EXPERT ANALYSIS FROM THE ANNUAL PERSPECTIVES IN RHEUMATIC DISEASES
The power of the central sensitization analogy – the idea that pain is best thought about as a stereo with the volume turned up – has led to the science of fibromyalgia becoming “lost in translation,” according to Dr. Brian Walitt.
This problem has appeared because the priorities of basic scientists and those of translational scientists are different, Dr. Walitt said at the annual Perspectives in Rheumatic Diseases held by Global Academy for Medical Education.
“For a basic scientist, anything that’s real is interesting because who knows what you may find, but a translational scientist is trying to help people,” he explained. “A lot of the time, things that we’re trying to find in basic science are up-translated into being meaningful when they may not be,” and then used to fit an analogy that is probably not true, said Dr. Walitt, director of clinical pain research at the National Center for Complementary and Integrative Health, Bethesda, Md.
Proponents of the popular central sensitization analogy have put forward five types of evidence – psychophysical, neuroimaging, genetic, neurotransmitters, and treatments – to support their view, but Dr. Walitt said that the evidence is weak, doesn’t prove anything, or seem legitimate. For instance, none of the treatments for fibromyalgia are particularly effective, at best giving a minimally clinically important difference that does not change patient outcomes.
Another issue with the analogy is that it is not possible to disprove the hypothesis. Any central nervous system measurements that correlate with differences in subjective pain reports can be presented as “mounting evidence” but not definite proof, he said. If the idea was changed from amplification of pain signals to distortion, the same data could be used to prove that, too. “Distortion is also bogus. It’s just another idea, another way of talking about it that shows that whatever you pick you can find ways to make a story that fits all the data,” Dr. Walitt said. However, analogies can be powerful, particularly if they wash away the complexity and difficulty in understanding neuroscience.
“But the truth of the matter, at least to me, is there is no analogy for pain and any analogy that we use is going to fall flat,” he said. “When we try to fit science to an idea or a story it can mislead us. Sometimes we’re better off letting the science speak for itself than try to make it fit a particular story.”
Dr. Walitt, however, acknowledged a caveat – that fibromyalgia is a very hard problem and that, even if we hadn’t been chasing analogies we may still not be better off. “If we don’t understand why we feel things to begin with, it means we may be further away than we think,” he said.
Dr. Walitt said he has no financial conflicts of interest to report. Global Academy for Medical Education and this news organization are owned by the same parent company.