PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Pain Perception”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Diurnal variations in pain perception and thermal sensitivity.

Pain and thermal sensitivity thresholds in healthy volunteers were examined for diurnal variations. The subjects were 11 men aged between 22 and 27 years (means = 23.5, S.D. = 1.5). Data were collected for 2 days, with 7 measurements per day. To ensure the pain specificity of the results the subliminal modality, i.e., thermal sensitivity thresholds to warm and cold stimuli, was investigated in addition to the threshold for perception of heat pain. Assessments were made on the right hand and foot, the stimuli being presented with a thermoelectric contact-thermode. Despite the influence of variables other than time of day (45-56% of the total variance), diurnal variations were found for some subjects on the pain threshold measure (significant correlation between days and relatively high frequency of 24 h component in Fourier analysis spectra). However, they could not be demonstrated for the thermal sensitivity measures. The diurnal variations in pain perception thresholds did not have a consistent pattern over all subjects (Friedman test). The small diurnal variations with interindividual differences in the pattern are therefore not sufficient to explain the variations seen in clinical pain, but they may be useful in detecting pain modulators by investigating correlations.

Adult↗

Evaluation of SET--a new device for the measurement of pain perception in comparison to standard measures of diabetic neuropathy.

BACKGROUND: Early detection of sensory impairment and loss of protective pain sensation is of major importance for the prevention of neuropathic foot ulceration. The aim of our study was to evaluate a new handheld device (SET, a prototype developed by Dr. W. Henniges, Zülpich, Germany) for measurement of pain perception, in comparison with established methods for diagnosis of diabetic neuropathy. METHODS: Sixty-one patients with diabetes mellitus (13 type 1, 48 type 2; 42 men, 19 women; mean +/- SD age 61.6 +/- 11.6 years) received measurement of pain perception threshold using the new SET device and a measurement of light touch sensation, temperature sensation, and vibration sensation by the use of standard clinical devices. In addition, warm, cold, heat pain and vibration perception thresholds were determined by the use of a computer-based peltier thermode and a vibration stimulator (TSA 2001, Medoc, Ramat Yishai, Israel). RESULTS: Using the new SET device, patients with sensory impairment showed significantly elevated pain perception thresholds at the dorsum of the foot (P < 0.001), while only a trend towards higher measurements could be observed at the plantar aspect of the foot. A significant correlation could be observed between plantar and dorsal measuring sites (r = 0.78, P < 0.0001) and between both feet (r = 0.85, P < 0.0001). Compared with other qualities of sensory dysfunction, pain perception measurement with the SET device provided the highest sensitivity (pain = 0.82; vibration = 0.61; temperature = 0.42; light touch = 0.11). CONCLUSIONS: Measurement of pain perception threshold using the SET device is an easy and reliable method for identifying patients with impaired small nerve fiber function.

Cold Temperature↗

Short term fluctuations in blood glucose concentrations do not alter pain perception in diabetic-patients with and without painful peripheral neuropathy.

Previous studies have suggested that acute hyperglycaemia may affect pain thresholds in non-diabetic subjects. We investigated the effects of acute fluctuations in blood glucose on the perception of pain in diabetic patients with and without painful diabetic neuropathy. Rapid swings in blood glucose concentration produced by IV glucose injection did not alter heat pain thresholds in diabetic patients without symptomatic neuropathy. Also, marked changes in neuropathic pain were not accompanied by significant alterations in blood glucose concentration in diabetic patients with painful neuropathy. Therefore, the alleged effects of acute hyperglycaemia on pain perception described in non-diabetic subjects are not reproduced in diabetic patients.

Adult↗

Modulation of pain perception in man by a vasopressin analogue.

The aim of the present experiment was to test whether vasopressin modulates pain perception in man. Twenty-four male volunteers participated in four sessions, each 2 weeks apart. After an adaptation session the subjects were treated intranasally with either 30 or 60 micrograms desmopressin (DDAVP) or placebo according to a cross-over double-blind design. Pain induction involved mechanical, thermal, and ischemic stimulation DDAVP had no unitary effects on pain perception in the different pain tests. The 30 micrograms dose induced sensitization to thermal stimuli. Neither treatment influenced ischemic pain perception. The mechanical pain threshold of the index finger was increased by the 60 micrograms dose only. After treatment with either dosage of DDAVP the subjects generally tolerated the pressure on their index finger for a longer time than after placebo treatment.

Administration, Intranasal↗

Relation between systemic hypertension and pain perception.

To test the hypothesis that hypertension diminishes pain perception, a study was made that evaluated the relation between arterial blood pressure and thermal pain perception in human subjects. The average mean arterial pressure in all 20 men studied (10 hypertensive, 10 normotensive) proved to be significantly related to both thermal pain threshold (p = 0.05) and tolerance (p = 0.003). The difference between normotensive and hypertensive groups in baseline and posttest plasma levels of beta endorphin was also significant (p = 0.02) and indicated an interaction between endogenous opioids and blood pressure. Other recent studies of hypertension in relation to hypalgesia were also reviewed. An increased pain threshold was found in hypertensive versus normotensive rats. In cats, electrical stimulation of vagal afferent nerves (cardiopulmonary baroreceptors) suppresses nociceptive responses, and both pharmacologic elevation of blood pressure and vascular volume expansion produce antinociception. Together with preliminary findings in human studies, these results indicate an interaction between pain-controlling and cardiovascular regulatory functions that is probably mediated by the baroreceptor system.

Adult↗

Imaging the pain of low back pain: functional magnetic resonance imaging in combination with monitoring subjective pain perception allows the study of clinical pain states.

Most brain imaging studies of pain are done using a two-state subtraction design (state-related design). More recently event-related functional magnetic reasonance imaging (fMRI) has also been used for studying pain. Both designs severely limit the application of the technology to clinical pain states. Recently we demonstrated that monitoring time fluctuations of perceived pain could be used with fMRI to identify brain regions involved in conscious, subjective perception of pain. Here we extend the methodology to demonstrate that the same approach can be used to study clinical pain states. Subjects are equipped with a finger-spanning device to continuously rate and log their perceived pain during fMRI data collection. These ratings are convolved with a canonical hemodynamic response function to generate predictor waveforms with which related brain activity can be identified. Chronic low back pain patients and a normal volunteer were used. In one series of fMRI scans the patient simply lies in the scanner and indicates spontaneous fluctuations of the subjective pain. In other fMRI scans, a straight-leg raising procedure is performed to exacerbate the back pain. In the normal volunteer, fMRI scans were done during painful and non-painful straight-leg raisings. The results indicate the feasibility of differentiating between different pain states. We argue that the approach can be generalized to identify brain circuitry underlying diverse clinical pain conditions.

Brain Mapping↗

Pain perception in major depression depends on pain modality.

One frequently described feature of depression is an increased vulnerability to pain complaints, and chronic pain is frequently accompanied by symptoms of depression. In contrast to this, a decreased sensitivity to experimental pain has been described in major depression. The physiological basis of this phenomenon is yet elusive. We investigated 30 patients suffering from a major depressive disorder and matched controls. Pain testing (threshold and tolerance) was performed on both sides of the body and included assessment of thermal, electrical and ischemic pain. While confirming hypoalgesia to heat and electrical pain in comparison to controls, we found hyperalgesia to ischemic muscle pain. Furthermore, thermal pain tolerance and electrical pain tolerance were significantly increased on the right hand side confirming previous results of a lateralized perception of pain in depression. Our main finding suggests that painful stimuli are processed differentially depending on the localization of pain induction in depression. This knowledge may enable us to understand and ultimately treat pain complaints more appropriately in depressed patients.

Adult↗

[Using tools for pain perception assessment in hospitalized pre-school children undergoing painful procedures].

The aim of this study was evaluate the utilization of tools for pain perception assessment in 41 hospitalized pre-school children submitted to painful procedures: care of wounds or blood extraction. The utilized tools were the faces scale, behavioral indicators and words which describe the pain. Most of the pre-schoolers understood and correctly answered to the faces scale, which can be noticed by the crescent movement 0 (no pain) 4 (maximum pain) during the choice of faces before and after the painful procedure. Crying, immortality and forehead wrinkling were the predominant behavioral indicators, intensified during the procedure. Pre-schoolers verbalizations about their pain showed up to be concrete terms or evaluative-indicative nature, resulting in variable or weakly precise concepts.

Age Factors↗

Psychological influences on pain perception and non-pharmacologic approaches to the treatment of pain.

Pain is a complex process, in part because it is mediated by so many different variables. However, because pain is the primary reason for seeking medical treatment and often a barrier to compliance, therapists treating painful disorders or injuries need to be familiar with those factors that influence pain perception and treatment approaches. How individuals perceive pain, and hence how clinicians treat it, depends upon a wide variety of psychosocial factors, including mood, age, gender, expectations, social support, and perceptions of control. Even the manner with which therapists interact with patients can minimize the pain experience and ultimately impact compliance and recovery rates. This paper overviews the multifaceted nature of pain by outlining how psychologic variables impact pain experiences. In addition, this article reviews a number of nonpharmacologic techniques and approaches (i.e., distraction, imagery, relaxation, biofeedback) that are available for assisting patients in dealing with pain.

Attitude to Health↗

Pain perception and serum beta-endorphin in trauma patients.

Acute traumatic injury engenders the production of beta-endorphin (BE) and other endogenous opioids. Elevated BE concentration putatively correlates with pain perception in trauma patients. The authors examined traumatic injury severity, pain perception, and BE concentration in patients admitted to an urban trauma center. Brief rating instruments for pain and unpleasantness were administered, and blood was drawn for BE analysis in 48 trauma admissions and 33 age-, gender-, and race-matched control subjects for comparison. The authors found no correlation between severity of pain perception and BE, but a significant correlation was found between BE and patient body weight (P < 0.05), physician pain rating (P < 0.01), and Injury Severity Score (P < 0.001). The results suggest that past findings associating trauma pain perception and BE concentration are spurious.

Adolescent↗

Effect of semiconductor GaAs laser irradiation on pain perception in mice.

The influence of subacute exposure (11 exposures within 16 days) of mice to the low power (GaAs) semiconductive laser-stimulated irradiation on pain perception was investigated. The pain perception was determined by the latency of foot-licking or jumping from the surface of a 53 degrees C hot plate. Repeated hot-plate testing resulted in shortening of latencies in both sham- and laser-irradiated mice. Laser treatment (wavelength, 905 nm; frequency, 256 Hz; irradiation time, 50 sec; pulse duration, 100 nsec; distance, 3 cm; peak irradiance, 50 W/cm2 in irradiated area; and total exposure, 0.41 mJ/cm2) induced further shortening of latencies, suggesting its stimulatory influence on pain perception. Administration of morphine (20 mg/kg) prolonged the latency of response to the hot plate in both sham- and laser-irradiated mice. This prolongation tended to be lesser in laser-irradiated animals. Further investigations are required to elucidate the mechanism of the observed effect of laser.

Animals↗

Possible mechanisms of pain perception in patients with episodic tension-type headache. A new experimental model of myofascial pain.

A new experimental human model of myofascial pain using intramuscular infusion of a combination of bradykinin, serotonin (5-hydroxytryptamine), histamine, and prostaglandin E2 was applied to patients with episodic tension-type headache (ETTH) in order to examine pain perception. Fifteen patients with ETTH and 15 healthy controls completed the randomized, balanced, double-blinded, placebo-controlled study. Pain intensity, punctate hyperalgesia and allodynia, and pain quality were recorded. The combination induced a moderate and prolonged pain in both patients (median 51 min) (P = 0.001) and controls (median 22 min) (P = 0.001). Patients reported more pain than controls both after the combination (P = 0.045) and after placebo (P < 0.001). The McGill pain score [PRI(R)] was significantly higher in patients (P = 0.002) and in controls (P = 0.001), whereas pain quality and hyperalgesia were similar after the combination compared with placebo in the two groups. Due to side-effects nine subjects did not complete the study. The increased pain response, but similar qualitative pain perception, in ETTH patients may be explained by sensitization of peripheral nociceptors even though central mechanisms may also be involved.

Adult↗

Pain perception of intravenous heroin users on maintenance therapy with levomethadone.

Methadone is a very potent analgesic drug. Accordingly, maintenance therapy of heroin addicts with methadone may conceal pain producing processes. Here we report on the pain perception of 42 patients on a levomethadone maintenance treatment for intravenous heroin users. Pain perception was measured by single-blind, non-invasive pressure stimulation of the nociceptors located in the dorsal extension aponeurosis and the underlying periosteum of the middle phalanx of a digit before and respectively 1,2, and 4 hours after oral routine drug administration. Measures were related to the individual levomethadone plasma levels. Under steady-state conditions, the pain perception of the patients did not differ from a drug-free placebo control group and was not related to individual levomethadone plasma levels, although an analgesic effect in the reabsorption phase was observed. It is concluded that the individual pain perception of maintained patients is adapted to a normal response range and that even prolonged opioid consumption does not diminish dynamic analgesic responsiveness to levomethadone.

Adult↗

Opioids and abnormal pain perception: New evidence from a study of chronic opioid addicts and healthy subjects.

Recent evidence reported on increased pain sensitivity in animals following parenteral opioid administration and in humans subsequent to intravenously of short-acting opioids and possibly in drug addicts. The aims of the present study were to explore the possibilities that (1) pain perception is altered in chronic opioid addicts (OAs); (2) if indeed so, the cessation of opioid consumption resets their altered pain perception. Sixty heroin or methadone OAs who attended a 4-week inpatient detoxification program were exposed to the cold pressor test (CPT) upon entrance to the program, at 7 and 28 days subsequent to the cessation of opioid consumption (verified by repeated urine toxicology tests). Latency of pain onset (s), pain intensity (0-100 VAS), and tolerance (time for hand withdrawal) in response to the CPT were measured. In comparison with 70 healthy controls, the OAs demonstrated prolonged latency (6.6+/-3.5s versus 10.9+/-7.7s; p < 0.0001); decreased VAS (74+/-16 versus 55+/-20; p < 0.0001); shorter tolerance (56.4+/-51.3s versus 31.7+/-40.7s; p = 0.001). No differences between the three time points in any of the three measures were detected in the OAs. The results provide further evidence of opioid-induced hyperalgesia in the OA population, as manifested by their quicker hand withdrawal. In addition, it appears that detoxification from opioids does not reset pain perception for at least 1 month.

Chronic Disease↗

Pain perception under chronic high-altitude hypoxia.

Following studies of respiratory sensory functions during high-altitude adaptation, pain perception investigations were carried out on European lowlanders during an expedition on the Bhrikuti peak, Himalaya (first ascent). Perception thresholds and discrimination performances of electrical stimuli applied to the skin were determined with a constant stimulus method. Additionally, Clark's Situational Pain Questionnaire was used to measure discriminability and response bias of the subjects' reports of pain. The tests were performed in the field under normoxic conditions, before and after ascent, and under hypoxic conditions at altitudes of 3500 and 5600 m. The tests were also performed in a control group under normoxic conditions and similar ambient temperatures. Under normoxic conditions, the expedition group differed from the control group and demonstrated a more stoic attitude and a lower pain threshold. At high altitudes, pain thresholds decreased through improved sensory discrimination performances. Hypoxia is supposed to be the main cause of this sensory adaptive reaction to altitude as psychological attitude remained unchanged and a decrease in ambient temperature was without effect on pain perception in the control group. Increased discrimination in pain perception may be a component of a general improvement in sensory processing during the early stages of altitude acclimatization.

Adult↗

Spatial summation for pain perception: interaction of inhibitory and excitatory mechanisms.

To study the relation between size of the surface stimulated and perceived pain intensity (spatial summation effect), subjects sequentially immersed predetermined segments of the surface of their arm, between the fingertips and the shoulder, in circulating nociceptive hot water. Immersion sessions were of three types: (i) increasing session (immersion beginning at fingertips and increasing to shoulder); (ii) decreasing session (immersion beginning at shoulder and decreasing to fingertips); and (iii) whole arm+increasing session (preliminary immersion of the whole arm up to shoulder, followed by an increasing session from fingertips to shoulder). Results showed a positive spatial summation effect (pain perception positively correlated to the size of the surface stimulated) during both the decreasing session and the whole arm+increasing session. However, no spatial summation effect was found during the increasing session (fingertips to shoulder). In addition, pain perceived for a surface area was less intense during the decreasing session compared to the increasing session. One possible explanation for the lack of a spatial summation effect during the increasing session is that inhibitory mechanisms are gradually recruited at the same time as excitatory afferences, thus 'cancelling out' any measurable spatial summation effect. The results obtained during the decreasing session and the whole arm+increasing session may be explained by inhibitory mechanisms being fully recruited at the beginning of the session with the immersion of the largest surface area (whole arm). The results are a shift of the pain perception curve and a positive relation between the surface stimulated and pain perception.

Adolescent↗

Comparative study of pain perception and polysynaptic blink reflex responses in man.

Stimulation of the first trigeminal branch using a 10 ms train of 5 pulses of 0.1 ms duration is performed on 17 healthy subjects (19-65 years of age) in order to assess the relationship between polysynaptic components of the blink reflex and perceptive and pain thresholds (ths). The mean value of tactile ths (Pth) is 2.22 +/- 0.86 mA; while R2, R3 and pain threshold values are 1.25 +/- 0.34, 3.52 +/- 1.94 and 4.78 +/- 2.77 times the Pth respectively. The pain ths average is 1.47 +/- 0.92 with regard to the R3 threshold. The R2 ths are very close to those of tactile perception, while those of R3 appear significantly related to the pain ths.

Adolescent↗

The influence of westernisation on pain perception in labour among parturients at the university college hospital Ibadan.

Pain perception as perceived by the parturient is determined by physical and psychological factors. The interplay of these factors is important to the healthcare professional who will be managing these women in labour. We therefore set out to assess the influence of educational attainment as a proxy for westernisation on pain perception by parturients. This was a cross-sectional study conducted among 765 parturients using a questionnaire with the Box Numerical Scale to assess pain score within 48 h of delivery. We studied women in labour at the University College Hospital Ibadan Nigeria from August 2003 to July 2004. A total of 1,000 consecutive parturients were enrolled into the study but 765 were included in the analysis after excluding women requiring caesarean section. Multiple linear regression with robust estimation of the Standard Error of the Mean (SEM) was utilised. The main outcome studied was the pain score obtained within 48 h of delivery using the Box Numerical Scale (BNS). The pain scores were highest among ethnic groups other than the predominant ethnic group (Yoruba) 9.13 (95% CI 8.13 - 9.33), it was lowest among those with no formal education. Multivariate analysis revealed educational attainment as a significant predictor of BNS. An interaction between age and educational attainment; only women between the ages of 25 - 30 had lower mean pain scores when educated compared with those without formal education -3.56 (95% CI -4.28, -2.87). In conclusion, findings in this study support the hypothesis that westernisation through education tends to increase perception of pain by parturients in this environment.

Adult↗