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6 Advanced skillfulness in clinical practice: The big challenges

Perhaps the biggest challenge in pain care is recognizing a pain problem when it presents in a manner that is atypical. Because common pain‐associated conditions sometimes present in atypical ways and uncommon pain‐associated conditions drive surprisingly more healthcare utilization than might otherwise reflect their prevalence, diagnostic challenges in pain medicine are not uncommon.

Pattern recognition is a diagnostic method commonly employed by experts, for this reason, and because pain‐conditions often have characteristic “patterns,” it is very helpful to learn some of the major pain patterns (Figure 6.1). Some are “referred pain patterns.” A referral pattern is the perception of pain in one part of the body in response to nociceptive signaling in another part. Referred pain characteristically results in pain being perceived in an unharmed part of the body. This can present a diagnostic challenge. A classic example is cardiac pain referring to the left arm or jaw. Another classic pattern is the association of foot, ankle, or leg pain with disease of the lumbar spine. This may be unknown to the public but should be known to healthcare providers. What is less well appreciated is that each major system in the body, including viscera, muscles, bones, as well as nerves, has a characteristic referral pattern. Other classic examples include the referral of pancreatic pain to the mid‐back; and renal pain to the flank or scrotum. Intriguingly, esophageal pain is generally well localized, whereas injury to the uterine cervix produces diffuse pelvic pain. Collectively, the referral patterns of pain perceived from visceral ailments is called the “viscerotome.” Less well known are the patterns of myotomes (muscle pain‐referral patterns) and sclerotomes (bone pain‐referral patterns) (Bähr and Frotscher 1998). Thus, an important challenge in pain medicine is recognizing the diverse presentations of pain‐associated conditions. Often so‐called “non‐anatomical” pain has a biological basis; it simply has not been recognized by the provider. The pictures in Figure 6.1, illustrate some examples of different, anatomical, pain patterns: dermatomes, viscerotomes, myotomes, sclerotomes, diffuse neuropathy, and named nerve patterns. But this catalogue of pain patterns is not exhaustive: still other patterns will be seen with conditions of vascular ischemia or specific pain syndromes such as migraine and chronic regional pain syndrome. Finally, local space occupying lesions can produce bizarre patterns of pain perception, as can neuropathic diseases like multiple sclerosis, transverse myelitis, chronic regional pain syndrome (CPRS), and peripheral neuropathy.

Figure 6.1 Pain patterns, examples. Pain can present with many different patterns, recognizing these is helpful to guiding diagnosis and treatment.

Another critical challenge in pain is: what the pain feels like, known as qualitative features or internal experience (Figure 6.2). In this respect, neuropathic pain is the great imitator of modern pain medicine. It is possible for an injured nerve to reproduce a wide variety of ordinary perceptions: burning, cold, and stabbing, as well as produce sensations that are completely bizarre: searing cold, painful numbness, swollen dullness, tingling cascades running down the back, crawling “ants” underneath the skin, and shocking pain so strong it causes the leg to buckle. All of these sensations may arise as the result of nerve damage or dysfunction in a person who, though perhaps somatically‐focused, is not otherwise prone to thought disorders or delusions. The distress that a person experiences in trying to describe these troubling sensations, or obtain validation within the context of the medical model, is quite real and reasonable.

Figure 6.2 Qualities of pain, examples.

The temporal course of pain is another major challenge in bridging the gap between patient and provider. Sometimes, a person seems to take “too long” to recover from a procedure or trauma. Other times pain seems to flair when stress levels are elevated. At times, we risk labeling a stressed “slow healer” as a person with “chronic pain.” Other times, there is an unrecognized trigger which prompts pain to come and go. One potential cause of profound, intermittent, low back pain is spondylolisthesis. In this disorder, there is an instability of one or more vertebrae. The “typical” experience is terrific pain after arising from being seated on a low support, sometimes getting up from a toilet is the culprit and the patient may be embarrassed. The chronically traumatized disc can become super‐sensitized through the ingrowth of pain‐sensitive (nociceptive) nerve endings making the pain seem atypical (Stefanakis et al. 2012). Skilled physical therapy, chiropractic, analgesia and core muscle strengthening can help reduce minor to moderate spondylolistheses, more severe instabilities may require surgery. Visceral pain‐associated syndromes, e.g. pancreatic, inflammatory bowel disease, and cystitis, are also characterized by a waxing and waning course.

A final challenge is the need to access reliable unbiased information about pain medicine diagnoses and treatments. Typically, little time is spent in clinical training on pain. As of 2009, most US medical schools taught only four hours of pain content over four years, this despite the fact that nearly half of patients presenting for medical care have pain of one form or another (Mezei et al. 2011). Not infrequently, providers have trouble determining what's wrong with a “pain patient,” because they were not adequately taught to recognize the problem the patient is describing. Exceptions are that osteopathic medical and physical therapy schools offer advanced training in musculoskeletal disorders and fellowship pain training is often excellent but may be focused on procedural management (Watt‐Watson et al. 2009). For many, collaborative interprofessional care is essential. Reliable resources include Biomed plus for patient‐oriented information, UpToDate online, or any of the standard textbooks of pain medicine (Fishman et al. 2009; McMahon et al. 2013; Warfield et al. 2016). Neuromuscular conditions are well characterized online (Pestronk 2017). In short, it is important to learn about common pain‐associated conditions and create a differential diagnosis to guide evaluation and treatment strategies.

References

1 Bähr, M. and Frotscher, M. (1998). Duus’ Topical Diagnosis in Neurology: Anatomy, Physiology, Signs, Symptoms, 5e. Stuttgart, New York: Thieme.

2 Fishman, S.M., Ballantyne, J.C., and Rathmell, J.P. (2009). Bonica’s Management of Pain (Fishman, Bonica’s Pain Management), 4e. Philadelphia: LWW.

3 McMahon, S., Koltzenburg, M., Tracey, I., and Turk, D. (eds.) (2013). Wall and Melzack’s Textbook of Pain, 6e. Philadelphia, PA: Elsevier Saunders.

4 Mezei, L., Murinson, B.B., and Johns Hopkins Pain Curriculum Development Team (2011). Pain education in North American medical schools. The Journal of Pain 12 (12): 1199–1208.

5 Pestronk A (2017) (Ed.). Washington University St. Louis Neuromuscular Disease Center. http://neuromuscular.wustl.edu/ (accessed 18 December 2017).

6 Stefanakis, M., Al‐Abbasi, M., Harding, I. et al. (2012). Annulus fissures are mechanically and chemically conducive to the ingrowth of nerves and blood vessels. Spine 37 (22): 1883–1891.

7 Warfield, C.A., Bajwa, Z.H., and Wootton, R.J. (2016). Principles and Practice of Pain Medicine, 3e. New York: McGraw‐Hill Education/Medical.

8 Watt‐Watson, J., McGillion, M., Hunter, J. et al. (2009). A survey of prelicensure pain curricula in health science faculties in Canadian universities. Pain Research & Management 14 (6): 439–444.