How should we define and assess painful sensitivity in the hand? An international e-Delphi study

BACKGROUND

Painful sensitivity in the hand is commonly seen with neuropathic pain, interfering with daily activities including rehabilitation. However, there are currently several terms used to describe the problem and a lack of guidance on what assessments should be used.

PURPOSE

To gather expert opinion a) identifying current and common terminology used in hand therapy, b) developing a consensus definition of hypersensitivity, and c) developing consensus guidance on how to best assess allodynia.

STUDY DESIGN

International e-Delphi survey study.

METHODS

We conducted an e-Delphi consensus study drawing on international experts in hand rehabilitation. We planned up to four rounds of consensus-seeking, defining consensus as 75% or more of participants agreeing with a definition or recommendation. Experts were identified from 21 countries, with the nomination of other experts encouraged for 'snowball sampling'. The first round included clinical vignettes describing 'painful sensitivity of the hand' and asked participants to describe how they would assess each case. Definitions for hypersensitivity, tactile hyperesthesia, and allodynia were also requested.

RESULTS

We invited 68 participants: 44 more were added through nominations. Sixty-three agreed to participate and were sent the round one survey; 54 participants from 19 countries completed this survey and were invited to participate in all subsequent rounds. No two definitions of hypersensitivity were the same, while 87% of the definitions for allodynia and 78% for tactile hyperesthesia were concordant with a published taxonomy. Over 700 assessment items were proposed in round one: ultimately 38 items representing eight distinct constructs reached a consensus for assessing allodynia.

CONCLUSIONS

Therapists definitions were consistent with an existing taxonomy for allodynia. Although hypersensitivity conceptualizations varied regarding the qualities of stimulus and response, a working definition was reached. Recommended assessments were relatively consistent internationally, holistic, and reflected a potential link between allodynia and central sensitization.

Quantitative Dynamic Allodynograph-A Standardized Measure for Testing Dynamic Mechanical Allodynia in Chronic Limb Pain

BACKGROUND

Dynamic mechanical allodynia (DMA) is both a symptom and a central sensitization sign, yet no standardized method for quantifying the DMA area has been reported. This study aimed to establish psychometric properties for Quantitative Dynamic Allodynography (QDA), a newly developed protocol measuring the DMA area as a percentage of the body surface.

METHODS

Seventy-eight patients aged 18-65 diagnosed with chronic complex regional pain syndrome (CRPS) participated in this study. Test-retest reliability was conducted twice, one week apart (N = 20), and inter-rater (N = 3) reliability was conducted on 10 participants. Disease severity (CRPS Severity Score, CSS), pain intensity (VAS), and quality of life (SF-36) measures were utilized to test construct validity.

RESULTS

High inter-rater reliability (intraclass correlation coefficient (ICC) = 0.96, p < 0.001) and test-retest reliability (r = 0.98, p < 0.001) were found. Furthermore, the QDA score was found to be correlated with the CSS (r = 0.47, p < 0.001), VAS (r = 0.37, p < 0.001), and the SF-36 physical health total (r = -0.47, p < 0.001) scores.

CONCLUSION

The QDA is the first developed reliable and valid protocol for measuring DMA in a clinical setting and may be used as a diagnostic and prognostic measure in clinics and in research, advancing the pain precision medicine approach.

Delphi study to define core clinical outcomes for inclusion in a complex regional pain syndrome international research registry and data bank

ABSTRACT

Complex regional pain syndrome (CRPS) clinical trials have historically captured a diverse range of outcomes. A minimum set of CRPS patient-reported outcomes has been agreed for inclusion in a future CRPS international clinical research registry and data bank. This study aimed to identify a complementary set of core clinical outcomes. Clinicians and researchers from the international CRPS community informed the content of a 2-round electronic Delphi study. Participation was invited from members of the International Association for the Study of Pain CRPS Special Interest Group and the International Research Consortium for CRPS. In round 1, participants rated the relevance of 59 clinical outcomes in relation to the question "What is the clinical presentation and course of CRPS, and what factors influence it?" (1 = not relevant and 9 = highly relevant). In round 2, participants rerated each outcome in the light of the round 1 median scores. The criterion for consensus was median score ≥7, agreed by 75% of respondents. The core study team considered the feasibility of data collection of each identified outcome in agreeing final selections. Sixty respondents completed both survey rounds, with responses broadly consistent across professions. Nine outcomes met the consensus criterion. Final outcomes recommended for inclusion in the core clinical set were record of medications, presence of posttraumatic stress disorder, extent of allodynia, and skin temperature difference between limbs. Study findings provide robust recommendations for core clinical outcome data fields in the future CPRS international clinical research registry. Alongside patient-reported outcomes, these data will enable a better understanding of CRPS.

The Effectiveness of Rehabilitation Interventions on Pain and Disability for Complex Regional Pain Syndrome: A Systematic Review and Meta-analysis

OBJECTIVES

To summarize and critically appraise the body of evidence on conservative management of complex regional pain syndrome (CRPS), we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We conducted a literature search from inception to November 2021 in the following databases: Embase, Medline, CINAHL, Google Scholar, PEDRO, and Psychinfo. Two independent reviewers conducted risk of bias and quality assessment. Qualitative synthesis and meta-analysis were the methods for summarizing the findings of the RCTs. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate the overall quality and certainty of the evidence on each treatment outcome.

RESULT

Through a database search, 751 records were found, and 33 RCTs were eligible for inclusion. Studies were published between 1995 and 2021. The overall risk of bias for 2 studies was low, 8 studies were unclear, and 23 studies were high.Low-quality evidence suggests that mirror therapy (as an addition to conventional stroke rehabilitation interventions) and graded motor imagery program (compared with routine rehabilitation interventions) may result in a large improvement in pain and disability up to 6-month follow-up in poststroke CRPS-1 patients. Low-quality evidence suggests that pain exposure therapy and aerobic exercises as an additive treatment to physical therapy interventions may result in a large improvement in pain up to a 6-month follow-up. The evidence is very uncertain about the effect of all other targeted interventions over conventional physical therapy or sham treatments on pain and disability.

DISCUSSION

There is an ongoing need for high-quality studies to inform conservative management choices in CRPS.

Tactile stimulation programs in patients with hand dysesthesia after a peripheral nerve injury: A systematic review

STUDY DESIGN

This is a systematic review performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards.

INTRODUCTION

Diverse approaches based on tactile stimulation are used in hand rehabilitation settings to treat touch-evoked dysesthesias. However, there is a lack of literature synthesis on the description and the effectiveness of the various approaches based on tactile stimulation that can be used for treating hand dysesthesia after nerve injury.

PURPOSE OF THE STUDY

The purpose of the study was to summarize the current evidence on tactile stimulation programs for managing touch-evoked hand dysesthesia due to nerve injury.

METHODS

The search was carried out on Medline, Embase, CINAHL, and the Cochrane Library databases. The selected studies had to present patients with touch-evoked dysesthesia after nerve injury who were treated with tactile stimulation approaches to reduce pain. The methodological quality of the included studies was assessed using the methodological index for nonrandomized studies scale, as well as the risk of bias.

RESULTS

Eleven studies met the inclusion criteria. These studies present tactile stimulation interventions that are heterogeneous relative to the target populations and the intervention itself (desensitization versus somatosensory rehabilitation method). Painful symptoms appear to diminish in patients with touch-evoked hand dysesthesia, regardless of the tactile stimulation program used. However, the included studies present significant risks of bias that limit the confidence in these results.

DISCUSSION

The evidence does not unequivocally support the beneficial effects of tactile stimulation to treat touch-evoked hand dysesthesia.

CONCLUSION

Future studies with more rigorous methodological designs, such as randomized controlled trials, are required to verify the potential benefits of these approaches.

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

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.