Austin, Texas — Assessing patient expectations about how much pain the patient is in, or what they expect the intensity of future pain may be, may help to guide physicians in how they treat that patient, according to a speaker at the American Pain Society 2016 Meeting.
“Pain expectation is a pain predictive cue,” Howard Fields, MD, PhD, who is a professor of neurology at the University of California, San Francisco said during the meeting. “The computation includes what the individual thinks is going to occur.”1
Dr Fields supported his statement by citing several articles, including a recently published paper by Stephanie Cormier et al in the journal Pain. 2
In Dr. Cormier’s observational study, the researchers looked at data on 2272 patients enrolled in pain treatment centers. The researchers gauged patients’ expectations regarding pain relief before the patients visited the centers, and concluded that: “structural equation modeling analyses showed significant positive relationships between expectations and most clinical outcomes, and this association was largely mediated by patients’ global impressions of change.”
Dr Fields explained that pain typically occurs in the setting of competing motivations, and he cited a humorous example of a mouse wearing a helmet trying to get a piece of cheese from a mouse trap as an example of these competing motivations.
“Your decision on how to respond to pain depends on hunger, fear, fatigue, thermoregulation,” Dr Fields said, pointing to the picture. “You’re almost always making the decision to respond to pain before you feel it.” He explained that there are two classes of neurons in the nucleus accumbens, expressing dopamine D1 and D2 receptors, which facilitate pain and pain control and play a role in this decision-making process.
So how does this anecdote about the mouse translate to clinical practice? Just as Dr Cormier’s data demonstrated that clinical outcome can be influenced by patient expectations of pain, Dr Fields noted that the physician can play a role in this expectation by early pain intervention in order to set a good expectation of relief.
“The sooner you show a patient they can get better, the more likely it is they’ll respond to whatever treatment you give them,” Dr Fields concluded.
1. Fields H. .Plenary Lecture. Motivation, Action, Learning, and Pain Sensation. Presented at: 35th Annual Scientific Meeting of the American Pain Society; May 11-14, 2016; Austin, Texas.
2. Cormier S, Lavigne G, Choiniere M, et al. Expectations predict chronic pain treatment outcomes. Pain. 2016; doi: 10.1097/j.pain.0000000000000379