Pain
-
Multimodal neuroimaging studies provide support for a role of alterations in sensory processing circuits and endogenous pain modulatory systems in provoked vestibulodynia (PVD). In this study, we tested the hypotheses that PVD compared with healthy controls (HCs) would demonstrate gray matter volume (GMV) alterations in regions associated with sensorimotor, corticothalamic, and basal ganglia circuits. We also tested the replicability of previously reported gray matter increases in basal ganglia and hippocampal volumes in PVD vs HCs. ⋯ Regional GMV alterations were associated with patient reports of pain during intercourse and muscle tenderness. The current findings provide further evidence that GMV is increased in PVD compared with HCs in several regions of the sensorimotor network and the hippocampus in patients with PVD. In addition, GMV distinct alterations in the sensorimotor network were identified between 2 pelvic pain disorders, PVD compared with IBS.
-
Although several studies have found that chronic pain is characterized by increased cross-network connectivity between salience network, sensorimotor network, and default mode network (DMN), a large sample-size investigation allowing for a more reliable evaluation of somatotopic specificity and subgroup analyses with linkage to clinical pain intensity has been lacking. We enrolled healthy adults and a large cohort of patients (N = 181) suffering from chronic low back pain (cLBP). To specifically link brain connectivity with clinical pain intensity, patients were scanned at baseline and after performing physical maneuvers that exacerbated pain. ⋯ Hence, increased information transfer between salience processing regions, particularly anterior insula, and DMN may be strongly influenced by pain catastrophizing. Increased information transfer between the salience network and S1 likely plays an important role in shifting nociceptive afference away from self-referential processing, reallocating attentional focus, and affective coding of nociceptive afference from specific body areas. These results demonstrate S1 somatotopic specificity for cross-network connectivity in encoding clinical back pain and moderating influence of catastrophizing for DMN/insula connectivity.
-
Migraine encompasses a broader spectrum of sensory symptoms than just headache. These "other" symptoms, eg, sensory phobias, cognitive and mood changes, allodynia, and many others indicate an altered sensitivity to sensory input which can be measured, in principle, by quantifying sensory threshold changes longitudinally over time. Photophobia, for example, can be quantified by investigating the discomfort thresholds towards the luminance of light. ⋯ In summary, there is evidence in the literature that migraine could be understood as a periodic sensory dysregulation originating from the brain. Nevertheless, the interstudy discrepancy is still high due to different study designs and a lack of focus on distinct migraine phases. Further well-designed and harmonized studies with an emphasis on the cyclic changes still need to be conducted.
-
Diffuse noxious inhibitory controls (DNICs) is a pain-inhibits-pain phenomenon demonstrated in humans and animals. Diffuse noxious inhibitory control is diminished in many chronic pain states, including neuropathic pain. The efficiency of DNIC has been suggested to prospectively predict both the likelihood of pain chronification and treatment response. ⋯ Systemic application of nor-binaltorphimine, a kappa opioid antagonist, did not ameliorate SNL-induced hyperalgesia but reversed loss of the behavioral DNIC response. Microinjection of nor-binaltorphimine into the right central amygdala (RCeA) of SNL rats did not affect baseline thresholds but restored DNIC both behaviorally and electrophysiologically. Cumulatively, these data suggest that net enhanced descending facilitations may be mediated by kappa opioid receptor signaling from the right central amygdala to promote diminished DNIC after neuropathy.
-
Chronic or persistent pain is a growing global health problem. Effective management of pain emerging in childhood may prevent long-term health and vocational consequences. Internationally, paediatric pain services are a limited resource and, as such, must strive to improve equity, outcomes, and value for money. ⋯ Opioid-containing medicines were used often or daily by 16%. Patients completing outcome measures at treatment end reported clinically significant improvement in pain intensity (49% of patients), functional ability (59%), and quality of life (69%). The PaedePPOC initiative has been successfully integrated into children's pain services, yielding timely point-of-care information to support clinicians and families, and valuable binational and service data to inform quality improvement and future sector planning.