A New Pain PILL: Lending a Personal Approach to Personalized Medicine

In caring for patients with chronic pain, I have tried all kinds of treatments to reduce bothersome symptoms, hoping to achieve improvements that are better than the usual one or two points on a visual analog scale. The list of these treatments is long—no doubt, you have tried the same ones—and include the expected array of traditional and not-so-traditional approaches. Not feeling very successful, I have decided it is time for something new. I am going to try the PILL.

Take This PILL

PILL is capitalized for good reason because, in this context, it does not refer to a tablet or capsule or any kind of pharmacotherapy to change how nociceptors flip and flop or how nerve impulses zip down axons to jolt the brain’s inner sanctums. Here, the PILL means the Pennybaker Index of Limbic Languidness. However amusing the name, the Pennybaker Index is quite real and, I think, powerfully incisive.

Pain is difficult to quantify and treat, but the PILL, administered regularly, can help rheumatologists manage this tricky symptom.

As a concept, limbic languidness is important to understand and treat fibromyalgia and other chronic painful conditions like temporo-mandibular joint pain. By a 54-item questionnaire, the PILL can assess a patient’s experience of bodily sensation by asking questions such as “How often do you itch?” or “How often do your ears ring?” The choices range from “never or almost never experienced” through “every month or so” to “more than once very week.” These choices receive a score of 1 to 4. The higher the score, the more symptoms a patient may report over time. In patients with fibromyalgia, the PILL is correlated with responses to tactile and auditory stimulation and the extent to which this stimulation is perceived as unpleasant or painful.

I learned of the PILL while reading the ACR Pain Management Task Force recommendations, which appear in Arthritis & Rheumatism.¹ The term “limbic languidness” was itself intriguing and I am still not sure what languidness means in the context of brain function. Nevertheless, once I started reading about the index, I found the idea fascinating and searched PubMed for still more articles. I became hooked on the PILL and think rheumatologists should become as familiar with this index as they are with measures such as the C-reactive protein, Disease Activity Score, or Health Assessment Questionnaire.

As rheumatologists well know, pain is almost an invariable symptom of diseases in our subspecialty. While this symptom can reflect multiple etiologies and involve events in both the central and peripheral nervous systems, much of the scholarship in our field (and education in our training programs) approaches this symptom more narrowly as a result of inflammation. Correspondingly, discussion of analgesic therapy tends to focus primarily on the nonsteroidal antiinflammatory drugs that, while able to blunt pain, also affect the immune response. Neuroleptics and narcotics receive some attention in the rheumatology literature, although there is only limited consideration of the neurophysiology of pain per se. Given this perspective in rheumatology, the social, cultural, and psychological dimensions of the pain experience often play second fiddle to the perturbations of the nervous system caused when the immune system goes astray.

The PILL, like other psychological tests, is relatively simple (you can take it online yourself in a few minutes at http://counsellingresource.com/quizzes/pill/index.html) and illuminates a patient’s tendency to experience symptoms. Like measures of this kind, the PILL can help construct a cognitive framework for clinical decision making. The PILL is not for diagnosis. Just as the finding of an elevated sedimentation rate influences choices during a diagnostic workup, an elevated score on the PILL can help a clinician determine, for example, the meaning of the headaches, myalgias, abdominal pains, and rashes that so often beleaguer patients with chronic pain.

From my brief (and nonexpert) review of this literature, I think that creating a psychological profile of a patient with the PILL could add value in the management of rheumatologic conditions other than fibromyalgia. Lupus has its share of fibromyalgia manifestations. I would also wager than at least some patients with rheumatoid arthritis who fail to respond to current disease-modifying agents actually have a pain syndrome rather than jazzed-up B cells or macrophages promiscuously stimulating T cells.

Focus on the Person in Personalized Medicine

Modern medicine is about to enter an era of personalized care. According to the precepts guiding this movement, a battery of genetic, genomic, proteomic, and metabolomic tests—using whiz-bang chips loaded with bells and whistles despite their small size—have the power to predict a patient’s susceptibility to disease, along with everything else from the response to therapy to the likelihood of complications. As current research is showing, however, the goal of personalized medicine may not be easy to achieve even with cutting-edge technology sharpened like a razor. Genetic variation in the population is huge—maybe too huge. As a result, determining genetic susceptibility factors in an individual or population is far from a slam dunk. Results from “omic” technology may also be inconsistent, varying with the time of the day or the month or what you had last night for dinner.

Given the complexity of molecular studies, I think that, in the near term, the use of psychological tests like the PILL, along with other off-the-shelf indices, is eminently reasonable and unequivocally puts the person center stage in personalized medicine.

The future of the science of pain and its management is very bright. Under the leadership of incoming President David Borenstein, MD, the ACR is doing a great job of positioning pain as a focus of inquiry, with its management ready for programs of quality improvement. I have been privileged to be part of this important initiative. The treatment of pain is inextricably tied to rheumatologic practice, and I look forward to a very exciting time as the ACR moves decisively into this rapidly moving field.

As a scientist, I gravitate toward numbers, especially quantifiable outcome measures, and am a great fan of questionnaires that patients can easily complete. The numbers generated are illuminating, often surprising, and can as readily bolster our clinical impression as refute them. Pennybaker’s index is such a measure. It is therefore with hope and anticipation that I await the day when rheumatologists routinely use this measure in practice and, harkening back to a bygone era, instruct their patients, “Please take this PILL. If you still hurt, please call me in the morning.”

Dr. Pisetsky is physician editor of The Rheumatologist and professor of medicine and immunology at Duke University Medical Center in Durham, N.C.

Reference

1. Report of the American College of Rheumatology Pain Management Task Force. Arthritis Care Res. 62: 590–599.