Fibromyalgia, Pain, and Attention

Patients with Fibromyalgia (and other kinds of chronic pain) often notice and complain of “getting dumb” as a result of their illness.  This could be a side-effect of the illness, but is more likely due to how chronic pain takes over all the brain’s attention.

Cognitive dysfunction in fibromyalgia and chronic fatigue syndrome: new trends and future directions. [Curr Rheumatol Rep. 2006] – PubMed – NCBI

Fibromyalgia (FM) and chronic fatigue syndrome (CFS) patients often have memory and cognitive complaints.

Objective cognitive testing demonstrates long-term and working memory impairments. In addition, CFS patients have slow information-processing, and FM patients have impaired control of attention, perhaps due to chronic pain.

Neuroimaging studies demonstrate cerebral abnormalities and a pattern of increased neural recruitment during cognitive tasks. Future work should focus on the specific neurocognitive systems involved in cognitive dysfunction in each syndrome.

Pain demands attention: a cognitive-affective model of the interruptive function of pain. [Psychol Bull. 1999] – PubMed – NCBI

Abstract: Pain interrupts and demands attention. The authors review evidence for how and why this interruption of attention is achieved.

The interruptive function of pain depends on the relationship between pain-related characteristics (e.g., the threat value of pain) and the characteristics of the environmental demands (e.g., emotional arousal).

A model of the interruptive function of pain is developed that holds that pain is selected for action from within complex affective and motivational environments to urge escape. The implications of this model for research and therapy are outlined with an emphasis on the redefinition of chronic pain as chronic interruption.

This is a novel idea that needs more emphasis. Many of us have difficulty explaining why physical pain leads to an inability to engage in mental tasks.


Below is a very long, very technical article about attention and pain perception:

Orienting Attention Modulates Pain Perception – PLoS One. June 2012

Research has shown that people with chronic pain have difficulty directing their attention away from pain. A mental strategy that incorporates focused attention and distraction has been found to modulate the perception of pain intensity. That strategy involves placing attention on the nociceptive stimulus felt and shifting attention to a self-generated sub-nociceptive image and rehearsing it. Event-related potential (ERP) was used to study the possible processes associated with the focus-then-orient strategy.

Introduction

The somatosensory cortices process afferent nociceptive sensation. Researchers have found that the lateral pathway to the somatosensory cortices mediates feelings of pain intensity, while the medial pathway to the limbic system mediates the affect resulting from that pain

When people down-regulate the sensation of pain, the central nervous system exerts efferent inhibitory control. This control is mediated by the periaqueductal grey, situated in the midbrain. Wiech and colleagues found that conscious down-regulation was associated with activity in the so-called “pain control center” located in the dorsolateral prefrontal cortex.

Common down-regulation strategies that help lessen pain include distraction and focused attention. Distraction involves reorienting attention from a pain sensation to a sensation that occurs at the same time, but is not the pain itself (a sensation or scenario). The common modalities used to initiate distraction are visual, auditory, or somatosensory. Studies have still not given a clear picture of exactly what mental processes people use during distraction from nociceptive sensation

Evidence from studies on distraction suggests that it is hard to actually shift attention away from pain using distraction. A fundamental problem in mental distraction is that participants need to focus their attention on attributes that are not a part of the painful stimulus.

In a review paper, van Damme and colleagues concluded that non-painful stimuli were less useful than pain-related stimuli for down-regulating bodily pain. They explained that participants are less motivated when the content of the intervention is not directly related to pain sensation.

This is exactly the problem with chronic pain: it becomes impossible to focus on anything that’s not related to the pain – it is all-consuming and leaves no room for any other thinking.

Another strategy for modulating pain perception is focused attention. Unlike distraction, focused attention has people attend to the sensory component of the nociceptive sensation, such as the intensity or location of the sensation.

This model proposes two exclusive parallel systems in pain networks that carry discriminative and emotional nociceptive information

The focused attention strategy would thus enable pain modulation by focusing on the objective representation of pain (such as intensity) and setting aside the subjective representation (such as anxiety)

Focused attention has been regarded as a better strategy than distraction for pain modulation because it motivates people to directly address the pain sensation.

Nevertheless, a few studies have reported that participants failed to continue the procedure because directing attention on the objective component could further intensify the pain sensation. This was particularly the case for people with severe pain. Even though it seems to work, the idea that directing focus onto the objective component will attenuate pain is still counter-intuitive.

This study attempts to combine the advantages of the focused-attention and distraction strategies for pain modulation, what we call “orienting attention.” In our design, participants first feel a brief nociceptive stimulus at the beginning of the trial and then bring to mind the image of the nociceptive stimulus or a corresponding sub-nociceptive image. Then they rate the pain they felt at the beginning of the trial. The focused-attention component is meant to place attention on the nociceptive stimulus felt, whereas the distraction component is meant to switch attention to a self-generated sub-nociceptive image and rehearse it before rating the pain.

This study makes several contributions. This study can extend our understanding of how focused attention followed by distraction (generating and rehearsing sub-nociceptive images) modulates nociceptive experiences. It can also shed light on the potential of using self-generated sub-nociceptive sensations to develop clinical interventions for pain modulation for people with chronic pain.

Key Findings

This study investigated the neural processes behind orienting attention from nociceptive to sub-nociceptive images in order to regulate nociceptive perception. This focus-then-orient attention approach shares the benefits of focused attention and distraction (or orienting) for modulating pain perception. The “focusing” component involved attending to the nociceptive stimulus and recognizing its intensity, while the “orienting” component involved generating and rehearsing a corresponding sub-nociceptive image from memory.

Behaviorally, participants might feel less pain from the recalled nociceptive images after they mentally rehearsed the sub-nociceptive images (imagery trials). However, the differences in the presentation schedule for the stimulus verification process (two times for perception trials versus one time for imagery trials) between the two conditions might confound the observable pain modulation effects.

Orienting Attention and Nociceptive Perception

average reduction in pain intensity in the imagery trials across all stimulation levels was −0.33 (average normalized pain NRS), which is rather small on an 11-point scale.

This tiny sliver of pain reduction would never be noticed in real life and will only appear when averaging many numbers. Personally, I would consider this amount of pain reduction utterly insignificant.

Conclusion

This study had participants orient attention from nociceptive stimuli and generate images of sub-nociceptive sensation to modulate perception of nociceptive images. The sequential focus-then-orient processing of somatosensory images incorporates

(1) the focused-attention strategy, which places attention on the nociceptive stimulus felt, and

(2) the distraction strategy, which switches attention to self-generated sub-nociceptive images and rehearses them.

The electrophysiological results reveal that this two-step approach involved inhibitory processes of reorienting the attention away from nociceptive stimuli followed by generating, maintaining, and rehearsing the sub-nociceptive images in working memory.

These processes seemed to influence the evaluation of the prior nociceptive stimuli, resulting in modulation of the feeling of pain.

Since emerging evidence suggests that chronic pain is associated with prefrontal lobe degeneration [3], the focus-then-orient attentional process developed in this study should be replicated on patients with chronic pain and/or frontal lobe dysfunction. The findings from that study could further substantiate the involvement of frontal lobe in pain modulation and shed light on the clinical application of this procedure to chronic pain patients.

Other thoughts?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.