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CHAPTER 23  Multidisciplinary Assessment of Patients with Chronic Pain

characteristic patterns of referred pain 48,49 and that ex- perts in myofascial pain have proposed characteristic patterns of referred pain from affected muscles. Thus, it is sometimes possible to explain widespread symptoms as indications of referred pain. However, the drawing shown in Figure 23.2 does not lend itself to such an inter- pretation because it does not conform to any known pat- tern of referred pain from an intervertebral disk, a facet joint, a ligament, or a muscle in the cervical region. The most plausible interpretation of such widespread pain is that it is a manifestation of altered perception based on CNSS (described later) or psychological factors. It is important to evaluate risk factors for delayed recovery in a patient with chronic neck pain. Unfortunately, research on the validity of many potential indicators is lacking. Thus, the following list of indicators should be viewed as plausible candidates for consideration during the medical evaluation of a chronic pain patient rather than as proven predictors. Another caveat is that although some of the potential indi- cators refer to medical variables, others refer to psychosocial variables that might be evaluated better by a psychologist than by a physician. • Presence of a systemic disorder of the musculoskeletal system, such as rheumatoid arthritis or one of the mus- cular dystrophies • Presence of general medical conditions that influence prognosis. For example, if a patient has severe cardio- vascular disease, this may have implications for his or her ability to function in a physical therapy program. A patient who has had a stroke may have difficulty following medical directions. • History of prior spinal injuries or of significant prior symptoms in the absence of injury • Evidence of severe spondylosis • High pain intensity • Severe functional limitations on examination • Chemical dependency. The patient’s history in this do- main is important because it may bear on the appropri- ateness of prescribing opioids or sedatives. • Sleep disturbance. Disturbed sleep is a common symp- tom reported by chronic pain patients, and most clini- cians who treat these patients accept the premise that disordered sleep plays a role in perpetuating symptoms and disability. 50 Thus, if a patient reports significantly disturbed sleep, a treatment plan for him or her should include interventions to promote normalization of sleep. • Evidence of severe emotional distress • Disability and litigation issues SPECIFIC EVALUATION PROCEDURES The physician should gather at least some information on most or all of the issues outlined earlier. For factors that are not bio- medical, it is important for the physician to at least identify areas of concern, so that follow-up evaluations can be provided by the appropriate specialists. Broadly speaking, the informa- tion will come from three sources: the patient’s history, the physical examination, and ancillary studies. History It is beyond the scope of this chapter to discuss the elements of a thorough history. It is worth noting, though, that in eval- uating a chronic pain patient, the physician should pay careful attention to certain historical items that are considered only cursorily in other clinical settings. In particular, the physician should be careful to assess the patient’s history with respect to ARE THERE RISK FACTORS FOR DELAYED RECOVERY?

chemical dependency, sleep disturbance, apparent severity of incapacitation, and his or her status with respect to litigation and compensation. Physical Examination A neurologic and musculoskeletal examination should be per- formed on all patients with chronic cervical spine pain. In a patient with a normal neurologic examination, a musculoskel- etal evaluation of the neck (including assessment of soft tissue hypersensitivity and range of motion) is often not especially revealing. 19 In particular, it is virtually impossible to identify a distinct pain generator on the basis of a physical examination of such patients. But some useful information can be gleaned from a musculoskeletal examination. First, the physician can determine the severity of the patient’s functional limitations, es- pecially restricted motion of the spine and pain-inhibited weak- ness of neck and extremity muscles. Second, the physician can check for hyperalgesia over muscles of the neck and shoulder girdle as well as more widespread hyperalgesia involving re- mote sites. Third, the physician can determine whether the pa- tient demonstrates significant apprehension and “nonorganic signs.” 51,52 Research indicates that patients with nonorganic signs usually have significant somatic anxiety. This emotional distress may impair their recoveries and may be a focus of treatment. One caution about physical examination concerns the re- liability of the assessment of factors such as range of motion. Evidence suggests that the interrater reliability of commonly performed physical examination tests is limited, 53,54 and thus, it is important to determine whether findings on a single exam- ination are consistent with a patient’s history, previous exam- ination findings, and diagnostic tests. Ancillary Studies Although laboratory studies and electrodiagnostic evaluations are occasionally helpful in the assessment of patients with chronic neck pain, imaging studies are the procedures that are done the most frequently. There is significant controversy about how and when imaging should be done on chronic pain patients. When judged against guidelines, one-third to two- thirds of spinal CT and MRI imaging may be inappropriate. 55,56 High imaging rates can be problematic because irrelevant but alarming findings, including herniated disks, are common in asymptomatic people. 2,57 Without attempting to resolve these controversies in any systematic way, we suggest the following: (1) for pain involving a trauma, it is reasonable to check for the possibility of a fracture or significant spinal instability using plain x-rays of the spine; (2) additional imaging is generally not needed for such a patient, unless there is clinical evidence of a neurologic injury. In that case, an MRI scan is generally indi- cated; and (3) CT scans and bone scans usually have a limited role—they can be obtained to identify an occult fracture or an inflamed facet joint. Another type of diagnostic test for patients with chronic neck pain is one that uses local anesthetic blocks of structures thought to be the pain generators. The logic underlying this approach is that if a patient reports dramatic relief following a local anesthetic injection of a structure in his or her neck, it is reasonable to assume that the structure is functioning as a pain generator for the patient. The most widely used procedures of this kind are nerve root blocks, medial branch blocks, and dis- cography. As discussed earlier, there is controversy about how valuable local anesthetic blocks are in the diagnosis of patients with chronic neck pain. We believe that nerve root blocks can play an important role in identifying the structural basis of ra- dicular symptoms and are often used to guide surgical decision making. We believe that medial branch blocks should be used selectively but can be helpful in the management of patients