Pain Recollection in FM Patients Changes over Time, Study Suggests

Pain Recollection in FM Patients Changes over Time, Study Suggests

Research suggests a bias in how people with fibromyalgia (FM) recall pain, with intense pain usually exaggerated in recall.

Researchers suggest that psychosocial factors, such as patients’ own assessment of their physical abilities, may affect FM patients’ pain recollection.

The study, “A longitudinal analysis of pain experience and recall in fibromyalgia,” was published in International Journal of Rheumatic Diseases.

Pain in FM is usually measured via self-reports; however, this has been shown to lead to disparate results, likely linked to the fact that how people experience pain is often different than their memory of that painful episode.

Increasing research suggests that memories of painful experiences are “more powerful predictors of future pain than the actual previous pain experiences,” researchers said.

“These findings engender questions of what pain recollections truly reflect, how pain recollection differs by populations, what factors moderate pain recollection accuracy and how they operate similarly across differing populations,” they stated.

Evidence shows that pain recall is affected by psychological, social, and biological factors — depression was shown to negatively affect pain recollection and one study showed that glucocorticoid cortisol, a hormone released during a stress response, also changed how a group of healthy males experienced pain during a controlled experiment.

While research into factors that affect pain recollection has been done in some populations of patients with an identifiable cause for their pain, “no research has been done to assess these processes among those with fibromyalgia.”

Researchers analyzed data from 572 FM patients to understand how they experience and recall memories of pain.

The patients were asked to perform — in five different moments over a period of one year — a self-assessment of their FM-related pain levels at that “present moment” (experiential pain or EP), an assessment of what they considered the level of the highest FM pain they had ever experienced (historical peak pain or HPP), and the level of their lowest FM pain (historical valley pain or HVP).

Recollections of FM pain were compared to recollections of other types of pain, such as the worst toothache pain, or the worst stomach pain, that were recorded at the same timepoints.

The authors found that pain recall in FM patients changes over time, with a tendency for a decrease of all FM pain experiences, which didn’t happen when patients were asked to recall other non-FM pain experiences.

Moreover, momentary pain experiences of those with FM are systematically closer to their lowest levels of pain than they are to their highest levels of pain.

Of note, and in accordance with previous studies, the accuracy in recalling pain levels was lower among depressed FM patients — this set of patients seems to have a tendency to inflate past peak pain levels and momentary pain, but not so with lowest pain levels. “Depression does not relate to inflations of all pain, but only peak recollections and present pain experiences,” the authors wrote.

The authors identified other factors that can contribute to fibromyalgia pain syndrome (FMS) pain recollection, such as self-efficacy (i.e. the assessment the patients do of their own ability to perform physical tasks), or sleep impairments.

In this study, higher self-efficacy seems to lessen pain experiences in FM and to deflate recall of the severity of historical pain, while impaired sleep was correlated with inflation of all FMS pain experiences.

Researchers could also corroborate previous data that suggest age seems to alter the intensity with which individuals remember past negative experiences, in this case peak FM pain.

Over the year that patients were asked to recall their current FM pain compared to past FM pain experiences, all of them said their pain experience levels decreased. This suggests that the act of recollection might help FMS patients cope with their momentary pain levels.

Because current pain levels were always closer to lowest historical pain, it seems that “asking patients to report their average pain on ‘good days’ (pain at its least) might be a good reflection of their typical daily pain experiences,” researchers said.

Moreover, these results suggest “that memory related to pain might be a worthwhile target for intervention,” the study concluded.