Pain
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Although religious belief is often claimed to help with physical ailments including pain, it is unclear what psychological and neural mechanisms underlie the influence of religious belief on pain. By analogy to other top-down processes of pain modulation we hypothesized that religious belief helps believers reinterpret the emotional significance of pain, leading to emotional detachment from it. Recent findings on emotion regulation support a role for the right ventrolateral prefrontal cortex (VLPFC), a region also important for driving top-down pain inhibitory circuits. ⋯ As confirmed by behavioral data, contemplation of the religious image enabled the religious group to detach themselves from the experience of pain. Critically, this context-dependent modulation of pain specifically engaged the right VLPFC, whereas group-specific preferential liking of one of the pictures was associated with activation in the ventral midbrain. We suggest that religious belief might provide a framework that allows individuals to engage known pain-regulatory brain processes.
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Somatosensory function in patients with persistent idiopathic types of orofacial pain like atypical odontalgia (AO) is not well described. This study tested the hypothesis that AO patients have significantly more somatosensory abnormalities than age- and sex-matched controls. Forty-six AO patients and 35 controls participated. ⋯ Between-group differences in pressure pain thresholds (P<0.02) were observed at the thenar eminence. In conclusion, significant abnormalities in intraoral somatosensory function were observed in AO, which may reflect peripheral and central sensitization of trigeminal pathways. More generalized sensitization of the nociceptive system may also be part of AO pathophysiology.
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Previous studies have shown that peripheral nerve injury in rats induces increased expression of the voltage gated calcium channel (VGCC) alpha-2-delta-1 subunit (Ca v alpha2 delta1) in spinal dorsal horn and sensory neurons in dorsal root ganglia (DRG) that correlates to established neuropathic pain states. To determine if injury discharges trigger Ca v alpha2 delta1 induction that contributes to neuropathic pain initiation, we examined allodynia onset and Ca v alpha2 delta1 levels in DRG and spinal dorsal horn of spinal nerve ligated rats after blocking injury induced neural activity with a local brief application of lidocaine on spinal nerves before the ligation. The lidocaine pretreatment blocked ligation-induced discharges in a dose-dependent manner. ⋯ In addition, preemptive intrathecal Ca v alpha2 delta1 antisense treatments blocked concurrently injury-induced allodynia onset and Ca v alpha2 delta1 upregulation in dorsal spinal cord. These findings indicate that injury induced discharges regulate Ca v alpha2 delta1 expression in the spinal dorsal horn that is critical for neuropathic allodynia initiation. Thus, preemptive blockade of injury-induced neural activity or Ca v alpha2 delta1 upregulation may be a beneficial option in neuropathic pain management.
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Randomized Controlled Trial Comparative Study
Evaluation of analgesic effect of skin-to-skin contact compared to oral glucose in preterm neonates.
Nonpharmacological interventions are important alternatives for pain relief during minor procedures in preterm neonates. Skin-to-skin contact or kangaroo mother care is a human and efficient way of caring for low-weight preterm neonates. The aim of the present study was to assess the analgesic effect of kangaroo care compared to oral glucose on the response of healthy preterm neonates to a low-intensity acute painful stimulus. ⋯ In group 3 (glucose, n=31), the neonate was in the prone position in the isolette and received oral glucose (1 ml, 25%) 2 min before heel lancing. A smaller variation in heart rate (p=0.0001) and oxygen saturation (p=0.0012), a shorter duration of facial activity (brow bulge, eye squeeze and nasolabial furrowing) (p=0.0001), and a lower PIPP (Premature Infant Pain Profile) score (p=0.0001) were observed in group 2. In conclusion, skin-to-skin contact produced an analgesic effect in preterm newborns during heel lancing.
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Comparative Study
Numbness in clinical and experimental pain--a cross-sectional study exploring the mechanisms of reduced tactile function.
Pain patients often report distinct numbness of the painful skin although no structural peripheral or central nerve lesion is obvious. In this cross-sectional study we assessed the reduction of tactile function and studied underlying mechanisms in patients with chronic pain and in healthy participants exposed to phasic and tonic experimental nociceptive stimulation. Mechanical detection (MDT) and pain thresholds (MPT) were assessed in the painful area and the non-painful contralateral side in 10 patients with unilateral musculoskeletal pain. ⋯ Irrespective of the mode of nociceptive stimulation (phasic vs. tonic) tactile hypaesthesia and hyperalgesia developed with a similar time course and disappeared within approximately 1 day. Hypaesthesia (numbness) often encountered in clinical pain can be reproduced by experimental nociceptive stimulation. The time course of effects suggests a mechanism involving central plasticity.