An international study to explore the feasibility of collecting standardised outcome data for Complex Regional Pain Syndrome: recommendations for an international clinical research registry.

Introduction: Complex Regional Pain Syndrome (CRPS) is a persistent pain condition with low prevalence. Multi-centre collaborative research is needed to attain sufficient sample sizes for meaningful studies. This international observational study: (1) tested the feasibility and acceptability of collecting outcome data using an agreed core measurement set (2) tested and refined an electronic data management system to collect and manage the data. Methods: Adults with CRPS, meeting the Budapest diagnostic clinical criteria, were recruited to the study from 7 international research centres. After informed consent, a questionnaire comprising the core set outcome measures was completed: on paper at baseline (T1), and at 3 or 6 months (T2) using a paper or e-version. Participants and clinicians provided feedback on the data collection process. Clinicians completed the CRPS severity score at T1 and optionally, at T2. Ethical approval was obtained at each international centre. Results: Ninety-eight adults were recruited (female n=66; mean age 46.6 years, range 19-89), of whom 32% chose to receive the T2 questionnaire in an electronic format. Fifty-five participants completed both T1 and T2. Eighteen participants and nine clinicians provided feedback on their data collection experience. Conclusion: This study confirmed the questionnaire core outcome data are feasible and practicable to collect in clinical practice. The electronic data management system provided a robust means of collecting and managing the data across an international population. The findings have informed the final data collection tools and processes which will comprise the first international, clinical research registry and data bank for CRPS.

Predictive factors and clinical effects of diabetic hand: A prospective study with 1-year follow-up.

AIMS: Diabetes mellitus is considered an etiological factor for hand-related conditions that are grouped under the term "diabetic hand" (DH), which includes limited joint mobility, Dupuytren's contracture, carpal tunnel syndrome, and trigger finger. This study aimed to identify predictive factors and the clinical effects of DH development among patients with diabetes. PATIENTS AND METHODS: Consecutive Japanese adults with diabetes were prospectively recruited at a single outpatient center. We assessed the presence of DH at baseline and at the 1-year follow-up, which was considered present if the patient exhibited one or more of the hand disorders at either examination. RESULTS: The 590 eligible subjects had a mean age of 57 years and included 155 patients (26%) with DH. Binary logistic regression analysis revealed that DH was significantly associated with older age, longer diabetes duration, and higher body mass index. Patients with DH had significantly lower hand function and quality of life (QOL) scores. We assessed 476 patients at the 1-year follow-up, including 96 patients (20%) who had DH at baseline. Although 25 of the 96 patients (26%) experienced resolution of DH without specific treatment, 83 of 380 patients (22%) without DH at baseline had developed new DH-related conditions. At the 1-year follow-up, the group with DH was significantly older than that without DH. CONCLUSION: Older age and prolonged duration of diabetes predicted the development of DH. Patients who are not old and do not have a prolonged duration of diabetes may experience DH resolution without specific treatment.

Radial Osteotomy for Kienböck Disease: Clinical and Radiological Comparison between Younger and Older Patients.

Background: The usefulness of radial osteotomy for older patients remains unclear. The purpose of this study was to compare the clinical and radiological outcomes of radial osteotomy with volar locking plate between younger and older patients with Kienböck disease stages II to IIIB. Methods: This was a retrospective comparative study of 21 consecutive patients treated at our department. Lichtman's classification was used for staging, and four patients had stage II, six patients had stage IIIA, and 11 patients had stage IIIB disease. We divided them into two groups to compare the radiological and clinical results between younger (younger than 40 years) and older patients. The mean follow-up periods in the younger and older groups were 4 and 3.6 years, respectively. For radiological assessment, we evaluated the carpal height ratio (CHR), Stahl index, and union of the fractured lunate. For clinical assessment, we examined the range of motion of the wrist, grip strength, numeric rating scale (NRS) for pain, and the patient-reported Hand20 score preoperatively and at the final follow-up. Results: There were 12 patients in the younger group with a mean age of 23 years (range, 12-37 years), and 9 in the older group with a mean age of 56 years (range, 40-74 years). There were no intra- and post-operative complications in either group. Radiological improvement, including CHR, Stahl index, and union of the fractured lunate, was more common in the younger group than in the older one, as was the case for clinical improvement. However, even in the older group, significant clinical improvement, including the range of motion of the wrist, NRS for pain, and the Hand20 score, was seen postoperatively. Conclusions: Radial osteotomy appears to be a safe and reliable option in older symptomatic patients with Kienböck disease stages II to IIIB.

Chronic pain-related cortical neural activity in patients with complex regional pain syndrome.

Quantitative objective measurement of chronic pain is important. We elucidated chronic pain-related cortical neural activity and neural connectivity among pain-related brain regions in complex regional pain syndrome (CRPS). Resting-state magnetoencephalography recordings were performed. Cortical current density and neural connectivity, revealed by amplitude envelope correlation (AEC), were estimated on standardized brain magnetic resonance imaging. Intra-experiment pain was assessed subjectively using a visual analogue scale (VAS). The correlation between current density and VAS scores was calculated for the occipital areas and pain-related cortices. Current density in the primary (SI) and secondary (SII) somatosensory cortex and precuneus in both hemispheres was negatively correlated with the pain VAS score. The AEC and VAS values were significantly correlated for the SII and the precuneus and for the SII and insular cortex in the alpha frequency band in the right hemisphere. In the theta frequency band, the AEC and VAS values correlated for the SII and posterior cingulate cortex in the right hemisphere. Our results suggested that disruption of pain processes and functions in the default mode network occurs in CRPS. Our method targeting the neural mechanism of pain has the potential to offer a clinically objective means of evaluating it.

Choice of control group treatments in hand osteoarthritis trials: A systematic review and meta-analysis.

OBJECTIVES: To assess how patient characteristics and study design influence the effectiveness of control interventions in hand OA trials. METHODS: The study protocol was registered in PROSPERO (CRD42020163473). Two authors independently searched four electronic databases from their inception to December 31, 2019. Randomized and non-randomized controlled hand OA trials were included if pain intensity was assessed using a validated scale. We allocated control groups into one of the following: placebo, add-on treatment, no treatment, or active treatment. The standardized mean differences (d) of pain, as well as subjective function and hand strength, were pooled with 95% confidence intervals (CI) and 90% prediction intervals using random-effects models. Meta-regression and post-hoc subgroup analyses were performed to investigate which factors potentially impacted placebo analgesia and between-study heterogeneity. RESULTS: Thirty-one placebo, 11 add-on, 12 no-treatment, and 10 active-treatment controls were included in meta-analyses. Effective pain relief was observed in placebo (d = -0.50, 95% CI -0.63 to -0.37), add-on (d = -0.35, 95% CI -0.59 to -0.12), and active-treatment (d = -0.92, 95% CI -1.35 to -0.48) groups. In subjective function, these treatments had smaller but beneficial effects; hand strength, contrastingly, was not improved. Placebo effects were larger when flare designs were used (d = -0.96) and more homogeneous when minimum pain thresholds were set (d = -0.46, 90% prediction intervals -0.79 to -0.14). CONCLUSION: Placebo, add-on, and active control treatments were more effective than the no treatment control in relieving hand pain and improving subjective function. By choosing minimum pain thresholds and flare requirements at patient enrollment, moderate pain relief may be replicated among control participants in future randomized placebo-controlled trials.

Cross-cultural translation, adaptation and validation of a Japanese version of the functional index for hand osteoarthritis (J-FIHOA).

BACKGROUND: Hand osteoarthritis (OA) has a wide spectrum of clinical presentations and physical function is one of the core domains where patients suffer. The Functional Index for Hand Osteoarthritis (FIHOA) is a leading assessment tool for hand OA-related functional impairment. Our objective was to make a Japanese version of FIHOA (J-FIHOA) and validate it among Japanese hand OA patients. METHODS: Forward and backward translation processes were completed to create a culturally adapted J-FIHOA. A prospective, observational multicenter study was undertaken for the validation process. Seventeen collaborating hospitals recruited Japanese hand OA patients who met the American College of Rheumatology criteria. A medical record review and responses to the following patient-rated questionnaires were collected: J-FIHOA, Hand20, Health Assessment Questionnaire (HAQ), numerical rating scale for pain (NRS pain) and Short Form 36 Health Survey (SF-36). We explored the structure of J-FIHOA using factor analysis. Cronbach's alpha coefficients and item-total correlations were calculated. Correlations between J-FIHOA and other questionnaires were evaluated for construct validity. Participants in clinically stable conditions repeated J-FIHOA at a one- to two-week interval to assess test-retest reliability. To evaluate responsiveness, symptomatic patients who started new pharmacological treatments had a 1-month follow-up visit and completed the questionnaires twice. Effect size (ES) and standardized response mean (SRM) were calculated with pre- and post-treatment data sets. We assessed responsiveness, comparing ES and SRM of J-FIHOA with other questionnaires (construct approach). RESULTS: A total of 210 patients participated. J-FIHOA had unidimensional structure. Cronbach's alphas (0.914 among females and 0.929 among males) and item-total correlations (range, 0.508 to 0.881) revealed high internal consistency. Hand20, which measures upper extremity disability, was strongly correlated with J-FIHOA (r = 0.82) while the mental and role-social components of SF-36 showed no correlations (r = - 0.24 and - 0.26, respectively). Intraclass correlation coefficient for test-retest reliability was 0.83 and satisfactory. J-FIHOA showed the highest ES and SRM (- 0.68 and - 0.62, respectively) among all questionnaires, except for NRS pain. CONCLUSIONS: Our results showed J-FIHOA had good measurement properties to assess physical function in Japanese hand OA patients both for ambulatory follow-up in clinical practice, and clinical research and therapeutic trials.

Hourglass-Like Constriction of the Brachial Plexus in the Posterior Cord: A Case Report.

BACKGROUND AND IMPORTANCE: Hourglass-like constrictions are fascicular conditions confirmed definitively by interfascicular neurolysis. Certain peripheral nerves have vulnerable areas such as around the elbow in the posterior interosseous nerve. We report the first hourglass-like constriction in the brachial plexus supplying the radial innervated forearm musculature. Preoperative magnetic resonance imaging (MRI) findings of the brachial plexus were consistent with neuralgic amyotrophy (NA). CLINICAL PRESENTATION: A 9-yr-old boy experienced worsening left arm pain and difficulty in elevating the shoulder. Sequentially, severe palsy emerged when extending the wrist, thumb, and fingers. Based on the clinical picture, we diagnosed him with NA. The oblique coronal T2-weighted short-tau inversion recovery images showed mildly diffuse enlargement and hyperintensity of the brachial plexus. He showed few signs of improvement and interfascicular neurolysis was performed 11 mo after the onset. One of the fascicles in the posterior cord had developed an hourglass-like constriction. Electrical stimulation confirmed that the fascicle supplied forearm muscles. His wrist and finger extension had almost recovered at the 12-mo postoperative visit. CONCLUSION: Hourglass-like constrictions can occur in the brachial plexus. Although surgical approaches for the constrictions are still controversial, several reports demonstrated their effectiveness. Meanwhile, concerning NA treatment, evidence on the surgical intervention is lacking. Brachial plexus MRI might help in discerning the lesion and planning treatment options including surgical interventions. Hourglass-like constrictions are a possible etiology for certain NA patients with residual symptoms or paresis.