Pain
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Clinical Trial
Muscle palpation with controlled finger pressure: new equipment for the study of tender myofascial tissues.
While manual palpation is the most important method for evaluation of tender myofascial tissues, it lacks reliability. Therefore, we have developed an instrument, called a 'palpometer', which allows the measurement of pressure exerted during palpation. The palpometer consists of a thin pressure-sensitive plastic device attached to the palpating finger, and of a scale recording the pressure applied to the device. ⋯ Thus, a reliable instrument for measuring pressure intensities during palpation of myofascial tissue has been developed. The large variation in palpation pressures between observers indicates that palpation of tender myofascial tissue may be considerably improved by use of the palpometer. This instrument will be indispensable in research studies employing palpation and in the training of physicians to diagnose myofascial pain disorders.
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Randomized Controlled Trial Clinical Trial
Chronic tension-type headache: amitriptyline reduces clinical headache-duration and experimental pain sensitivity but does not alter pericranial muscle activity readings.
In a double-blind, placebo-controlled trial, the effect of 75 mg of a slow-release formulation of amitriptyline on the clinical severity of chronic tension-type headache and on headache-associated neurophysiological parameters (EMG activity, exteroceptive suppression of temporal muscle activity, contingent negative variation (CNV) and experimental pain sensitivity) was investigated. All of the patients treated had a history of headaches of many years' standing and many of them had failed attempts at treatment. In the amitriptyline group, a significant reduction in daily headache duration was already found in the 3rd week of treatment, while in the placebo group no significant changes in headache duration were to be seen. ⋯ The sensitivity to suprathreshold experimental pain, however, was significantly reduced. The data show a statistically relevant reduction of daily headache duration. However, they also show that amitriptyline can only partly alleviate chronic headaches but cannot cure them.
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Case Reports Comparative Study Clinical Trial
Altered pain and temperature perception following cingulotomy and capsulotomy in a patient with schizoaffective disorder.
Recent studies have renewed interest in the role of limbic structures, such as the cingulate cortex, in nociception. To investigate the involvement of the limbic system in pain and temperature perception further, we have quantified ratings of innocuous and noxious thermal stimuli in a patient with schizoaffective disorder before and after 2 surgical procedures. Psychophysical tests were conducted at a control session prior to surgery. ⋯ These altered ratings of noxious heat and cold stimuli were reflected on both a pain intensity and pain affect (unpleasantness) scale. In summary, these data suggest that cingulotomy and capsulotomy disinhibited the patient's noxious heat and cold appreciation. These findings provide support for a role of the cingulate cortex and frontal cortical regions in the perception of innocuous and noxious thermal stimuli and suggest that under normal conditions, these areas may act to suppress the subjective intensity of noxious heat and cold.
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Seventeen drawings of localised low-back pain were analysed by two assessors using 4 systems. Three were grid-based systems and one was by computer. The mean area or 'extent' was calculated to be 7.7%, 4.7%, 3.6% and 2.3% of the body outline using 45, 200, 560 and 61,102 section analyses, respectively. ⋯ Correlation coefficients of extent between the systems varied from 0.46 to 0.94. Correlation was highest between systems of adjacent magnitude of sections. It is concluded that grid-based assessment of small areas overestimates the actual area of pain and this may account for the lack of sensitivity to change in clinical status.
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This study evaluated the pain-related behaviours induced by 2 models of peripheral sciatic nerve injuries in the rat: transient nerve crush and chronic constriction injury (CCI). Various lesions of the saphenous nerve were performed in order to investigate the role of saphenous innervation in behavioural disorders induced by these nerve injuries. Behavioural testing included assessment of responses to phasic stimulation (mechanical and thermal) and observation of 'spontaneous' pain-related behaviour. ⋯ Section without ligation of the saphenous nerve induced comparable results in rats with sciatic crush, but did not significantly modify nociceptive behaviours in rats with CCI. These data emphasise the role of adjacent saphenous nerve in the mechanisms of pain-related disorders induced by these peripheral nerve lesions. On the contralateral paw, pain-related modifications were also observed in both models, suggesting that unilateral nerve lesions induce remote modifications extending beyond the site of the injured nerve.