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.