European journal of pain : EJP
-
Deep tissue pain can be related to reduced muscle blood flow, which comprises the metabolic demand under muscle work. The tissues and receptors involved in nociception after ischaemic muscle contractions are not known. The concentration of adenosine is increased after ischaemic contractions and might act as an algesic substance. ⋯ During hypertonic saline infusions, the pressure pain threshold was decreased compared with before and immediately after the pain had vanished. The present study shows that pharmacological levels of adenosine in skeletal muscle did not induce pain. Excitation of muscle nociceptors by hypertonic saline evoked hyperalgesia, larger areas of pain, and a different quality of pain compared with ischaemic contractions, suggesting that the pain after ischaemic contractions is mediated by other populations of nociceptors in muscle and/or other tissues than excited by hypertonic saline.
-
Fifteen to 50% of AIDS-patients suffer from distal predominantly sensory neuropathy (DSP), which is commonly associated with painful symptoms. In the present study, we have focused on the function of fine calibre nerve channels, in 36 consecutive HIV-1-infected patients with painful (PPN) (n=20; 54%) and non-painful (PN) (n=16) sensory neuropathy, assessed by clinical, quantitative thermal testing (QTT) (31/36), and peripheral nerve conduction examination (32/36). Control QTT data were obtained from 49 healthy subjects with a corresponding age- and sex distribution. ⋯ Furthermore, increased pain sensitivity to cold was found only in patients with painful symptoms (p<0.05). An abnormal outcome of any QTT parameter was found in all patients with pain, but only among 62% of patients without pain, p<0.01, and the cumulative frequency of abnormalities in any of the four thermal percepts (warmth, cold, heat pain, and cold pain) was higher in patients with painful symptoms, p<0.0001. This study demonstrates a more pronounced impairment of C-fibre-mediated innocuous warm perception in patients with painful neuropathy, which in the setting of impaired or absent heat pain perception suggests a more generalised loss of function in somatosensory C-fibre channels.
-
Increased anxiety is believed to correlate with increased pain sensitivity in men and women. However, one laboratory-based study and one clinical-based study have offered evidence to suggest that the effect of anxiety in modulating pain sensitivity is specific to men only. The aim of the present study was to examine further whether anxiety differentially effects men and women's report of experimentally induced pain. ⋯ Anxiety is an important factor when considering gender differences in pain perception and warrants further investigation.
-
The aim of this research was to explore the impact that diagnostic status has on information processing biases among chronic pain (CP) and ankylosing spondylitis (AS) patients. AS patients, CP patients, and healthy hospital staff controls, completed a questionnaire and short computer task. During the computer task participants endorsed sensory, depression, illness, and neutral adjectives, following a cue question (which facilitated encoding of the adjectives in relation to the self). ⋯ The diagnosed AS group showed a bias towards sensory stimuli, perhaps reflecting the presence of an enduring and over-riding pain schema. The non-pain control group also displayed a sensory bias, which was attributed to a frequency effect as a result of working in an environment where they were regularly exposed to sensory language. The results are discussed in relation to existing literature in this area and implications for clinical practice are provided.
-
Randomized Controlled Trial Clinical Trial
Prophylactic tolperisone for post-exercise muscle soreness causes reduced isometric force--a double-blind randomized crossover control study.
The role of tolperisone hydrochloride, a centrally acting muscle relaxant in relieving painful muscle spasm is recently being discussed. The present study hypothesizes that the prophylactic use of tolperisone hydrochloride may effectively relieve post-exercise muscle soreness, based on the spasm theory of exercise pain. Twenty male volunteers, aged 25.2 +/- 0.82 years (mean +/- SEM) participated in 10 sessions in which they received oral treatment with placebo or the centrally acting muscle relaxant tolperisone hydrochloride (150 mg) three times daily for 8 days, in randomized crossover double-blind design. ⋯ The EMG RMS amplitude was also reduced immediately after the exercise, but was increased at 24 and 48 h. Isometric force was reduced immediately after the exercise as compared to days 1, 6, and the 24 and 48 h post-exercise assessments with a greater reduction following the tolperisone hydrochloride treatment and the reduction was more in tolperisone group as compared to the placebo group. The results suggest, that the prophylactic intake of tolperisone hydrochloride provides no relief to pain in course of post-exercise muscle soreness but results in reduction in isometric force.