Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifteen adults with chronic low back pain (M = 4 years), age 18 to 43 years (M = 29 years), participated. All but one were moderately to highly hypnotizable (M = 7.87; modified 11-point Stanford Hypnotic Susceptibility Scale, Form C [Weitzenhoffer & Hilgard, 1962]), and significantly reduced pain perception following hypnotic analgesia instructions during cold-pressor pain training. In Part 1, somatosensory event-related potential correlates of noxious electrical stimulation were evaluated during attend and hypnotic analgesia (HA) conditions at anterior frontal (Fp1, Fp2), midfrontal (F3, F4), central (C3, C4), and parietal (P3, P4) regions. During HA, hypothesized inhibitory processing was evidenced by enhanced N140 in the anterior frontal region and by a prestimulus positive-ongoing contingent cortical potential at Fp1 only. During HA, decreased spatiotemporal perception was evidenced by reduced amplitudes of P200 (bilateral midfrontal and central, and left parietal) and P300 (right midfrontal and central). HA led to highly significant mean reductions in perceived sensory pain and distress. HA is an active process that requires inhibitory effort, dissociated from conscious awareness, where the anterior frontal cortex participates in a topographically specific inhibitory feedback circuit that cooperates in the allocation of thalamocortical activities. In Part 2, the authors document the development of self-efficacy through the successful transfer by participants of newly learned skills of experimental pain reduction to reduction of their own chronic pain. Over three experimental sessions, participants reported chronic pain reduction, increased psychological well-being, and increased sleep quality. The development of "neurosignatures of pain" can influence subsequent pain experiences (Coderre, Katz, Vaccarino, & Melzack, 1993; Melzack, 1993) and may be expanded in size and easily reactivated (Flor & Birbaumer, 1994; Melzack, 1991, 1993). Therefore, hypnosis and other psychological interventions need to be introduced early as adjuncts in medical treatments for onset pain before the development of chronic pain.
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PMID:Hypnotic analgesia: 1. Somatosensory event-related potential changes to noxious stimuli and 2. Transfer learning to reduce chronic low back pain. 943 5

Pethidine (meperidine) is a compound with both local anaesthetic and opioid agonist properties. We have in a recent study demonstrated that pethidine could be an interesting alternative to prilocaine in arthroscopy with local anaesthetic technique. Therefore, we investigated, in a controlled randomized double-blind study, the effect of three doses of pethidine compared with a standard local anaesthetic, in patients subjected to arthroscopic knee joint surgery. Ten patients in each group received 50 mg (P50), 100 mg (P100), 200 mg (P200) of pethidine or prilocaine (5 mg/ml) + adrenaline (4 mg/ml) (PC), injected intra-articularly (i.a.) before surgery. We measured pain intensity and discomfort during arthroscopy and pain intensity at rest and at movement, nausea and tiredness for 3 days post-operatively at regular intervals using the VAS-technique. We also measured the concentration of pethidine and its demethylated metabolite, norpethidine, in plasma by collecting blood samples at 20, 40, 60, 80, 140 and 200 min following injection, and in synovial fluid which was collected through the arthroscope at the start and the end of the surgery. It was found that significantly more patients in the P50 group (n = 6) needed general anaesthesia due to intense pain than those in the P100 group (n = 1), P200 group (n = 0) or the PC group (n = 1). The PC group required significantly more analgesics and had a significantly higher calculated total sum of pain scores at movement post-operatively, than the other three groups. The P200 group more often reported tiredness post-operatively than the other three groups. We conclude that 100 or 200 mg pethidine i.a. produces satisfactory anaesthesia for surgery. There was a rapid transfer of pethidine from synovial fluid to plasma, resulting in plasma levels earlier reported to produce centrally mediated effects, such as analgesia and tiredness. We found much higher concentrations of norpethidine in the synovial fluid than in plasma, suggesting a local demethylation in the knee joint tissues. This site of drug oxidation has not earlier been demonstrated neither in vitro nor in vivo. The results suggest that pethidine given i.a. in the dose range of 50 to 200 mg results in analgesia due to both peripheral and central mechanisms. The significant systemic uptake of pethidine can cause unwanted side-effects.
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PMID:A comparison of 50, 100 and 200 mg of intra-articular pethidine during knee joint surgery, a controlled study with evidence for local demethylation to norpethidine. 1020 35

Somatosensory event-related potentials (SERPs) to painful electric standard stimuli under an odd-ball paradigm were analyzed in 12 high hypnotizable (HH), 12 medium hypnotizable (MH), and 12 low hypnotizable (LH) subjects during waking, hypnosis, and a cued eyes-open posthypnotic condition. In each of these conditions subjects were suggested to produce an obstructive imagery of stimulus perception as a treatment for pain reduction. A No-Analgesia treatment served as a control in waking and hypnosis conditions. The subjects were required to count the number of delivered target stimuli. HH subjects experienced significant pain and distress reductions during posthypnotic analgesia as compared to hypnotic analgesia and between these two analgesic conditions as compared to the two control conditions. Outside of hypnosis, these subjects remembered less pain and distress levels than they reported during hypnotic and posthypnotic analgesia treatments. In contrast, for waking-analgesia treatment, HH subjects remembered similar pain and distress levels to those they reported concurrently with the stimulation. HH subjects, during hypnotic and posthypnotic analgesia treatments, detected a smaller number of target stimuli and displayed a significant amplitude reduction of the midline frontal and central N140 and P200 SERP components. No significant SERP differences were observed for these subjects between treatments in waking condition and between hypnotic and posthypnotic analgesic treatments. For the MH and LH subjects no significant N140 and P200 amplitude changes were observed among analgesic conditions as compared to control conditions. These amplitude findings are seen as indicating that hypnotic analgesia can affect earlier and later stages of stimulus processing.
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PMID:Focused analgesia in waking and hypnosis: effects on pain, memory, and somatosensory event-related potentials. 1803 43

Continuous theta burst stimulation (cTBS) applied over the primary motor cortex (M1) can alleviate pain although the neural basis of this effect remains largely unknown. Besides, the primary somatosensory cortex (S1) is thought to play a pivotal role in the sensori-discriminative aspects of pain perception but the analgesic effect of cTBS applied over S1 remains controversial. To investigate cTBS-induced analgesia we characterized, in two separate experiments, the effect of cTBS applied either over M1 or S1 on the event-related brain potentials (ERPs) and perception elicited by nociceptive (CO2 laser stimulation) and non-nociceptive (transcutaneous electrical stimulation) somatosensory stimuli. All stimuli were delivered to the ipsilateral and contralateral hand. We found that both cTBS applied over M1 and cTBS applied over S1 significantly reduced the percept elicited by nociceptive stimuli delivered to the contralateral hand as compared to similar stimulation of the ipsilateral hand. In contrast, cTBS did not modulate the perception of non-nociceptive stimuli. Surprisingly, this side-dependent analgesic effect of cTBS was not reflected in the amplitude modulation of nociceptive ERPs. Indeed, both nociceptive (N160, N240 and P360 waves) and late-latency non-nociceptive (N140 and P200 waves) ERPs elicited by stimulation of the contralateral and ipsilateral hands were similarly reduced after cTBS, suggesting an unspecific effect, possibly due to habituation or reduced alertness. In conclusion, cTBS applied over M1 and S1 reduces similarly the perception of nociceptive inputs originating from the contralateral hand, but this analgesic effect is not reflected in the magnitude of nociceptive ERPs.
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PMID:Theta burst stimulation applied over primary motor and somatosensory cortices produces analgesia unrelated to the changes in nociceptive event-related potentials. 2397 82

Previous studies have suggested that looking at the hand can reduce the perception of pain and the magnitude of the ERPs elicited by nociceptive stimuli delivered onto the hand. In contrast, other studies have suggested that looking at the hand can increase tactile sensory discrimination performance, and enhance the magnitude of the ERPs elicited by tactile stimulation. These opposite effects could be related to differences in the crossmodal effects between vision, nociception, and touch. However, these differences could also be related to the use of different experimental designs. Importantly, most studies on the effects of vision on pain have relied on a mirror to create the illusion that the reflected hand is a direct view of the stimulated hand. Here, we compared the effects of direct versus mirror vision of the hand versus an object on the perception and ERPs elicited by non-nociceptive and nociceptive stimuli. We did not observe any significant effect of vision on the perceived intensity. However, vision of the hand did reduce the magnitude of the nociceptive N240 wave, and enhanced the magnitude of the non-nociceptive P200. Our results confirm that vision of the body differentially affects nociceptive and non-nociceptive processing, but question the robustness of visual analgesia.
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PMID:Looking at the hand modulates the brain responses to nociceptive and non-nociceptive somatosensory stimuli but does not necessarily modulate their perception. 2591 17

We evaluated the influence of hypnotizability, pain expectation, placebo analgesia in waking and hypnosis on tonic pain relief. We also investigated how placebo analgesia affects somatic responses (eye blink) and N100 and P200 waves of event-related potentials (ERPs) elicited by auditory startle probes. Although expectation plays an important role in placebo and hypnotic analgesia, the neural mechanisms underlying these treatments are still poorly understood. We used the cold cup test (CCT) to induce tonic pain in 53 healthy women. Placebo analgesia was initially produced by manipulation, in which the intensity of pain induced by the CCT was surreptitiously reduced after the administration of a sham analgesic cream. Participants were then tested in waking and hypnosis under three treatments: (1) resting (Baseline); (2) CCT-alone (Pain); and (3) CCT plus placebo cream for pain relief (Placebo). For each painful treatment, we assessed pain and distress ratings, eye blink responses, N100 and P200 amplitudes. We used LORETA analysis of N100 and P200 waves, as elicited by auditory startle, to identify cortical regions sensitive to pain reduction through placebo and hypnotic analgesia. Higher pain expectation was associated with higher pain reductions. In highly hypnotizable participants placebo treatment produced significant reductions of pain and distress perception in both waking and hypnosis condition. P200 wave, during placebo analgesia, was larger in the frontal left hemisphere while placebo analgesia, during hypnosis, involved the activity of the left hemisphere including the occipital region. These findings demonstrate that hypnosis and placebo analgesia are different processes of top-down regulation. Pain reduction was associated with larger EMG startle amplitudes, N100 and P200 responses, and enhanced activity within the frontal, parietal, and anterior and posterior cingulate gyres. LORETA results showed that placebo analgesia modulated pain-responsive areas known to reflect the ongoing pain experience.
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PMID:Hypnotizability and Placebo Analgesia in Waking and Hypnosis as Modulators of Auditory Startle Responses in Healthy Women: An ERP Study. 2748 48