17 Physical Medicine in the Treatment of Pain
The Massachusetts General Hospital Handbook of Pain Management
Physical Medicine in the Treatment of Pain
Joseph F. Audette
What is needed most in architecture today is the very thing that is needed most in life—integrity. Just as it is needed in a human being, so integrity is the deepest quality in a building. . . . Integrity is not something to be put on and taken off like a garment. Integrity is a quality within and of the man himself. . . . It cannot be changed by any other person either, nor by the exterior pressures of any outward circumstances; integrity cannot change except from within because it is that in you which is you—and due to which you will try to live your life. . .in the best possible way. To build a man or building from within is always difficult.
—From The Natural House, Frank Lloyd Wright (1954)
I. Physiatric assessment
2. Physical examination
II. Physiatric treatment of pain
1. Physical and occupation therapy referral
2. Therapeutic injections
3. Pharmacologic management
III. Physiatric assessment and treatment of specific pain syndromes
1. Back and neck pain
2. Myofascial pain
Physical medicine and rehabilitation (PM&R) is one of the medical specialties that evaluates and treats patients with chronic pain conditions. The primary focus of the physiatrist’s treatment approach is to restore structural integrity and maximize function rather than focusing solely on eliminating pain. To initiate a successful treatment plan, the physical and psychological obstacles to functional normalization must be identified and treated with the same aggressiveness that would be used to identify and treat the cause of nociception. As a corollary, the extent to which our patients have learned to be passive in the face of their chronic condition is a vitally important part of the chronic pain syndrome. Through this approach, we are able to help patients regain an internal locus of control in order to become active in the rehabilitation of their painful condition.
PM&R referrals should be made when a determination of a patient’s residual functional capacity and potential for further functional restoration is needed. In particular, pain conditions with an industrial or work-related cause are often best treated with such a functional focus. In addition, physiatrists typically work in a team with physical and occupational therapists, mental health providers, and others to manage complex pain patients in an interdisciplinary setting.
I. PHYSIATRIC ASSESSMENT
In addition to obtaining a standard medical and surgical history, the physiatrist gives special attention to determining the extent to which these historical factors may have an impact on future function. For example, the fact that a patient has had multiple prior surgical or other procedures may indicate a poor prognosis. This can suggest passive participation in the therapeutic process and dependence on multiple external sources for a “cure” despite repeated failures.
Internal fixation with hardware or implantation of devices such as pumps or stimulators may have a structural impact on rehabilitation. In the vast majority of cases, however, erroneous, limiting beliefs about the functional implications of the hardware or devices should be explored with the patient and eliminated. For instance, a history of spinal fusion does not mean a patient is permanently disabled.
The way a patient takes medication is just as important as what they take. Frequent use of short-acting analgesics can indicate an overdependence on medications and poorly developed internal resources to cope with normal fluctuations in pain intensity. Determine if nonpharmacologic approaches for pain management such as distraction, relaxation, ice, heat, and stretching are used.
Assess whether analgesics are being used to treat emotional distress more than nociception. Does the patient do more if he or she is in less pain?
Psychosocial issues relevant to a detailed pain assessment are discussed elsewhere (see Chapter 15). Two especially important issues to elucidate are (a) a family history of disability (which can be a negative prognostic indicator), and (b) readiness to change (the patient’s comfort with the current level of disability is revealing; ongoing litigation can interfere with a patient’s readiness to change).
History of prior and present function
An accurate assessment of a patient’s functional status can be difficult to acquire in a medical interview. Ask specifically “What can’t you do?” rather than “What can you do?” Determining the level of function prior to the onset of the pain syndrome helps set the goals of treatment. Do not assume that, just because other physicians, including surgeons, have reinforced the patient’s disability, they are correct. Numerous studies have shown that even after spinal surgery, patients can return to their former work capacity if motivated to do so.
History of prior treatments
The nature of prior physical rehabilitation should be determined. There are two broad categories: passive, or modality- and handson-driven treatments, and active, or patient-participation-driven treatments. If patients have failed an active rehabilitation program, it is important to determine the cause. Fear of increased pain during treatment or belief that they are at risk for harm with movement requires active psychological treatment in conjunction with continued active therapy. Some increase in pain, initially, is unavoidable in rehabilitation. Appropriate use of therapeutic injections and medications can ameliorate this.
2. Physical examination
Pain, and in particular chronic pain, causes significant alteration in body mechanics and can lead to pain perpetuation and continued disability despite appropriate treatment of the principal nociceptor involved. Addressing these structural factors and the resultant biomechanical perpetuators of pain and disability are a critical part of a comprehensive treatment plan.
GAIT. Antalgic gaits are common with chronic pain. Use of assistive devices, except in the elderly, is usually a sign of illness behavior and is rarely necessary for safety.
A compensated Trendelenburg gait is a sign of hip abductor weakness, caused either by true neurologic weakness (rare) or by reflex inhibition of the hip abductor as a result of sacroiliac (SI) joint dysfunction or hip joint disease.
SPINE. Congenital scoliosis can be distinguished from a functional or acquired scoliosis by forward flexion of the spine, bringing out the rotatory component of congenital scoliosis (the Adams test).
Apparent short leg syndrome (ASLS), best seen with patient lying supine, is caused by muscle shortening of the hip rotators such as the gluteus medius and piriformis, and it is commonly associated with SI joint dysfunction. The short leg in this syndrome is more externally rotated while supine because of the contraction of the hip external rotators. Use of a lift in the shoe is contraindicated, as it could exacerbate the problem.
Thoracic kyphosis with a thrust-forward head, extended cervical spine, and internally rotated shoulders is common with pain syndromes of the mid back, head, and neck. This puts the patient at risk for myofascial pain and muscular nerve entrapment syndromes at the occipitocervical junction and the anatomic thoracic inlet.
II. PHYSIATRIC TREATMENT OF PAIN
1. Physical and occupational therapy referral
The type of physical therapy referral depends on the conditions found in the assessment phase of the evaluation. This topic is discussed in further detail in Chapter 16. Brief guidelines for establishing physical therapy should include determination of any contraindications or limitations to a full functional restoration treatment plan. Special consideration is warranted if there is a cardiopulmonary impairment that may impact therapeutic conditioning and medication trials. Severe psychological or motivational impairments should be identified and treated by mental health professionals before any pain rehabilitation is initiated.
Referral options should be considered for patients with chronic pain who exhibit the following characteristics:
a) Chronic pain with moderate functional limitations but without major psychological impairments
If motivational issues are not predominant, and there are no return-to-work issues, refer the patient to physical therapy, with goals of correcting structural deviations seen on examination, improving strength, and increasing aerobic conditioning. Emphasize an active program rather than a passive, modality-based treatment. Desensitization techniques, including transcutaneous electrical nerve stimulation (TENS), thermal modalities, and selfmassage, can be taught.
If motivational issues are more predominant or there are return-to-work issues, refer the patient to a quota-based rehabilitation program (Table 1).
Table 1. Goals of quota base system
b) Chronic pain with major functional and psychological impairments.
Refer the patient to a multidisciplinary functional restoration program. This treatment team is more robust, usually involving medical, psychological, and rehabilitative (both physical therapy and occupational therapy) services. Treatment is still goal based but can be more individualized and is not limited to treatment of spine pathology (Table 2).
Table 2. Details of services offered in functional restoration program
Occupational therapy referrals can be useful when work dynamic issues are influencing the pain. Ergonomic factors can be assessed and corrected, and issues of pacing and functional adaptations to various tasks can be addressed. Upper extremity pain and cervical pain with headaches are special areas of expertise of occupational therapy, which can complement a good physical therapy program.
2. Therapeutic injections
When used by a physiatrist, an invasive technique (see Chapter 12) is never the sole method of treatment for a painful condition but rather an adjunct to allow better participation of the patient in the process of functional restoration. Many physiatrists have training in spinal injections as well as other techniques such as joint injections for the knee, shoulder, ankle, wrist, and digits (Table 3).
Table 3. Common sites of injectiona
Injection techniques for myofascial pain vary widely. Typically, a 25- to 27-gauge needle 1½ to 2 inches long is adequate. The local anesthetic varies, but generally 0.5 to 10 mL of either 0.5% to 1% lidocaine or 0.25% bupivacaine is used, depending on the size of the muscle and the technique used. Dry needling either with a standard needle (as just described) or with an acupuncture needle (32 to 34 gauge) is also effective.
Botulinum toxin (Botox or Myobloc) injections into trigger points are being studied in many centers. Botulinum toxin binds irreversibly to the presynaptic motor endplate and prevents the release of acetylcholine, leading to chemical denervation. This technique essentially inactivates the muscle for up to 2 to 4 months. Some people advocate its use in myofascial trigger point injections, using anywhere from 20 to 100 units (Botox) depending on muscle size.
3. Pharmacologic management
Certain patients with chronic pain are unlikely to benefit greatly from invasive measures. In these cases, the appropriate use of medication can help achieve the functional goals of rehabilitation. The goals of medication are to restore sleep, to modulate pain without causing excessive dependence or dysfunction, and to stabilize mood. Often, psychopharmacologic assessment is needed to optimize treatment. In general, short-acting opioids (see Chapter 9) are avoided so that the patient recognizes the value of nonpharmacologic approaches to managing pain.
III. PHYSIATRIC ASSESSMENT AND TREATMENT OF SPECIFIC PAIN SYNDROMES
1. Back and neck pain
Spinal pain syndromes are among the most common presenting problems in pain clinics and can be complicated by issues of secondary gain and excessive illness behavior (Table 4). The Waddell signs are not evidence of malingering but rather signs of disease affirmation, conviction, and psychological distress.
Table 4. Characteristics of abnormal illness behavior
CERVICAL FACET SYNDROME. Often associated with trigger points in specific zones of occipital region (C2-3), neck (C4-5, C5-6), and scapular region (C6-7, T1-2, T2-3, and down). Positive local pain with Spurling test (extension and rotation of neck with compression).
LUMBAR FACET SYNDROME. Increased pain with extension, less with flexion, or increased pain with extension together with rotation. Occasional referred pain to buttocks and anterior thigh.
SI JOINT DYSFUNCTION. Pain can radiate to groin or in sciatic nerve distribution. Lying supine, patient may have shortened and externally rotated leg. Pain on palpation over the joint when lying prone.
2. Myofascial pain
Myofascial pain syndrome (MPS) can mimic a number of clinical conditions, making diagnosis by history alone difficult (Table 5). Physical examination of myofascial trigger points should include more than identification of point tenderness over a muscle, which can be seen in many conditions (e.g., myositis, polymyalgia rheumatica, fibromyalgia, muscle spasm, and focal dystonias). Spot tenderness, the presence of a taut band, and pain recognition by the patient are the most reliable indicators.
Table 5. Clinical presentation of myofascial pain
Successful treatment demands an identification of the underlying cause. This can include anything from overuse syndromes, to prolonged structural deviations in body mechanics, to facet syndrome and underlying radiculopathies. Initial treatment should not be directed at the trigger point but at the identified cause, either with appropriate rehabilitation or injections. If there continues to be local muscle irritability, trigger point injections will have a sustained effect. Low-dose tricyclic antidepressants are particularly useful to correct associated sleep disorders and modulate the pain. Once adequate release of muscle tension is achieved, an aggressive strengthening program should be initiated to harden the muscle.
Fibromyalgia can be distinguished from MPS by the diffuseness of the tender points that may or may not be trigger points. These points are symmetrically distributed and affect both upper and lower parts of the body in fibromyalgia but not in MPS. In addition, historical factors, such as sleep disturbance, depression, chronic fatigue, irritable bowel, dysmenorrhea, cystitis, and chronic sinusitis, are more commonly found in fibromyalgia. Fibromyalgia is a systemic not a localized disease.
Treatment should focus exclusively on functional restoration, as pain elimination is generally not possible. Use of both low-dose tricyclic antidepressants at night and the newer antidepressants such as the serotonin uptake inhibitors during the day may be helpful. Pharmacologic treatment should be combined with skilled relaxation training and other cognitive and behavioral techniques to modulate pain. Although the use of opioids in fibromyalgia has some proponents, in general there is a risk of poor functional outcome and worsening depression and fatigue.
Physical rehabilitation should focus on flexibility and conditioning rather than aggressive strengthening to avoid pain exacerbation. Invasive procedures should be avoided unless there is a comorbid condition such as a radiculopathy or joint effusion that would have a reasonable probability of responding.
Physiatrists have a very broad understanding of the physical and psychological factors contributing to pain and are therefore in a strong position to evaluate pain patients, to determine if specialist treatment is indicated, and to treat patients whose pain is not amenable to, or has been failed by, other specialist treatment. Their role and that of physical treatments in the management of chronic pain patients are invaluable.
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