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The analgesic responses of humans and laboratory animals are characterized by substantial individual differences. The genetic basis of this variability can be studied experimentally in rodents using a program of selective breeding. One such program selected for high (HA) and low (LA) swim stress-induced analgesia (SSIA) on the hot-plate (56°C) test in Swiss-Webster mice. These lines, which have...
Forty male veterans who had been injured during their military service in the Israeli Defense Forces were assessed for pain threshold and tolerance in a thermal pain procedure. Based on their medical records, subjects were classified by three independent judges as having been either severely or lightly injured. Veterans who had been severely injured had much higher threshold and tolerance for thermal...
A patient suffered multiple fractures of the right leg and a left brain-stem infarction involving the anterolateral fasciculus of the central nociceptive system following multiple trauma. Later, the right leg was amputated, resulting in spontaneous and touch-evoked phantom pain and mechanical stump allodynia. However, quantitative sensory testing revealed considerable impairment of sensations normally...
A previous study of this laboratory showed that an acute myositis (which is associated with increased activity in slowly conducting muscle afferent fibres) is followed by marked excitability changes in the dorsal horn within a few hours. The present work addresses the question as to how the responsiveness of dorsal horn neurones changes when the same muscle nerve is transected. In anaesthetized...
Extending the earlier work of Mikail et al. (1993), a confirmatory factor analysis (CFA; LISREL VII) of a 4-factor model of pain assessment was tested. This model, comprised of the Beck Depression Inventory (BDI) and 13 subscales of the McGill Pain Questionnaire (MPQ) and the West Haven-Yale Multidimensional Pain Inventory (WHYMPI), adequately accounted for the pain experience with minimal overlap...
An electromyographic (EMG) study was carried out in 40 anaesthetized rats to determine if the activity of jaw and neck muscles could be influenced by injection of the small-fibre excitant and inflammatory irritant mustard oil into the region of the temporomandibular joint (TMJ). Injection of a vehicle (mineral oil, 20 μl) did not produce any significant change in EMG activity. In contrast, injection...
In 40 rats anaesthetized with enflurane, we identified convergent dorsal horn neurones responding to both noxious (pinch) and innocuous (brush) mechanical stimulation of their receptive fields on the tail. We recorded extracellular activity before and during ischaemia of the receptive fields, as well as during subsequent reperfusion. Two NSAIDs, indomethacin and diclofenac sodium, or saline were...
The question whether opioids relieve neuropathic pain remains a controversial issue. Experimental as well as clinical studies report contradictory results. This study investigated the consumption of fentanyl, a short-acting opioid, in rats with neuropathic pain, induced by partial sciatic nerve injury. The experiment consisted of a drug choice procedure in which the animals could choose between...
Because a variety of mechanisms may generate pain in neuropathic pain syndromes, conventional clinical trial methods may fail to identify some potentially useful drugs; a drug affecting just a single mechanism may work in too few patients to yield a statistically significant result for the trial. To test a previous clinical observation that approximately one-quarter of patients with painful diabetic...
The PIPER (Prompting Intensity of Pain Electronic Recorder) is a compact data-logging device, easily worn by a subject. It emits audible beeps at pre-programmed times, prompting the subject to enter a pain rating by button press. Ratings are stored, for later down-loading. We report two studies suggesting that PIPER pain ratings have good reliability, and good validity assessed against the VAS...
In this review, the effectiveness of behavioral and pharmacological treatments for pediatric migraine was quantitatively summarized following the meta-analytic approach outlined by Hedges and Olkin (1985). A first meta-analysis based on treatment outcome within treatment conditions revealed that thermal biofeedback and interventions combining biofeedback and progressive muscle relaxation seem to...
The present study examined the maturation of nociceptive primary afferents using expression of Fos-like immunoreactivity in the second-order spinal cord neurons as an anatomical and functional marker. Pinch, immersion in hot water, or formalin injection applied to the hindpaw was used as the peripheral noxious stimulus in awake 0-, 1-, 2-, 3-, and 14-day-old rat pups. On the day of birth, all 3...
Reflex sympathetic dystrophy (RSD) is a pain syndrome that is characterised by autonomic, motor and sensory disturbances. The syndrome has often been associated with sympathetic dysfunction. Therefore, we investigated whether there are disturbances in the sympathetic function of skin microcirculation in the various clinical stages of RSD. Laser Doppler flowmetry (LDF) was used to obtain information...
The antinociceptive action of the systematically administered α 2 -adrenoceptor agonist clonidine was evaluated in a rat model of peripheral unilateral mononeuropathy produced by loose ligatures around the common sciatic nerve, using nociceptive tests based on mechanical (vocalization threshold to paw pressure) or thermal (struggle latency to paw immersion in a cold (10°C) or hot (44°C) water...
In this study, we recorded the single-unit activity of the dorsal raphe nucleus (DRN) in rats tested first awake and, a few days later, anesthetized with sodium pentobarbital and recorded again. This was achieved by means of a small chronically implanted device supporting a 25 μm platinum-iridium wire as the recording electrode. In both the awake and anesthetized conditions, and in agreement with...
Pain intensity in carpal tunnel syndrome (CTS) was correlated with neuro- and psychophysiological parameters related to the function of different nerve fiber classes within the median nerve in 23 patients. Control data were obtained from 16 normal subjects.Mean intensity of all pain attacks which occurred 14 days before surgical treatment was assessed on visual analogue scales (average CTS pain)...