Assessment Of Pain Perception Research Articles

AB0596 Association between pressure and thermal pain thresholds in knee osteoarthritis

BackgroundOsteoarthritis (OA) is a major cause of chronic pain; however, the exact pathophysiology of OA pain remains poorly understood. Quantitative sensory testing (QST) is a tool used to assess pain...

Salivary alpha-amylase: a new non-invasive biomarker for assessment of pain perception in epileptic children

The aim of this study was to evaluate pain perception in epileptic children during an invasive procedure as the collection of venous blood through salivary alpha-amylase (sAA) activity determination, and to compare it with that of healthy children. In the study 23 children, 12 with epilepsy and 11 healthy controls were enrolled. From all children of both groups, one sample of saliva was collected through a non-invasive device, 15 min before (t 0), during (t 1), and 15 min later (t 2) blood withdrawal, and sAA activity was then determined through a kinetic-colorimetric assay. A statistically significant difference (p < 0.001) was found at t 2 between the sAA activity in the two groups, suggesting that epileptic children have an increased sensitization to pain, while at t 0 the difference was at the limit of statistical significance and at t 1 no statistically significant difference was found indicating that in both groups the venipuncture equally induced a state of stress. Our data suggest that sAA activity could represent a new objective and non-invasive biomarker for the assessment of pain perception in epileptic children.

The analgesic effect of benzocaine mucoadhesive patches on orthodontic pain caused by elastomeric separators, a preliminary study

Objectives: To study the effect of benzocaine mucoadhesive patches (20%) on orthodontic pain caused by elastomeric separators. Subjects and methods. A split-mouth design was used in 30 patients (12 female, 18 male, aged 23 ± 3.75 years). They were instructed to apply benzocaine and placebo patches randomly for right or left first permanent molars of maxillary/mandibular arches for 20 min and repeat this procedure every 6 h with a similar type patch. A 10 cm Visual Analogue Scale (VAS) was used for pain perception assessment in patients who were given benzocaine (benzocaine group) or placebo (placebo group) patches. Pain perception (VAS) was recorded immediately after separator placement and after 2, 6, 12, 18, 24, 48 and 72 h. Results. The mean VAS (SD) for the placebo and benzocaine groups were 2.28 (1.08) and 1.63 (0.67), respectively. The pain peaked at 24 h. Significant pain perception differences were observed between groups at 2, 18, 24, 48 and 72 h. Pain perception was not different between genders or jaws investigated (p > 0.05). The Friedman test revealed significant differences in pain perception among various time intervals for benzocaine (χ2 = 99.84, p = 0.000) and placebo (χ2 = 102.361, p = 0.000) groups. Significant negative correlations (ρ) were found only between pain perception scores and patient's ages in the placebo group at 18 (−0.438), 24 (−0.526), 48 (−0.565) and 72 h (−0.458). Conclusion. The recorded mean VAS values were relatively low; however, the benzocaine 20% patches significantly reduced the post-separation orthodontic pain.

Pain and Body Awareness: Evidence from Brain-Damaged Patients with Delusional Body Ownership

A crucial aspect for the cognitive neuroscience of pain is the interplay between pain perception and body awareness. Here we report a novel neuropsychological condition in which right brain-damaged patients displayed a selective monothematic delusion of body ownership. Specifically, when both their own and the co-experimenter’s left arms were present, these patients claimed that the latter belonged to them. We reasoned that this was an ideal condition to examine whether pain perception can be “referred” to an alien arm subjectively experienced as one’s own. Seventeen patients (11 with, 6 without the delusion), and 10 healthy controls were administered a nociceptive stimulation protocol to assess pain perception. In the OWN condition, participants placed their arms on a table in front of them. In the ALIEN condition, the co-experimenter’s left (or right) arm was placed alongside the participants’ left (or right) arm, respectively. In the OWN condition, left (or right) participants’ hand dorsum were stimulated. In the ALIEN condition, left (or right) co-experimenter’s hand dorsum was stimulated. Participants had to rate the perceived pain on a 0–5 Likert scale (0 = no pain, 5 = maximal imaginable pain). Results showed that healthy controls and patients without delusion gave scores higher than zero only when their own hands were stimulated. On the contrary, patients with delusion gave scores higher than zero both when their own hands (left or right) were stimulated and when the co-experimenter’s left hand was stimulated. Our results show that in pathological conditions, a body part of another person can become so deeply embedded in one’s own somatosensory representation to effect the subjective feeling of pain. More in general, our findings are in line with a growing number of evidence emphasizing the role of the special and unique perceptual status of body ownership in giving rise to the phenomenological experience of pain.

Effects of physical activity programmes in the workplace (PAPW) on the perception and intensity of musculoskeletal pain experienced by garment workers

The physical activity programmes in the workplace (PAPW) are applied to minimize the prevalence, incidence and intensity of pain. This study evaluated the perception of pain and quantifies its intensity among garment workers before and after performing a PAPW. We included 61 workers of a clothing company, who were classified randomly into experimental group (n = 44) 28.7 ± 8.8 years old and a control group (n = 17) 27.8 ± 7.4 years (20-43 years). The Trigger Points test questionnaire was used to assess pain perception and quantify its intensity. The PAPW was conducted in 15-minute sessions per day, consisting of stretching exercises (40%), muscular endurance (40%), self-massage relaxation and massage techniques (10%), and group dynamics (10%). The garment workers who participated in the PAPW showed a significant reduction of pain felt in the neck and wrists, and also a reduction in pain intensity in shoulders, arms, fingers and wrists that are most often strained during sewing. Our findings suggest that PAPW that target muscle groups that are more tense in sewing tasks, may be considered by companies for supporting adaptation to the work environment and improving health by reducing muscle and joint pain.

Validation of the Pain Sensitivity Questionnaire in chronic pain patients

Recently, a self-rating measure for pain perception based on imagined painful daily life situations, the Pain Sensitivity Questionnaire (PSQ), has been developed and shown to correlate with experimentally obtained pain intensity ratings in healthy subjects. Here, we assessed the validity of the PSQ for investigation of general pain perception (ie, pain perception outside the site of clinical pain) in chronic pain patients. PSQ scores were obtained in 134 chronic pain patients and compared to those of 185 healthy control subjects. In a subgroup of 46 chronic pain patients, we performed experimental pain testing outside the clinical pain site, including different modalities (heat, cold, pressure, and pinprick) and different measures (pain thresholds, pain intensity ratings). Results show that PSQ scores were significantly correlated with both experimental pain intensity ratings (Pearson’s r=0.71, P<.001) and experimental pain thresholds (r=−0.52, P<.001). In addition, chronic pain patients exhibited significantly elevated PSQ scores as compared to healthy controls, consistent with the generalized increase of experimentally determined pain perception that has repeatedly been reported in chronic pain patients. These results demonstrate that the PSQ constitutes a valid self-rating measure of pain perception outside the clinical pain site in chronic pain patients and might serve as an alternative to experimental assessment of pain perception outside the clinical pain site in situations where experimental pain testing is not feasible.

Homeward Bound: Pain Control and Recovery After Major Gynecologic Surgery

The trend toward shorter postoperative hospital stays means that the acute recovery phase occurs at home increasingly often; however, few published data address this experience. Investigators at a U.S. teaching hospital assessed pain perception and use of analgesics following hospital discharge for abdominal or vaginal gynecologic surgery (primarily hysterectomy) for benign indications; laparoscopic procedures were excluded. Reported pain …

The Influence of Kinesio Taping on the Effects of Physiotherapy in Patients after Laparoscopic Cholecystectomy

Physiotherapy in patients after laparoscopic cholecystectomy (CHL) is impeded by postoperative pain which causes a decline in patients' activity, reduces respiratory muscles' function, and affects patients' ability to look after themselves. The objective of this work was to assess the influence of Kinesio Taping (KT) on pain level and the increase in effort tolerance in patients after CHL. The research included 63 patients after CHL. Test group and control group included randomly selected volunteers. Control group consisted of 32 patients (26 females, 6 males), test group consisted of 31 patients (22 females, 9 males). Both groups were subjected to complex physiotherapy, and control group had additional KT applications. Before surgery, during and after physiotherapy, patients were given the following tests: 100-meter walk tests, subjective pain perception assessment, and pain relief medicines intake level assessment. The level of statistical significance for all tests was established at P < 0.05. Statistical analysis showed a significant decrease in the time required to cover a 100-meter distance and a decrease in pain perception presented by significantly lower painkillers' intake in the test group in comparison with the control group. The improvement in clinical condition observed in the research indicates the efficiency of KT as a method complementing physiotherapy in patients after laparoscopic cholecystectomy.

Assessment of Pain Perception in Irritable Bowel Syndrome: Towards an Optimal Definition of Rectal Hypersensitivity

controlled trials (duration 4-12 weeks; PRU dose 0.5-4mg q.d.) in patients with CC were pooled, and different AE categories were compared between elderly and adults. RESULTS: 2717 patients were treated with PRU (exposure: 406 patient-yrs), of which 564 were ≥65 yrs (exposure: 63 patient-yrs). Exposure time to 2mg (recommended dose for adults) was 165 pt-yrs (n=938); exposure to 1mg (recommended dose for elderly) was 8 pt-yrs (n= 113). In the elderly, the incidence of the different AE categories was comparable between PRU and PLA, and comparable to those seen in adults except for serious AEs (SAEs). SAEs were reported at a higher rate in elderly (most commonly infections, infestations or respiratory disorders), with no difference observed between PRU and PLA (Table). Three elderly patients died, 2 on PRU, due to pneumonia or bronchitis (not considered related to study medication) and 1 on PLA due to arrhythmia/myocardial infarction. Most common AEs with PRU in both age groups were gastrointestinal symptoms (nausea, diarrhea, abdominal pain) and headache. Results in subgroups of patients 65-75 yrs and patients ≥75 yrs were similar to those observed in the whole group of elderly patients. The proportion of patients on PRU discontinuing therapy among the elderly and adults was similar. The incidence of cardiovascular AEs of interest (palpitations, corrected QT interval-related AEs, and ventricular arrhythmias) was comparable in both age groups, as well as for PRU and PLA. Cardiac ischemia and atrial arrhythmia-related AEs were more common in elderly, but their incidence was not different for PRU and PLA. The majority of ischemic and atrial rhythm-related AEs were reported by the investigator as unrelated to the study medication or doubtful. CONCLUSIONS: In 14 double-blind, PLA-controlled, Phase II/III trials of PRU, the safety and AE profiles were similar relative to PLA in adult and elderly patients with CC.

Perioperative Schmerztherapie

Scientific studies have proven without doubt that an optimized perioperative pain therapy will improve patient comfort, reduce postoperative complications, enhance postoperative recovery and shorten the length of postoperative hospital stay. It is necessary to incorporate the acute pain therapy into a perioperative multimodal and interdisciplinary therapeutic concept. Local or regional anesthesia will provide the best analgesic effect after surgery and should be considered in all patients. Optimal treatment of patients with peripheral nerve blocks, spinal or epidural analgesia should be treated by a specialized acute pain service. However, only 15-20% of all surgical cases will be taken care of by such a pain service. Therefore, most surgical patients will only receive adequate analgesia if surgeons are familiar with the principles of postoperative pain therapy. Regular assessment of pain perception is the cornerstone of optimized pain therapy. Furthermore, pain assessment will allow the administration and to some extent dosage of analgesic therapy to be delegated to nursing personnel.

Test–retest reliability of Quantitative Sensory Testing in knee osteoarthritis and healthy participants

Quantitative Sensory Testing (QST), which assesses somatosensory function by recording participant's responses to external stimuli of controlled intensity, is a useful tool to provide insight into the complex pathophysiology of osteoarthritis (OA) pain. However, QST is not commonly used in rheumatology because the test-retest reliability properties of QST in OA patients have not yet been established. This brief report presents the finding of a study which assessed the test-retest reliability of light touch thresholds, pressure pain thresholds, thermal sensation thresholds and thermal pain thresholds in 50 knee OA patients and 50 healthy participants. Pressure pain thresholds were found to be the least variable measurement, as median thresholds did not differ significantly over the 1 week period and the results were highly correlated. This provides support for the inclusion of pressure algometry in studies assessing pain perception abnormalities in OA.

Pain Perception During Miniplate-assisted Orthodontic Therapy

Miniplate and screw devices are widely used for fracture repair and fixation of osteotomies. Currently, these miniplate systems are being used as orthodontic treatments for skeletal anchorage. However, despite the widespread use of these treatments, patients are apprehensive when they need to undergo miniplate procedures. Recently, we assessed pain perception using the visual analog scale (VAS) score (0-100 mm) in patients who had undergone miniplate procedures. Thirty miniplates were positioned in the maxilla as skeletal anchors for orthodontic treatment. On the first day after insertion of the fixed orthodontic appliances, the mean VAS score was 36.3 mm. The mean VAS score at 24 hours after insertion of the miniplate was 58 mm. Three months after orthodontic force was applied to the miniplate, the mean VAS scores during eating and speaking gradually decreased to 20 mm and 15 mm, respectively. The mean VAS score at 24 hours after removal of the miniplate was 41.3 mm. Three months after removal of the skeletal anchors, the VAS score decreased to 5 mm. Eighty-eight percent of patients stated that they would be prepared to undergo these new and more efficient treatment modalities in the future. The miniplate system was successfully used in this study as a skeletal anchor, and the patients could endure the pain and discomfort of this orthodontic treatment.

Pain perception and tolerance in patients with frontotemporal dementia

Pain management in elderly people with cognitive impairment poses special challenges, due to difficulties in pain assessment and specific neurodegenerative changes along pain pathways. Most studies have concentrated on Alzheimer’s disease (AD) patients, in whom some contrasting findings have been found. For example, while psychophysical data suggest a selective blunting of the affective dimension of pain, pain-related fMRI signal increases have also been described. Few data have been reported in patients with frontotemporal dementia (FTD). By electrical stimulation, we have measured pain threshold and pain tolerance in clinically diagnosed FTD patients with SPECT cerebral hypoperfusion. We performed our analysis on two separate and overlapping subgroups selected on the basis of (1) neuropsychological scores below cut-off values (2) a strictly localized frontal and/or temporal hypoperfusion. We observed increased pain threshold in the first group and increased pain threshold and pain tolerance in the second group. Our results suggest differences in pain processing changes in distinct types of dementia, while at the same time caution that pain perception assessment may depend on the criteria adopted for diagnosis.

Self-reported pains during hysterosalpingography

The aim of this study was to determine the effect of the site of clipping of the cervix on the degree of pain experienced by the women undergoing hysterosalpingography. One hundred and twenty women who met the inclusion criteria were recruited for the study. Strict sterile procedure for hysterosalpingography was carried out on all women and verbal detector scales were used to assess pain perception. Pearson's correlation analysis was carried out to assess the relationship between sites of clipping of the cervix with the degree of pain reported by the women. Tests were two-tailed with P&lt;0.05 indicating statistical significance. Age correlated negatively but significantly (r=0.32, P=0.02) with pain. This suggests that younger women are more sensitive to pain than older women. None of the sites for clipping of the cervix correlated significantly with the pain experienced by the women.

Impact of demographic and psychosocial factors on hysterosalpingography pain and discomfort

ABSTRACTBackgroundHysterosalpingography (HSG) is an important diagnostic procedure in the investigation of infertility. It is the radiographic delineation of uterine and tubal cavities and is part of the diagnostic evaluation of conjugal infertility.1 This diagnostic procedure is associated with high levels of anxiety, pain and stress from various causes. This study was designed to investigate the impact of demographic and psychosocial factors on HSG pain and discomfort.MethodOne hundred hysterosalpingography referrals were recruited for this study. Verbal detector scales were used to assess pain perception, Likert scales were used to assess the psychosocial variables, while visual analogue scales were used to assess discomfort. Pearson's correlations were conducted. Tests were two-tailed, with p < 0.05 indicating statistical significance.ResultsSome of the patients (34%) indicated that the administration of analgesics prior to the procedure reduced the pain and discomfort associated with the procedure. Mean ± standard deviation of pain and discomfort were 2.82 ± 0.77 and 6.36 ± 2.19 respectively. Age correlated significantly with pain perception (r = -0.22, P < 0.05), while pain correlated significantly with perception of discomfort (r = -0.46, P < 0.05).ConclusionAge significantly correlated with pain. This is a factor that could be harnessed for clinical use.

Experimental and Clinical Applications of Quantitative Sensory Testing Applied to Skin, Muscles and Viscera

Quantification of the human painful sensory experience is an essential step in the translation of knowledge from animal nociception to human pain. Translational models for assessment of pain are very important, as such models can be used in: 1) basic mechanistic studies in healthy volunteers; 2) clinical studies for diagnostic and monitoring purposes; 3) pharmacological studies to evaluate analgesic efficacy of new and existing compounds. Quantitative pain assessment, or quantitative sensory testing (QST), provides psychophysical methods that systematically document alterations and reorganization in nervous system function and, in particular, the nociceptive system. QST is defined as the determination of thresholds or stimulus response curves for sensory processing under normal and pathophysiological conditions. The modern concept of advanced QST for experimental pain assessment is a multimodality, multitissue approach where different pain modalities (thermal, mechanical, electrical, and chemical) are applied to different tissues (skin, muscles, and viscera) and the responses are assessed by psychophysical methods (thresholds and stimulus-response functions). Many new and advanced technologies have been developed to help relieve evoked, standardized, and painful reactions. Assessing pain has become a question of solving a multi-input, multi-output problem, with the solution providing the possibility of teasing out which pain pathways and mechanisms are involved, impaired, or affected. Many methodologies have been developed for quantitative assessment of pain perception and involved mechanisms. This paper describes the background for the different methods, the use in basic pain experiments on healthy volunteers, how they can be applied in drug profiling, and the applications in clinical practice.

Assessment of pain perception during ophthalmic surgical procedures

Assessment of pain perception during ophthalmic surgical procedures

Assessing pain perception using the Painmatcher® in patients with whiplash-associated disorders

To evaluate the Painmatcher, in terms of reliability, and to explore the relationship between pain magnitude matching and pain threshold assessments in patients with whiplash-associated disorders. Also, to investigate gender differences in pain thresholds and explore the correlation between pain-related cognitions and pain threshold. A test-retest study. Forty-seven patients with whiplash-associated disorders. A visual analogue scale and a Painmatcher (an instrument for comparing pain magnitude) were used to evaluate pain intensity. Pain threshold was assessed using the Painmatcher. Pain-related cognitions were assessed using the Painometer and the Tampa Scale for Kinesiophobia. The Painmatcher demonstrated reliable pain magnitude matching scores, but the pain threshold assessment indicated a systematic disagreement. Women exhibited significantly lower pain thresholds than men (p < 0.01). There was a weak but significant correlation between the pain intensity according to the visual analogue scale and the Painmatcher (r = 0.46) (p < 0.01). There was a significant correlation between the emotional experience of pain and pain threshold (r = -0.33) (p < 0.001), but no significant correlation between fear of movement/(re)injury and pain threshold. Measuring pain with the Painmatcher is a reliable method, but may include a possible bias in threshold assessments and seems to be associated with unpleasantness.

The Effect of Sub-MAC Anesthesia and the Radiation Setting on Repeated Tail Flick Testing in Rats

The tail flick (TF) response is regarded as a spinal reflex that is influenced by supraspinal structures. The TF test using radiant heat is the most common way to assess pain perception; however, there are few reports dealing with the heat source's properties and score consistency. This study examined the usefulness of light anesthesia for suppressing supraspinal signals and the effects of radiant heat on skin temperature during TF testing. The fluctuations of TF latency over one hour were evaluated while the rats were given oxygen and 0%, 0.5%, 1.0%, or 1.5% isoflurane. The stimulator's infrared radiant (IR) power flux was measured over time, and the tail skin surface temperature was predicted using a non-linear regression equation. TF latencies were measured at various heat source intensities, and response temperatures were estimated. Inhalation anesthesia suppressed the TF reflex according to the inspiratory concentration of the volatile anesthetic. IR power fluxes reached constant power 2.5 s after the stimulator was turned on, and the predicted skin temperature depended on the maximum IR power flux of the IR intensity and the radiation time. One percent isoflurane inhalation and an IR20 heat intensity (which was 161.5 mW/cm(2) and resulted in a skin temperature of 65 degrees C after 10 s of radiation) provided reliable TF latencies on repeated TF testing. Given these results, it can be concluded that the stimulator setting influenced TF latency, and that the inhalation of light anesthesia provided consistent scores on repeated TF testing.

Assessing pain perception in fish from physiology to behaviour

Assessing pain perception in fish from physiology to behaviour