Beyond numbers: integrating qualitative analysis into quantitative sensory testing for neuropathic pain

This article investigates the benefits of adopting qualitative and quantitative sensory testing (QQST) in sensory assessment, with a focus on understanding neuropathic pain. The innovative QQST method combines participant qualitative experiences with quantitative psychophysical measurements, offering a more varied interpretation of sensory abnormalities and normal sensory function. This article also explores the steps for the optimization of the method by identifying qualitative signs of sensory abnormalities and standardizing data collection. By leveraging the inherent subjectivity in the test design and participant responses, the QQST method contributes to a more holistic exploration of both normal and abnormal sensory experiences. This article positions the QQST approach as a foundational element within the Sensory Evaluation Network, uniting international experts to harmonize qualitative and quantitative sensory evaluation methods.

Abnormal Laryngopharyngeal Sensation in Adductor Laryngeal Dystonia Compared to Healthy Controls

BACKGROUND/OBJECTIVES

Laryngeal sensory abnormality has been implicated as a component of adductor laryngeal dystonia (AdLD). The study objective was to assess laryngopharyngeal sensation in AdLD utilizing a calibrated, tactile aesthesiometer to deliver differential stimuli to lateral pyriform sinus (LPS), aryepiglottic fold (AEF), and false vocal fold (FVF).

METHODS

Patients with known Botox-responsive AdLD underwent sensory testing using a previously-validated methodology involving calibrated tactile stimuli (6-0, 5-0, 4.5-0, 4-0 nylon monofilaments). Laryngeal adductor reflex (LAR) and participant-rated perceptual strength of stimulI were evaluated. Responses were compared to normative controls (n = 33). Two-samples, Mann-Whitney and Fisher exact tests compared mean strength ratings and LAR between AdLD and control groups. Mixed-effects logistic regression and linear models assessed association of filament size, stimulus site, age, sex, and LD status on LAR and perceptual strength rating respectively.

RESULTS

Thirteen AdLD patients (nine women, mean age 60+/-15 years) completed testing. Average LAR response rates were higher amongst all filament sizes in AdLD versus controls at LPS (56.3% vs. 35.7%) and AEF (96.1% vs. 70.2%) with comparable rates at FVF (90.2% vs. 91.7%). AdLD had 3.3 times the odds of observed LAR compared to controls (p = 0.005), but differences in subjective detection of stimuli, perceptual strength ratings, and cough/gag rates were insignificant on multivariate modeling (p > 0.05).

CONCLUSIONS

This is the first study to objectively assess laryngopharyngeal sensation in AdLD. Findings demonstrated increased laryngopharyngeal sensation in AdLD compared to controls. The identification of increased laryngeal hypersensitivity in these patients may improve understanding of AdLD pathophysiology and identify future targets for intervention.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2271-2278, 2023.

Multimodal hypersensitivity derived from quantitative sensory testing predicts pelvic pain outcome: an observational cohort study

ABSTRACT

Multimodal hypersensitivity (MMH)-greater sensitivity across multiple sensory modalities (eg, light, sound, temperature, pressure)-is associated with the development of chronic pain. However, previous MMH studies are restricted given their reliance on self-reported questionnaires, narrow use of multimodal sensory testing, or limited follow-up. We conducted multimodal sensory testing on an observational cohort of 200 reproductive-aged women, including those at elevated risk for chronic pelvic pain conditions and pain-free controls. Multimodal sensory testing included visual, auditory, and bodily pressure, pelvic pressure, thermal, and bladder pain testing. Self-reported pelvic pain was examined over 4 years. A principal component analysis of sensory testing measures resulted in 3 orthogonal factors that explained 43% of the variance: MMH, pressure pain stimulus response, and bladder hypersensitivity. The MMH and bladder hypersensitivity factors correlated with baseline self-reported menstrual pain, genitourinary symptoms, depression, anxiety, and health. Over time, MMH increasingly predicted pelvic pain and was the only component to predict outcome 4 years later, even when adjusted for baseline pelvic pain. Multimodal hypersensitivity was a better predictor of pelvic pain outcome than a questionnaire-based assessment of generalized sensory sensitivity. These results suggest that MMHs overarching neural mechanisms convey more substantial long-term risk for pelvic pain than variation in individual sensory modalities. Further research on the modifiability of MMH could inform future treatment developments in chronic pain.

Understanding the Effects of Smart-Speaker-Based Surveys on Panelist Experience in Immersive Consumer Testing

Utilizing immersive technologies to reintroduce the environmental context (i.e., visual, auditory, and olfactory cues) in sensory testing has been one area of research for improving panelist engagement. The current study sought to understand whether pairing smart-speaker questionnaires in immersive spaces could positively affect the panelist experience through enhanced ecological validity. To this end, subjects performed an immersive consumer test in which responses were collected using a traditional computer-based survey, a smart-speaker approach incorporating a direct translation of the computer questionnaire into a verbal survey requiring numeric responses, and an optimized smart-speaker survey with alternative question formatting requiring spoken word-based responses. After testing, participants answered the Engagement Questionnaire (EQ) to assess participant engagement during the test, and the System Usability Scale (SUS) survey to understand the ease, and potential adoption, of using the various survey technologies in the study. Results indicated that the traditional computer-based survey was the most engaging (p < 0.001) and usable (p < 0.001), with no differences found between the two smart-speaker surveys (p = 0.803 and p = 0.577, respectively). This suggests that the proposed optimizations for the smart-speaker surveys were not robust enough to influence engagement and usability, and further research is needed to enhance their conversational capabilities.

Does Your Bedside Neurological Examination for Suspected Peripheral Neuropathies Measure Up?

SYNOPSIS: Neurological testing is essential for screening and diagnosing suspected peripheral neuropathies. Detecting changes in somatosensory and motor nerve function can also have direct implications for management decisions. Nevertheless, there is considerable variation in what is included in a bedside neurological examination and how it is performed. Neurological examinations are often used as screening tools to detect neurological deficits but not used to their full potential for monitoring progress or deterioration. Here, we advocate for better use of the neurological examination within a clinical reasoning framework. Constrained by the lack of research in this field, our Viewpoint is based on neuroscientific principles. We highlight 6 challenges for clinicians when conducting neurological examinations and propose ways to overcome these challenges in clinical practice. We challenge widely held ideas about how the results of neurological examinations for peripheral neuropathies are interpreted and how the examinations are performed in practice. J Orthop Sports Phys Ther 2023;53(3):107-112. Epub: 28 October 2022. doi:10.2519/jospt.2022.11281.

Sensory testing might not be perfect - but it is the best biomarker for pain phenotypes we have right now

Currently available treatments for neuropathic pain fail in roughly half of the patients - and it is impossible to predict which treatments will help patients. Stratification of neuropathic pain patients is needed, and sensory profiling has so far been the most promising approach: it has been shown to be responsive to treatment, linked to potential mechanisms, and, most importantly, predictive of treatment success. Despite a number of limitations, it is the currently most promising stratification tool and should be refined rather than disregarded.

Early detection of sensory nerve function impairment in leprosy under field conditions

Aim To assess the fine sensation of palms and soles in field conditions, to enable early detection of nerve function impairment before the loss of protective sensation, thus preventing the development of disability. Methods A cross-sectional descriptive study was conducted at seven tertiary referral hospitals located in different states in India. This study included all newly diagnosed patients affected by leprosy, who were registered during the period between March 2011 and April 2012. A detailed history was taken along with charting and voluntary muscle testing /sensory testing (VMT/ST) for the diagnosed patients. The sensation was measured using 0.2 gm Semmes-Weinstein filaments for palms and 4 gm for soles first, followed by 2 gm Semmes-Weinstein filaments for palms and 10 gm for soles. Results Among the 374 patients, 106 were identified with sensory nerve function impairment. Of the 106 patients, 84 were identified with absence of both fine and protective sensation and 22 patients had a loss of fine touch sensation with protective sensation intact. Limitation This study was conducted only among patients who were newly diagnosed with leprosy. Hence, future longitudinal studies in a larger population will add more validity to the study. Conclusion The patients who had loss of fine sensation would have been missed by the normal leprosy programme protocol which uses 2 gm and 10 gm filaments for testing sensory loss before initiating steroid therapy. Further research is needed to determine whether testing for fine sensation with 0.2 gm Semmes-Weinstein filaments for palms and 4 gm for soles can be introduced at all specialized leprosy centres to detect nerve function impairment at an earlier stage followed by steroid therapy.

Assessment of sensory block during labour epidural analgesia: a prospective cohort study to determine the influence of the direction of testing

PURPOSE

Assessment of sensory block level during labour epidural analgesia is an essential component of clinical practice and patient safety. Nevertheless, the methods and direction of testing are not standardized. In our hospital, sensory block testing to ice is routinely used, but while some anesthesiologists test the block from a nonanesthetized to an anesthetized area, some do it in the opposite direction. It is unknown how these two different practices affect identification of the sensory block level. The objective of this study was to determine the agreement between these two practices.

METHODS

We enrolled 31 patients admitted to the labour and delivery unit in a prospective cohort study. At their request, labour epidural analgesia was performed as per institutional routine. Sensory block level to ice was assessed using opposite directions by two randomly assigned independent investigators, one and two hours after the loading dose was administered.

RESULTS

Sensory block levels to ice assessed from an anesthetized area to a nonanesthetized area were lower than those when assessed with the stimulus applied in the opposite direction, typically one segment lower.

DISCUSSION

Given the small difference detected with both methods, it may be acceptable to use either in clinical practice. Nevertheless, the lack of standardization may have a significant impact when comparing studies involving assessment of sensory block to ice.

STUDY REGISTRATION

www.

CLINICALTRIALS

gov (NCT03572439); registered 28 June 2018.

Spinal Cord Tissue Bridges Validation Study: Predictive Relationships With Sensory Scores Following Cervical Spinal Cord Injury

Background

Using magnetic resonance imaging (MRI), widths of ventral tissue bridges demonstrated significant predictive relationships with future pinprick sensory scores, and widths of dorsal tissue bridges demonstrated significant predictive relationships with future light touch sensory scores, following spinal cord injury (SCI). These studies involved smaller participant numbers, and external validation of their findings is warranted.

Objectives

The purpose of this study was to validate these previous findings using a larger independent data set.

Methods

Widths of ventral and dorsal tissue bridges were quantified using MRI in persons post cervical level SCI (average 3.7 weeks post injury), and pinprick and light touch sensory scores were acquired at discharge from inpatient rehabilitation (average 14.3 weeks post injury). Pearson product-moments were calculated and linear regression models were created from these data.

Results

Wider ventral tissue bridges were significantly correlated with pinprick scores (r = 0.31, p < 0.001, N = 136) and wider dorsal tissue bridges were significantly correlated with light touch scores (r = 0.31, p < 0.001, N = 136) at discharge from inpatient rehabilitation.

Conclusion

This retrospective study's results provide external validation of previous findings, using a larger sample size. Following SCI, ventral tissue bridges hold significant predictive relationships with future pinprick sensory scores and dorsal tissue bridges hold significant predictive relationships with future light touch sensory scores.

Associations between Pain Severity, Clinical Findings, and Endodontic Disease: A Cross-Sectional Study

INTRODUCTION

Thorough pain assessment and thermal and mechanical testing are the primary diagnostic tools used to assess the status of pulp and periapical tissues in teeth with potential endodontic pathology. This study evaluated predictors of acute odontogenic pain to better understand the relationship between endodontic pain, clinical testing, endodontic disease, and diagnoses.

METHODS

Participants (N = 228) presenting with acute odontogenic pain underwent standardized clinical testing and reported their pain intensity. Univariate and multiple regression analyses were performed to evaluate the predictors of acute endodontic pain. Chi-square tests with Bonferroni adjustments were conducted to measure the frequency of endodontic diagnostic test findings and clinical observations in patients with different pulpal diagnoses.

RESULTS

A negative response to cold stimulation on the causative tooth and percussion hypersensitivity on the healthy adjacent tooth were the strongest predictors of higher levels of acute endodontic pain. Percussion hypersensitivity on the healthy adjacent tooth was present in a quarter of the cohort and was reported with equal frequency in teeth diagnosed with irreversible pulpitis, necrotic pulp, and previously initiated/treated teeth. Although painful percussion on the causative tooth was more frequently reported in teeth diagnosed with necrotic pulp, painful palpation was more frequently reported on teeth diagnosed with previously initiated/treated teeth.

CONCLUSIONS

Percussion hypersensitivity on the healthy adjacent tooth may reveal a lowered pain threshold and heightened pain sensitization. It is also possible that the 2 commonly performed mechanical sensory tests, percussion and palpation hypersensitivity, may detect different aspects of endodontic pathophysiology and pain processing.

Altered somatosensory processing in secondary trigeminal neuralgia: A case report

Secondary trigeminal neuralgia might be very rarely preceded by trigeminal neuropathic pain. The patient, in this case, presented with paroxysmal pain in the left mandible and numbness of the lower lip and tongue. Sensory testing of these areas revealed cold and heat hyperalgesia and mechanical hyposensitivity in the mandibular region. Magnetic resonance imaging showed a mass in the left cerebellopontine angle. The patient was prescribed systemic mirogabalin (2.5 mg/day), which provided some relief until the tumor was removed. The histopathological diagnosis was an epidermoid tumor. This article discusses the clinical characteristics and sensory testing findings that distinguish secondary trigeminal neuralgia from trigeminal neuropathic pain based on the International Classification of Orofacial Pain.

Simple Indigenous Two-Point Discrimination Testing Device

Background

Measurement of two-point discrimination (2-PD) is used in clinical practice to evaluate the severity of nerve injuries, neuropathy, and recovery of patients following nerve repair. Commercially available 2-PD testing devices are costly and therefore not available everywhere.

Methods and Material

We made an economical indigenous 2-PD testing device from off-the-shelf components and tested its efficacy in volunteers.

Statistical Analysis

The data were analyzed using Minitab Statistical Software Version 17.0 and Kappa statistics were used in the assessment of agreement between two devices.

Results

A total of 30 (23 men, 7 women) subjects were included in the study. There was good agreement between the measurements of static 2-PD with the two different test devices: from fair (Kappa = 0.408, P = 0.018) to strong (Kappa = 0.618-0.795, P = 0.000).

Conclusions

This device is simple to make, very economical, and obtains accurate 2-PD measurements.

Sensory Perception in Lumbosacral Radiculopathy with Radicular Pain: Feasibility Study of Multimodal Bedside-Suitable Somatosensory Testing

Background

Somatosensory testing could be useful in stratifying pain patients and improving pain treatment guidelines. Bedside-suitable techniques are searched for application in daily clinical practice. This study aimed to characterize chronic unilateral lumbosacral radiculopathy (LSR) patients with radicular pain using multimodal bedside-suitable somatosensory testing.

Materials and methods

We evaluated 50 chronic unilateral LSR patients with radicular pain (LSR group) and 24 controls (Control group). Sensory testing was performed using a battery of bedside sensory tests (10g monofilament, 200–400 mN brush, Lindblom rollers with controlled 25°C and 40°C temperature, and 40g neurological pin and investigator’s finger pressure). Participants had to rate their sensory perceptions on both legs at multiple test points within L3 to S2 dermatomes. Characteristics of the testing process and sensory disturbances were analyzed.

Results

LSR group showed sensory disturbances in 82% of patients. The Control group showed no sensory disturbances. Sensory testing took longer (p < 0.001) in the LSR group (29.3 ± 6.5 minutes per patient) than in the Control group (20.5 ± 5.2). Nine sensory phenotypes were detected in the LSR group according to individual sensory disturbances within 5 superficial tests.

Conclusions

The applied multimodal bedside-suitable somatosensory testing battery is suitable for sensory evaluation and characterization of LSR patients. Grouping of allied sensory phenotypes revealed some tendencies in pain intensity characteristics.

Central neuropathic pain in multiple sclerosis is associated with impaired innocuous thermal pathways and neuronal hyperexcitability

OBJECTIVE

About a third of patients with multiple sclerosis (MS) suffer from chronic and excruciating central neuropathic pain (CNP). The mechanism underlying CNP in MS is not clear, since previous studies are scarce and their results are inconsistent. Our aim was to determine whether CNP in MS is associated with impairment of the spinothalamic-thalamocortical pathways (STTCs) and/or increased excitability of the pain system.

DESIGN

Cross sectional study.

SETTING

General hospital.

SUBJECTS

47 MS patients with CNP, 42 MS patients without CNP, and 32 healthy controls.

METHODS

Sensory testing included the measurement of temperature, pain, and touch thresholds and the thermal grill illusion (TGI) for evaluating STTCs function, and hyperpathia and allodynia as indicators of hyperexcitability. CNP was characterized using interviews and questionnaires.

RESULTS

The CNP group had higher cold and warm thresholds (p < 0.01), as well as higher TGI perception thresholds (p < 0.05), especially in painful body regions compared to controls, whereas touch and pain thresholds values were normal. The CNP group also had a significantly greater prevalence of hyperpathia and allodynia. Regression analysis revealed that whereas presence of CNP was associated with a higher cold threshold, CNP intensity, and the number of painful body regions were associated with allodynia and hyperpathia, respectively.

CONCLUSIONS

CNP in MS is characterized by a specific impairment of STTC function; the innocuous thermal pathways, and by pain hyperexcitability. Whereas CNP presence is associated with STTC impairment, its severity and extent are associated with pain hyperexcitability. Interventions that reduce excitability level may therefore mitigate CNP severity.

Item reduction of the 39-item Rotterdam Diabetic Foot Study Test Battery using decision tree modelling

AIMS

Pedal sensory loss due to diabetes-related neuropathy can be graded by testing static two-point discrimination (S2PD), moving two-point discrimination (M2PD), static one-point discrimination (S1PD; eg, 10-g monofilament), and vibration sense and is included in the Rotterdam Diabetic Foot (RDF) Study Test Battery. The aim of this study is to investigate if decision tree modelling is able to reduce the number of tests needed in estimating pedal sensation.

METHODS

The 39-item RDF Study Test Battery (RDF-39) scores were collected from the prospective RDF study and included baseline (n = 416), first follow-up (n = 364), and second follow-up (n = 135) measurements, supplemented with cross-sectional control data from a previous study (n = 196). Decision tree analysis was used to predict total RDF-39 scores using individual test item data. The tree was developed using baseline RDF study data and validated in follow-up and control data. Spearman correlation coefficients assessed the reliability between the decision tree and original RDF-39.

RESULTS

The tree reduced the number of items from 39 to 3 in estimating the RDF-39 sum score. M2PD (hallux), S2PD (first dorsal web, fifth toe), vibration sense (interphalangeal joint), and S1PD (first dorsal web, fifth toe) measurements proved to be predictive. The correlation coefficients to original scores were high (0.76 to 0.91).

CONCLUSIONS

The decision tree was successful at reducing the number of RDF Test Battery items to only 3, with high correlation coefficients to the scores of the full test battery. The findings of this study aids medical decision making by time efficiently estimating pedal sensory status with fewer tests needed.

Extending Aging of Beef Longissimus Lumborum From 21 to 84 Days Postmortem Influences Consumer Eating Quality

Our objective was to determine the effect of extending postmortem aging from 21 to 84 days on consumer eating quality of beef longissimus lumborum. Strip loins were collected from 108 carcasses. The longissimus lumborum muscle was isolated from strip loins and assigned to one of ten postmortem aging periods from 21 to 84 days (7-day increments) and balanced within four anatomical positions within the muscle. Consumer evaluations for tenderness, juiciness, flavor, and overall liking were conducted using untrained consumer sensory panels consisting of 1080 individual consumers, in accordance with the Meat Standards Australia protocols. These scores were then used to calculate an overall eating quality (MQ4) score. Postmortem aging had no effect (P > 0.05) on tenderness, but juiciness, flavor liking, overall liking, and MQ4 declined (P < 0.05) as aging period increased. Samples aged 21 to 42 days were most preferred having greater (P < 0.05) overall liking and greater (P < 0.05) MQ4 scores than samples aged 70 to 84 days postmortem. These results suggest that longissimus lumborum samples should not be wet-aged longer than 63 days to prevent potential negative eating experiences for consumers; however, altering storage conditions, specifically reducing temperature, could potentially allow for longer chilled storage without such negative effects on flavor and overall liking.

Exploring Consumer Palatability of Australian Beef Fajita Meat Enhanced with Phosphate or Sodium Bicarbonate

The objective of this study was to determine the consumer eating quality of five Australian beef muscles (outside skirt/diaphragm, inside skirt/transversus abdominis, inside round cap/gracilis, bottom sirloin flap/obliquus abdominis internus, and flank steak/rectus abdominis) served as fajita strips. All the muscles were divided in half and enhanced (12%) with a brine solution containing either phosphate, a “clean label” ingredient sodium bicarbonate, or not enhanced. Muscle and enhancement independently influenced (P < 0.01) tenderness, juiciness, flavor, and overall liking. Overall, the bottom sirloin flap was liked the most (P < 0.05) when compared with all the other muscles, while the inside round cap was liked less but did not differ (P > 0.05) from the inside skirt or flank steak. Samples enhanced with sodium bicarbonate were the most (P < 0.05) tender and juicy; samples enhanced with phosphate were intermediate, and the control samples were the least tender and juicy, regardless of the muscle. Flavor and overall liking were similar (P > 0.05) between clean and phosphate-enhanced samples, and both were liked more than the control samples. Enhancement was necessary for acceptable eating quality of all the muscles evaluated in this study; however, the inside round cap was the least suitable. These results indicate that a “clean label” enhanced fajita product is possible without compromising cooking yield or consumer satisfaction.

Influence of Kiwifruit Extract Infusion on Consumer Sensory Outcomes of Striploin (M. longissimus lumborum) and Outside Flat (M. biceps femoris) from Beef Carcasses

Actinidin is a cysteine protease enzyme which occurs in kiwifruit and has been associated with improved tenderness in red meat. This study evaluated the impact of actinidin, derived from kiwifruit, on consumer sensory outcomes for striploin (M. longissimus lumborum) and outside flat (M. biceps femoris). Striploins and outside flats were collected from 87 grass-fed steers. Carcasses were graded to the Meat Standards Australia (MSA) protocols. Striploins and outside flats were then dissected in half and allocated to one of the following two treatments: (1) not infused (control) and (2) infused with a kiwifruit extract (enhanced), and then prepared as grill and roast samples. Grill and roast samples were then aged for 10 or 28 days. Consumer evaluations for tenderness, juiciness, flavor, and overall liking were conducted using untrained consumer sensory panels consisting of 2080 individual consumers, in accordance with the MSA protocols. These scores were then used to calculate an overall eating quality (MQ4) score. Consumer sensory scores for tenderness, juiciness, flavor, overall liking, and MQ4 score were analyzed using a linear mixed-effects model. Kiwifruit extract improved consumer scores for tenderness, juiciness, flavor, overall liking, and MQ4 scores for striploins and outside flat (p < 0.05). These results suggest that kiwifruit extract provides an opportunity to improve eating experiences for consumers.

Predicting ulcer-free survival using the discriminative value of screening test locations

BACKGROUND

Current guidelines recommend screening the feet of diabetic subjects with a 10-g monofilament or tuning fork. We investigated which tests and locations on the feet have the best predictive value regarding 1-year ulcer-free survival in diabetic subjects participating in the prospective Rotterdam Diabetic Foot Study.

METHODS

Decision tree analysis was used to predict ulcer-free survival based on responses from individual test locations (monofilaments on 10 sites, vibration sense was tested on both halluces and medial malleoli). Separate trees for patients with and without a history of diabetic foot ulcer (DFU) were developed.

RESULTS

Four hundred sixteen subjects (mean [SD] age, 61.8 years [12.4]; range, 21.6-90.2) were measured, of whom 24 developed new DFUs. Three tests exhibited discriminative and predictive properties: testing vibration sense on the medial malleolus and monofilament testing on heel and hallux. The decision tree to predict ulcer-free survival in patients with a history of DFU yielded a sensitivity of 87.0%, which was 99.6% for the tree of patients without a history of DFU.

CONCLUSION

The findings of this study aids medical decision making by discriminating between high- and low-risk patients of developing DFU using selective testing on sites with predictive properties.

Monitoring regional blockade

This review attempts to draw on the published literature to address three practical clinical questions. First, what means of testing the degree of regional blockade pre-operatively are available, and can eventual success or failure be determined soon after injection? Second, is it possible to predict if a block inserted after the induction of general anaesthesia will be effective when the patient wakes? Third, what features, and what duration, should cause concern when a block does not resolve as expected after surgery? Although the relevant literature is limited, we recommend testing of multiple sensory modalities before surgery commences; temperature and thermographic changes may offer additional early warning of success or failure. There are a number of existing methods of assessing nociception under general anaesthesia, but none has yet been applied to gauge the onset of a regional block. Finally, criteria for further investigation and neurological referral when block symptoms persist postoperatively are presented.

Vibration testing: Optimizing methods to improve reliability

INTRODUCTION

In this study we assessed the test-retest reliability of a Rydel-Seiffer tuning fork and an electronic vibrameter with hand-held and fixed probes.

METHODS

Fifty healthy volunteers were assessed twice in the upper and lower limb 15 minutes apart. Reliability was assessed by intraclass correlation coefficient (ICC) and standard error of measurement (SEM). The effect of stimulus parameters on vibration disappearance threshold (VDT) was assessed by analysis of variance.

RESULTS

All 3 tools showed good reliability (ICCs = 0.65-0.95). Vibrameter recordings with the fixed probe showed high variability. The vibrameter was more sensitive in detecting body-site and age differences in vibration thresholds than the tuning fork. Significantly higher VDT was observed when higher starting amplitudes and slower rates of change were used.

DISCUSSION

The hand-held vibrameter is a superior tool to monitor vibration sense. The stimulus amplitude and rate of change are important to control as they alter VDT. Muscle Nerve 59:229-235, 2019.

The Potential Role of Sensory Testing, Skin Biopsy, and Functional Brain Imaging as Biomarkers in Chronic Pain Clinical Trials: IMMPACT Considerations

Valid and reliable biomarkers can play an important role in clinical trials as indicators of biological or pathogenic processes or as a signal of treatment response. Currently, there are no biomarkers for pain qualified by the U.S. Food and Drug Administration or the European Medicines Agency for use in clinical trials. This article summarizes an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials meeting in which 3 potential biomarkers were discussed for use in the development of analgesic treatments: 1) sensory testing, 2) skin punch biopsy, and 3) brain imaging. The empirical evidence supporting the use of these tests is described within the context of the 4 categories of biomarkers: 1) diagnostic, 2) prognostic, 3) predictive, and 4) pharmacodynamic. Although sensory testing, skin punch biopsy, and brain imaging are promising tools for pain in clinical trials, additional evidence is needed to further support and standardize these tests for use as biomarkers in pain clinical trials.

PERSPECTIVE

The applicability of sensory testing, skin biopsy, and brain imaging as diagnostic, prognostic, predictive, and pharmacodynamic biomarkers for use in analgesic treatment trials is considered. Evidence in support of their use and outlining problems is presented, as well as a call for further standardization and demonstrations of validity and reliability.

Quantification of rat supraglottic laryngeal sensation threshold

OBJECTIVE

Laryngeal adductor response (LAR) to air puff is used as a reliable method in evaluating sensation thresholds (ST) in human laryngeal sensory disorders. This method has been difficult to perform in small subjects such as rodents. The aims of this study were to 1) evaluate ST to air puff under binocular microlaryngoscopy in rats to evaluate laryngeal sensory disorders, 2) determine sensory thresholds at varying target locations, and 3) determine the ideal depth of anesthesia.

STUDY DESIGN

Animal study.

METHODS

Rats were induced with ketamine/xylazine. The level of anesthesia was monitored by spontaneous glottic closure and corneal reflex testing. Air puffs were delivered to the epiglottis, arytenoid, and piriform sinus at varied pressures with pulse time kept constant. Sensation thresholds were determined by direct visualization of the larynx using a binocular microscope. Topical lidocaine was then applied to the larynx and ST was determined. Trials were repeated in a small subset of animals.

RESULTS

Twenty-six trials were performed in 14 rats. Mean STs were 39 ± 9.7 mm Hg at the epiglottis, 48.8 ± 10.5 at the arytenoid, and not detectable at the pyriform sinus. Repeated trials demonstrated consistent results. Lidocaine effectively ablated the LAR in each trial. The LAR was difficult to induce while corneal reflex was absent and was difficult to distinguish from spontaneous glottic closures while under lighter sedation.

CONCLUSION

Air pulse stimulation in rats is a simple, reliable, and effective way to determine laryngopharyngeal STs in rats and can be used as an efficient and affordable method for experimentation involving laryngeal sensory disorders.

LEVEL OF EVIDENCE

NA. Laryngoscope, 127:E265-E269, 2017.

Prognostic value of quantitative sensory testing in low back pain: a systematic review of the literature

Quantitative sensory testing (QST) measures have recently been shown to predict outcomes in various musculoskeletal and pain conditions. The aim of this systematic review was to summarize the emerging body of evidence investigating the prognostic value of QST measures in people with low back pain (LBP). The protocol for this review was prospectively registered on the International Prospective Register of Systematic Reviews. An electronic search of six databases was conducted from inception to October 2015. Experts in the field were contacted to retrieve additional unpublished data. Studies were included if they were prospective longitudinal in design, assessed at least one QST measure in people with LBP, assessed LBP status at follow-up, and reported the association of QST data with LBP status at follow-up. Statistical pooling of results was not possible due to heterogeneity between studies. Of 6,408 references screened after duplicates removed, three studies were finally included. None of them reported a significant association between the QST measures assessed and the LBP outcome. Three areas at high risk of bias were identified which potentially compromise the validity of these results. Due to the paucity of available studies and the methodological shortcomings identified, it remains unknown whether QST measures are predictive of outcome in LBP.

Reliability and Validity of the Sensory Component of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI): A Systematic Review

BACKGROUND

Since 1982, the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) has been used to classify sensation of spinal cord injury (SCI) through pinprick and light touch scores. The absence of proprioception, pain, and temperature within this scale creates questions about its validity and accuracy.

OBJECTIVE

To assess whether the sensory component of the ISNCSCI represents a reliable and valid measure of classification of SCI.

METHODS

A systematic review of studies examining the reliability and validity of the sensory component of the ISNCSCI published between 1982 and February 2013 was conducted. The electronic databases MEDLINE via Ovid, CINAHL, PEDro, and Scopus were searched for relevant articles. A secondary search of reference lists was also completed. Chosen articles were assessed according to the Oxford Centre for Evidence-Based Medicine hierarchy of evidence and critically appraised using the McMasters Critical Review Form. A statistical analysis was conducted to investigate the variability of the results given by reliability studies.

RESULTS

Twelve studies were identified: 9 reviewed reliability and 3 reviewed validity. All studies demonstrated low levels of evidence and moderate critical appraisal scores. The majority of the articles (~67%; 6/9) assessing the reliability suggested that training was positively associated with better posttest results. The results of the 3 studies that assessed the validity of the ISNCSCI scale were confounding.

CONCLUSIONS

Due to the low to moderate quality of the current literature, the sensory component of the ISNCSCI requires further revision and investigation if it is to be a useful tool in clinical trials.

Reliability and Validity of the Sensory Component of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI): A Systematic Review

BACKGROUND

Since 1982, the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) has been used to classify sensation of spinal cord injury (SCI) through pinprick and light touch scores. The absence of proprioception, pain, and temperature within this scale creates questions about its validity and accuracy.

OBJECTIVE

To assess whether the sensory component of the ISNCSCI represents a reliable and valid measure of classification of SCI.

METHODS

A systematic review of studies examining the reliability and validity of the sensory component of the ISNCSCI published between 1982 and February 2013 was conducted. The electronic databases MEDLINE via Ovid, CINAHL, PEDro, and Scopus were searched for relevant articles. A secondary search of reference lists was also completed. Chosen articles were assessed according to the Oxford Centre for Evidence-Based Medicine hierarchy of evidence and critically appraised using the McMasters Critical Review Form. A statistical analysis was conducted to investigate the variability of the results given by reliability studies.

RESULTS

Twelve studies were identified: 9 reviewed reliability and 3 reviewed validity. All studies demonstrated low levels of evidence and moderate critical appraisal scores. The majority of the articles (~67%; 6/9) assessing the reliability suggested that training was positively associated with better posttest results. The results of the 3 studies that assessed the validity of the ISNCSCI scale were confounding.

CONCLUSIONS

Due to the low to moderate quality of the current literature, the sensory component of the ISNCSCI requires further revision and investigation if it is to be a useful tool in clinical trials.

Early changes in somatosensory function in spinal pain: protocol for a systematic review

BACKGROUND

Back and neck pain are common conditions that have a high burden of disease. Changes in somatosensory function in the periphery, the spinal cord and the brain have been well documented at the time when these conditions have become chronic. It is unknown, however, how early these changes occur, what the timecourse is of sensory dysfunction and what the specific nature of these changes are in the first 12 weeks after onset of pain. In this paper, we describe the protocol for a systematic review of the literature on somatosensory dysfunction in the first 12 weeks after pain onset.

METHODS AND DESIGN

We will conduct a comprehensive search for articles indexed in the databases Ovid MEDLINE, Ovid Embase, Ovid PsycINFO and Cochrane Central Register of Controlled Trial (CENTRAL) from their inception to August 2013 that report on any aspect of somatosensory function in acute or subacute neck or back pain. Two independent reviewers will screen studies for eligibility, assess risk of bias and extract relevant data. Results will be tabulated and a narrative synthesis of the results conducted.

DISCUSSION

Currently, there is a gap in our knowledge about the timing of somatosensory changes in back and neck pain. The systematic review outlined in this protocol aims to address this knowledge gap and inform developments in diagnostic tools and pain mechanism-based treatments.

TRIAL REGISTRATION

Our protocol has been registered on PROSPERO, CRD42013005113.

Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment

Two-point discrimination is widely used to measure tactile spatial acuity. The validity of the two-point threshold as a spatial acuity measure rests on the assumption that two points can be distinguished from one only when the two points are sufficiently separated to evoke spatially distinguishable foci of neural activity. However, some previous research has challenged this view, suggesting instead that two-point task performance benefits from an unintended non-spatial cue, allowing spuriously good performance at small tip separations. We compared the traditional two-point task to an equally convenient alternative task in which participants attempt to discern the orientation (vertical or horizontal) of two points of contact. We used precision digital readout calipers to administer two-interval forced-choice versions of both tasks to 24 neurologically healthy adults, on the fingertip, finger base, palm, and forearm. We used Bayesian adaptive testing to estimate the participants’ psychometric functions on the two tasks. Traditional two-point performance remained significantly above chance levels even at zero point separation. In contrast, two-point orientation discrimination approached chance as point separation approached zero, as expected for a valid measure of tactile spatial acuity. Traditional two-point performance was so inflated at small point separations that 75%-correct thresholds could be determined on all tested sites for fewer than half of participants. The 95%-correct thresholds on the two tasks were similar, and correlated with receptive field spacing. In keeping with previous critiques, we conclude that the traditional two-point task provides an unintended non-spatial cue, resulting in spuriously good performance at small spatial separations. Unlike two-point discrimination, two-point orientation discrimination rigorously measures tactile spatial acuity. We recommend the use of two-point orientation discrimination for neurological assessment.

Barostat or dynamic balloon distention test: which technique is best suited for esophageal sensory testing?

Esophageal sensation is commonly assessed by barostat-assisted balloon distension (BBD) or dynamic balloon distension (DBD) technique, but their relative merits are unknown. Our aim was to compare the usefulness and tolerability of both techniques. Sixteen healthy volunteers (male/female = 6/10) randomly underwent graded esophageal balloon distensions, using either BBD (n= 8) or DBD (n= 8). BBD was performed by placing a 5-cm long highly compliant balloon attached to a barostat, and DBD by placing a 5-cm long balloon attached to a leveling container. Intermittent phasic balloon distensions were performed in increments of 6 mm Hg. Sensory thresholds and biomechanical properties were assessed and compared. Sensory thresholds for first perception (mean ± standard deviation; 21 ± 6 vs. 21.2 ± 5, mm Hg, P= 0.9), discomfort (38 ± 8 vs. 35 ± 9, P= 0.5), and pain (44 ± 4 vs. 45 ± 3, P= 0.7) were similar with BBD and DBD techniques. However, more subjects tolerated DBD (7/8, 88%) when compared with BBD (4/8, 50%). Forceful expulsion of balloon into stomach (n= 4), pulling around the mouth (n= 4), chest discomfort (n= 2) and retching (n= 2) were overlapping reasons for intolerance with BBD. Esophageal wall distensibility was similar with both techniques. Both techniques provided comparable data on biomechanical properties. However, DBD was better tolerated than BBD for evaluation of esophageal sensation. Hence, we recommend DBD for performing esophageal balloon distension test.

Use of sensory methods for detecting target engagement in clinical trials of new analgesics

The translation of analgesic efficacy seen in preclinical pain models into the clinic is problematic and is associated with a number of factors that may result in the failure of clinical trials to detect the effect of investigational therapeutic agents. The use of translational pain biomarkers in phase I trials can potentially reduce some of these risks by measuring the interaction between the drug and its target (termed target engagement) in humans. To serve this purpose, sensory tests and other measures of pharmacological activity in nociceptive pathways need to be identified, based on the preclinical profile of the drug being tested and the feasibility of human assessments. Here we discuss some examples to assess the utility of sensory and related pain biomarkers in the early phase of evaluation of novel analgesics for confirmation of target engagement in humans. The emphasis is on the TRPV1 antagonists, but some other target mechanisms are also discussed in examining the validity of this approach.

Electrical perceptual threshold testing: a validation study

BACKGROUND/OBJECTIVE

To investigate inter-rater and intra-rater reliability of electrical perceptual threshold (EPT) testing in assessing somatosensory function in healthy volunteers.

STUDY DESIGN

Prospective experimental.

SETTING

Hospital-based spinal cord injuries unit.

METHODS

Cutaneous electrical stimulation of 4 dermatomes at ASIA sensory key points (C3, T1, L3, and S2) was performed on 40 control subjects. The lowest ascending stimulus intensity at which sensation was perceived was recorded as the EPT. Mean EPT values for each dermatome, as determined by 2 testers at 2 time points, were examined and plotted against a normative template. Differences and associations between intra- and inter-rater measurements and left-right measurements were studied. EPT results for 2 people with spinal cord injuries were also examined.

RESULTS

EPT measurements from left and right sides, obtained from the 2 time points and 2 testers, were found to be strongly associated, with the exception of left and right side measurements at the S2 dermatome. No significant differences in the mean EPT for tester or time period were found. The intra- and inter-rater reliability was good for all dermatomes tested. Mean EPT measurements fell within the range of a normative template at each of the 4 dermatomes tested.

CONCLUSION

EPT is an objective, reproducible, and quantifiable method of assessing sensation in a control group. However, caution should be applied in certain dermatomes such as S2, where there was large variation between left and right side measurements.

Rater agreement on the ISCSCI motor and sensory scores obtained before and after formal training in testing technique

BACKGROUND/OBJECTIVE

The purpose of this study is to report the results of rater agreement for the International Standards for Neurological Classification of Spinal Cord Injury (ISCSCI) motor and sensory scores before and after training in the testing technique.

METHODS

Six raters performed sequential motor and sensory examinations on 5 adolescents with SCI according to the ISCSCI manual. After completion of the first examinations, all raters were provided with a half-day formal training session on testing techniques, after which the raters repeated the examinations. Intraclass correlation coefficients (ICCs) and 95% confidence intervals (CIs) were calculated to provide parameters for ICC interpretation: > 0.90 = high agreement; 0.75 to 0.90 = moderate agreement; < 0.75 = poor agreement.

RESULTS

After training, there was improvement in rater agreement of summed motor scores (MS) from ICC -0.809 to 0.862 and discrimination scores from ICC = 0.786 to 0.892. There was moderate rater agreement for light touch scores (LTS) before and after training. After training, there was improvement in 95% CIs except for ICCs for LTS, but for all ICCs, the lower 95% CI value remained less than 0.75.

CONCLUSIONS

Training improved rater agreement on MS and discrimination, but 95% CIs remained unacceptably wide. The positive effect of training in motor and sensory testing techniques is supported by the study data. Unlike previous studies that have suggested the ISCSCI has acceptable reliability for clinical trials, the results of this study do not fully support the use of the ISCSCI for clinical trials without better standardization to establish a lower 95% CI value of at least 0.75.