Showing papers in "Pain in 1981"
TL;DR: It is indicated that pain scale preference does not influence pain intensity report, but there are some clinical situations in which a numeric scale is likely to yield a better measure of pain intensity.
Abstract: Chronic pain patients reported pain intensity on each of 3 pain intensity scales, the visual analog, numerical and adjectival scales, and then ranked the scales in order of perceived best communication of pain intensity. All patients were able to complete an adjectival scale but 11% were unable to complete a visual analog scale and 2% failed at a numeric scale. The intensity of the pain ratings on the 3 scales were significantly correlated and there were no reliable differences in reported intensity as a function of preference. Pain intensity was reliably higher on each scale for depressed-anxious patients as compared to non-depressed/non-anxious patients. Patients completing all 3 scales indicated a significant preference for the adjectival scale but the basis for this preference did not appear related to sex, etiology of pain, affective variables nor selected psychological variables. These data indicate that pain scale preference does not influence pain intensity report. Nevertheless, there are some clinical situations in which a numeric scale is likely to yield a better measure of pain intensity.
566 citations
554 citations
TL;DR: The chronic presence of scratching, and the effects of morphine and naloxone on it, allow us to consider it as a possible pain‐related behaviour and therefore as aossible parameter for the study of chronic pain in animals.
Abstract: Adjuvant-induced arthritic rats were observed clinically and behaviourally. The clinical disease has a duration of greater than 1 month and can be divided into a pre-clinical (1–10 days), an acute (15–30 days), postacute (30–50 days) and a late phase (> 50 days). Adjuvant arthritis induces significantly quantitative changes in the rats' behaviour. Two types of behavioural change merit special attention: freezing (arresting) and scratching. Freezing is significantly increased in the acute and postacute phases; it is increased by morphine, this effect being blocked by naloxone. Scratching is significantly increased in the acute, postacute and late phases; it is decreased by morphine, this effect being blocked by naloxone. The chronic presence of scratching, and the effects of morphine and naloxone on it, allow us to consider it as a possible pain-related behaviour and therefore as a possible parameter for the study of chronic pain in animals.
200 citations
TL;DR: The cross‐modality matching methods of Stevens have been used by Gracely and his colleagues to provide numerical values for “verbal pain descriptors” that provide reliable, objective and valid ratio‐level measurement of the sensory and affective dimensions of pain.
Abstract: The cross-modality matching methods of Stevens [16] have been used by Gracely and his colleagues [4–6] to provide numerical values for “verbal pain descriptors”. These numerical values, it is claimed, provide reliable, objective and valid ratio-level measurement of the sensory and affective dimensions of pain. Each of these claims is critically examined.
198 citations
TL;DR: It is concluded that spinothalamic neurons that convey nociceptive input from the skin may also respond to noxious visceral stimuli, and viscerosomatic convergence provides a neural substrate for the phenomenon of cutaneous referral of visceral pain.
Abstract: The responses of 66 primate spinothalamic neurons to natural stimulation of the urinary bladder and testicle were studied with extracellular recording techniques in order to elucidate the neural basis for referral of visceral pain. Thirty-eight out of 53 cells located at the thoraco-lumbar junction or in sacral segments responded to noxious cutaneous stimuli, and 84% of these also exhibited phasic and/or tonic excitatory responses to distension of the urinary bladder. Seventeen out of 20 of these units, all located at the thoraco-lumbar junction, were excited by compression of the ipsilateral testicle. The response was graded with the compressive force. Excitatory responses to noxious heat and an irritant chemical (KCl) applied to the exposed testicular surface were also observed. Twelve sacral units having inputs from deep receptors of the tail exhibited mixed excitatory and inhibitory responses to bladder distension. A further 2 cells located at the thoracolumbar junction responded only to cutaneous tactile stimuli, and 13 cells located at the lumbosacral enlargement were tonically inhibited by bladder distension. It is concluded that spinothalamic neurons that convey nociceptive input from the skin may also respond to noxious visceral stimuli. Such viscerosomatic convergence provides a neural substrate for the phenomenon of cutaneous referral of visceral pain.
164 citations
TL;DR: The research suggests that the affective dimension score of the McGill Pain Questionnaire can serve as a useful index of the overall affective status of pain patients and given this interpretation the dimension has good construct validity.
Abstract: The research reported here used a population of chronic benign pain patients and examined the relationship between scores in the affective dimension of the McGill Pain Questionnaire and independent measures of affect and infirmity. The data indicated that patients who reported high affective dimensional scores were significantly more depressed and anxious and somatized more than patients who reported low affective scores. Similarly, these high affective patients reported significantly greater perceived infirmity secondary to their pain. These results suggest that the affective dimension score of the McGill Pain Questionnaire can serve as a useful index of the overall affective status of pain patients and given this interpretation the dimension has good construct validity.
150 citations
TL;DR: In this article, the authors measured β-endorphin cerebrospinal fluid (CSF) content in 13 patients without pain problems and found a time dependent increase of CSF β endorphin in the group of patients studied.
Abstract: To test the hypothesis of opiate-like peptide release after transcutaneous electrotherapy we measured β-endorphin cerebrospinal fluid (CSF) content in 13 patients without pain problems. The results indicate a time dependent increase of CSF β-endorphin in the group of patients studied. This fact suggests that the analgesic properties of the treatment may be ascribed to an involvement of the endogenous opiates system, independently from the basal clinical conditions of the patients.
144 citations
TL;DR: Observation that in groups receiving progressively higher doses of morphine, the percentage of patients within the low pain level cluster increased is most consistent with the concept that there is a step component for narcotic analgesia.
Abstract: The effects of placebo and varying doses of intravenous morphine were studied in 74 patients. All patients underwent extraction of impacted mandibular third molars. Two hours after onset of anesthesia all patients received a placebo (intravenous saline). One hour after the placebo administration each patient received either a second placebo or, 4, 6, 8 or 12 mg of morphine, double blind, via a hidden intravenous line. Pain level was evaluated 50 min after morphine administration using a visual analog scale. Pooled data from all patients produced a dose-response curve asymptotic by 8 mg. The mean pain relief following the second placebo was found to be between that obtained following hidden administration of 4 and 6 mg of morphine. When pain level reports for individuals were plotted two unexpected features appeared. First, no patient reported complete relief, even at the highest dose of morphine (12 mg). Second, pain level reports 50 min following each dose of morphine tended to be in two clusters. Within each cluster the average pain was independent of the dose of morphine administered. However, in groups receiving progressively higher doses of morphine, the percentage of patients within the low pain level cluster increased. These latter observations are most consistent with the concept that there is a step component for narcotic analgesia.
141 citations
126 citations
TL;DR: It appears that the PAG‐ and NRM‐induced effects on the reflex and oralis neurons are not dependent on relays via caudalis, and some of the suppressive influences on responses to oral‐facial stimuli could be reversed by the administration of the opiate antagonist naloxone.
Abstract: 1. (1) The effects of stimulation of the nucleus raphe magnus (NRM) and the periaqueductal gray (PAG) were tested on the digastric (jaw-opening) reflex and on the activity of functionally identified single neurons recorded in trigeminal (V) subnucleus oralis in the brain stem. Reflex and neuronal responses evoked by tooth pulp stimulation could be readily suppressed for 250–1000 msec by PAG and NRM conditioning stimuli. The effects were not specific for tooth pulp afferent inputs, however, since suppression was also apparent in jaw-opening reflex responses evoked by low-intensity electrical or tactile stimulation of oral-facial sites, and in the mechanically or electrically evoked responses of oralis neurons with localized low-threshold mechanoreceptive fields. 2. (2) The modulatory effects on the jaw-opening reflex and oralis neuron activity were not altered by reversible cold block of synaptic transmission in V subnucleus caudalis. Thus it appears that the PAG- and NRM-induced effects on the reflex and oralis neurons are not dependent on relays via caudalis. 3. (3) Some of the suppressive influences on responses to oral-facial stimuli could be reversed by the administration of the opiate antagonist naloxone. This suggests that some of the modulatory influences involve endogenous opiate-related mechanisms. 4. (4) Many of the oralis neurons were identified as trigeminothalamic relay neurons on the basis of their antidromic response to ventrobasal thalamic stimulation; PAG and NRM conditioning produced not only a suppression of their orthodromic responses to oral-facial stimuli but also caused a decrease in the antidromic excitability of the relay neurons. This decrease may be indicative of raphe-induced postsynaptic inhibition of oralis neurons, and/or presynaptic facilitation of their thalamic endings.
121 citations
TL;DR: It is hypothesized that anhedonia is a measure separate from depression and may be more closely linked to suffering behavior than to pain behavior, as it did not discriminate among facial pain patients and in particular did not distinguish between so‐called functional and organic illness.
Abstract: Depression, anhedonia, state anxiety (A-state), trait anxiety (A-trait), and self-reported pain estimate were measured in almost 500 facial pain patients. These patients were divided into 3 diagnostic categories: myofascial pain dysfunction syndrome (MPD) [8], arthritis of the temporomandibular joints (TMJ arthritis), and trigeminal neuralgia. Three control groups were measured for comparison. They consisted of a normal, or non-patient group, a group of arthritis patients, and a group of movement disorder patients attending a neurology clinic. Among the facial pain patients and the normal controls few differences were found with regard to anhedonia and depression. The arthritis and neurology patients produced significantly higher depression and anhedonia scores than did several of the facial pain groups. Pain estimate ranged from 0 for the controls, to a mean of 67.6 ± 31.3 for the trigeminal neuralgia patients with the MPD ( x = 56.2 ± 32.5 ) and the TMJ arthritis patients ( x = 46.7 ± 30.8 ) somewhat lower. Clinical variables such as duration of pain, help seeking behavior and total number of symptoms were correlated with depression but not with anhedonia scores. It is hypothesized that anhedonia is a measure separate from depression and may be more closely linked to suffering behavior than to pain behavior. Psychological variables did not discriminate among facial pain patients and in particular did not distinguish between so-called functional and organic illness.
TL;DR: It is concluded that there are chemical changes in the spinal cord terminals of fine afferents after local peripheral capsaicin.
Abstract: (1) Capsaicin solution was applied for 15 min around a 1 cm length of sciatic nerve in the mid upper leg of adult rats. (2) Electron microscopic examinations of the nerve in the treated region after 14 days shows no signs of degeneration of either myelinated or unmyelinated fibres attributable to the capsaicin. (3) Fluoride resistant acid phosphatase FRAP disappears from the central terminals of the treated nerve by 7 days. (4) 1.5 mM capsaicin is sufficient to product a complete reduction of FRAP in the spinal cord. (5) The peptides substance P and cholecystokinin (CCK) are markedly depleted in the region of spinal cord terminations of the treated nerve at 14 days. (6) Substance P and CCk are not affected in spinal cord regions other than in the unmyelinated afferent terminal zone. Similarly neurotensin and neurophysin which are not present in afferent fibres are not influenced by capsaicin treatment of the sciatic. (7) It is concluded that there are chemical changes in the spinal cord terminals of fine afferents after local peripheral capsaicin.
TL;DR: The weakness of the association between the quality of sensation and masseter inhibitory period configuration was demonstrated in a double‐blind study of the effects of a narcotic analgesic, fentanyl, and although the strengths of non‐pain and pain sensations were reduced significantly after fentanyl, there were no changes in the masseter inhibitedory periods.
Abstract: The masseter inhibitory period and sensations evoked by electrical tooth pulp stimulation were assessed in 30 human subjects. Five intensities of electrical stimuli, producing sensations varying from below sensory detection threshold to suprathreshold pain, were applied to upper central incisors. At each stimulus intensity a train of 30, 1-msec, cathodal pulses with an interpulse interval of 2 sec was applied. The averaged masseter activity evoked by the 30 pulses at a fixed stimulus intensity was compared to the quality of the sensation elicited. The threshold for the masseter inhibitory period coincided approximately with an individual's detection threshold for the tooth pulp stimulation. Three configurations of masseter inhibitory periods (single, double and merged) were produced by different stimulus intensities. However, no particular configuration was associated unequivocally with pain sensation. Increases in stimulus intensity evoked changes both in the configuration of the masseter inhibitory period and in the quality of the sensation produced. Chi square analyses showed significant, but progressively weaker, associations between: (1) masseter inhibitory period configuration and stimulus intensity; (2) quality of sensation and stimulus intensity; and (3) quality of sensation and masseter inhibitory period configuration. The weakness of the association between the quality of sensation and masseter inhibitory period configuration also was demonstrated in a double-blind study of the effects of a narcotic analgesic, fentanyl. Although the strengths of non-pain and pain sensations were reduced significantly after fentanyl, there were no changes in the masseter inhibitory periods.
TL;DR: It is concluded that transcutaneous nerve stimulation is a valuable pain reducer and gives a more rapid restoration of cervical mobility in acute cervical pain.
Abstract: Thirty patients with acute cervical pain were randomized into 3 groups and treated with neck collar, transcutaneous nerve stimulation, or manual therapy. The improvement was rapid in all groups, but the restoration of the cervical mobility was significantly more rapid in the transcutaneous nerve stimulation group. Some of the patients with manual therapy treatment had remarkably quick symptom reduction, although this was not significantly better than the collar alone. It is concluded that transcutaneous nerve stimulation is a valuable pain reducer and gives a more rapid restoration of cervical mobility in acute cervical pain.
TL;DR: It appears that a central nervous system abnormality best accounts for the clinical features of causalgia, which is the presence of continuous, burning pain distal to a site of injury.
Abstract: In this report, the following criteria were used for the diagnosis of causalgia: (a) the presence of continuous, burning pain distal to a site of injury; (b) hyperalgesia and allodynia in the painful area; and (c) a traumatic event occurring proximal in the painful area and within weeks prior to the onset of pain. The McGill pain questionnaire was used to test the selected pain population for homogeneity. The scores were similar among the patients and different from the scores in other pain syndromes. It is concluded that the above criteria are sufficient to make the diagnosis of causalgia. In addition, it appears that a central nervous system abnormality best accounts for the clinical features of causalgia.
TL;DR: Results indicate a consistent negative relationship, i.e., the more exercise performed, the fewer the pain behaviors, contrary to the frequently observed physician prescription with chronic pain to limit exercise when pain increases.
Abstract: Chronic pain patients typically display reduced activity level attributed to pain and implying a positive correlation between exercise or activity and pain complaints. This study correlated observed pain complaints with amount of prescribed exercise performed by chronic pain patients when exercising to tolerance. Patients were in evaluation of earliest stages of multi-modal treatment. Exercises were physician prescribed to assess use of involved body parts and to promote general activity level. Patients were instructed to do exercise repetitions until pain, weakness of fatigue caused them to stop. Patients decided when to stop. Observations of amount of exercise performed were correlated with observed visible or audible indications of pain or suffering (pain behaviors). Results indicate a consistent negative relationship, i.e., the more exercise performed, the fewer the pain behaviors. This finding is contrary to the frequently observed physician prescription with chronic pain to limit exercise when pain increases.
TL;DR: In the patients who experienced pain reduction there was usually a best point at which vibration had a greater pain alleviating effect than at other points, and at some points the stimulation added to the pain.
Abstract: The present paper describes the effect of vibratory stimulation on pain of dental origin in 36 patients. The patients were from a clinic for dental surgery and all had suffered pain from pulpal inflammation, apical periodontitis or postoperative pain following extraction of an impacted wisdom tooth for more than 2 days. Vibration at 100 Hz was applied to various points in the facial region or the skull. All the patients except three experienced an effective reduction of the intensity of the pain. In the patients who experienced pain reduction there was usually a best point at which vibration had a greater pain alleviating effect than at other points. At some points the stimulation added to the pain. In 16 patients the stimulation caused a reduction in pain intensity of 75--100%; out of these 12 patients reported a complete relief of pain.
TL;DR: Electrical stimulation in the midbrain periaqueductal gray (PAG) and lateral midbrain reticular formation (LRF) strongly suppresses the responses of spinal dorsal horn neurons to noxious heating of the skin.
Abstract: Electrical stimulation in the midbrain periaqueductal gray (PAG) and lateral midbrain reticular formation (LRF) strongly suppresses the responses of spinal dorsal horn neurons to noxious heating of the skin. The possible role of serotonin (5-hydroxytryptamine, 5-HT) was investigated by quantitatively comparing certain parameters of descending inhibition from PAG and LRF in normal cats [14,15] and cats whose central 5-HT levels had been reduced by pretreatment with p-chlorophenylalanine (PCPA, 300 or 500 mg/kg i.p., 72 h prior to acute experiment). Single lumbar dorsal horn neuronal responses to noxious radiant heating of glabrous footpad skin(50 degrees C, 10 sec, 1/3 min) were recorded in normal and PCPA-pretreated cats anesthetized with sodium pentobarbital and N2O. Inhibition of neuronal heat-evoked responses during midbrain stimulation (mean frequency 30 Hz, up to 800 microA current intensity) was expressed as percent of the unit's control response in the absence of midbrain stimulation. Inhibition by PAG stimulation of units from cats pretreated with 300 mg/kg PCPA (mean inhibition at 450 microA to 60% of control in 12 units) was not detectably different from that in control (non-pretreated) cats. However, inhibition by PAG stimulation was significantly weaker in units from cats pretreated with 500 mg/kg PCPA (mean to 83.4% of control in 9 units). In the latter group, mean current threshold for inhibition was higher, and slope of current-intensity plots lower, than in the control and 300 mg/kg PCPA pretreatment groups. In contrast, mean inhibition by LRF stimulation was enhanced in the 300 and 500 mg/kg PCPA treatment groups in a dose-related manner. In normal (non-pretreated) cats, systemic administration of the putative 5-HT antagonist methysergide (0.07--1 mg/kg) reduced or abolished inhibition by PAG stimulation in each of 8 units. Low doses of methysergide had little or no effect on inhibition produced by LRF stimulation in 6 units. The results suggest pharmacologically distinct mechanisms of inhibition produced by stimulation in PAG and LRF.
TL;DR: The ability of the maximal C volley from the treated nerve to excite cells in the spinal cord was substantially decreased 13–21 days after local capsaicin, and the size of the myelinated and unmyelinated volleys evoked by maximal stimulation of the Capsaicin treated nerve were unchanged.
Abstract: (1) Systemic capsaicin treatment of neonatal and adult rats is known to affect unmyelinated afferents. However, the systemic route of administration presents several disadvantages and in order to overcome these a method was explored where a single nerve in adult rats was locally treated. (2) Sciatic nerves were exposed and a 10 mm length was soaked for 15 min in 1.5% capsaicin in vehicle or in the vehicle alone (10% Tween 80, 10% ethyl alcohol in saline). (3) Both the capsaicin solution and the vehicle caused acute block of the C compound action potential while in contact with the nerve. Removal of the solutions, however, resulted in substantial recovery of C fibre conduction. The A fibre volley was totally unaffected. (4) 13-21 days after treatment, the size of the myelinated and unmyelinated volleys evoked by maximal stimulation of the capsaicin treated nerve were unchanged but there was a 20% decrease of conduction velocity in the C fibres. (5) The ability of the maximal C volley from the treated nerve to excite cells in the spinal cord was substantially decreased (by 50%) 13-21 days after local capsaicin.
TL;DR: Age, sex and pharmacological effects paralleled those found with psychophysical techniques in part I of this study and in randomized, double‐blind placebo controlled trials, both aspirin and morphine significantly diminished the N120 component at high stimulus intensities.
Abstract: Somatosensory evoked potentials (EPs) to stimuli ranging from barely perceptible to painful were recorded in 153 normal adults. Reliability of amplitude and amplitude/intensity slopes were demonstrated in 29 individuals tested twice, two or more weeks apart. In randomized, double-blind placebo controlled trials, both aspirin and morphine significantly diminished the N120 component at high stimulus intensities. Age, sex and pharmacological effects paralleled those found with psychophysical techniques in part I of this study.
TL;DR: Patients who had the best outcome in terms of pain relief were significantly more likely to show improvements in other outcome measures and were less likely to be on disability or to have had multiple surgical procedures.
Abstract: The response of 111 chronic low back pain patients to a comprehensive behavioral treatment program emphasizing relaxation procedures is examined Over the course of treatment, significant reductions were obtained on measures of subjective tension, EMG activity, and pain Many patients also decreased their intake of analgesic/narcotic agents and reported an increase in activity level In order to examine individual differences in pain relief, the 28 patients who had the greatest decreases in pain were compared to those who had the least decreases in pain Patients who had the best outcome in terms of pain relief were significantly more likely to show improvements in other outcome measures In addition, these patients rated their pain initially as more severe, had continuous pain for fewer years, and were less likely to be on disability or to have had multiple surgical procedures These results are discussed in the light of recent data from other behavioral treatment studies with chronic low back pain patients and implications for behavioral assessment and treatment are discussed
TL;DR: Words related to pain were collected by asking 59 students and 18 patients to create a list by free association and words were chosen for the pain vocabulary which reflected a statistically significant intensity change and were most often to be found in the world‐list.
Abstract: Words related to pain were collected by asking 59 students and 18 patients to create a list by free association. Each subject was then given a dictionary-derived Finnish version of the McGill Pain Questionnarie (MPQ) with the words arranged in alphabetical order and was asked to place his own words among the dictionary-derived words which appeared most appropriate. Simultaneously, each word was allocated on a visual analogue scale (VAS) in order of increasing intensity. A vocabulary using the MPQ groups was then collated using the words for which at least one-half of the subjects agreed as to classification. The words in each group were presented in alphabetical order. The list was then given to 76 university students whose job was to decide if in fact each word did belong to the class assigned. Following this, the words were arranged on a VAS scale in intensity order. The words mm-mean differences were then compared using a t -test. Those words were chosen for the pain vocabulary which reflected a statistically significant intensity change and were most often to be found in the world-list. The same method is applicable irrespective of language. Words are replaceable by numerical values so that follow-up and renewed investigations become statistically comparable.
TL;DR: Differences in pain threshold between the two sides were significantly reduced and the EMG pattern became normal following treatment with injections of local anaesthetic into tender periarticular areas and systemic administration of lysine acetylsalicylate.
Abstract: Electrical stimulation pain thresholds and EMG activity were studied, using the vastus medialis muscle of healthy control subjects and of patients with osteoarthritis of the knee. Various categories of sensation elicited by progressive increases of the level of electrical stimulation (including one defined as pain threshold) were defined for control subjects. For patients. muscular pain thresholds differed significantly for the two sides of the body; they were usually lower in the more affected side. Involuntary activity of certain motor units and delayed relaxation following voluntary contraction were consistently observed in patients. The involuntary activity was affected by limb position and by mechanical stimulation of tender areas of the muscle or joint. Differences in pain threshold between the two sides were significantly reduced and the EMG pattern became normal following treatment with injections of local anaesthetic into tender periarticular areas and systemic administration of lysine acetylsalicylate. In standing patients, abnormal EMG activity (which was characteristically sensitive to body load and its variations) was found. Injection of a local anaesthetic into the joint cavity was able to induce a rapid subjective improvement and a consistent reduction of EMG activity.
TL;DR: There was statistically significant pain relief by TENS and half of the patients chose to continue using TENS for pain control after the test month, however, at one year's follow-up, only two patients had sufficient benefit to continued using the device.
Abstract: Ten patients with pain due to osteoarthritis of the knee were treated in a double-blind cross-over study with two weeks of transcutaneous electrical nerve stimulation (TENS) and placebo. There was statistically significant pain relief by TENS and half of the patients chose to continue using TENS for pain control after the test month. However, at one year's follow-up, only two patients had sufficient benefit to continue using the device.
TL;DR: Somatovisceral convergence was demonstrated in recordings from 15 of 16 spinothalamic tract cells in the lower thoracic spinal cords of anesthetized monkeys.
Abstract: Somatovisceral convergence was demonstrated in recordings from 15 of 16 spinothalamic tract cells in the lower thoracic spinal cords of anesthetized monkeys. Inputs were produced by mechanical (or sometimes electrical) stimulation of the skin over the lower trunk and by electrical stimulation of the greater splanchnic nerve through a buried electrode. The volley in the greater splanchnic nerve was monitored using a buried electrode on the sympathetic chain. Spinothalamic tract cells could be excited by activity in Aδ and C fibers, but noteffects produced by Aβ fibers were noted. In some cases inhibitory effects were observed due to movement of hair on the trunk, and inhibitory interactions could be demonstrated between cutaneous and visceral afferent volleys.
TL;DR: Stimulation of the tooth pulp of volunteers was carried out at an intensity that produced bearable pain and a progressive decrease in all polygraphic responses was observed which coincided with a decrease in the reported sensation of pain.
Abstract: Stimulation (1/10 sec, 1–2 msec) of the tooth pulp of volunteers was carried out for 120 min at an intensity that produced bearable pain. Cortical evoked potentials, electroencephalographic activity, electromyograms of the superciliary and masseter muscles and galvanic skin response were recorded. Every 30 min, without suspending the stimulation, the subjects were questioned with respect to the sensations accompanying the stimuli. A progressive decrease in all polygraphic responses was observed which coincided with a decrease in the reported sensation of pain. This effect could be reversed by applying heterosensorial stimulation (questioning). It is suggested that this is a phenomenon of habituation to pain since dishabituation, potentiation of habituation, and habituation to dishabituation were found.
TL;DR: Chronic thoracic spinal lesions placed in monkeys of 6 different species indicated that the release of the syndrome was dependent upon the integrity of a widespread bilateral spinal pathway for peripheral nociception, but was independent of the Integrity of specific sensory tracts.
Abstract: Chronic thoracic spinal lesions were surgically placed in 35 monkeys of 6 different species In a very large percent of the cases, a bizarre behavioral pattern was released, which persisted for many months of observation This syndrome was one in which the monkey severely attacked an hypoalgesic area of the body, namely, the leg The syndrome resulted from contralateral anterolateral cordotomy or hemisection It was very similar to the deafferentation syndrome which results from extensive dorsal rhizotomies Bilateral spinal lesions indicated that the release of the syndrome was dependent upon the integrity of a widespread bilateral spinal pathway for peripheral nociception, but was independent of the integrity of specific sensory tracts The deafferentation syndrome is considered to be a behavioral response to abnormal subjective sensations of central neural origin, and appears not to be relieved by morphine therapy The incidence of this syndrome in the primate was subject to genetic variation
TL;DR: This reply to Hall will first address the specific issues he has raised regarding the original publications of verbal descriptor scales, and present the general approach to the problem of pain assessment in humans including a discussion of the attributes of ideal assessment techniques.
Abstract: Wayne Hall has written a review [30] that focuses on our first papers using cross-modality matching procedures to quantify verbal decriptors of the sensory intensity and unpleasantness of the pain experience [22--24]. Unfortunately, Hall not only has misinterpreted our earlier methods, results and conclusions, but has failed to review recent studies that present our general approach to the problem of pain assessment in humans [ 16,17,21,33, 36,53,54). We have tried to avoid the dangers associated with the exclusive use of one psychophysical method. As Stevens remarked, \"Methodology can easily become methodolatry\" [60]. Instead, we have attempted to develop a catalogue of techniques that approach the ideal assessment method. Furthermore, we have applied these various assessment methods to the study of pain mechanisms and analgesia. In this reply to Hall's paper, we will first address the specific issues he has raised regarding our original publications of verbal descriptor scales. Second, we will present our general approach to the problem of pain assessment in humans including a discussion of the attributes of ideal assessment techniques. Finally, we will review experiments, utilizing assessment as a research tool, on the neural mechanisms of pain and the treatment of pain conditions.