How emotions influence pain perception in chronic pain

Emotions change how we perceive pain. In healthy volunteers, positive affect is associated with reduced pain, while negative mood is associated with amplification of pain sensations (Meagher, Arnau, & Rhudy, 2001). Healthy participants rate painful experimental stimuli during the viewing of positive pictures as less intense and unpleasant than those experienced while viewing negative pictures. This has been tested in a number of studies, which generally report pain decreasing effects for positive emotions in healthy subjects; however, the data on negative emotions is not as clear.

Our recent manuscript explores this affective modulation in patients with chronic pain (Kamping, Bomba, Kanske, Diesch, & Flor, 2013). One could speculate that pain patients might be more influenced by negative pictures and pain perception would increase, while they may benefit more from positive images if the emotions they elicit are a less common occurrence for them compared with healthy individuals. Therefore, we compared healthy controls to  patients with fibromyalgia (FMS), a disease characterized by widespread musculoskeletal pain and tenderness along with cognitive symptoms and fatigue (Wolfe et al., 2010). There is an ongoing debate whether processing of nociceptive input is altered in FMS. Some evidence suggests that FMS have lower pain thresholds and altered brain activation in response to pain (Gracely, Petzke, Wolf, & Clauw, 2002), while others have shown that this is not necessarily the case (Jensen et al., 2010).

We presented FMS patients and control subjects with positive, neutral and negative pictures and measured their brain activity using functional magnetic resonance imaging (fMRI). No group differences emerged in the perception of emotions.  When painful stimuli were also applied to the participant’s hands while they viewed the set of pictures, control subjects reacted in the expected direction. Findings indicated that pain was perceived as less intense and less unpleasant during a positive context than during a negative context. For FMS patients however, painful stimuli in the presence of positive emotional context were not perceived as less painful than those during neutral picture presentation and were rated as almost as painful as those delivered during negative picture presentation. These findings suggest that being in a positive mood does not reduce pain for FMS patients.

In addition, the difference in pain modulation was reflected in reduced brain activation in areas of the brain that are involved in processing painful stimuli and emotions (right ventral anterior cingulate cortex, bilateral insula, right secondary somatosensory cortex, and left orbitofrontal cortex).

Interestingly, FMS patients showed a negative correlation of brain activation during positive picture-pain trials with picture valence in the bilateral striatum. The striatum is involved in emotion perception and is important for the coupling of salient contextual stimuli and internally rewarding events. Thus, these findings suggest that the more positively patients rated the picture, the less rewarding it was, emphasizing the deficient connection between positive emotions and pain.

This disrupted ability of FMS patients of orienting to an emotional context and impaired emotion recognition when positive picture stimuli are presented together with painful stimuli has important implications for therapeutic approaches in chronic pain. For example, rather than increasing the amount of positive emotions (e.g. by including more and more positive activities into ones daily life), a better treatment option may be to increase the strength of the positive emotions that already exist. This can be achieved through cognitive strategies. Reappraisal, for example, attempts to keep the focus on the emotional stimulus and encourages individuals to re-evaluate its meaning and personal relevancy.

About Sandra Kamping

Sandra KampingSandra Kamping is a post-doctoral researcher in the Department of Cognitive and Clinical Neuroscience at the Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University. She obtained her PhD in 2012 on the emotional modulation of pain in chronic pain patients. She continues to work on factors that modulatepain, including placebo analgesia, cognitive factors, and stress induced analgesia. Sandra is currently involved in a project that examines the relationship between pain and suffering. This year (2013) she obtained her license to work as a cognitive behavioral psychotherapist.

References

Gracely RH, Petzke F, Wolf JM, & Clauw DJ (2002). Functional magnetic resonance imaging evidence of augmented pain processing in fibromyalgia. Arthritis Rheum, 46(5), 1333-43 PMID: 12115241

Jensen KB, Petzke F, Carville S, Fransson P, Marcus H, Williams SC, Choy E, Mainguy Y, Gracely R, Ingvar M, & Kosek E (2010). Anxiety and depressive symptoms in fibromyalgia are related to poor perception of health but not to pain sensitivity or cerebral processing of pain. Arthritis Rheum, 62 (11), 3488-95 PMID: 20617526

Kamping S, Bomba IC, Kanske P, Diesch E, & Flor H (2013). Deficient modulation of pain by a positive emotional context in fibromyalgia patients. Pain, 154 (9), 1846-55 PMID: 23752177

Meagher MW, Arnau RC, & Rhudy JL (2001). Pain and emotion: effects of affective picture modulation. Psychosom Med, 63 (1), 79-90 PMID: 11211069

Wolfe F, Clauw DJ, Fitzcharles MA, Goldenberg DL, Katz RS, Mease P, Russell AS, Russell IJ, Winfield JB, & Yunus MB (2010). The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis care & research, 62 (5), 600-10 PMID: 20461783

Comments

  1. Anna Dawson says

    Thanks for the share. How will you conclude the psychological aspect of pain? Will it be same as for emotion?

    Sandra Reply:

    Hi Anna,
    sorry, I don’t think I understand your question fully. What psychological aspects of pain?
    Cheers,
    Sandra

  2. Christine Phillips says

    Is this an example of the tendency of the sensitised CNS in chronic pain conditions to interpret multiple types of sensory input as painful, in this case visual? Would be interesting to repeat this study with sound/music/smell.
    I agree with Michel, the article provided no evidence that focusing on existing positive emotional triggers would be a helpfull approach, but it is worth investigating.

    Sandra Reply:

    Hi Christine,
    You are right. We do not have any evidence that it would help. However, the results we obtained make us believe that it would. But this is just a hypothesis that would need to be tested in further research.
    In regard to your question, visual stimuli were not perceived as painful. The painful stimulation we applied at the same time as emotional pictures were presented were differentially modulated in FMS compared to controls.
    Best wishes,
    Sandra

    Christine Phillips Reply:

    Can you explain what led you to this conclusion?

    Sandra Reply:

    We showed emotional pictures to controls and patients and did not see any differences in ratings or brain activation. When we coupled the picture presentation with pain, we saw a difference during presentation of positive pictures. Here the pain was rated as more intense in the FMS group than in the healthy controls (interaction of group * emotion). Thus the emotional modulation of pain (i.e., the reduction of pain by positive emotions) did not work for the patients. Additionally during positive emotions plus pain, we saw decreased activation in areas that are involved in the recognition of, orientation to and processing of emotions in patients.
    We believe that when pain is involved the orientation, processing and recognition of positive emotions is impaired in patients. This is also supported by the correlational analysis showing that the “more positive” the positive picture was rated, the less striatum activation (in patients). Somehow the rewarding value of the positive emotion is lost.
    Thus if we (in theory) help patients in boosting the positivity of positive situations or emotions the network should be normalized and the emotional modulation should reappear. However, one would need to conduct studies on emotion regulation to prove that. It is at this point just speculation that arose from the data we collected. But we didn’t prove it with our data.

    Hope that helps,
    Sandra

  3. Really interesting research, schocking to see the difference in reaction to positive stimuli for FMS patients. I dont understand the recommendation for treating FMS patients with enforcing positive emotions that already exist. I cant see any indication in this article that it could be a better option. As the reaction to negative stimuli is there, isn’t it better to reduce these, or hand coping strategies?

    Sandra Reply:

    Hi Michael,
    there was no difference regarding the modulation of pain by negative emotions between controls and fibromyalgia patients. This modulation in pain patients was totally “normal”. We found that positive emotions do not reduce pain in the patients we examined to the same extend as for control subjects. Thus normalization of the modulation of the positive emotions need to be adressed.
    Additionally, this deficient modulation was seen only when the emotional pictures were presented at the same time as the experimental pain was present. Processing of emotions was not disrupted in general.
    We believe that the rewarding value of the positive emotion is reduced in the presence of pain – and that a stronger focus should be placed on this during therapeutic interventions.
    Best wishes,
    Sandra