Disruption of default mode network dynamics in acute and chronic pain states

Abstract

It has been proposed that pain competes with other attention-demanding stimuli for cognitive resources, and many chronic pain patients display significant attention and mental flexibility deficits. These alterations may result from disruptions in the functioning of the default mode network (DMN) which plays a critical role in attention, memory, prospection and self-processing, and recent investigations have found alterations in DMN function in multiple chronic pain conditions. Whilst it has been proposed that these DMN alterations are a characteristic of pain that is chronic in nature, we recently reported altered oscillatory activity in the DMN during an acute, 5 minute noxious stimulus in healthy control subjects. We therefore hypothesize that altered DMN activity patterns will not be restricted to those in chronic pain but instead will also occur in healthy individuals during tonic noxious stimuli. We used functional magnetic resonance imaging to measure resting state infra-slow oscillatory activity and functional connectivity in patients with chronic orofacial pain at rest and in healthy controls during a 20-minute tonic pain stimulus. We found decreases in oscillatory activity in key regions of the DMN in patients with chronic pain, as well as in healthy controls during tonic pain in addition to changes in functional connectivity between the posterior cingulate cortex and areas of the DMN in both groups. The results show that similar alterations in DMN function occur in healthy individuals during acute noxious stimuli as well as in individuals with chronic pain. These DMN changes may reflect the presence of pain per se and may underlie alterations in attentional processes that occur in the presence of pain.

A Pilot Study Examining Neural Response to Pain in Adolescents With and Without Chronic Pain

“…Notably, this pattern of differential activation persisted not only across all levels of pressure stimuli, but also during the anticipation phase preceding pain stimuli. This suggests that, compared to controls, adolescents with chronic pain may have stimulus-independent, sustained impairments in default mode network disengagement in the presence or anticipation of potentially painful stimuli, similar to disruptions in the default mode network during rest seen in adults with chronic pain (30). It is possible this persistent alteration in adolescent neurocircuitry could lead to a re-wiring of the brain during this vulnerable developmental period, and explain both the continuation of pain into adulthood, as well as future negative mental health outcomes, which implicate this circuitry.…”

Sustained perturbation in functional connectivity induced by cold pain

“…Healthy volunteer studies facilitate examining pain mechanisms independently of these differences, but surprisingly, rs-fMRI studies evaluating tonic painful stimulation in these individuals remain relatively scarce. Reports of experimentally-induced tonic muscle pain (Alshelh et al, 2018) produced decreased oscillatory power in the main DMN hubs (posterior cingulate cortex-PCC, inferior parietal cortex, and vmPFC) and a pilot study of pain-inducing intramuscular hypertonic saline injection described insula-DMN connectivity changes (Zhang et al, 2014).…”

Changes in resting‐state functional connectivity in nonacute sciatica with acupuncture modulation: A preliminary study

“…However, the exact effects of acupuncture on the DMN for pain relief are unclear. Disruption of the resting state of the DMN in PCC-FC in the precuneus region has recently been reported in patients with chronic orofacial neuropathic pain (Alshelh et al, 2018).…”

“…The PCC/PCu plays a crucial role in the DMN (Fransson & Marrelec, 2008). Disruption of the resting state of the DMN in PCC-FC in the precuneus region has recently been reported in patients with chronic orofacial neuropathic pain (Alshelh et al, 2018). The DMN is associated with self-processing, attention, and memory (Buckner et al, 2008(Buckner et al, , 2005Spreng & Grady, 2010) and contributes to acute and chronic pain (Alshelh et al, 2018).…”

“…Our results further emphasize that the PCC/PCu is also a key brain region for acupuncture-treated nonacute/chronic sciatica. The DMN is associated with self-processing, attention, and memory (Buckner et al, 2008(Buckner et al, , 2005Spreng & Grady, 2010) and contributes to acute and chronic pain (Alshelh et al, 2018). However, the exact effects of acupuncture on the DMN for pain relief are unclear.…”