Inter- and intra-rater-reliability of a clinical framework for spine-related neck-arm pain.

OBJECTIVE: A mechanism-based clinical framework for spine-related pain differentiates (i) somatic referred pain, ii) heightened nerve mechanosensitivity, iii) radicular pain, iv) radiculopathy and mixed-pain. This study aimed to determine the reliability of proposed framework. METHOD: Fifty-one people with unilateral spine-related neck-arm pain were assessed and categorized by examiner-1. The classifications were compared to those made by two other examiners, based on written documentation of examiner-1. Cohens kappa was calculated between examiner-pairs; Fleiss Kappa among all examiners to assess agreement in classifying subgroups and entire framework. RESULT: Inter-rater-reliability showed moderate to almost perfect reliability (somatic: no variation, mechanosensitivity: 0.96 (95% CI 0.87-1.0) to 1.0 (95% CI: 1.0-1.0), radicular pain: 0.46 (95% CI: 0.19-0.69) to 0.62 (95% CI: 0.42-0.81), radiculopathy: 0.65 (95% CI: 0.43-0.84) to 0.80 (95% CI: 0.63-0.96) mixed-pain: 0.54 (95% CI: 0.21-0.81) to 0.75 (95% CI: 0.48-0.94). There was almost perfect to moderate reliability among all examiners (somatic: no variation, mechanosensitivity: 0.97 (95% CI: 0.82-1.0), radicular pain: 0.56 (95% CI: 0.40-0.71), radiculopathy: 0.74 (95% CI: 0.58-0.90), mixed-pain: 0.63 (95% CI: 0.47-0.79), entire framework: 0.64 (95% CI: 0.57-0.71)). Intra-rater-reliability showed substantial to almost perfect reliability (somatic: no variation, mechanosensitivity: 0.96 (95% CI: 0.87-1.0), radicular pain: 0.76 (95% CI: 0.57-0.92), radiculopathy: 0.84 (95% CI: 0.67-0.96), mixed-pain: 0.83 (95% CI: 0.60-1.0), entire framework: 0.80 (95% CI: 0.61-0.92). CONCLUSION: Moderate to almost perfect reliability in subgrouping people with spine-related neck-arm pain and substantial reliability for entire framework support this classification's reliability.

Replication of epidemiological associations of carpal tunnel syndrome in a UK population-based cohort of over 400,000 people.

INTRODUCTION: Several phenotypic factors are associated in the literature with an increased risk of carpal tunnel syndrome (CTS). Along with female sex and older age, certain systemic diseases show an association with CTS, with varying degrees of evidence. METHODS: This study was performed using the UK Biobank resource - a cohort study of over 500,000 participants who have allowed linkage of phenotypic data with their medical records. We calculated the prevalence of CTS and a sex-specific prevalence ratio and compared the body mass index (BMI) between cases and controls. We performed a series of nested case-control studies to compute odds ratios for the association between CTS and three systemic diseases. RESULTS: There were 12,312 CTS cases within the curated UK Biobank dataset of 401,656 (3.1% prevalence), and the female:male ratio was 1.95:1. CTS cases had, on average, a BMI > 2.0 kg/m2 greater than controls. Odds ratios for the association with CTS for three systemic diseases were 2.31 (95% CI 2.17-2.46) for diabetes, 2.70 (95% CI 2.44-2.99) for rheumatoid arthritis, and 1.47 (95% CI 1.38-1.57) for hypothyroidism. Adjusted for BMI, these odds ratios fell to 1.75 (95% CI 1.65-1.86), 2.43 (95% CI 2.20-2.69), and 1.35 (95% CI 1.26-1.43), respectively. DISCUSSION: We harnessed the size and power of UK Biobank to provide robust replication of evidence for the associations between CTS and female sex, raised BMI, and three systemic diseases, which are only mediated in part by raised BMI.

Can widespread hypersensitivity in carpal tunnel syndrome be substantiated if neck and arm pain are absent?

Recent studies demonstrated that patients with carpal tunnel syndrome (CTS) have signs of thermal and mechanical hyperalgesia in extra-median territories suggesting an involvement of central pain mechanisms. As previous studies included patients with shoulder/arm symptoms or neck pain, a potential influence of these coexisting disorders cannot be excluded. This study therefore evaluated whether widespread sensory changes (hypoesthesia or hyperalgesia) are present in patients with unilateral CTS in the absence of coexisting disorders. Twenty-six patients with unilateral CTS with symptoms localised to their hand and 26 healthy controls participated in the study. A comprehensive quantitative sensory testing (QST) protocol including thermal and mechanical detection and pain thresholds was performed over the hands (median, ulnar and radial innervation area), lateral elbows, neck and tibialis anterior muscle. Patients with CTS demonstrated thermal and mechanical hypoesthesia in the hand but not at distant sites. Thermal or mechanical hyperalgesia was not identified at any location with traditional QST threshold testing. However, patients with CTS rated the pain during thermal pain testing significantly higher than healthy participants. This was especially apparent for heat pain ratings which were elevated not only in the affected hand but also in the neck and tibialis anterior muscle. In conclusion, CTS alone in the absence of coexisting neck and arm pain does not account for sensory changes outside the affected hand as determined by traditional QST threshold testing. Elevated pain ratings may however be an early indication of central pain mechanisms.

Study of platelet-activating factor acetylhydrolase in the perioperative period of patients undergoing cardiac surgery.

After operations with cardiopulmonary bypass, patients often show early symptoms of the systemic inflammatory response syndrome (SIRS). Potential mediators of SIRS include the platelet-activating factor (PAF), which has been linked to septic shock and multiple organ dysfunction. We studied the effect of cardiac surgery on PAF acetylhydrolase, the PAF-degrading plasma enzyme, as well as the relationship between the enzyme and the postoperative state of the patients. PAF acetylhydrolase activity decreased by 38+/-8% after instituting cardiopulmonary bypass because of plasma dilution and returned to near-preoperative levels within 6 h postsurgery. After that, enzyme levels decreased again, resulting in a 24+/-12% reduction until at least 3 days postsurgery. Patients in poor postoperative condition (Acute Physiology Score >9) had a lower preoperative PAF acetylhydrolase activity than did normal patients (12+/-4 vs. 17+/-4 nmol min(-1) mL(-1); p < .05). Likewise, patients who developed postoperative SIRS had a lower preoperative PAF acetylhydrolase activity than did patients without SIRS (12+/-3 vs. 17+/-4 nmol min(-1) mL(-1); p < .05). The data suggest that PAF acetylhydrolase deficiency is among the factors associated with postoperative distress after cardiac surgery.