Clinical aspects

Description

Many neurologic conditions may be associated with chronic impairments, sudden-onset, subacute, or chronically progressive. Evidence for benefits for specific therapy interventions and technologies is accumulating (73). Conditions such as stroke, Alzheimer disease, Parkinson disease, cerebral palsy, and spinal cord injury have larger bodies of evidence investigating the effectiveness of rehabilitation, but support for rehabilitation for Huntington disease, functional neurologic disorder, and epilepsy is also mounting. Innovations in the delivery of rehabilitation have also grown, with the use tele-rehabilitation accelerated by the COVID-19 pandemic (75). In addition, evidence for the use of innovative treatment tools to enhance rehabilitation efficiency and outcomes is also increasing (73).

On the other hand, rehabilitation therapy is a finite resource, limited by therapist availability and subspecialty training, insurance or financial limitations, and access (including transportation and scheduling constraints) (67; 25). Many patients’ rehabilitation needs are frequently not met (67; 25; 61). Efficient utilization of therapy resources requires informed clinical decision making on behalf of the neurologist. However, navigating the literature on the multitude of interventions can be complex due to the complexity of the nervous system, the heterogeneity in therapy quality and quantity, and the difficulty in controlling for the randomness of daily life. Therefore, it can be helpful to take a top-down approach in identifying the goals of therapy.

Goals of rehabilitation therapy. Neurologic therapy can increase function via one or multiple goals or “mechanisms.” These include, but are not limited to, the following:

1. Restoration

2. Compensation

3. Increasing activity tolerance / decreasing symptoms

4. Assessment for assistive technology

5. Caregiver training

6. Community re-integration

Restoration. Restoration refers to the reduction of deficits of a specific bodily impairment caused by neurologic injury (39; 59). For instance, therapy might aim to restore upper extremity motor function after stroke. Restoration relies on neural plasticity (49), which occurs at all levels of the nervous system to varying degrees, although it is generally more active in the brain versus the spinal cord or peripheral nervous system (70). Restoration may occur spontaneously after injury as a result of reactive plasticity (39). In contrast, neurologic rehabilitation primarily operates via experience-dependent plasticity (39). Restorative therapy is achieved by mass practice or mass repetition of task-specific exercise that has salience for the individual (49). The mechanisms involved are complex and include long-term potentiation, axonal sprouting, remyelination, neuronal memory allocation, and network reorganization or vicariation (39). Restoration may also aim to reverse or prevent maladaptive plasticity where development of deleterious signaling patterns lead to a decrease of function. Synkinesis of the eye and lip after Bell palsy is an example of maladaptive plasticity; its risk may be minimized with early neuromuscular re-training (38).

The effective “dose” of task-specific exercise—the number of good quality repetitions that are required to maximize the restoration of a deficit—is not known. Nudo and colleagues determined in their seminal work that restoration of upper extremity impairment and measurable reorganization of primary motor cortex could be detected in a squirrel monkey stroke model, when animal subjects performed 600 repetitions of a pellet retrieval task per day (56). By contrast, in observed therapy sessions targeting upper extremity rehabilitation, task-specific exercise occurred in just 51% of sessions, with an average of 32 repetitions per session (41). New technologies seek to increase the volume of massed practice. Partially supervised tele-rehabilitation is being studied to increase the dose of task-specific exercise after stroke (22). Gamification and virtual reality provide immersive and engaging ways for patients to increase task-specific exercise (84). Robotic rehabilitation is promising for increasing practice volume--not just for sensorimotor impairments but also for cognitive impairment (28; 84).

Task-specific exercise can be enhanced to increase its efficiency using priming and augmenting tools. Priming tools increase the excitability of the central nervous system, preparing it for plasticity. The VNS-REHAB trial demonstrated that transcutaneous stimulation of the left vagus nerve during occupational therapy for chronic upper extremity motor stroke can significantly increase upper extremity function (16). Augmenting tools amplify the action of an exercise at the level of the peripheral nerve or muscle (59). A 2023 network meta-analysis comparing therapy interventions for upper extremity function after stroke found that, in the subacute phase of stroke, augmenting task-specific training with neuromuscular electrical stimulation (NMES) had the strongest evidence for an effect at the end of the intervention (74).

Compensation. When a severe impairment has limited potential for restoration, efforts can instead focus on compensation to complete functional tasks. For instance, a patient with a cervical spinal cord injury at C6 may have absent finger function, but there might be enough wrist extension to use a tenodesis splint to achieve an adaptive pincer grip (50). An individual with left hemiplegia might learn how to use the right arm to put on or take off a shirt. A patient with dysphagia and reduced laryngeal elevation might learn the “chin tuck” maneuver to improve swallowing function. This maneuver involves placing the chin closer to the chest, which can favorably modify pharyngeal dimensions to direct the bolus toward the pharynx and esophagus (66).

Compensation and restoration both rely on experience-dependent plasticity (39). A fine line may exist between restoration and compensation when compensatory mechanisms functionally support, or replace, components of an impairment. For instance, imaging correlates during motor rehabilitation for Parkinson disease support that both restorative and compensatory mechanisms participate in improving parameters of gait (05).

Increasing activity tolerance / decreasing symptoms. Immobility and deconditioning are common with neurologic disease and can result in reduced activity tolerance (48; 61). Evidence increasingly supports the benefit of exercise after neurologic injury for both functional and health outcomes. Progressive aerobic exercise in multiple sclerosis resulted in clinically relevant reductions in fatigue; however, there was a small effect on walking and no effect on quality of life (42). Supervised exercise was superior to unsupervised home exercise in improving fatigue, strength, and quality of life in chronic Guillain-Barré syndrome (69). In subacute stroke, body weight–supported treadmill training led to improved cardiovascular fitness and walking ability that endured at 1-year (48). Aerobic exercise in mild Parkinson disease could attenuate off-state motor signs (78). Exercise might be helpful as a priming agent for upper extremity restoration therapy (15).

Neurologic conditions can be associated with headache, pain, or vertigo and can be alleviated with therapy in certain cases. Therapy in the form of sub-symptom threshold aerobic exercise has emerged as a first-line treatment for sport-related concussion and may be more effective with a higher number of oculomotor or vestibular symptoms (14; 45). In children with cerebral palsy, range of motion is a cornerstone of treatment of spasticity, and interruption of therapy can result in worsened spasticity and decreased ankle joint range of motion (46). In migraine, four weekly sessions of manual therapy of the cervical spine using low velocity, high-amplitude movements were associated with decreased symptoms and increased quality of life, although headache specialists are generally cautious in accepting manual therapy as efficacy is difficult to prove (54).

Assessment for assistive technology. Therapists can help select individualized assistive technology to maximize patient function. Assistive technology refers to any product or device designed with the purpose of maintaining or improving an individual’s function or independence and ranges from communication devices to prosthetics and wheelchairs (31). Special training and certifications are available for assistive technology. For a patient with impaired vocal communication due to motor speech symptoms, his or her speech therapist might find that a particular AAC device with text-to-voice technology can allow the patient to effectively communicate with others (02). A physical or occupational therapist might fit a patient for any variety of mobility-related assistive technology devices or mobility aids, such as walkers or wheelchairs. A therapist specializing in wheelchair seating often works in collaboration with an assistive technology professional (ATP) for chair selection; furthermore, evaluation by an ATP is required by Medicare for all but the most basic power wheelchairs (53). Wheelchairs serve as an important means of functional independence for a variety of neurologic conditions, such as spinal cord injury (55; 53).

Care partner training. Neurologic impairments may result in dependence on other people to complete activities of daily living, such as grooming or toileting, or to achieve mobility through transfers and locomotion (82). However, formal professional caregiving can be costly. Members of a patient’s support system, such as family or friends, often provide informal caregiving. An important goal of therapy is educating informal care partners on how to assist a patient in a variety of functional tasks (82). Speech therapists can help care partners understand the communicative intent of patients with dementia (43). Physical therapists may instruct care partners on safe transfers that minimize the risk of injury. In some cases, and where there is adequate space in the patient’s residence, introducing transfer aids may be useful. Therapists may also instruct family members on how to administer caregiver-mediated exercise as a means of increasing exercise volume (79). Of note, there are opportunities for care partners to be certified for competency; in certain settings, eg, Veterans Administration, care partners may receive financial compensation as part of the patient’s health care entitlements.

Community re-integration. Often, rehabilitation can have a higher-level goal of maximizing community participation. Driving is a primary means of transportation for many individuals, and loss of individual driving ability after neurologic conditions such as stroke can result in reduced health outcomes and lowered rates of community integration (77). Driving rehabilitation can be pursued to assess readiness to return to driving, maximize safe driving behaviors, or evaluate for assistive technology, such as hand controls for those with paraplegia due to spinal cord injury (18). Vocational rehabilitation (or occupational rehabilitation) focuses on overcoming barriers to access or to return to employment, school, or other useful occupation (10). Outpatient and vocational rehabilitation are best tightly interlinked in order to anticipate and address patients’ functional needs before and after they become obstacles to return to work (76).

Delivering effective rehabilitation. Successful rehabilitation is person- and family-centered, goal-oriented with meaningful outcomes, inter-professional, evidence-based, satisfying, and safe (81). Effective rehabilitation begins with the formation of a rehabilitation contract between patients and the rehabilitation team (59). Rehabilitation team structures are often multidisciplinary or interdisciplinary (37). In multidisciplinary teams, disciplines work together but stay largely within their own boundaries (12). In inter- and trans-disciplinary teams, representatives of different disciplines and professions overlap in their competencies, view patients’ success as a shared responsibility, and harmonize links between them to form a coordinated whole (12; 37). Data support that using such team models can result in better outcomes for a range of neurologic conditions (35; 63; 68). Inter-professional collaboration can also be effective when delivered remotely. Patient satisfaction was high for a tele-rehabilitation program that provided physical therapy, occupational therapy, and speech therapy within the same tele-rehabilitation visit (75). Although interdisciplinary team models are thought to have certain benefits over multidisciplinary models, they rely on effective communication between team members, which can require additional resources. Barriers to implementation of an interdisciplinary team include differences in members’ individual priorities and vocabularies (63).

Behavioral health and rehabilitation. Identification of behavioral health conditions related to neurologic disease is vital to maximize rehabilitation success. Suboptimal health behavior, depression, and other psychiatric symptoms are prevalent in many neurologic diseases but are often underrecognized and undertreated (58). Fostering resilience is a main goal of both the acute inpatient and long-term outpatient rehabilitation. This responsibility is to be shared by care partners, therapists, physicians, psychologists, dietitians, nurses, social workers, and others. Post-stroke depression is associated with multiple negative outcomes, including higher functional decline (52). Psychological distress has been shown to have an inverse relationship to functional improvement in post-stroke patients (32). A trial determined that treatment of post-stroke depression with either citalopram or cognitive behavioral therapy along with rehabilitation showed greater benefit in depression scales than rehabilitation alone (26).

Indications

Providers should have a low threshold to refer patients to outpatient rehabilitation services. Rehabilitation can be beneficial regardless of disease progression, whether it be slowly progressive, as in Parkinson disease, monophasic as in spinal cord trauma, or episodic as in multiple sclerosis with relapses. In most cases, rehabilitation can be initiated regardless of disease stage. Stroke is an exception; the VECTORS and AVERT trials showed poorer outcomes with very early rehabilitation after stroke (21).

Contraindications

Patients with chronic neurologic syndromes may have comorbid health conditions that limit strenuous physical activity. Formal exercise testing may be indicated in patients with heart failure, exertional dyspnea, chest pain, or known arrhythmias to identify safe parameters of rehabilitation therapy (30).

Patients with Parkinson disease or spinal cord injury often develop autonomic instability. This can manifest as orthostatic hypotension leading to drops in blood pressure on sitting upright or standing. Symptomatic orthostatic hypotension may limit a patient’s ability to safely participate in exercise, and consultation with the patient’s provider may be required prior to initiation of rehabilitation services. Slow initiation of activities, abdominal binders, and medication adjustment may be helpful.

Pregnancy itself is not a contraindication to outpatient physical therapy though prior consultation with an obstetrician should be considered; in such instances, modification may be necessary (03).

A relative contraindication is cognitive impairment, which may reduce significant rehabilitation benefit due to impaired learning. On the other hand, and as an example, care partner education regarding fall risk may benefit the patient with dementia.

Outcomes

Outcomes of outpatient rehabilitation therapies on Parkinson disease, stroke, and select other neurologic conditions are presented here. This list is not comprehensive, and the curious reader is encouraged to reference other relevant MedLink articles.

Parkinson disease. Positive rehabilitation outcomes can be achieved in Parkinson disease, the fastest growing neurologic condition in the world (23). The main goal of treatment is maintenance of mobility and physical function. One trial found that aerobic exercise is associated with changes in functional connectivity, cognitive control, and reduced brain atrophy (36). A variety of therapy modalities and programs are in use for Parkinson disease; however, data on the comparative effectiveness and long-term durability of these programs remain limited (23). One such popular program is the Lee Silverman Voice Treatment (LSVT LOUD^®) program, which seeks to increase vocal loudness and may improve the immediate and long-term sound pressure of patients with Parkinson disease (62). In contrast, the Lee Silverman Voice Treatment BIG (LSVT BIG^®) program focuses on increasing the amplitude and speed of movement and was associated with improved motor function on part III of the Unified Parkinson's Disease Rating Scale (UPDRS) (51). Enjoyable group exercises, such as noncontact boxing (“Rock Steady Boxing”), table tennis (“Ping Pong Parkinson”), and dancing, highlight the potential benefits of social engagement for Parkinson disease. Formal evidence for their functional benefits remains limited, though noncontact boxing is associated with higher quality of life (44; 71).

External cues during exercise training are particularly helpful for patients with Parkinson disease who have trouble initiating voluntary movement (60). Such cues can be visual (such as floor markings, or lasers attached to assistive devices), auditory, or tactile. A review by Rutz and Benninger concluded that visual and auditory cuing as well as supervised slackline training were effective in reducing freezing of gait and that these interventions could be combined (65).

Stroke. Rates of functional recovery, whether due to restorative or compensatory mechanisms, are highest in the first 3 months after stroke (47). Stroke is considered chronic after 6 months (29). It is possible that timing of therapy may influence therapy outcomes, but this is incompletely understood. The C-PASS trial suggested a critical period of heightened plasticity in the subacute phase of stroke (days 60 to 90 post-stroke), when a high volume of additional task-specific exercise above standard therapy may have an enhanced benefit (21).

Emerging data challenge the convention that restoration potential is limited in the chronic phase, particularly when therapy is paired with effective priming and augmenting agents (39). A network meta-analysis determined that, augmentation of task-specific training with NMES in subacute upper extremity motor stroke had effect at the end of the intervention and improved activities of daily living at follow-up (mean period of 2.89 months) (74). The VNS-REHAB trial demonstrated that vagus nerve stimulation to prime upper extremity task-specific therapy in chronic stroke was associated with higher rates of improvements of upper extremity function versus therapy alone (16). The role of the contralesional hemisphere in plasticity after stroke is increasingly recognized. The IpsiHand brain-computer interface pairs noninvasive EEG with exoskeleton-based augmentation during upper extremity therapy to upregulate plasticity of the uninjured, ipsilesional hemisphere in chronic stroke (64).

A Cochrane review found that speech therapy for post-stroke aphasia could improve functional communication, reading, writing, and expressive language (08). One specific speech therapy modality is intensive language-action therapy (ILAT), which focuses on constraint, embedded communication, and massed practice; ILAT may improve not just aphasia after stroke, but also post-stroke depression (40; 07).

Several studies highlight benefits of exercise for risk factors for recurrent stroke (09). A meta-analysis determined that aerobic exercise after stroke impacts systolic blood pressure and fasting glucose; this effect was comparable to combined strength training and aerobic exercise (09). Outpatient rehabilitation alone or following inpatient rehabilitation reduced the risk of recurrent vascular events, readmission, and mortality for an average of 32 months (11).

Other neurologic conditions. A Cochrane review determined that rehabilitation in multiple sclerosis can improve functional outcomes, such as mobility and aerobic capacity, and quality of life (01). As per a systematic review on diabetic peripheral neuropathy, exercise therapy was associated with not only improved gait speed and daily physical activity level, but also reduced neuropathic pain (33). Aerobic exercise in slowly progressive neuromuscular diseases was determined to be safe in one meta-analysis and led to moderate post-intervention improvement of aerobic capacity; however, long-term efficacy was not clear (57).

The benefits of an interprofessional approach on outcomes in other neurologic disorders have also been demonstrated. A systematic review of therapy in Huntington disease demonstrated improved motor function, gait speed, and balance along with improved quality of life (24). Functional neurologic disorder can be successfully treated with a combination of rehabilitation therapy and behavioral health therapy (04).