Quantitative Sensory Measures Research Articles

Characteristics of Abnormalities in Somatosensory Submodalities Observed in Residents Exposed to Methylmercury.

Hundreds of thousands of people living along the Yatsushiro Sea coast have been exposed to methylmercury from the contaminated water of the Chisso factory in Minamata. The most common neurological disorder caused by methylmercury is somatosensory disturbance, but very few studies have been conducted in the world to determine its pathophysiology and origin, including the Japanese cases, which have produced numerous intoxicated individuals. We have already shown in previous studies the body part where the disorder occurs and that its cause is not peripheral nerve damage but damage to the parietal lobes of the cerebrum. We reanalyzed the results of subjective symptoms, neurological findings, and quantitative sensory measurements in 197 residents (63.2 ± 10.7 years old) from contaminated areas exposed to methylmercury from seafood and 130 residents (63.7 ± 9.3 years old) from control areas, the same subjects as in previous studies, to determine the characteristics of somatosensory disturbance in detail. The most commonly affected sensory modalities were superficial peripheral touch and pain in the extremities, followed by two-point discrimination and deep senses, and in the most severe cases, full-body sensory dysfunction and impairment of all sensory submodalities. The severity of sensory submodalities correlated with each other but not with peripheral nerve conduction test indices, further confirming the correctness of our assertion about the responsible foci of sensory disturbance. The health effects of chronic methylmercury toxicosis can be elucidated by a detailed examination of sensory deficits.

Sensory, functional and electromyographic variables show different recovery patterns over a seven day period following exercise-induced pain in the hamstrings

BackgroundDelayed-onset muscle soreness (DOMS) is common after unaccustomed exercises and can restrict performance if intense physical activities are performed while the muscle is still sore. This study aimed to evaluate the recovery process following exercise-induced DOMS over a seven-day period by evaluating sensory, functional, and electromyographic parameters. MethodsTwenty-four healthy males participated in four experimental sessions (Day-0, Day-2, Day-4, Day-7). Pain perception, pressure pain sensitivity, active range of motion, maximal isometric strength, and muscle activity of the hamstrings during the maximal isometric contraction were assessed bilaterally at each session. A single-leg deadlift eccentric exercise (5-sets of 20-reps) was performed at the end of Day-0 to induce DOMS in the dominant leg. FindingsAt Day-2, the DOMS-side showed increased pain sensitivity and decreased active range of motion, strength and muscle activity compared to Day-0 (P < 0.015). Muscle activity on the DOMS-side reached similar values than at baseline on Day-4, whereas pain perception, pressure pain sensitivity, maximal isometric strength, and active range of motion had returned to the baseline state on Day-7. No changes over time were observed on the control-side, showing all variables an excellent reliability between values at Day-0 and Day-7 (Intraclass Correlation Coefficient > 0.90). InterpretationSurface electromyographic values during a maximal isometric contraction recover faster than the other parameters. Given the heterogeneous path of altered variables towards DOMS recovery, trainers and clinicians should consider a multimodal assessment, including quantitative sensory and functional measures in addition to the subjective perception of recovery.

Effects of adding aerobic physical activity to strengthening exercise on hip osteoarthritis symptoms: protocol for the PHOENIX randomised controlled trial

BackgroundHip osteoarthritis (OA) is a leading cause of musculoskeletal pain. Exercise is a core recommended treatment. Most evidence is based on muscle-strengthening exercise, but aerobic physical activity has potential to enhance clinical benefits. The primary aim of this study is to test the hypothesis that adding aerobic physical activity to a muscle strengthening exercise leads to significantly greater reduction in hip pain and improvements in physical function, compared to a lower-limb muscle strengthening exercise program alone at 3 months.MethodsThis is a superiority, 2-group, parallel randomised controlled trial including 196 people with symptomatic hip OA from the community. Following baseline assessment, participants are randomly allocated to receive either i) aerobic physical activity and muscle strengthening exercise or; ii) muscle strengthening exercise only. Participants in both groups receive 9 consultations with a physiotherapist over 3 months. Both groups receive a progressive muscle strengthening exercise program in addition to advice about OA management. The aerobic physical activity plan includes a prescription of moderate intensity aerobic physical activity with a goal of attaining 150 min per week. Primary outcomes are self-reported hip pain assessed on an 11-point numeric rating scale (0 = ‘no pain’ and 10 = ‘worst pain possible’) and self-reported physical function (Western Ontario and McMaster Universities Osteoarthritis Index physical function subscale) at 3 months. Secondary outcomes include other measures of self-reported pain (assessed at 0, 3, 9 months), self-reported physical function (assessed at 0, 3, 9 months), performance-based physical function (assessed at 0, 3 months), joint stiffness (assessed at 0, 3, 9 months), quality of life (assessed at 0, 3, 9 months), muscle strength (assessed at 0, 3 months), and cardiorespiratory fitness (assessed at 0, 3 months). Other measures include adverse events, co-interventions, and adherence. Measures of body composition, serum inflammatory biomarkers, quantitative sensory measures, anxiety, depression, fear of movement and self-efficacy are included to explore causal mechanisms.DiscussionFindings will assist to provide an evidence-based recommendation regarding the additional effect of aerobic physical activity to lower-limb muscle strengthening on hip OA pain and physical function.Trial registrationAustralian New Zealand Clinical Trials Registry reference: ACTRN 12619001297112. Registered 20th September 2019.

Association of Pain Sensitization and Conditioned Pain Modulation to Pain Patterns in Knee Osteoarthritis.

To examine the cross-sectional association of ascending pain mechanisms, implicated in pain sensitization, and descending pain modulation with pain patterns and unpredictability of pain. The Multicenter Osteoarthritis Study is a longitudinal cohort of older adults with or at risk of knee osteoarthritis. Peripheral and central ascending pain mechanisms were assessed using quantitative sensory tests, pressure pain thresholds using a handheld pressure algometer (knee/peripheral and wrist/central), and temporal summation using weighted probes (wrist/central). Descending modulation was assessed by conditioned pain modulation using pressure pain thresholds and a forearm ischemia test. Pain patterns were characterized based on responses to the Intermittent and Constant Osteoarthritis Pain questionnaire: 1) no intermittent or constant pain, 2) intermittent pain only, 3) constant pain only, and 4) combined constant and intermittent pain. A question regarding frequency assessed unpredictable pain. We assessed the association of quantitative sensory test measures to pain patterns using regression models with generalized estimating equations. There were 2,794 participants (mean age 63.9 years, body mass index 29.5 kg/m2 , and 57% female). Lower pain sensitization by wrist pressure pain threshold (odds ratio [OR] 0.80 [95% confidence interval (95% CI) 0.68, 0.93]) and adequate conditioned pain modulation (OR 1.45 [95% CI 1.10, 1.92]) were associated with having constant ± intermittent pain compared with intermittent pain only. Higher pain sensitization (by pressure pain thresholds and temporal summation) was associated with a higher likelihood of unpredictable pain. Knee pain patterns appear to be related to peripheral ± central facilitated ascending pain mechanisms and descending modulatory mechanisms. These findings highlight the need for a broader approach to understanding pain mechanisms by symptomatic disease progression.

Relative contributions of the nervous system, spinal tissue and psychosocial health to non-specific low back pain: Multivariate meta-analysis.

Nervous system, psychosocial and spinal tissue biomarkers are associated with non-specific low back pain (nsLBP), though relative contributions are unclear. MEDLINE, EMBASE, CINAHL, PsycINFO and SPORTDiscus were searched up to 25 March 2020. Related reviews and reference lists were also screened. Observational studies examining structural and functional nervous system biomarkers (e.g. quantitative sensory tests, structural and functional brain measures), psychosocial factors (e.g. mental health, catastrophizing) and structural spinal imaging biomarkers (e.g. intervertebral disc degeneration, paraspinal muscle size) between nsLBP and pain-free controls were included. For multivariate meta-analysis, two of three domains were required in each study. Random-effects pairwise and multivariate meta-analyses were performed. GRADE approach assessed evidence certainty. Newcastle-Ottawa scale assessed risk of bias. Main outcomes were the effect size difference of domains between nsLBP and pain-free controls. Of 4519 unique records identified, 33 studies (LBP=1552, referents=1322) were meta-analysed. Psychosocial state (Hedges' g [95%CI]: 0.90 [0.69-1.10], p<0.001) in nsLBP showed larger effect sizes than nervous system (0.31 [0.13-0.49], p<0.001; difference: 0.61 [0.36-0.86], p<0.001) and spine imaging biomarkers (0.55 [0.37-0.73], p<0.001; difference: 0.36 [0.04-0.67], p=0.027). The relationship between domains changes depending on if pain duration is acute or chronic. Psychosocial effect sizes in nsLBP are greater than those for spinal imaging and nervous system biomarkers. Limitations include cross-sectional design of studies included and inference of causality. Future research should investigate the clinical relevance of these effect size differences in relation to pain intensity and disability. PROSPERO-CRD42020159188. Spinal structural lesions (e.g. intervertebral disc degeneration), psychosocial (e.g. depression) and nervous system factors (detected by e.g. quantitative sensory tests, structural and functional measures) contribute to non-specific low back pain. However, psychosocial factors may be more compromised than nervous system and spinal imaging biomarkers. This relationship depends on if the pain is acute or chronic. These findings underscore that the 'non-specific' label in back pain should be reconsidered, and more specific multidimensional categories evaluated to guide patient management.

Utilization of Descriptive Sensory Analysis and Volatile Analysis to Determine Quality Indicators of Aquacultured Whiteleg Shrimp (Litopanaeus vannemei) during Refrigerated Storage

ABSTRACT Traditionally, shrimp meat quality has been evaluated using subjective qualitative (pass/fail grading) sensory methods. This study aims to develop quantitative sensory indicators that contribute to a more objective and reliable evaluation of shrimp quality. A headspace solid-phase microextraction (HS-SPME) method was optimized and coupled with gas chromatography-mass spectrometry (GC-MS) to identify and semi-quantify 35 volatiles accumulated by the end of storage at 4°C. A trained descriptive sensory panel developed eight aroma descriptors associated with quality changes of shrimp. Five out of the eight aroma descriptors are potential quality indicators due to significant correlations with the storage time and good alignment with presumed shrimp grading cutoffs, including one indicator of freshness (“salty water”) and four indicators of spoilage of shrimp (“oxidized oil,” “natto water,” “sour milk,” and “dirty sock”). The intensity ratings of these sensory indicators significantly correlated with the concentration changes of volatiles that were identified to be important chemical spoilage indicators of shrimp. Overall, the aroma indicators determined in this study can lead to quantitative sensory measurements of shrimp quality that correspond well with the results of objective analytical methods.

The relationship between immediate comfort and plantar foot sensitivity during running in cushioned versus minimal shoes

In addition to footwear characteristics, it has been hypothesised that plantar foot sensitivity influences the perception of footwear comfort during running. This study examined the relationship between plantar foot sensitivity to light tough, mechanical pain, vibration and pressure pain and footwear comfort rankings of cushioned and minimal shoes during running. Seventy-five participants (Females = 39, Age 35 (SD 8.9) years, BMI 23.7 (3.6) kg/m2), who identified as regular recreational runners, underwent a standardised protocol of quantitative sensory measures. They then ran on a pre-specific 900 m, outdoor track in each shoe. At the completion of both runs, participants were asked to rank the shoes in order of comfort. Participants were grouped based on their top comfort ranking. The 47 individuals who ranked the cushioned shoe as most comfortable were significantly more sensitive to mechanical pain at their heel (mean difference 109.2 mN, 95% confidence interval 9.6 to 208.7; p = 0.032) and lateral midfoot (87.7 mN, 13.2 to 162.2; p = 0.022). They were also significantly less sensitive to vibration at their medial forefoot (mean difference −2.33 s, 95% CI −4.43 to −0.23; p = 0.03) and lateral midfoot (−1.76 s, −3.51 to −0.2; p = 0.048). This study demonstrates that there is an association between plantar foot sensitivity profiles and immediate footwear comfort. This may have implications when advising individuals who prefer cushioned shoes to run in minimal shoes. It may expose them to potentially painful stimuli with detrimental effects on soft tissue.

Test–retest reliability of quantitative sensory testing for mechanical somatosensory and pain modulation assessment of masticatory structures

Assessing the reliability of medical measurements is a crucial step towards the elaboration of an applicable clinical instrument. There are few studies that evaluate the reliability of somatosensory assessment and pain modulation of masticatory structures. This study estimated the test-retest reliability, that is over time, of the mechanical somatosensory assessment of anterior temporalis, masseter and temporomandibular joint (TMJ) and the conditioned pain modulation (CPM) using the anterior temporalis as the test site. Twenty healthy women were evaluated in two sessions (1 week apart) by the same examiner. Mechanical detection threshold (MDT), mechanical pain threshold (MPT), wind-up ratio (WUR) and pressure pain threshold (PPT) were assessed on the skin overlying the anterior temporalis, masseter and TMJ of the dominant side. CPM was tested by comparing PPT before and during the hand immersion in a hot water bath. anova and intra-class correlation coefficients (ICCs) were applied to the data (α = 5%). The overall ICCs showed acceptable values for the test-retest reliability of mechanical somatosensory assessment of masticatory structures. The ICC values of 75% of all quantitative sensory measurements were considered fair to excellent (fair = 8·4%, good = 33·3% and excellent = 33·3%). However, the CPM paradigm presented poor reliability (ICC = 0·25). The mechanical somatosensory assessment of the masticatory structures, but not the proposed CPM protocol, can be considered sufficiently reliable over time to evaluate the trigeminal sensory function.

Mindful Yoga Pilot Study Shows Modulation of Abnormal Pain Processing in Fibromyalgia Patients.

Published findings from a randomized controlled trial have shown that Mindful Yoga training improves symptoms, functional deficits, and coping abilities in individuals with fibromyalgia and that these benefits are replicable and can be maintained 3 months post-treatment. The aim of this study was to collect pilot data in female fibromyalgia patients (n = 7) to determine if initial evidence indicates that Mindful Yoga also modulates the abnormal pain processing that characterizes fibromyalgia. Pre- and post-treatment data were obtained on quantitative sensory tests and measures of symptoms, functional deficits, and coping abilities. Separation test analyses indicated significant improvements in heat pain tolerance, pressure pain threshold, and heat pain after-sensations at post-treatment. Fibromyalgia symptoms and functional deficits also improved significantly, including physical tests of strength and balance, and pain coping strategies. These findings indicate that further investigation is warranted into the effect of Mindful Yoga on neurobiological pain processing.

Quantitative sensory and motor measures detect change over time and correlate with walking speed in individuals with multiple sclerosis

BackgroundImpairments of sensation, strength, and walking are common in multiple sclerosis (MS). The relationship among these abnormalities and how they change over time remains unclear. ObjectiveTo determine the extent that quantitative lower extremity sensory and motor measures detect abnormalities over time, relate to global disability, and to walking speed in individuals with MS. MethodsThis prospective, longitudinal analysis evaluated 136 MS subjects. Measures included measures of leg strength, sensation, the Expanded Disability Status Scale(EDSS) and timed 25-foot walk test (T25FW). Mixed effects regression models were used. ResultsOur cohort׳s mean age is 44.3±10.8 years (mean±SD), EDSS score range 0–7.5, 66% were females, and follow-up time was 2.1±1.2 years. Strength significantly changed over time; the RRMS group demonstrated the greatest changes in ADF (3.3lbs/yr) while the PPMS group showed significant HF changes (−2.1lbs/yr). Walking speed was affected most by HF, especially in the weakest individuals (HF<20lbs); T25FW increased by 0.20s for each 1lb loss (p=0.001). Likewise T25FW changed by 0.19s for each 1lb change in ADF (p<0.01). ConclusionQuantitative measures detected changes in sensation and strength over time, despite a stable respective functional systems scores of the EDSS. Quantitative measurement tools may improve the sensitivity of disability measures in MS and further investigation of these tools as outcomes in future clinical trials of rehabilitative and neuroreparative interventions is warranted.

Investigating dynamic pain sensitivity in the context of the fear-avoidance model.

Although nearly everyone at some point in their lives experiences back pain; the amount of interference with routine activity varies significantly. The fear-avoidance (FA) model of chronic pain explains how psychological variables, such as fear, act as mediating factors influencing the relationship between clinical pain intensity and the amount of interference with daily activities. What remains less clear is how other mediating factors fit within this model. The primary objective of this report was to examine the extent to which a dynamic measure of pain sensitivity provides additional information within the context of the FA model. To address our primary objective, classic mediation and moderated mediation analyses were conducted on baseline clinical, psychological and quantitative sensory measures obtained on 67 subjects with back pain (mean age, 31.4 ± 12.1 years; 70% female). There was a moderately strong relationship (r = 0.52; p < 0.01) between clinical pain intensity and interference, explaining about 27% of the variance in the outcome. Mediation analyses confirmed fear partially mediated the total effect of clinical pain intensity on interference (Δβ = 0.27; p < 0.01), and accounted for an additional 16% of the variance. In our FA model, pain sensitivity did not demonstrate additional indirect effects; however, it did moderate the strength of indirect effects of fear. This preliminary modelling suggests complex interactions exist between pain-related fear and pain sensitivity measures that further explain individual differences in behaviour.

Signs and symptoms of methylmercury contamination in a First Nations community in Northwestern Ontario, Canada

In 1970, fish caught in the English–Wabigoon River system in northwestern Ontario, Canada, were found to be contaminated with mercury coming from a chlor-alkali plant in the province. In the 1970s, patients exhibiting some of the symptoms of the Hunter–Russell syndrome (e.g. paresthesias, visual field constriction, ataxia, impaired hearing, and speech impairment) were reported by some researchers. However attempts to diagnose the patients as suffering from methylmercury poisoning proved to be controversial. In order to research the presence of methylmercury contamination, and show that the patients, through eating contaminated fish, were suffering from methylmercury poisoning, we studied the results of subjective complaints, neurological findings, and quantitative somatosensory measurements gathered in Grassy Narrows Indian Reservation, Ontario, in March, 2010. At that time, the population of the Grassy Narrows settlement was around 900. Ninety-one residents volunteered to be examined. From them, we selected 80 people who were older than 15years old, and divided them into two groups. Canadian Younger (CY): 36 residents who were from 16 to 45years old. Canadian Older (CO): 44 residents who were from 46 to 76years old. We compared them to Japanese Exposed (JE): 88 methylmercury exposed residents from the Minamata district in Japan, and Japanese Control (JC): 164 control residents from non-polluted areas in Japan. Complaints and abnormal neurological findings were more prevalent and quantitative sensory measurements were worse in the two Canadian groups and the Japanese Exposed group than in the Japanese Control group. Complaints, neurological findings and quantitative sensory measurements were similar in Canadian Older and Japanese Exposed. The results for Canadian Younger fell between those of Canadian Older and Japanese Control. These findings indicate that the clinical signs and symptoms of the residents of Grassy Narrows are almost the same as those recorded for Minamata disease in Japan.

The Relationship Between Cortical Excitability and Pain Catastrophizing in Myofascial Pain

Pain catastrophizing regularly occurs in chronic pain patients. It has been suggested that pain catastrophizing is a stable, person-based construct. These findings highlight the importance of investigating catastrophizing in conceptualizing specific approaches for pain management. One important area of investigation is the mechanism underlying pain catastrophizing. Therefore, this study explored the relationship between a neurophysiological marker of cortical excitability, as assessed by transcranial magnetic stimulation, and catastrophizing, as assessed by the Brazilian Portuguese Pain Catastrophizing Scale, in patients with chronic myofascial pain syndrome. The Pain Catastrophizing Scale is a robust questionnaire used to examine rumination, magnification and helplessness that are associated with the experience of pain. We include 24 women with myofascial pain syndrome. The Brazilian Portuguese Pain Catastrophizing Scale and cortical excitability were assessed. Functional and behavioral aspects of pain were evaluated with a version of the Profile of Chronic Pain scale and by multiple pain measurements (eg, pain intensity, pressure pain threshold, and other quantitative sensory measurements). Intracortical facilitation was found to be significantly associated with pain catastrophizing (β = .63, P = .001). Our results did not suggest that these findings were influenced by other factors, such as age or medication use. Furthermore, short intracortical inhibition showed a significant association with pressure pain threshold (β = .44, P = .04). This study elaborates on previous findings indicating a relationship between cortical excitability and catastrophizing. The present findings suggest that glutamatergic activity may be associated with mechanisms underlying pain catastrophizing; thus, the results highlight the need to further investigate the neurophysiological mechanisms associated with pain and catastrophizing. PerspectiveThis study highlights the relationship between cortical excitability and catastrophizing. Cortical measures may illuminate how catastrophizing responses may be related to neurophysiological mechanisms associated with chronic pain.

Women with knee osteoarthritis have more pain and poorer function than men, but similar physical activity prior to total knee replacement

BackgroundOsteoarthritis of the knee is a major clinical problem affecting a greater proportion of women than men. Women generally report higher pain intensity at rest and greater perceived functional deficits than men. Women also perform worse than men on function measures such as the 6-minute walk and timed up and go tests. Differences in pain sensitivity, pain during function, psychosocial variables, and physical activity levels are unclear. Further the ability of various biopsychosocial variables to explain physical activity, function and pain is unknown.MethodsThis study examined differences in pain, pain sensitivity, function, psychosocial variables, and physical activity between women and men with knee osteoarthritis (N = 208) immediately prior to total knee arthroplasty. We assessed: (1) pain using self-report measures and a numerical rating scale at rest and during functional tasks, (2) pain sensitivity using quantitative sensory measures, (3) function with self-report measures and specific function tasks (timed walk, maximal active flexion and extension), (4) psychosocial measures (depression, anxiety, catastrophizing, and social support), and (5) physical activity using accelerometry. The ability of these mixed variables to explain physical activity, function and pain was assessed using regression analysis.ResultsOur findings showed significant differences on pain intensity, pain sensitivity, and function tasks, but not on psychosocial measures or physical activity. Women had significantly worse pain and more impaired function than men. Their levels of depression, anxiety, pain catastrophizing, social support, and physical activity, however, did not differ significantly. Factors explaining differences in (1) pain during movement (during gait speed test) were pain at rest, knee extension, state anxiety, and pressure pain threshold; (2) function (gait speed test) were sex, age, knee extension, knee flexion opioid medications, pain duration, pain catastrophizing, body mass index (BMI), and heat pain threshold; and (3) physical activity (average metabolic equivalent tasks (METS)/day) were BMI, age, Short-Form 36 (SF-36) Physical Function, Kellgren-Lawrence osteoarthritis grade, depression, and Knee Injury and Osteoarthritis Outcome Score (KOOS) pain subscale.ConclusionsWomen continue to be as physically active as men prior to total knee replacement even though they have significantly more pain, greater pain sensitivity, poorer perceived function, and more impairment on specific functional tasks.

A Randomized, Controlled Investigation of Motor Cortex Transcranial Magnetic Stimulation (TMS) Effects on Quantitative Sensory Measures in Healthy Adults

There is emerging evidence that transcranial magnetic stimulation (TMS) can produce analgesic effects in clinical samples and in healthy adults undergoing experimentally induced pain; and the field of minimally invasive brain stimulation for the management of pain is expanding rapidly. Although motor cortex is the most widely used cortical target for TMS in the management of neuropathic pain, few studies have systematically investigated the analgesic effects of a full range of device parameters to provide initial hints about what stimulation intensities and frequencies are most helpful (or even potentially harmful) to patients. Further, there is considerable inconsistency between studies with respect to laboratory pain measurement procedures, TMS treatment parameters, sophistication of the sham methods, and sample sizes. This study used a sham-controlled, within-subject, cross-over design to examine the effects of 5 different TMS treatment parameters across several quantitative sensory measures in a sample of healthy adult volunteers. Sixty-five participants underwent quantitative sensory testing procedures pre and post-40-minutes of real and sham motor cortex TMS. TMS was delivered at 1 Hz 80% resting motor threshold (rMT), 1 Hz 100% rMT, 10 Hz 80% rMT, 10 Hz 100% rMT, or 50 Hz triplets at 90% of active motor threshold (intermittent theta-burst). The mean painfulness rating of real TMS stimulation itself was 3.0 (SE=0.36) out of 10 and was significantly greater than zero [t(64)=8.17, P<0.0001]. The sham TMS methods used permitted matching between real and sham TMS-induced scalp sensations and participants were successfully blinded to condition (real versus sham). Findings suggest that the effects of motor cortex TMS on quantitative sensory tests in healthy adults vary across different treatment parameters with the smallest observed effect for intermittent theta-burst stimulation (Cohen's d=0.03) and the largest for 10 Hz 100% rMT (d=0.34). Overall, TMS was associated with statistically significant effects on warm and cool sensory thresholds, cold pain thresholds, suprathreshold stimulus unpleasantness ratings, and wind-up pain. With respect to device parameter effects, higher frequency stimulation seems to be associated with the most analgesic and antisensitivity effects with the exception of intermittent theta-burst stimulation. The present findings support several clinical research findings suggesting that higher TMS frequencies tend to be associated with the most clinical benefit in patients with chronic pain.

A Randomized, Controlled Investigation of Motor Cortex Transcranial Magnetic Stimulation (TMS) Effects on Quantitative Sensory Measures in Healthy Adults: Evaluation of TMS Device Parameters

A Randomized, Controlled Investigation of Motor Cortex Transcranial Magnetic Stimulation (TMS) Effects on Quantitative Sensory Measures in Healthy Adults: Evaluation of TMS Device Parameters

A randomised controlled study examining the short-term effects of Strain–Counterstrain treatment on quantitative sensory measures at digitally tender points in the low back

Strain–Counterstrain (SCS) intervention has been claimed to elicit immediate and sustained reductions in tenderness at digitally tender points (DTPs), however, there is little experimental evidence to support this. Twenty-eight volunteer participants with low back pain – LBP (17 females and 11 males with mean [SD] age of 39.2 [11.1] and Oswestry disability index of 15.7 [8.6]) participated in this controlled, within-participants study of the immediate and short-term effects of SCS intervention, on pressure pain threshold (PPT) electrical detection threshold (EDT) and electrical pain threshold (EPT) at DTPs in the low back region. Immediate increases in PPT at DTPs were found following all interventions; control intervention: 30.7 kPa [CI 95% – 3.3–64.8] ( p = 0.041), sham-SCS intervention: 48.2 kPa [CI 95% 14.8–81.7] ( p = 0.008) and SCS intervention: 93.4 kPa [CI 95% 60.0–126.9] ( p < 0.0001). Results suggest that SCS intervention does elicit an immediate quantifiable reduction in tenderness at DTPs but that some of this reduction is attributable to the manual-contact component of the treatment. Increases in PPT at DTPs following SCS intervention did not appear to be maintained between 24 and 96 h after treatment. A further finding was that the control intervention elicited significant increases in both EDT ( p = 0.044) and EPT ( p = 0.026). The explanation for these findings is unclear.

Predicting Postoperative Pain Based on Preoperative Pain Perception

Predicting Postoperative Pain Based on Preoperative Pain Perception

Contribution of individual, workplace, psychosocial and physiological factors to neck pain in female office workers

This study investigated the relative contribution of individual, workplace, psychosocial and physiological features associated with neck pain in female office workers towards developing appropriate intervention programs. Workers without disability (Neck Disability Index (NDI) score ⩽ 8, n = 33); workers with neck pain and disability (NDI ⩾ 9/100, n = 52) and 22 controls (women who did not work and without neck pain) participated in this study. Two logistic regression models were constructed to test the association between various measures in (1) workers with and without disability, and (2) workers without disability and controls. Measures included those found to be significantly associated with higher NDI in our previous studies: psychosocial domains; individual factors; task demands; quantitative sensory measures and measures of motor function. In the final model, higher score on negative affectivity scale (OR = 4.47), greater activity in the neck flexors during cranio-cervical flexion (OR = 1.44), cold hyperalgesia (OR = 1.27) and longer duration of symptoms (OR = 1.19) remained significantly associated with neck pain in workers. Workers without disability and controls could only be differentiated by greater muscle activity in the cervical flexors and extensors during a typing task. No psychosocial domains remained in either regression model. These results suggest that impairments in the sensory and motor system should be considered in any assessment of the office worker with neck pain and may have stronger influences on the presenting symptoms than workplace and psychosocial features.

Quantitative sensory measures distinguish office workers with varying levels of neck pain and disability

This study was undertaken to investigate any relationship between sensory features and neck pain in female office workers using quantitative sensory measures to better understand neck pain in this group. Office workers who used a visual display monitor for more than four hours per day with varying levels of neck pain and disability were eligible for inclusion. There were 85 participants categorized according to their scores on the neck disability index (NDI): 33 with no pain (NDI < 8); 38 with mild levels of pain and disability (NDI 9–29); 14 with moderate levels of pain (NDI ⩾ 30). A fourth group of women without neck pain ( n = 22) who did not work formed the control group. Measures included: thermal pain thresholds over the posterior cervical spine; pressure pain thresholds over the posterior neck, trapezius, levator scapulae and tibialis anterior muscles, and the median nerve trunk; sensitivity to vibrotactile stimulus over areas of the hand innervated by the median, ulnar and radial nerves; sympathetic vasoconstrictor response. All tests were conducted bilaterally. ANCOVA models were used to determine group differences between the means for each sensory measure. Office workers with greater self-reported neck pain demonstrated hyperalgesia to thermal stimuli over the neck, hyperalgesia to pressure stimulation over several sites tested; hypoaesthesia to vibration stimulation but no changes in the sympathetic vasoconstrictor response. There is evidence of multiple peripheral nerve dysfunction with widespread sensitivity most likely due to altered central nociceptive processing initiated and sustained by nociceptive input from the periphery.