; intensive use of the impaired limb supported return of its functional use. CIMT is a therapeutic strategy developed to overcome learned nonuse of the paretic limb, and although applied primarily to stroke survivors, it has also been used in other neurological disorders.15 The unaffected arm is restrained with a sling or glove, and the patient is involved in intensive, repetitive training to maximize the use of the paretic arm through the performance of functionally oriented activities. Some studies supported actual structural changes in the motor network, presumably occurring as a result of this treatment.16

Candidates for CIMT should have some degree of extension in the paretic extremity, conventionally 10 to 15 degrees of extension at the elbow, wrist, and fingers. Candidates should also have the cognitive skills and personal maturity to make a commitment to the therapy, enforced via a behavioral contract in a “transfer package.”17 A major advantage of the CIMT approach is that it is low risk and feasible in many settings. The main cost is therapist time, which, unfortunately, many third-party payers may not reimburse. There are several differences between the CIMT approach and typical outpatient therapy for stroke survivors. First, typical outpatient physical, occupational, and speech therapy programs involve two to three sessions of about 45 minutes per week, for a period of a few weeks to months, depending on patient needs.

However, a CIMT program involves more frequent, long sessions over a shorter period. A CIMT program can run for three to six hours each day for two weeks, with individualized outcome assessment. CIMT can be effective even years after the stroke occurs, but typically stroke survivors are not prescribed outpatient therapy beyond the first six months after the stroke. The important transfer package or behavioral contract involves the need to make a conscious agreement to work toward therapy progress as a joint goal through this contract between the therapist and patient, increasing its patient-centered properties.

Constraint-induced language therapy (CILT) is a novel approach that applies the principles of constraint-induced motor rehabilitation to treat aphasia. Patients with aphasia receiving CILT receive longer, more frequent sessions as with CIMT. However, the constraint applied is restriction to the ability to use compensatory communication strategies, such as gesturing and drawing. In some settings, this constraint is a physical barrier to block gestures; in other settings, therapists as conversation partners simply withhold response to communicative output that is nonverbal.

Intensive practice occurs in one-to-one exchanges or in group exercises such as a modified card game. The goal is to implement constraints to facilitate the patient’s engagement in massed practice of language functions. As above, CILT is believed to be effective because it supports beneficial remodeling of brain language networks; participants can experience improved language performance within 10 days of implementation.18 Although most people receiving CILT in research or clinical settings have nonfluent aphasia syndromes, it is not yet clear which people with aphasia respond best to the technique. It is widely agreed, however, that clients must have sufficient pragmatic comprehension to take part voluntarily in the constraint aspect of treatment. This fits the concept of person-centered care as a central part of constraint-induced therapies, and the importance even in CILT of a behavioral contract or therapy agreement.

Focused, Intensive Therapy for Right Brain Stroke Recovery
The Stroke Progress Review Group13 emphasized that deficit-targeted rehabilitation results in maximum benefit. It is thus surprising that we often prescribe the same rehabilitation regimen to survivors of left and right brain stroke, when more than one-half of the survivors of right brain stroke suffer from an inability to report, respond, or act on one side of space referred to as spatial neglect.19 Although many physicians believe this problem is a visual disorder, it affects how the survivor sits (survivors can lean abnormally to one side, leading to pressure ulcers and falls), dresses, and performs tasks guided by auditory, tactile, and movement coordinates. For these survivors, a simple intensive visual-movement training with off-the-shelf optical prisms, Prism Adaptation Training (PAT) is a feasible treatment that allows for short rehabilitation sessions either in the hospital or as part of outpatient therapy.

Patients repeatedly point to targets or perform continuous manual tasks while the view of their own arm movements is partially blocked. A major advantage to using PAT is its action on low-level, implicit brain systems—clients make more leftward movements after right brain stroke, but this is not because they are told to do so but because their movement system automatically readjusts. Since patients with right brain stroke frequently overestimate their own abilities,20 this lightens the burden for a patient who already has difficulty knowing when to use strategies and when they are not needed. The ideal patient for PAT has spatial neglect as defined by a standard assessment,21 can sit up, and has vision in at least one eye that is adequate to point to a target. Although the currently recommended treatment period, as with CIMT, is only 10 consecutive sessions, longer periods of treatment may also be helpful for patients who continue to show evidence of spatial neglect affecting their ability to transfer, use a wheelchair, eat, or perform higher-level tasks such as working or sports.

Challenges to Optimal Stroke Rehabilitation

Introducing the Rehabilitation Plan and Expectations
The Centers for Disease Control and Prevention reports that as many as 70% of stroke survivors may not receive rehabilitation when they leave the acute hospital setting after stroke.22 Stroke survivors often slip through the cracks in part because the team helping during the first hours and days after stroke may not help patients to prepare their “wish list” for a therapy and rehabilitation plan in the months and years to come. Although it is important to focus on rapidly delivering acute care, it is also important to explain to the therapy team which health care professionals will resume care at the next stages. This team includes psychologists and neuropsychologists, social workers, occupational and physical therapists, speech-language pathologists, dietitians, and other physician and allied health specialists such as physiatrists, orthotists, wheelchair and driving specialists, vocational rehabilitation staff, and community resources such as stroke associations, social groups, and peer support.

Stroke survivors and families should be familiar with the rehabilitation roadmap and the resources available for the chronic stage of recovery, extending from the acute inpatient hospital to inpatient rehabilitation, long term acute care or skilled nursing care, home nursing, outpatient care, and rehabilitation. Too frequently, survivors and families assume that rehabilitation options end at one month, three months, or six months; they may have left the hospital unprepared to self-advocate and take an active role in identifying therapy resources that might be available at nearby colleges, research programs, peer support centers, or other organizations. An informed stroke survivor and family can partner with the family physician to find the best options available at each stroke recovery stage.

Planning During Inpatient Care
Ideally, rehabilitation planning starts at the time the stroke emergency pathway is initiated. Assessments by therapists and a neurorehabilitationist during the first 48 hours of inpatient care not only help to avert adverse consequences of dysphagia and immobility but can also help guide recommendations for care during the postacute stage and even the home-based and outpatient stages of care. Frequently, this early consultation identifies resources that the stroke survivor and family can draw upon later to supplement family physician care.

Organizing multidisciplinary Therapy and Focused Treatment
Figure 1 portrays the neurorehabilitation team that participates in the acute and postacute care process. The focused, intensive treatment approaches discussed earlier in this article must be carefully coordinated among the group. As discussed in another article on brain-based rehabilitation,23 the multidisciplinary team must take care to maintain focus not only within treatment sessions but between sessions. A well-coordinated multidisciplinary team will identify two or three treatment targets or tasks of interest so an intensive treatment theme can be maintained even as the practitioners rotate in working with the patient.

Final Thoughts
Traditional rehabilitation practice has often focused on strengthening exercises and compensatory training. This article emphasizes restorative treatments to reestablish lost functions through intensive task-based practice or direct brain stimulation. Evolving knowledge about the ways the brain structure, function, and properties change with successful recovery will lead to advancement in stroke therapy. However, the most important component in stroke rehabilitation is involved and supportive health care professionals, who help stroke survivors and their families navigate a successful path from the acute hospital, through postacute inpatient or outpatient settings, to community-based resources available to provide rehabilitative options at three months, six months, a year, two years, and even five years or more following stroke, as they return to their activities and their lives.

— Mosunmola Oyawusi, MD, is a postdoctoral fellow in stroke rehabilitation research at the Kessler Foundation and stroke rehabilitation at the Kessler Institute for Rehabilitation.

— Uri Adler, MD, is the director of stroke rehabilitation services at the Kessler Institute for Rehabilitation at the Saddle Brook campus. He is an assistant professor of physical medicine and rehabilitation at Rutgers-New Jersey Medical School.

— A.M. Barrett, MD, is the director of stroke rehabilitation research at the Kessler Foundation and chief of neurorehabilitation program innovation at the Kessler Institute for Rehabilitation. She is a professor of physical medicine and rehabilitation at Rutgers-New Jersey Medical School and past president of the American Society for Neurorehabilitation.

References
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