Human Studies

Previous studies comparing laser (LEPs) and contact heat evoked potentials (CHEPs) consistently reported higher amplitudes following laser compared to contact heat stimulation. However, none of the studies matched the perceived pain intensity, questioning if the observed difference in amplitude is due to biophysical differences between the two methods or a mismatch in stimulation intensity. The aims of the current study were twofold: (1) to directly compare the brain potentials induced by intensity matched laser and contact heat stimulation and (2) investigate how capsaicin-induced secondary hyperalgesia modulates LEPs and CHEPs. Twenty-one healthy subjects were recruited and measured at four experimental sessions: (1) CHEPs + sham, (2) LEPs + sham, (3) CHEPs + capsaicin, and (4) LEPs + capsaicin. Baseline (sham) LEPs latency was significantly shorter and amplitude significantly larger compared to CHEPs, even when matched for perceived pain. Neither CHEPs nor LEPs was sensitive enough to detect secondary hyperalgesia. These differences provide evidence that a faster heating rate results in an earlier and more synchronized LEPs than CHEPs. To our knowledge, this was the first study to match perceived intensity of contact heat and laser stimulations, revealing distinct advantages associated with the acquisition of LEPs.

Chronic pain constitutes a significant burden for the individuals affected, and is a frequent reason why patients seek health care services. While in-person psychosocial interventions can be of support to people living with chronic pain, such interventions are not always accessible. eHealth interventions may provide greater accessibility, but the evidence and use of digital self-management solutions for chronic pain are still limited and the lack of health care provider input in the development process of such solutions a concern. Therefore, the aim of the current study was to investigate health care providers' experiences of treating patients with chronic pain, their attitudes towards, and use of, digital solutions in pain management, and their suggestions for content and design elements for a potential digital pain self-management intervention.

To classify paediatric chronic pain referrals in Ireland using the ICD-11 classification. In addition, differences between primary and secondary pain groups were assessed.

This is the first double-blind, randomized, controlled trial evaluating the efficacy and safety of intravenous immunoglobulin (IVIg) versus placebo in patients with idiopathic small fiber neuropathy (I-SFN).

The inter-session Intraclass Correlation Coefficient (ICC) is a commonly investigated and clinically important metric of reliability for pressure pain threshold (PPT) measurement. However, current investigations do not account for inter-repetition variability when calculating inter-session ICC, even though a PPT measurement taken at different sessions must also imply different repetitions. The primary aim was to evaluate and report a novel metric of reliability in PPT measurement: the inter-session-repetition ICC. One rater recorded ten repetitions of PPT measurement over the lumbar region bilaterally at two sessions in twenty healthy adults using a pressure algometer. Variance components were computed using linear mixed-models and used to construct ICCs; most notably inter-session ICC and inter-session-repetition ICC. At 70.1% of the total variance, the source of greatest variability was between subjects ([Formula: see text] = 222.28 N), whereas the source of least variability (1.5% total variance) was between sessions ([Formula: see text] = 4.83 N). Derived inter-session and inter-session-repetition ICCs were 0.88 (95%CI: 0.77 to 0.94) and 0.73 (95%CI: 0.53 to 0.84) respectively. Inter-session-repetition ICC provides a more conservative estimate of reliability than inter-session ICC, with the magnitude of difference being clinically meaningful. Quantifying individual sources of variability enables ICC construction to be reflective of individual testing protocols.

To analyze industry payments to pain medicine physicians in the United States.

During the past few years, the research of chronic neuropathic pain has focused on neuroinflammation within the central nervous system and its impact on pain chronicity. As part of the ERA-Net NEURON consortium we aimed to identify immune cell patterns in cerebrospinal fluid (CSF) of patients with herpes zoster neuralgia (HZ) and polyneuropathy (PNP), which may contribute to pain chronicity in these neuropathic pain conditions.CSF of 41 patients (10 HZ, 31 PNP) was analyzed by flow cytometry identifying lymphocyte subsets: CD4+- (T-helper-cells), CD8+- (cytotoxic T-cells), CD19+- (B-cells), and CD56+- (natural killer; NK) cells. At baseline and at follow-up, the somatosensory phenotype was assessed with QST. Additionally, the patients answered epidemiological questionnaires and the PainDETECT. Immune cell profiles and somatosensory profiles, as well as PDQ-scores were analyzed and correlated in order to determine specific immune cell patterns, which contribute to chronic pain.We found a negative correlation (p= 0.004, r=-0.596) between the frequency of natural killer cells and mechanical pain sensitivity (MPS), one of the most relevant QST markers for central sensitization; a high frequency of NK-cells correlated with low MPS. The analysis of the individual follow-up showed a worsening of the pain condition if NK-cell frequency was low.Low NK-cell frequency is associated with signs of central sensitization (MPS), whereas high NK-cell frequency might prevent central sensitization. Therefore, NK-cells seem to play a protective role within the neuroinflammatory cascade and may be used as marker for pain chronicity.