Pain
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A link between fibromyalgia syndrome (FMS) and posttraumatic stress disorder (PTSD) has been suggested because both conditions share some similar symptoms. The temporal relationships between traumatic experiences and the onset of PTSD and FMS symptoms have not been studied until now. All consecutive FMS patients in 8 study centres of different specialties were assessed from February 1 to July 31, 2012. ⋯ In 4.0% of patients' most burdensome traumatic experience, PTSD and FMS symptoms occurred in the same year. FMS and PTSD are linked in several ways: PTSD is a potential risk factor of FMS and vice versa. FMS and PTSD are comorbid conditions because they are associated with common antecedent traumatic experiences.
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Multicenter Study
Intraoral somatosensory abnormalities in patients with atypical odontalgia--a controlled multicenter quantitative sensory testing study.
Intraoral somatosensory sensitivity in patients with atypical odontalgia (AO) has not been investigated systematically according to the most recent guidelines. The aims of this study were to examine intraoral somatosensory disturbances in AO patients using healthy subjects as reference, and to evaluate the percent agreement between intraoral quantitative sensory testing (QST) and qualitative sensory testing (QualST). Forty-seven AO patients and 69 healthy control subjects were included at Universities of Washington, Malmö, and Aarhus. ⋯ The most frequent LossGain code was L0G2 (no somatosensory loss with gain of mechanical somatosensory function) (31.9% of AO patients). Percent agreement between corresponding QST and QualST measures of thermal and mechanical sensitivity ranged between 55.6% and 70.4% in AO patients and between 71.1% and 92.1% in control subjects. In conclusion, intraoral somatosensory abnormalities were commonly detected in AO patients, and agreement between quantitative and qualitative sensory testing was good to excellent.
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Recent functional brain connectivity studies have contributed to our understanding of the neurocircuitry supporting pain perception. However, evoked-pain connectivity studies have employed cutaneous and/or brief stimuli, which induce sensations that differ appreciably from the clinical pain experience. Sustained myofascial pain evoked by pressure cuff affords an excellent opportunity to evaluate functional connectivity change to more clinically relevant sustained deep-tissue pain. ⋯ Moreover, greater connectivity during pain between contralateral S1/M1 and posterior insula, thalamus, putamen, and amygdala was associated with lower cuff pressures needed to reach the targeted pain sensation. These results demonstrate that sustained pain disrupts resting S1/M1 connectivity by shifting it to a network known to process stimulus salience. Furthermore, increased connectivity between S1/M1 and both sensory and affective processing areas may be an important contribution to interindividual differences in pain sensitivity.
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Conditioned pain modulation (CPM) (ie, diffuse noxious inhibitory controls) is characterized by reduced perception of pain caused by intense pain in a remote body area. The conditioning stimuli used to trigger CPM causes pain, but also important cardiovascular responses. Higher blood pressure has been associated with reduced pain sensitivity. ⋯ A significant positive association was observed between CPM magnitude and the increase in blood pressure during the CPT. These results show that resting blood pressure values are related to acute pain tolerance, while descending pain inhibition is associated with increases in blood pressure. The rise in blood pressure caused by the conditioning stimulus is an important factor predicting the extent of endogenous pain inhibition in healthy subjects.