Reliability study of thermal quantitative sensory testing in healthy Chinese

Background: Test–retest reliability is important to establish for any diagnostic tool. The reliability of quantitative sensory testing (QST) in the trigeminal region has recently been described in Caucasians as well as differences in absolute thresholds and responses between Caucasians and Chinese. However, the test–retest reliability has not been determined in a Chinese population.

Objective: To provide novel information on the test–retest reliability of thermal QST in the trigeminal and spinal system in healthy Chinese.

Methods: Twenty healthy volunteers (10 women and 10 men) participated. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), and heat pain threshold (HPT) were measured at two sites: the surface of the left hand and the left masseter. The testing was performed over three consecutive stimuli trials, three sessions conducted on one day and repeated one week later. Data were analyzed with intra-tester reliability test and four-way analysis of variance (ANOVA) for repeated measures.

Results: There was a tendency for the first trial in CDT (p?=?0.005), CPT (p?=?0.02), and HPT (p?p?=?0.003) and HPT (p?=?0.045) with higher sensitivity at the masseter muscle. There were significant gender differences with higher sensitivity in women for CPT (p?=?0.001) and HPT (p?=?0.001).

Conclusion: Test site and gender affect thermal thresholds substantially. The test–retest reliability of most thermal threshold measures were acceptable for assessing somatosensory function, however, innocuous thresholds appear to be associated with larger variability than noxious thresholds in a Chinese population.     

Comparison of unpleasant and pain thresholds of thermal stimuli in the orofacial regions: a psychophysical study using quantitative sensory testing in healthy young men

Abstract

Purpose/Aim: To gain a better understanding of the psychophysics of thermal pain perception in a clinical setting, this study investigated whether thermal thresholds of unpleasantness are different from pain thresholds of cold and heat stimuli. Of particular interest was the relationship between unpleasantness and pain thresholds for cold vs heat stimuli.

Material and methods: Thirty healthy male volunteers (mean age 26.1?years, range 23 to 32?years) participated. Thermal detection, cold pain (CPT) and heat pain (HPT) thresholds were measured at 5 trigeminal sites by the method of limits using quantitative sensory testing (QST), followed by cold unpleasant (CUT) and heat unpleasant (HUT) thresholds.

Results: The temperatures at which individuals first reported thermal sensations as unpleasant or painful substantially differed among subjects. CUT exhibited a higher mean value with less variability than CPT, and HUT presented a lower mean than HPT (p?<?.001). As with CPT, CUT did not show any significant difference between the test sites. On the other hand, HUT, like HPT, exhibited site differences (p?<?.001). There was moderate correlation between CUT and CPT, whereas HUT and HPT were strongly correlated. The relationship between unpleasant and pain thresholds of cold vs heat stimuli was significantly different even when controlling for test site variability (p?<?.001).

Conclusion: These findings indicate that unpleasant and pain thresholds to thermal stimuli differ in healthy young men. Of particular note is the distinct relationship of unpleasant and pain thresholds of cold vs heat stimuli, revealing the thermal difference in temperature transition from unpleasantness to pain.     

Effect of a reversal mirror condition on orofacial mechanical sensitivity

The aim of this study was to investigate whether watching one’s own face being touched in a reversal mirror condition modulates orofacial somatosensory sensitivity. A total of 37 healthy volunteers participated in a pilot study, the main study, and a control experiment. In the main experiment, 16 participants received seven different intensities of pinprick stimuli in the right infraorbital region. The perceived stimulus intensity was rated on a 0–50–100 numerical rating scale (NRS). In addition, the pinprick threshold (PiPT) was evaluated in the same region using an electronic von Frey device. During stimuli, participants were watching their own face in two different conditions (normal and reversal mirror) in randomized order. Subjective experiences during each condition were assessed with a questionnaire containing nine statements. The participants rated their level of agreement with the statements using a 7-item Likert scale. There were significant main effects on NRS scores of stimulus forces (p?p?Post hoc analyses showed that stimulation with higher force levels induced significantly higher NRS scores (p?p?p?=?0.184). The experimental condition influenced the response to several statements significantly (p?相似文献   

Evaluating a sensitive issue: reliability of a clinical evaluation for allodynia severity

Abstract

Purpose/Aim: Allodynia is a common feature of neuropathic pain with few validated clinical evaluation options. We identified a need to estimate the measurement properties of the standardised evaluation procedure for static mechanical allodynia severity popularised by the somatosensory rehabilitation of pain method, known as the rainbow pain scale. This study (www.clinicaltrials.gov. NCT02070367) undertook preliminary investigation of the inter-rater and test-retest reliability of the rainbow pain scale.

Methods: Persons with pain in one upper extremity after Complex Regional Pain Syndrome, a peripheral nerve injury or a recent hand fracture were recruited for assessment of static mechanical allodynia threshold using calibrated monofilaments by two raters at baseline, and repeated assessment one week later.

Results: Single measures estimates suggested inter-rater reliability was substantial for the rainbow pain scale [intra-class correlation coefficient?=?0.78 (n?=?31), p?<?0.001]. Test-retest reliability was also excellent at with an intraclass correlation coefficient of 0.87 [n?=?28, p?<?0.001]. However, confidence intervals suggest the true values could be more moderate, with lower bounds of the 95% confidence interval at 0.60 and 0.74, respectively.

Conclusions: This pilot study has generated preliminary support for the inter-rater and test-retest reliability of the rainbow pain scale. Future studies should seek to increase confidence in estimates of reliability, and estimate validity and responsiveness to change in persons with somatosensory disorders.     

Comparative study of observed actions,motor imagery and control therapeutic exercise on the conditioned pain modulation in the cervical spine: a randomized controlled trial

Abstract

Aim: The aim of this study was to compare the effects of cervical exercise, motor imagery (MI) and action observation (AO) of cervical exercise actions on conditioned pain modulation and pressure pain thresholds. The second objective was to assess the effects of these interventions on cervical motor activity (ranges of motion and muscle endurance), attention, and the ability to generate motor images.

Study design: Single-blinded randomized controlled trial.

Materials and methods: Fifty-four healthy subjects were randomly assigned to each group. Response conditioned pain modulation, pressure pain threshold, were the main variables. The secondary outcome measures included, cervical range of motion, Neck flexor endurance test, mental movement representation associated and psychosocial variables.

Results: All groups showed significant differences in time factor for all evaluated variables (p?<?.01) except pressure pain threshold over the tibial region. The post hoc analysis revealed significant within-group differences in the AE and AO groups in conditioned pain modulation (p?<?.05), with medium effect size in time [AE (d –0.61); AO (d –0.74)].

Conclusion: The results showed that within-group changes in conditioned pain modulation, cervical muscle endurance, and attention where founded only in the AE and AO groups. Variations in pain thresholds at pressure in the trapezium area were also obtained in the three groups. Changes in the ranges of flexion-extension and rotation movement were presented exclusively in the exercise group, and in the capacity to generate motor images only in the AO group. However, there was no difference in the pressure pain threshold over the tibial region.     

Corticomotor correlates of somatosensory reaction time and variability in individuals with post concussion symptoms

Abstract

Persistent post concussion symptoms (PPCS) describe the condition when an individual experiences chronic symptoms, particularly fatigue, beyond the expected time of recovery. The aim of this study was to quantify the effect of fatigue and related ongoing symptoms on somatosensory and corticomotor pathways using reaction time (RT) testing, and single-pulse and paired-pulse transcranial magnetic stimulation (TMS). Eighty-three participants (nine female, mean age 37.9?±?11.5?years) were divided into two groups (persistent symptoms versus asymptomatic) following self-report based upon previously published clinical symptom scores. All participants completed somatosensory and visuomotor RT testing, as well as corticomotor excitability and inhibition measurements via TMS. Participants in the persistent symptom group (n?=?38) reported greater number of previous concussions (t?=?2.81, p?=?0.006) and significantly higher levels of fatigue and related symptoms in the asymptomatic group (n?=?45; t?=?11.32, p?<?0.006). Somatosensory RT showed significant slowing and increased variability in the persistent symptoms group (p?<?0.001), however no significant differences were observed between groups for visuomotor RTs. Transcranial magnetic stimulation revealed differences between groups for intracortical inhibition at all stimulus intensities and paired pulse measures. The results indicate that somatosensory and corticomotor systems reflect on-going fatigue. From a practical perspective, objective and simplistic measures such as somatosensory and corticomotor measures can be used in the assessment of PPCS and gauging the efficacy of post concussion rehabilitation programmes.     

Sensory retraining improves light touch threshold of the paretic hand in chronic stroke survivors: a single-subject A-B design

Abstract

Background: Light touch, one of the primary and basic sensations, is often neglected in sensory retraining programmes for stroke survivors.

Objective: This study aimed to investigate the effects of sensory retraining on the light touch threshold of the hand, dexterity and upper limb motor function of chronic stroke survivors.

Methods: Five chronic stroke survivors with sensory impairment participated in this single-subject A-B design study. In baseline (A) phase, they only received standard rehabilitation. In the treatment (B) phase, they received a 6-week sensory retraining intervention in addition to standard rehabilitation. In both phases, they were evaluated every 3 days. Light touch threshold, manual dexterity and upper limb motor function were assessed using Semmes-Weinstein Monofilaments, Box-Block Test and Fugl-Meyer Assessment, respectively. Visual analysis, nonparametric Mann-Whitney U test and, c-statistic were used for assessing the changes between phases.

Results: All participants indicated changes in trend or slope of the total score of light touch or both between the two phases. The results of the c-statistic also showed the statistical difference in the total score of light touch between baseline and treatment in all participants (p?<?0.001). Also, the results of the c-statistic and Mann-Whitney U test supported the difference of manual dexterity and motor function of the upper limb between baseline and treatment in all participants (p?<?0.001).

Conclusion: Current findings showed that sensory retraining may be an effective adjunctive intervention for improving the light touch threshold of the hand, dexterity and upper limb motor function in chronic stroke survivors.     

Forward head posture is associated with pressure pain threshold and neck pain duration in university students with subclinical neck pain

Abstract

Objective: The aims of this study are to investigate the association between: (i) forward head posture (FHP) and pressure pain thresholds (PPTs); (ii) FHP and maladaptive cognitive processes; and (iii) FHP and neck pain characteristics in university students with subclinical neck pain.

Materials/methods: A total of 140 university students, 90 asymptomatic and 50 with subclinical neck pain, entered the study. Demographic data, anthropometric data, FHP, and PPTs were collected for both groups. In addition, pain characteristics, pain catastrophizing, and fear of movement were assessed for participants with neck pain. FHP was characterized by the angle between C7, the tragus of the ear, and the horizontal line. Correlation analysis and multivariate regression analysis were conducted.

Results: Participants with subclinical neck pain showed significantly lower PPTs than participants without neck pain (p?<?.05), but similar FHP (p?>?.05). No significant association was found between FHP and PPTs in the asymptomatic group. In the group of participants with subclinical neck pain, PPTs at the right trapezius and neck pain duration explained 19% of the variance of FHP (R²?=?0.23; adjusted R²?=?0.19; p?<?.05).

Conclusion: This study suggests that FHP is not associated with PPTs in asymptomatic university students. In university students with subclinical neck pain, increased FHP was associated with right trapezius hypoalgesia and with neck pain of shorter duration. These findings are in contrast with current assumptions on the association between neck pain and FHP.     

Adaptation to warming but not cooling at slow rates of stimulus change in thermal threshold measurements

The relationship between thermal detection threshold and rate of temperature change of the thermal stimulus when slow (<1°C?s^?1) rates of change are employed was investigated. Using both the reaction time (RT) inclusive Method of Limits and RT exclusive Method of Levels healthy volunteers had warming (WDT) and cooling detection thresholds (CDT) measured at four different rates of temperature change (0.3, 0.5, 0.7 and 1.0°C?s^?1) from the thenar and/or mental regions using a contact thermode. With the Method of Limits, CDT increased linearly with rate of temperature change suggesting increments were due to RT artefacts. This was further supported by threshold assessment with the Method of Levels which showed CDT were unaffected by the rate of change in the RT exclusive method (P?>?0.1). In contrast, WDT did not increase linearly with rate of stimulus temperature change when the Method of Limits was used and threshold assessment with the Method of Levels showed WDT assessed using a 0.3°C?s^?1 ramp rate were significantly higher than those measured with a 1°C?s^?1 rate of change (P?<?0.05). This study indicates that adaptation to a warming stimulus can occur at faster rates of stimulus change than previously anticipated and identifies differences in warming and cooling pathways in sensitivity to adaptation.     

Characteristics of attention-related body sensations. Temporal stability and associations with measures of body focus,affect, sustained attention,and heart rate variability

Aim: This study investigated the temporal stability and correlates of attention-related body sensations that emerge without external stimulation during rest and due to focused attention on a body part.

Materials: To assess attention-related body sensations, participants were asked to focus on a freely chosen body area with closed eyes, and had to report whether the sensation of that area had changed. Self-report questionnaires were used to assess various aspects of body focus (body awareness, body responsiveness, somatosensory amplification, subjective somatic symptoms), and positive and negative affectivity. Previous experiences in body–mind therapies were also measured. PEBL Continuous Performance Test was used to assess sustained attention. Heart rate variability scores were based on a 3-minute long resting heart rate measurement.

Methods: Fifty-eight university students (22.3?±?3.95 years; 34 females) participated in the study. The stability of attention-related body sensations was measured 8?weeks later on a randomly chosen sub-group (n?=?28).

Results: Attention-related body sensations showed a mediocre temporal stability (r_ρ?=?0.47, p?=?0.012). People reporting attention-related body sensations showed significantly higher body awareness, somatosensory amplification, and resting heart rate; and marginally higher somatic symptoms. No relation was found with body–mind practice, body responsiveness, positive and negative affect, the vagal component of heart rate variability, and performance in the sustained attention task.

Conclusion: Attention-related sensations are relatively stable over time. They are connected to some, but not to all of the aspects of body focus. Further studies are needed to elaborate the influencing stable and situational factors.     

Visual motor imagery predominance in professional Spanish dancers

Abstract

Purpose: The main objectives of the study were to analyse the predominant motor imagery modality used by professional Spanish dancers and to compare Spanish dancers’ ability to perform mental motor imagery with that of non-dancers, and to analyse differences between male and female dancers. As a secondary aim, to compare the motor imagery ability between two styles of Spanish dance: classical Spanish dancers and Flamenco dancers.

Methods: A total of 74 participants were classified into two groups: professional Spanish dancers (n?=?37) and sedentary participants (n?=?37). The professional Spanish dancer group was composed of two dance disciplines: flamenco dancers (n?=?17), and classical dancers (n?=?20).

Results: Professional Spanish dancers used predominantly visual imagery modalities over kinesthetics to generate motor imagery, with a moderate effect size (p?<?.01, d?=?0.68). Regarding the ability to generate motor imagery, significant intergroup differences between professional Spanish dancers and sedentary participants were observed in all variables, with a large effect size (p?<?.05, d?>?0.80). Differences were obtained between men and women among non-dancers group (t?=??3.34; p?=?.03; d?=?0.5). No differences between Flamenco and classical dancers were observed.

Conclusion: Visual motor imagery modality was easier than the kinaesthetic modality in the generation of motor imagery for professional Spanish dancers regardless of the dance style. Spanish dancers had a greater ability to perform motor imagery compared with non-dancer individuals, needing less time to perform these mental tasks. Men non-dancers had a greater ability to generate motor imagery than women. Reinforcing the training of kinaesthetic motor imagery might be useful for professional Spanish dancers.     

Diagnostic value of exercise-induced changes in circulating high sensitive troponin T in stable chest pain patients

Abstract

Objective: We investigated the diagnostic value of exercise-induced increase in cardiac Troponin T (cTnT) in stable chest pain subjects.

Methods: CTnT was measured before and 20?h after an exercise test in 157 subjects suspected of coronary artery disease (CAD).

Results: CAD subjects (n?=?41) had higher baseline cTnT levels compared to non-CAD subjects (n?=?116), 6.39?ng/l and 3.00?ng/l, respectively, p?<?0.0001, and were more likely to increase in cTnT (70.7% versus 27.6%, p?<?0.0001). Net Reclassification Index for the combined variable was 19%, p?=?0.02.

Conclusions: Exercise-induced increase in cTnT was found to be associated with CAD and cTnT measurements improved the diagnostic evaluation.     

Accuracy and precision of a wrist movement when vibrotactile prompts inform movement speed

Abstract

Purpose: This study investigated the effect of movement speed on task accuracy and precision when participants were provided temporally oriented vibrotactile prompts. Materials and methods: Participants recreated a simple wrist flexion/extension movement at fast and slow speeds based on target patterns conveyed via vibrating motors affixed to the forearm. Each participant was given five performance-blinded trials to complete the task at each speed. Movement accuracy (root mean square error) and precision (standard deviation) were calculated for each trial in both the spatial and temporal domains. Results: 28 participants completed the study. Results showed temporal accuracy and precision improved with movement speed (both: fast?>?slow, p?<?0.01), while all measures improved across trials (temporal accuracy and precision: trial 1?<?all other trials, p?<?0.05; spatial accuracy: trial 1 and 2?<?all other trials, p?<?0.05; spatial precision: trial 1?<?all other trials, p?<?0.05). Conclusions: Overall, temporal and spatial results indicate participants quickly recreated and maintained the desired pattern regardless of speed. Additionally, movement speed seems to influence movement accuracy and precision, particularly within the temporal domain. These results highlight the potential of vibrotactile prompts in rehabilitation paradigms aimed at motor re-education.     

Age- and sex-related changes in vibrotactile sensitivity of hand and face in neurotypical adults

Abstract

Sensory perception decreases with age, and is altered as a function of sex. Very little is known about the age- and sex-related changes in vibrotactile detection thresholds (VDTs) of the face relative to the glabrous hand. This study utilized a single-interval up/down (SIUD) adaptive procedure to estimate the VDT for mechanical stimuli presented at 5, 10, 50, 150, 250, and 300?Hz at two sites on the face, including the right non-glabrous surface of the oral angle and the right lower lip vermilion; and on the hand on the glabrous surface of the distal phalanx of the right dominant index finger. Eighteen right-handed healthy younger adults and 18 right-handed healthy older adults participated in this study. VDTs were significantly different between the three stimulus sites (p?<?0.0001), and dependent on stimulus frequency (p?<?0.0001) and the sex of the participants (p?<?0.005). VDTs were significantly higher for older adults when compared to younger adults for the finger stimulation condition (p?<?0.05). There were significant differences (p?<?0.05) in cheek and lower lip VDTs between male and female subjects. Difference in the VDTs between the three stimulation sites is presumed to reflect the unique typing and distribution of mechanoreceptors in the face and hand. Age-related differences in finger skin sensitivity are likely due to changes in the physical structure of skin, changes in the number and morphology of the mechanoreceptors, differences in the functional use of the hand, and its central representation. Sex-related differences in the VDTs may be due to the differences in tissue conformation and thickness, mechanoreceptor densities, skin hydration, or temperature characteristics.     

Association between ABO blood types and pain perception

Aim of the study: Pain perception is associated with different phenotypic characteristics such as sex, eye, and hair color. Hence, it is assumed that ABO blood type can also affect pain perception.

Materials and methods: In order to investigate this hypothesis, an experimental study with healthy volunteers (18–40?years) was designed. The experimental procedure included a blood type test and two rounds of pressure pain threshold assessments separated by a cold pressor test. Pressure pain threshold was assessed bilaterally at the temporalis, masseter, and deltoid muscles, where the muscle sites were randomized. Cold pressor test was conducted by immersion of participants’ non-dominant hand into iced water of 1–4?°C for 2?min.

Results: Thirty-seven healthy volunteers, distributed in the four blood type groups, completed the study. Participants with blood type B scored the highest pressure pain thresholds at the examined craniofacial muscles, while participants with blood type AB tended to score the lowest. Furthermore, participants with blood type AB displayed the highest elevation in pressure pain thresholds after cold pressor test.

Conclusions: Participants with blood type B displayed the lowest mechanical pain sensitivity and the blood type AB group exhibited the strongest conditioned pain modulation effect. These findings emphasize the necessity of considering ABO blood types in future pain research.     

Comparison of cortical activation patterns by somatosensory stimulation on the palm and dorsum of the hand

Abstract

Objectives: Little is known about differences of cortical activation according to body location. We attempted to compare brain activation patterns by somatosensory stimulation on the palm and dorsum of the hand, using functional magnetic resonance imaging (fMRI).

Method: We recruited 15 healthy right-handed volunteers for this study. fMRI was performed during touch stimulation using a rubber brush on an area of the same size on the palm or dorsum of the hand. Regions of interest (ROIs) were drawn at the primary sensory–motor cortex (SM1), posterior parietal cortex, and secondary somatosensory cortex.

Results: Group analysis of fMRI data indicated that touch stimulation on the palm resulted in production of more activated voxels in the contralateral SM1 and posterior parietal cortex than on the dorsum of the hand. The most activated ROI was found to be the contralateral SM1 by stimulation of the palm or dorsum, and the number of activated voxels (5875) of SM1 by palm stimulation was more than 2 times that (2282) of dorsum stimulation. The peak activated value in the SM1 by palm stimulation (16.43) was also higher than that of the dorsum (5.52).

Conclusion: We found that stimulation of the palm resulted in more cortical activation in the contralateral SM1 than stimulation of the dorsum. Our results suggested that the palm of the hand might have larger somatotopy of somatosensory representation for touch in the cerebral cortex than the dorsum of the hand. Our results would be useful as a rehabilitation strategy when more or less somatosensory stimulation of the hand is necessary.     

Biomarkers of age effect on renal function in Down syndrome

Objective: To assess differences in kidney function between Down syndrome (DS) individuals and a control group related to aging.

Methods: Creatinine (Cr) and specific gravity (SG) were assessed by spectrophotometric and refractometric assays in urine samples of 103 individuals with DS and 82 age-matched controls.

Results: Significantly lower levels of Cr and SG were found in DS after puberty. Significant correlations were found between SG and age as well as between Cr and SG in DS and controls (p?≤?0.05).

Conclusions: Premature aging in kidneys of DS patients could lead to an impaired renal function.     

Serum creatine is not a reliable marker of muscular fitness in young adults

Purpose: Elevated serum creatine and higher handgrip strength are individually associated with better health profiles yet the link between two variables remains unknown. In this cross-sectional study, we evaluated serum creatine levels in relation to handgrip strength in a cohort of 130 young healthy adults (61 women and 69 men; age 23.3?±?2.6?years), while controlling for age, gender, fat-free mass and biomarkers of creatine metabolism as effect modifiers.

Materials and methods: Serum creatine, creatinine and guanidinoacetic acid (GAA) levels were measured with liquid chromatography-tandem mass spectroscopy, while handgrip strength was assessed with a hydraulic hand dynamometer.

Results: Hierarchical multiple regression revealed that our model as a whole explained 79.9% of the variance in handgrip strength (p?p?p?>?0.05).

Conclusions: Having higher blood creatine appears to be unrelated with better physical performance in young healthy adults. Serum creatine was not a reliable marker of muscular fitness in this population.     

Back extension exercises decompress the spinal root and improve standing mobility in patients with sub-acute lumbosacral radiculopathy

Purpose: Repeated back extension exercises (RBEEs) have been reported to cause changes in the distribution and intensity of radicular symptoms. Therefore, the objective of this study was to investigate the effects of RBEEs on the neurophysiology of the compromised nerve root and on standing mobility and pain intensity in patients with sub-acute and chronic lumbosacral radiculopathy (LSR).

Subjects and methods: A total of 40 patients with unilateral sub-acute/chronic LSR voluntarily participated in the study; the patients performed three sets of 10 RBEEs in the prone position with 1?min of rest between the sets. The soleus H-reflex, standing mobility, and pain intensity were recorded before and after the RBEEs.

Results: The results of the study showed that the RBEEs significantly improved the H-reflex, standing mobility, and pain intensity in patients with sub-acute LSR (p?p?Conclusion: RBEEs in the prone position are recommended for improving the neurophysiological function of the compromised nerve root and standing mobility in patients with sub-acute LSR.