The journal of pain : official journal of the American Pain Society
-
In this clinical and skin biopsy study, we aimed to investigate whether fibromyalgia-associated small-fiber pathology (SFP), consisting of an intraepidermal nerve fiber loss, implies damage of dermal autonomic nerve fibers and how this damage is associated with autonomic symptoms that patients with fibromyalgia syndrome experience. Using skin biopsy, we investigated intraepidermal nerve fiber density, piloerector muscle, and sweat gland nerve fiber density (SGNFD) in 138 participants, that is, 58 patients with fibromyalgia syndrome, 48 healthy subjects, and 32 patients with small-fiber neuropathy. In patients with fibromyalgia-associated SFP, we also investigated how the different skin biopsy variables correlated with autonomic symptoms, as assessed with the Composite Autonomic Symptom Score 31 questionnaire. ⋯ However, the autonomic small-fiber damage we found had no correlation with the severity of autonomic symptoms, and thus its clinical impact is still undetermined. PERSPECTIVE: In patients with fibromyalgia, SFP also affects autonomic fibers. These novel data provide additional insights into the pathophysiology of fibromyalgia syndrome, highlighting the complex role of small-fiber damage in the clinical picture of fibromyalgia.
-
This survey investigated the prevalence of de novo widespread musculoskeletal post-COVID pain and risk factors for its development in nonhospitalized COVID-19 survivors. A nationwide exploratory cross-sectional study was conducted, including a cohort of 593,741 Danish residents who had suffered from a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection from March 2020 to December 2021. A questionnaire was distributed to the Danish population via the digital mail system (e-Boks). ⋯ PERSPECTIVE: This article presents de novo widespread post-COVID pain prevalence in a cohort of 130,443 citizens infected with COVID-19. The study identifies potential risk factors associated with the development of these new pain symptoms. The results may increase focus on this patient group and potentially help identify predictors for postinfection pain development.
-
Mechanisms underlying neuropathic pain (NP) are complex with multiple genes, their interactions, environmental and epigenetic factors being implicated. Transcriptional changes in the trigeminal (TG) and dorsal root (DRG) ganglia have been implicated in the development and maintenance of NP. Despite efforts to unravel molecular mechanisms of NP, many remain unknown. ⋯ This study provides a basis for further in-depth studies investigating transcriptional changes, pathways, and upstream regulation in TG and DRG in rats exposed to peripheral nerve injuries. PERSPECTIVE: Although trigeminal and dorsal root ganglia are homologs of each other, they respond differently to nerve injury and therefore treatment. Activation/inhibition of number of biological pathways appear to be ganglion/system specific suggesting that different approaches might be required to successfully treat neuropathies induced by injuries in spinal and trigeminal systems.
-
Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) is a murine model for multiple sclerosis. This model is characterized by chronic and progressive demyelination, leading to impairment of motor function and paralysis. While the outcomes of the disease, including impaired motor function and immunological changes, are well-characterized, little is known about the impact of EAE on the electrophysiology of the motor and sensory systems. ⋯ The findings also suggest an increase in p25 amplitude before motor deficits appear, indicating SEP as a predictive marker for disease progression. PERSPECTIVE: This article assesses p25, a new sensory electrophysiology wave that correlates with pain-related behavior in MOG-induced EAE mice and appears prior to the clinical symptoms. Motor electrophysiology correlates with traditional motor behavior scoring and histology.
-
We conducted a meta-epidemiological study on all non-specific low back pain (NSLBP) trial registrations on the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov. We aimed to 1) assess the uptake of the core outcome set (COS) for NSLBP in clinical trials; 2) assess the uptake of the core outcome measurement set for NSLBP in clinical trials; and 3) determine whether specific study characteristics are associated with the COS uptake. After applying the relevant filters for the condition, study type, and phase of the trial, 240 registry entries were included in this study. ⋯ We evaluated whether trial registrations are using this set of outcomes when testing interventions for low back pain. Full uptake was found only in 21% of the sample, and this is not increasing over time. Researchers should use the COS to ensure that trials measure relevant outcomes consistently.