Pain
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Previous studies have provided evidence of an increased sensitivity to pain, a decreased hypothalamic opioid tone, and decreased cerebrospinal fluid (CSF) beta-endorphin (beta-EP) concentration in patients with primary chronic headache. We applied separate specific radioimmunoassays for beta-EP in CSF and plasma on samples from age-matched controls and a group of 50 patients with chronic tension-type headache (CTH) fulfilling the diagnostic criteria set by the International Headache Society. ⋯ Plasma and CSF beta-EP concentrations did not correlate. Reversed-phase high performance liquid chromatography (HPLC) of CSF pools from the headache patients and controls revealed similar profiles of beta-EP-immunoreactivity both when C-terminally and N-terminally directed antisera were used, suggesting a normal post-translational processing of the pro-opiomelanocortin gene in patients with CTH. beta-EP is not involved in the pathogenesis of CTH, or such a role is not reflected in CSF or plasma concentrations of the neuropeptide.
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Although reflexes are recognized as protective responses to noxious stimuli, less is known about voluntary behavioral responses to cancer pain, which could provide clinicians with important diagnostic and therapeutic information. Forty-five patients with lung cancer were studied in their homes on 2 occasions to identify pain behaviors and to examine relationships between behaviors and selected variables. Patients completed the McGill Pain Questionnaire (MPQ) and Visual Analogue scale (VAS). ⋯ Simultaneous multiple regression indicated that length of time pain was experienced, number of pain sites, pain quality, and pain intensity accounted for 41% of the variance in the number of pain control behaviors. None of the taped behaviors was reported as performed to express pain, and few of the patients reported that pain prevented behavior during the video session. Results clarify the pain-behavior construct, provide insight about the multidimensional nature of lung cancer pain, and suggest directions for behavioral interventions to augment pharmacological therapy for lung cancer pain.
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Pressure-pain threshold (PPT) measurements were performed with a pressure algometer, at 22 specified points in the head in patients with cervicogenic headache (n = 32), migraine (with and without aura) (n = 26) and tension-type headache (n = 17). Comparisons were made with a group of healthy controls (n = 20). The average PPT differed significantly between the groups (ANOVA, F = 9.5, P < 0.0005), largely caused by the low threshold in cervicogenic headache patients. ⋯ The ratio between the dominant and non-dominant sides (all 11 points on each side) was 0.85 in cervicogenic headache, whereas it was 0.99 in migraine patients with side preponderance of the pain. The present results support the view that the pathogenesis of cervicogenic headache differs from that of migraine and tension-type headache. The results may further support the theory that fibres from the C2 level (innervating the occipital part of the head) may be included in the pathogenetic mechanism in cervicogenic headache.
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The principle finding of the present study is that there are two types of mechanical hyperalgesia developing in human hairy skin following injurious stimuli. Mechanical hyperalgesia comprises a dynamic component (brush-evoked pain, allodynia) signalled by large myelinated afferents and a static component (hyperalgesia to pressure stimuli) signalled by unmyelinated afferents. While the static component is only found in the injured area, the dynamic component also extends into a halo of undamaged tissue surrounding the injury. ⋯ The effect of a nerve compression block of the superficial radial nerve on these sensations was tested in 14 experiments. When the ability to perceive light touch had been abolished, there was also no touch-evoked pain, indicating that this component of mechanical hyperalgesia is mediated by large-diameter primary afferents. At a later stage of the block when the subjects' ability to perceive cold stimuli had also been lost, application of cool stimuli still eliminated on-going burning pain, suggesting that pain relief afforded by cooling the skin acts at the peripheral receptor level and not by central masking.(ABSTRACT TRUNCATED AT 400 WORDS)
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Neuro-anatomical and behavioral findings suggest that spontaneous and deliberate facial expressions are regulated by separate systems. The present study examined whether spontaneous and deliberate expressions of pain could be distinguished and, if so, the dimensions on which they differ. Forty subjects were exposed to electric shocks that varied from painless to strong pain. ⋯ The intensity of deliberate expressions was related to role-playing ability. The results suggest that deliberate and spontaneous expressions of pain probably differ in intensity, topography and temporal features. They suggest that facial expressions of pain have different determinants than other forms of pain behavior.