Deficiency in endogenous modulation of prolonged heat pain in patients with Irritable Bowel Syndrome and Temporomandibular Disorder

Abstract

Females with Irritable Bowel Syndrome (IBS) and Temporomandibular Disorder (TMD) are characterized by enhanced sensitivity to experimental pain. One possible explanation for this observation is deficiencies in pain modulation systems like Diffuse Noxious Inhibitory Control (DNIC). In a few studies that used brief stimuli, chronic pain patients demonstrate reduced DNIC. The purpose of this study was to compare sensitivity to prolonged heat pain and the efficacy of DNIC in controls to IBS and TMD patients. Heat pain (experimental stimulus; 44.0-49.0°C), which was applied to left palm, was continuously rated during three 30-second trials across three separate testing sessions under the following conditions: without a conditioning stimulus; during concurrent immersion of the right foot in a 23.0°C (control); and during noxious cold immersion in a (DNIC; 8.0-16.0°C) water bath. Compared to controls, IBS and TMD patients reported increased sensitivity to heat pain and failed to demonstrate pain inhibition due to DNIC. Controls showed a significant reduction in pain during the DNIC session. These findings support the idea that chronic pain patients are not only more pain sensitive and demonstrate reduced pain inhibition by pain, possibly because of dysfunction of endogenous pain inhibition systems.

(236) Impaired conditioned pain modulation in youth with functional abdominal pain

“…Thus, impaired CPM appears to accompany functional -but not organic -abdominal pain. These findings add to a growing literature highlighting the potential utility of impaired CPM as a shared vulnerability mechanism across a variety of chronic pain conditions [17,10,22,32].The median CPM reduction in healthy youth was 19%, which is similar to the 23% reduction reported by another study of healthy children and adolescents [42] but somewhat lower than the 29% reduction reported by a review of studies conducted in healthy adults [34]. These developmental differences are consistent with prior research suggesting that CPM effects strengthen from childhood to adolescence [42] but begin to weaken by middle age [10,21,38,50].…”

“…Diminished CPM (relative to control samples) has been observed in a variety of chronic pain conditions, including fibromyalgia [19,22], temporomandibular disorder [17], and chronic headache [32]. Impaired CPM has also been found in adults with IBS [14,17,31,51] and is linked to greater distress and discomfort in these individuals [15].Few evoked pain studies have been conducted in healthy youth [4,26,28,34] and only two have examined CPM [29,42]. Relatively little is known about experimental pain responses in youth with FAP.…”

Sensory function after cavernous haemangioma: a case report of thermal hypersensitivity at and below an incomplete spinal cord injury

“…This technique is known to induce temporal summation of psychophysically rated sensory responses 7 and has been interpreted as evidence for central noxious sensitization, as demonstrated recently in two different pain pathologies. 8 Here, we show that thermal quantitative sensory testing, using both short (1 s) and tonic (10 s) stimuli, demonstrates that IH leads to an increase in below-level cold pain threshold combined with widespread thermal allodynia.…”

Dysfonctionnements musculaires douloureux de l’appareil manducateur et dysfonctionnements cervicaux et linguaux connexes (3e partie)

“…En effet, ce système modulateur endogène est déficitaire (activité pro-nociceptive) dans les ADAM [42], dans la fibromyalgie [43] et a priori dans les cervicalgies post-traumatiques [44]. Or parmi les patients fibromyalgiques, chez ceux qui sont en outre déprimés, ce système modulateur est encore moins efficace [45].…”