European journal of pain : EJP
-
Randomized Controlled Trial
Quality discrimination for noxious stimuli in secondary somatosensory cortex: a MEG-study.
A complex cortical network is believed to encode the multi-dimensionality of the human pain experience. In the present study, we used magnetoencephalography (MEG) to examine whether the cortical processing of noxious stimuli with different psychophysical properties differs in primary (S1) and secondary (S2) somatosensory cortices. Noxious low (condition 1) and high (condition 2) current density stimulations of equal stimulus intensities were applied at the left forearm in 12 subjects in a randomised order. ⋯ Higher activations of bilateral S2 were significantly correlated with higher scores for the sensory-discriminative component during condition 2. In contrast, corresponding scores for the affective-motivational pain dimension did not differ between both conditions. Therefore, concerning the sensory dimension of the human pain experience we conclude that the S2 cortex is involved in the encoding of quality discrimination.
-
Randomized Controlled Trial
Effect of somatostatin analogue octreotide on pain relief after major abdominal surgery.
Octreotide acetate is an 8-amino-acids synthetic octapeptide analogue of somatostatin with much-enhanced duration of action and lower incidence of side effects. We assessed the utility of using intravenous octreotide as an adjuvant to opioid analgesia that might exert a post-operative opioid-sparing effect. ⋯ We demonstrated that perioperative octreotide intravenous infusion could be an adjuvant to opioid analgesia as it exerted a piritramide opioid-sparing effect. We encountered more systemic side effects such as nausea, abdominal discomfort, and diarrhea in the octreotide group than in the control group. Our findings could be beneficial to patients who cannot tolerate the adverse effects of opioids.
-
Randomized Controlled Trial Comparative Study
Activating endogenous visceral pain modulation: a comparison of heterotopic stimulation methods in healthy controls.
All sensory input underlies modulation by endogenous central nervous system pathways. Dysfunctional endogenous pain modulation has been demonstrated in central sensitization and in several pain syndromes, including Irritable Bowel Syndrome (IBS) Activation of endogenous visceral pain modulation by heterotopic stimulation was compared using different methods. Rectal electrical or distension pain alone or with simultaneous (i.e. heterotopic) noxious hand or foot cold stimulation were investigated in randomized sequence in 14 male and 1 female healthy subjects. ⋯ Potent and consistent activation of endogenous visceral pain inhibition was achieved with heterotopic cold pain limb stimulation. Somato-visceral convergence did not affect the effectiveness of induction of endogenous visceral pain inhibition in healthy subjects, as hand and foot heterotopic stimulation resulted in similar pain inhibition. Pain facilitation, as shown earlier in IBS patients, was not evident in healthy controls.
-
Randomized Controlled Trial Comparative Study
Gastrointestinal symptoms under opioid therapy: a prospective comparison of oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine.
The purpose of this trial was to evaluate the effect of long-term treatment with oral sustained-release hydromorphone, transdermal fentanyl, and transdermal buprenorphine on nausea, emesis and constipation. ⋯ Gastrointestinal symptoms of cancer pain patients undergoing an opioid therapy are related to multifactorial causes. Transdermal opioids showed no benefit over oral controlled-release hydromorphone with regard to gastrointestinal symptoms. The conversion ratios for transdermal fentanyl, transdermal buprenorphine, and oral hydromorphone did not accord to the literature, because of differing occurrences of opioid tolerance after long-term therapy.
-
Randomized Controlled Trial
Temporal summation of pressure pain during muscle hyperalgesia evoked by nerve growth factor and eccentric contractions.
Nerve growth factor (NGF) has a key role in the generation and potentiation of pain. Its centrally sensitizing effects may facilitate pain responses to noxious stimulus. This study assessed (1) the influence of NGF on delayed onset muscle soreness (DOMS) in shoulder muscles; and (2) the temporal summation of pressure pain during hyperalgesia induced by NGF and DOMS. ⋯ The NGF injected side had higher pain ratings during temporal summation at 1s ISI compared with the contralateral side 24h after injections. Intramuscular administration of NGF intensified the DOMS responses, evoking facilitated temporal summation. Central as well as peripheral sensitization mechanisms may play a role in the facilitation.