By Melanie Swan, OTR/L
The Pain Practitioner. Fall 2007
Neuropathic pain is characterized by a dysfunction or disease within the peripheral or central nervous system. It involves damage to nerve tissue, typically from injury or metabolic dysfunction, leading to pain that is more intense and complex than usual for the injury and that usually persists beyond the healing time of the involved tissue. Typical symptoms of neuropathic pain include burning, tingling, numbness, electric shock or shooting pain, and allodynia.
There are several different categories of neuropathic pain:
- Neuropathy: peripheral neuropathy (related to conditions such as diabetes or alcoholism) or entrapment/compressive neuropathy (such as carpal tunnel, cubital tunnel, radiculopathy, thoracic outlet)
- Neuralgia: post-herpetic neuralgia (experienced after an onset of shingles) or trigeminal neuralgia (often known as atypical fascial pain)
- Neuroma: a mass of neural tissue and scar after an injury, such as an amputation, or a tumor within the nervous system, that can be benign or malignant
- Myelopathy: damage to the spinal cord as a result of compression or degeneration of the spine
- Complex Regional Pain Syndrome (CRPS), also known as Reflex Sympathetic Dystrophy (RSD) or causalgia
- Phantom limb pain
Most physical and occupational therapists are introduced to the pathophysiology and treatment of myelopathy, neuropathy, and neuroma during their clinical education process. Clinicians are also generally exposed to phantom limb pain, neuroma, and CRPS. However, few clinicians enter their practice with a strong repertoire of treatment approaches for CRPS.
CRPS: A Mysterious Condition
Complex Regional Pain Syndrome (CRPS) is often seen (by patients and practitioners alike) as a perplexing condition of unknown or unclear etiology. The onset of CRPS is frequently associated with trauma or nerve damage, but can also occur without previous injury or illness. Diagnosis is based on clinical signs and symptoms, and supported by diagnostic work. However, there are currently no diagnostics that clearly or objectively indicate absence or presence of CRPS.
Despite technical explanations from physicians, patients often do not fully understand their diagnosis of CRPS. Vast amounts of information are available via the internet, but the content and quality vary greatly. Patients who find articles related to a particular course of treatment may require explanation. Or, patients may read accounts of fellow CRPS patients who report becoming debilitated by their symptoms or who allege that ineffective medical management of their symptoms resulted in CRPS spreading to other areas of their bodies. Some patients become wary of healthcare providers after multiple encounters that have not improved their pain relief or function. All these experiences can fuel patient anxiety, particularly for those recently diagnosed.
Much of the confusion surrounding CRPS stems from the array of treatment approaches associated with the condition and the limited awareness of CRPS among the general population. Many healthcare providers have some exposure to assessing or treating CRPS, but a smaller number have extensive experience in these areas. Much of the literature written on CRPS is confusing or contradictory and studies showing promising treatment results often do not hold up under randomized controlled trials. This can lead patients to have little confidence that one approach will be more effective than another. To add to the confusion, symptoms of CRPS are variable and patients may experience different symptoms at different stages in the syndrome.
The most common symptom of CRPS is unremitting pain or sensitivity that is more severe or lasts longer than the anticipated recovery time for the associated injury or illness. Other common symptoms include unusual or prolonged swelling and a feeling of burning or extreme coldness in the affected area. In addition, changes in physical appearance may become more obvious as the condition progresses. The skin over the affected area may thicken, may become tight or shiny in appearance, or may change color (presenting as bluish, purple, or mottled) as circulation to the area changes. There may be abnormal hair growth (darker, coarser in texture) to part or all of the affected area, as well as abnormal nail growth (thick, yellowed, ridged) resulting in even greater fear about the condition.
As the condition progresses, many patients begin to dissociate from their affected extremity, as if it no longer belongs to them. They may be self-conscious about the changes in physical appearance or unsure how to explain their condition to others when they don’t fully understand it themselves. Unremitting pain increases underlying fear and anxiety of a more malicious, yet undiagnosed, disease process. This often results in increased guarding and disuse of the area. Hypersensitivity may lead patients to cover the affected extremity entirely to protect it from accidental touch or changes in temperature.
Diagnosis and Treatment
Physicians vary in their initial approach to diagnosis and treatment of CRPS. Though recent efforts to establish validated diagnostic criteria are underway, there is still sufficient ambiguity with clinical signs causing concern for over- or under-diagnosis of the condition. Once a clinical diagnosis has been made, physicians often initiate medication management or an interventional approach to address the associated symptoms. Many utilize a combination of approaches to interrupt the pain cycle and promote the return of function to the area.
Frequently, they will want to refer patients to physical or occupational therapists who will aide in maximizing functional outcomes. Then the hunt is on to locate a therapist familiar or experienced with treatment of CRPS.
Therapists less familiar with CRPS may not understand the subtle differences in treating CRPS versus similar symptoms associated with other conditions. Some interventions for edema management and range of motion limitations can result in a flare up or exacerbation of symptoms, thereby increasing patients’ fear or anxiety and decreasing their confidence in the skills of the therapist. However, clinicians with limited experience in treating CRPS can still be effective in guiding their patients toward more functional outcomes by networking with more experienced clinicians.
A combination of treatments is often most effective in restoring function to the affected area and education is key to developing patient trust. Assessment of the affected area can be challenging due to the intensity of the pain and hands-on or objective measures may be limited by guarding. For physical or occupational therapists, evaluation should include a thorough visual inspection of the area, noting changes in appearance, muscle atrophy, abnormal movement patterns, and posturing. Ideally, measurements for edema and active range of motion should also be taken.
At the initial session, however, it may be more important to explain and educate the patient about CRPS and the evaluation and treatment process in order to establish rapport. Evaluation at this session may be limited to gross assessment of active range of motion and functional movement, while noting restrictions in movement due to guarding or edema. More formal evaluation measures for range of motion, coordination, strength, and edema can be taken at a subsequent session. It is also important to listen to how patients talk about their affected areas in order to better understand how they feel about themselves and their condition. This can be very useful in planning meaningful treatment activities and anticipating response to intervention (eg reluctance, fear, anxiety, or indifference).
Continuous education and positive reinforcement are critical to facilitate success with treatment. Equally important is helping patients identify or reframe what they consider to be a successful outcome. Is success defined by less pain regardless of improvement in function or is success defined by greater function without an increase in pain? Is success the return of a more normal physical appearance?
In addition, patients need to understand how the pain cycle that is occurring within their bodies is an abnormal pain response to sensations or stimuli that are not traditionally painful. As a clinician, you can facilitate better understanding of this by having patients apply a non-painful stimulus to a non-affected area and then to the affected area. This will demonstrate that an increase in pain is not necessarily an accurate indication of injury or harm. Ongoing education regarding expected responses to treatment is critical in maintaining trust, especially when increased pain or swelling may be a result of interventions.
It’s important for patients to understand and embrace their role in the recovery process. The therapist can coach, mentor, and design treatment, but if patients are unable or unwilling to follow through with regular participation in treatment exercises and activities outside of designated therapy sessions, the results will be minimal. Empowering patients to understand their condition and take control of treatment minimizes apprehension and builds rapport. The more actively patients participate in treatment planning and the more compliant they are with individualized home programs, the greater the chance they will regain function and manage pain. Engaging in or working toward functional activities that are most meaningful to patients can help them overcome fear of movement and distract them from the pain associated with the activity.
The stress loading protocol, published by Carlson and Watson, can be an effective tool for treatment and management of CRPS. Stress loading is comprised of two components: scrubbing and carrying. Each component engages the affected extremity in consistent weight bearing activities within a small range of movement for gradually increasing periods of time. These activities “load” the affected joints or extremity. This, in turn, provides inhibitory proprioceptive input to the nervous system, through the use of deep pressure. The key to stress loading is providing as much force or weight bearing as can be consistently tolerated during scrubbing and carrying, gradually increasing the frequency and duration of these activities throughout the day. Loading the affected area to tolerance and gradually increasing the frequency and duration of weight bearing activities enables the nervous system to acclimate to these stimuli. This acclimation progressively desensitizes the heightened pain response and allows the nervous system to “remodel” itself; the nervous system shifts from recognizing the stimulus presented as threatening, to accepting it as a normal sensation once again.
Scrubbing applies constant force through the affected area for progressively increasing periods of time without a break. Scrubbing for the upper extremity may be done with a towel or a hand-held scrub brush. The towel or brush is moved back and forth against a solid surface, as if scrubbing a stubborn stain off that surface. Scrubbing for the lower extremity may be done wearing a sock or by adding a strap to a deck brush to secure it to the foot. The sock foot or scrub brush is then moved back and forth against the floor from a standing or seated position. In order for scrubbing to have the maximum effect, consistent pressure must be maintained while moving the brush in both directions and the weight bearing as tolerated. The initial protocol for scrubbing calls for three minute scrubbing sessions, three times per day, gradually increasing in frequency and duration over a period of days or weeks, until ten to fifteen minutes of scrubbing can be tolerated at least three times per day.
Carrying involves toting a weighted object for increasing periods of time with the affected extremity or on the affected side, in order to provide “loading” to the area. Carrying weighted objects in a handled bag or briefcase is effective for the upper extremity. Walking and weight shifting can be an effective means of loading for the lower extremity. Creativity in treatment design can facilitate longer periods of carrying and distract from the painful task at hand (or foot!). Otherwise, inconsistent participation or frequent breaks during these activities can result in increased pain and lead to greater disuse of the affected area.
Desensitization techniques can be used to decrease hypersensitivity to cutaneous stimuli. Various textures or fabrics can be presented to the area, progressing from least noxious to most noxious, and consistent to intermittent application, to improve tolerance to light touch or pressure. The process may take several weeks or months to achieve tolerance of all stimuli. Desensitization to a particular texture or fabric may not mean that the stimulus that previously invoked pain now feels good. Desensitization typically enables a stimulus to be tolerated for longer periods with a lower pain response.
Success with desensitization may enable patients to be more flexible with choice of clothing items or to tolerate various bed linens during sleep. Temperature desensitization can be achieved by gradually varying air or water temperature to challenge tolerance to warm or cold. As with stress loading, these techniques should be performed for gradually increasing periods of time without a break.
Edema should be addressed with edema management garments (such as Isotonerâ gloves, Jobstâ garments, or Cobanâ wrap) and active range of motion. Passive retrograde massage and passive range of motion should be avoided initially as they can stimulate an inflammatory response resulting in greater pain and swelling, jeopardizing the trust between the patient and practitioner. Splinting may be necessary in severe cases of CRPS to maintain joint integrity and promote adequate circulation and nutrition to the tissues. However, once patients are able to achieve some pain management with a medication regiment and the use of stress loading and desensitization techniques, they can often actively engage in range of motion activities that promote improved circulation, increased movement and decreased swelling, thus minimizing or eliminating the need for edema management garments or splinting.
Active range of motion activities should be geared toward improving function with the affected hand, such as drinking from a cup, turning a doorknob, or using a knife. With the affected leg, activities can include pushing off for reciprocal stair climbing or fast walking. As guarding is decreased or eliminated and range of motion is restored, initiate strengthening. Education remains critical at this stage to guide the patients to appropriately dose and progress their rehabilitation programs and avoid “over-doing it.” Continued support and reinforcement gives patients the confidence to challenge themselves consistently throughout the day. Finding the balance between enough and too much can enable patients to successfully resume activities in all areas of life: occupation, home, self, leisure, and community. Additional pain management techniques, such as biofeedback or relaxation and distraction, can also be useful in pacing activities and modulating pain response.
A comprehensive approach to CRPS treatment can facilitate restoration of function by empowering patients to manage their pain and understand their condition. Patients are able to stay motivated for treatment when they can maintain control of their own progress through collaboration with their therapists, when it comes to how much and how frequently to challenge their “comfort” zone to achieve their goals.
Melanie Swan, OTR/L is an occupational therapist and the former Clinical Manager of the Rehabilitation Institute of Chicago Chronic Pain Care Center. Her focus is on improving special functions related to work, home, and leisure. She has been a contributor to the RSDSA Review since January 2004 and is affiliated with the American Occupational Therapy Association and the Illinois Occupational Therapy Association.
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