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.
7 Cognitive factors that influence pain
There are many cognitive influences on pain; some of these lessen pain while others increase it. Several cognitive influences are modifiable and have clinical utility in treating pain. Selected cognitive influences on pain are outlined here.
Cognitive influences that increase pain:
Catastrophizing. Catastrophizing describes maladaptive cognitive patterns in response to challenges, especially: imagining a symptom means something ominous (magnification), focusing on a problem (rumination), and feeling unable to resolve a problem (helplessness). Catastrophizing about pain can amplify pain intensity and suffering and is associated with poorer long‐term outcomes (Quartana et al. 2009). Originally conceptualized by Ellis, catastrophizing has had a great impact on pain research however, large‐scale studies are generally needed to show statistical significance. Clinically, effects of catastrophizing on pain are moderate. Cognitive behavioral therapy can help patients shift negative cognitions and replace defeating “self‐talk” with more positive messages, it is not known whether single interventions are effective, or whether physicians can administer brief interventions (Turk 2003). For patients with chronic pain who catastrophize, clinical psychological evaluation is indicated.
Anxiety. Anxiety facilitates pain perception. The mechanisms of this are not fully established but one study induced acute pain‐associated anxiety which produced increased experimental pain (Rainville et al. 2005). Chronic anxiety is also associated with increased pain in a clinical setting. It is important for healthcare environments to reduce anxiety where possible and ideally providers will create therapeutic relationships sensitive to patients' anxieties. Measures including: reduced jargon, shared decision‐making, and utilizing web interfaces and videos to explain procedures in advance can help reduce anxieties. When anxiety is excessive, it is treated with medication and psychotherapy.
Anger. Anger can increase pain. One study of pain‐related emotions used hypnotic suggestion to modulate the mood of normal volunteers while pain was tested. In those patients for whom anger was induced, there was a significant increase