Quantitative sensory testing in painful hand osteoarthritis demonstrates features of peripheral sensitisation.

Hand osteoarthritis (HOA) is a prevalent condition for which treatments are based on analgesia and physical therapies. Our primary objective was to evaluate pain perception in participants with HOA by assessing the characteristics of nodal involvement, pain threshold in each hand joint, and radiological severity. We hypothesised that inflammation in hand osteoarthritis joints enhances sensitivity and firing of peripheral nociceptors, thereby causing chronic pain. Participants with proximal and distal interphalangeal (PIP and DIP) joint HOA and non-OA controls were recruited. Clinical parameters of joint involvement were measured including clinical nodes, VAS (visual analogue score) for pain (0-100 mm scale), HAQ (health assessment questionnaire), and Kellgren-Lawrence scores for radiological severity and pain threshold measurement were performed. The mean VAS in HOA participants was 59.3 mm ± 8.19 compared with 4.0 mm ± 1.89 in the control group (P < 0.0001). Quantitative sensory testing (QST) demonstrated lower pain thresholds in DIP/PIP joints and other subgroups in the OA group including the thumb, metacarpophalangeal (MCPs), joints, and wrists (P < 0.008) but not in controls (P = 0.348). Our data demonstrate that HOA subjects are sensitised to pain due to increased firing of peripheral nociceptors. Future work to evaluate mechanisms of peripheral sensitisation warrants further investigation

Development and initial validation of a sensory threshold examination protocol (STEP) for phenotyping canine pain syndromes

Objective To study feasibility and test-retest repeatability of a sensory threshold examination protocol (STEP) and report quantitative sensory threshold distributions in healthy dogs. Study design Prospective, observational, cohort study. Animals Twenty-five healthy client-owned dogs. Methods Tactile sensitivity (TST) (von Frey filaments), mechanical thresholds (MT with 2, 4 and 8 mm probes), heat thresholds (HT) and responsiveness to cold stimulus (CT at 0 °C) were quantitatively assessed for five body areas (BA: tibias, humeri, neck, thoracolumbar region and abdomen) in a randomized order on three different occasions. Linear Mixed Model and Generalised Linear Mixed models were used to evaluate the effects of body weight category, age, sex, BA, occasion, feasibility score and investigator experience. Test-retest repeatability was evaluated with the Intra-class Correlation Coefficient (ICC). Results The STEP lasted 90 minutes without side effects. The BA affected most tests (p = 0.001). Higher thresholds and longer cold latencies were scored in the neck (p = 0.024) compared to other BAs. Weight category affected all thresholds (p = 0.037). Small dogs had lower MT (~1.4 N mean difference) and HT (1.1 0C mean difference) than other dogs (p = 0.029). Young dogs had higher HT than adults (2.2 0C mean difference) (p = 0.035). Gender also affected TST, MT and HT (p < 0.05) (females versus males: TST OR= 0.5, MT= 1.3 N mean difference, HT= 2.2 0C mean difference). Repeatability was substantial to moderate for all tests, but poor for TST. There was no difference in thresholds between occasions, except for CT. Test-retest repeatability was slightly better with the 2 mm MT probe compared to other diameters and improved with operator experience. Conclusions and clinical relevance The STEP was feasible, well tolerated and showed substantial test-retest repeatability in healthy dogs. Further validation is needed in dogs suffering pain

Local and Widespread Pressure Pain Hyperalgesia Is Not Side Specific in Females with Unilateral Neck Pain that Can Be Reproduced during Passive Neck Rotation

Current evidence for widespread hyperalgesia in non-specific neck pain (NSNP) is unclear. It is currently recommended to group NSNP patients according to pain-provoking movements. The aim of this study was to investigate local and widespread pain sensitivity in females with unilateral NSNP that is reproducible during passive neck rotation compared with matched controls, and to compare the side specific effect of pain location on pressure pain sensitivity among females with unilateral NSNP. Thirty-six females with unilateral NSNP evoked during passive ipsilateral (n = 20) or contralateral (n = 16) rotation toward the painful side were compared with 20 controls. Participants reported their pain intensity at rest and during passive neck rotation and completed the Neck Disability Index. Pressure pain thresholds (PPTs) were assessed bilaterally over the anterior scalene; the sternocleidomastoid; the levator scapulae; lateral to the spinous process of C6; the median, ulnar, and radial nerves; and the tibialis anterior. The ANOVA revealed lower PPTs in females with unilateral NSNP compared with the controls (all at p < 0.001), but no differences were found between the sides, nor was there any Groupside interaction. Among females with NSNP, those with higher pain intensity during ipsilateral rotation toward the painful side showed lower PPTs over the anterior scalene, median nerve, ulnar nerve, and tibialis anterior (all, p < 0.05) than females with higher pain intensity during contralateral rotation toward the painful side. These findings demonstrated bilateral local and widespread pressure pain hyperalgesia in females with unilateral NSNP that was reproducible during passive neck rotation compared with controls. There was no side specific effect of pain location on PPTs among females with unilateral NSNP.Ministerio de Educación, Cultura y Deporte (CAS 16/00046

The challenge of evaluating pain and a pre-incisional local anesthetic block.

Background. Our objective was to test the effectiveness of a local anesthetic line block administered before surgery in reducing postoperative pain scores in dogs undergoing ovariohysterectomy (OVHX). Methods. This study is a prospective, randomized, blinded, clinical trial involving 59 healthy female dogs. An algometric pressure-measuring device was used to determine nociceptive threshold, and compared to three subjective pain scales. Group L/B received a line block of lidocaine (4 mg/kg) and bupivacaine (1 mg/kg) subcutaneously in the area of the incision site and saline subcutaneously as premedication; group L/BM (positive control) received a similar block and morphine (0.5 mg/kg) subcutaneously for premedication; and group SS (negative control) received a saline line block and saline premedication. Criteria for rescue analgesia were defined before the study. Dogs were assessed prior to surgery, at extubation (time 0) and at 2, 4, 6, 8 and 24 h post-recovery. The data were analyzed with one-way ANOVA, and a Split Plot Repeated Measures ANOVA with one grouping factor and one repeat factor (time). P &lt; 0.05 was considered statistically significant. Results. Approximately 33% of dogs required rescue analgesia at some point during the study, with no significant difference between groups. There was no significant difference between treatment groups with any assessment method. Conclusions. As there were no statistically significant differences between positive and negative controls, the outcome of this technique cannot be proven

Algometer Precision for Quantifying Mechanical Nociceptive Threshold When Applied to the Udder of Lactating Dairy Cows.

Objectives of this study were to: (1) quantify the reliability of an algometer for measuring mechanical nociceptive thresholds when applied to the udder of dairy cows; and (2) evaluate whether covariates, such as cow characteristics or time of the day, would influence algometer measurements. This prospective study was performed in a university herd of 37 lactating cows during five consecutive days, involving two raters. Two types of measurement were obtained: one qualitative binary measure (i.e., reaction vs. no reaction) and one quantitative measure presented in kilograms (i.e., mechanical nociceptive threshold, MNT) for the cows that reacted. Kappa statistics were used to investigate test-retest and inter-rater reliability for the qualitative measure, while concordance correlation coefficient (CCC) and limits of agreement plot were used for the quantitative measure. Whether algometer measurements were influenced by several covariates (i.e., time of the day, level of milk production, days in milk, and parity) was then evaluated using logistic or linear regression models, depending on the outcome. The algometer was moderately reliable; there was moderate test-retest reliability (Kappa = 0.53; CCC = 0.58) and inter-rater reliability (Kappa = 0.42; CCC = 0.54). The MNT varied substantially as a function of time of the day and parity. This is the first study reporting reliability of a pressure algometer for quantifying MNT and investigating covariates possibly affecting this measurement when applied to the udder of dairy cows. It is concluded that the use of an algometer for quantifying MNT on the udder is only moderately repeatable and is influenced by extraneous covariates. Its usage in research setting to quantify changes in sensitivity at the udder level should, therefore, be considered very cautiously or it should be further developed

Features of central sensitisation in patients with shoulder pain : A feasibility study

Design. A case-control feasibility study, comparing people with unilateral shoulder pain and pain free controls. Background. Previous studies have suggested that central sensitisation (CS) may be present in people with shoulder pain, mostly based on testing of nociception rather than mechanosensitivity, both of which can change as part of CS. Changes in mechanosensitivity are important for physiotherapy, which often involves non-noxious mechanoreceptor stimulation. Objectives. This study tested sensitivity to arangea range of mechanical stimuli potentially associated with CS in people with and without shoulder pain, compared to asymptomatic individuals. It was hypothesised that if CS was present, the response to mechanoreceptor stimulation would be increased. Methods. Both shoulders in both groups were tested for sensitivity of static and dynamic touch, vibration and punctate stimulation, plus temporal summation and pressure pain threshold (PPT). Participants completed a demographic questionnaire, pain scales, PainDETECT for neuropathic pain, and QuickDASH for upper limb function. Results. PPT was found to be significantly lower in the affected compared to the unaffected shoulders (p<0.003), but no other statistically significant between-group differences were found. Conclusion. This study found a lowered PPT in people with unilateral shoulder pain compared with asymptomatic individuals, but no evidence of a heightened response to other forms of mechanoreceptor stimulation. The study protocol was suitable for future studies and the required participant numbers were established. The variation in findings between studies suggests that a larger longitudinal study may be warranted .Peer reviewedFinal Published versio

Conditioned place preference reveals ongoing pain in calves 3 weeks after disbudding.

Hot-iron disbudding, a routine procedure that prevents horn bud growth through cauterization, is painful for calves. The resulting burns remain sensitive to touch for weeks, but it is unknown whether calves experience ongoing, non-evoked pain. We evaluated conditioned place preference for analgesia in 44 calves disbudded or sham-disbudded 6 hours (Day 0) or 20 days (Day 20) before testing (n = 11/treatment). Calves were conditioned to associate the effects of a lidocaine cornual nerve block with the location and pattern of a visual stimulus, and a control injection of saline with the contrasting stimulus. On Day 0, disbudded calves tended to prefer the lidocaine-paired stimulus over the saline-paired one, suggesting that they found analgesia rewarding. On Day 20, sham calves avoided the lidocaine-paired stimulus, consistent with humans' experience of this drug being painful. Disbudded calves on Day 20 did not show this aversion, suggesting that they traded off the short-term pain of the lidocaine with the longer-term analgesia provided. Day 0 sham calves did not avoid the lidocaine-paired stimulus, likely because they received less than half the dose of Day 20 calves during conditioning. Thus, higher doses of lidocaine are aversive to uninjured animals, but disbudded calves are willing to engage in this cost. We conclude that calves experience ongoing pain 3 weeks after disbudding, raising additional welfare concerns about this procedure

Improvements in Pain, Well-being, Arterial Pressure, and Lower Limb Volume Following Andullation Therapy in Healthy and Unhealthy Humans

Our aim was to test the effects of Andullation therapy on pain threshold, pain perception, feeling of well-being, arterial pressure, and leg volume in healthy and unhealthy patients. We used a multidirectional vibration (frequency range: 5–40 Hz; peak-to-peak amplitude: 2–8 mm; acceleration: 0.4–2 m/s 2 ) in an undulatory way through the surface of the body when the patient was in contact with a mattress (“andullation”). The vibes traveled from the heel to the head in a random fashion while the participants (N = 50) were lying on the mattress. We measured the pain threshold using an algometer; pain perception and well-being through a visual analog scale (VAS); arterial pressure with an electronic sphygmomanometer; and leg volume with Kuhnke’s technique. Measurements were made just before the first andullation session and after the fifth andullation session. Every participant received andullation sessions of 30 min a day for 5 consecutive days. The patients’ pain threshold significantly (P <.001) increased by 34.48% and 25.79% in the lumbar and trapezius zones, respectively, after 5 sessions of therapy. The subjective perception of pain decreased by 52.3% and the feeling of well-being increased by 45.1%. The systolic and diastolic pressures significantly (P <.001) decreased by 6.44 and 4.68 mm Hg on average, respectively. Leg volume significantly decreased (P <.01) by 64.39 mL after the fifth andullation session. Despite not including a control group in our study, the andullation intervention showed an improvement in pain, well-being, arterial pressure, and lower limb volume in the studied population.Fundación para la Investigación de la Universidad de Sevilla FIUSHome Health Products HH

The Immediate Effects of Cervicothoracic Manipulation versus Stretching on Upper Trapezius Pressure Pain Thresholds and Range of Motion in Individuals without Neck Pain

Background and Purpose: Myofascial pain may be considered one of the most common clinical findings in patients with neck pain (NP). Motor aspects of myofascial pain include disturbed motor function and muscle weakness secondary to motor inhibition, muscle stiffness, and restricted range of motion (ROM). Currently, it is unclear which interventions may have the greatest immediate impact on pressure pain sensitivity and ROM. Several studies have demonstrated improved pressure pain thresholds (PPT) after cervical manipulation; however, it is not clear if manipulation targeted to the cervicothoracic (CT) junction will have a similar effect. Others recommend stretching as a method to reduce muscle soreness; however, the immediate effects of passive stretching to the upper trapezius on PPT and ROM have not been studied. The purpose of this project was to evaluate the influence of CT manipulation and passive stretching to the upper trapezius on PPT and ROM in individuals without recent complaint of NP. Subjects: Ninety (90) subjects without current complaint of NP were enrolled into the study. Methods: PPT was assessed on both the right and left upper trapezius musculature. Cervical range of motion (CROM) was assessed in the frontal, sagittal, and transverse planes. Subjects were randomized into one of three groups for intervention (CT manipulation, passive upper trapezius stretching, or control). CROM was reassessed immediately after the intervention. PPT levels were reassessed at 5 and 10 minutes post intervention by a blinded examiner. Mean and standard deviations for PPT and ROM were calculated. Repeated measures two-way ANOVA was used to assess within group (pre- and post- treatment) differences as well as difference among treatment conditions (Control, CT Manip, and Stretch groups). Post-hoc one-way ANOVA tests were used to examine the effects of group assignment/time points in the event of significant interactions between time and group assignment. Statistical significant was set at p \u3c0.05. Results: The two-way ANOVA test showed that there was a significant interaction between time and group assignment for CROM in the sagittal and transverse planes, however the post-hoc comparisons did not reveal a significant difference among 3 treatment group or among 3 time points. ANOVA also showed that there was not a difference in frontal plane CROM between time and group assignment. Similarly, although the two-way ANOVA test revealed a significant interaction between time and group assignment for PPT, post-hoc analyses showed that there was no difference between the 3 groups or among 3 time points for either side of the upper trapezius. Discussion: No significant difference in any plane of motion CROM or PPT pre-treatment to post-treatment between treatment groups brings into question the cause of the improved measures with time. Trends found with increased CROM and PPT over time are clouded by increased measures in the control group. The need for further research exists to better understand the relationship between CT manipulation and upper trapezius stretching and their effects on pain pressure thresholds and CROM. Conclusion: Upper trapezius stretching and CT manipulation may both be viable options for treatment by improving CROM and increasing PPT. Further high powered studies focusing on reducing the learning effects between measures and lowering participant uneasiness with research methods could produce clearer results

Effectiveness of an Eye-Cervical Re-Education Program in Chronic Neck Pain: A Randomized Clinical Trial

Objectives. Proprioceptive training is popularly applied as a therapeutic exercise method in physiotherapy. Its effects on pain and range of motion are only poorly evaluated. Therefore, this study assesses the effectiveness of proprioceptive training with an Eye-Cervical Re-education Program to decrease pain and increase the joint range in chronic neck pain patients. Material and Methods. Design. A randomized, no-blinded, controlled clinical trial. Setting. Physiotherapy consultation. Participants. 44 people were divided into two groups. Interventions. All patients were treated with a multimodal physiotherapy intervention. The experimental group was supplemented with an exercise program that included eye-cervical proprioception. Outcomes. The primary outcomes included pain pressure thresholds (upper trapezius, levator scapulae, and splenius capitis) and cervical range of motion. The secondary outcomes included pain measured by the Visual Analogical Scale and the McGillSpv Questionnaire. Results. The proprioception treatment was effective in reducing the pain pressure threshold in the right upper trapezius (p=0.001), left upper trapezius (p=0.014), right levator scapula (p=0.040), and left splenius capitis (p=0.021). The increase in the joint range was statistically significant (p<0.05) in favor of the Eye-Cervical Re-education Program for all movements assessed. Conclusions. The Eye-Cervical Re-education Program is effective at relieving pain pressure thresholds in the upper trapezius, right levator scapula, and left splenius capitis and especially effective for increasing the cervical range of motion. This trial is registered with (retrospective registration)