Human Studies

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. 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. Single measures estimates suggested inter-rater reliability was substantial for the rainbow pain scale [intra-class correlation coefficient = 0.78 ( = 31),  < 0.001]. Test-retest reliability was also excellent at with an intraclass correlation coefficient of 0.87 [ = 28,  < 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. 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.

There is no consensus regarding the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) for chronic musculoskeletal or low back pain. A review of previous trial methodology identified problems with treatment fidelity. Qualitative research with experienced TENS users identified specific contexts for TENS use, leading to individualised outcomes. There is little information available to guide the selection of Patient Reported Outcome Measures (PROMs) appropriate for TENS evaluation.

Pain hypersensitivity has been described as one of the most disabling symptoms of fibromyalgia syndrome (FMS). Here we analyzed the relationship between an anti-inflammatory diet profile and the pressure pain thresholds (PPTs) of tender point sites and other fibromyalgia-related symptoms in patients with FMS.

Central neuropathic pain (CNP) after spinal cord injury (SCI) is debilitating and immensely impacts the individual. CNP is relatively resistant to treatment administered after it develops, perhaps owing to irreversible pathological processes. Although preemptive treatment may overcome this shortcoming, its administration necessitates screening patients with clinically relevant biomarkers that could predict CNP early post-SCI. The aim was to search for such biomarkers by measuring pro-nociceptive and for the first time, anti-nociceptive indices early post-SCI.Participantswere 47 patients with acute SCI and 20 healthy controls (HC). Pain adaptation, conditioned pain modulation (CPM), pain temporal summation (TSP), windup pain, and allodynia were measured above, at, and below the injury level, at 1.5 months post-SCI. HC were tested at corresponding regions. SCI patients were monitored for CNP emergence and characteristics at 3-4, 6-7, and 24 months post-SCI.CNP prevalence was 57.4%. CNP severity, quality and aggravating factors but not location somewhat changed over 24 months. SCI patients who eventually developed CNP exhibited early, reduced at-level pain adaptation and CPM magnitudes than those who did not. The best predictor for CNP emergence at 3-4 and 7-8 months was at-level pain adaptation with odds ratios of 3.17 and 2.83, respectively (∼77% probability) and a cut-off value with 90% sensitivity. Allodynia and at-level CPM predicted CNP severity at 3-4 and 24 months, respectively.Reduced pain inhibition capacity precedes, and may lead to CNP. At-level pain adaptation is an early CNP biomarker with which individuals at risk can be identify to initiate preemptive treatment.

To explore strategies used by people living with chronic pain when participating in physical activity and exercise and their recommendations for health care providers when promoting participation in physical activity and exercise.