Pain
-
A cerebral upregulation of the translocator protein (TSPO), a biomarker of glial activation, has been reported in fibromyalgia subjects (FMS). The TSPO binding affinity is genetically regulated by the Ala147Thr polymorphism in the TSPO gene (rs6971) and allows for a subject classification into high affinity binders (HABs) and mixed/low affinity binders (MLABs). The aim of the present multimodal neuroimaging study was to examine the associations of the TSPO polymorphism with: (1) conditioned pain modulation, (2) expectancy-modulated pain processing assessed during functional magnetic resonance imaging, and (3) the concentration and balance of glutamate and γ-aminobutyric acid in the rostral anterior cingulate cortex and thalamus using proton magnetic resonance spectroscopy in FMS (n = 83) and healthy controls (n = 43). ⋯ Translocator protein HABs in both groups (FM and healthy controls) were found to have higher thalamic glutamate concentrations and exhibit a pattern of positive correlations between glutamate and γ-aminobutyric acid in the rostral anterior cingulate cortex, not seen in MLABs. Altogether, our findings point to TSPO-related mechanisms being HAB-dependent, brain region-specific, and non-FM-specific, although in FMS the disadvantage of an aberrant pain regulation combined with an HAB genetic set-up might hamper pain modulation more strongly. Our results provide evidence for an important role of TSPO in pain regulation and brain metabolism, thereby supporting the ongoing drug development targeting TSPO-associated mechanisms for pain relief.
-
Randomized Controlled Trial
Pregabalin versus placebo to prevent chronic pain after whiplash injury in at-risk individuals: results of a feasibility study for a large randomised controlled trial.
There are few effective treatments for acute whiplash-associated disorders (WADs). Early features of central sensitisation predict poor recovery. The effect of pregabalin on central sensitisation might prevent chronic pain after acute whiplash injury. ⋯ Minor adverse events were more common in the pregabalin group. A definitive large randomised controlled trial of pregabalin for acute whiplash injury is warranted. Feasibility issues would need to be addressed with modifications to the protocol.
-
Pain increases with age, disproportionately affects women, and is a major contributor to decreased quality of life. Because pain is dynamic, trajectories are important to consider. Few studies have examined longitudinal trajectories of pain, by gender, in Mexico. ⋯ Insurance status was negatively associated with pain in the low-stable group, but positively associated with pain in the moderate-increasing group. We identified 2 trajectories of activity-limiting pain, among older Mexican adults (50+) over 17 years of follow-up. Understanding gender differences in pain trajectories in later life and the factors associated with trajectory development is crucial to improve quality of life, especially in vulnerable populations.
-
A significant proportion of children/adolescents report chronic widespread pain (CWP), but little is known about clinically relevant CWP or what factors lead to onset in this population. Objectives were to report the primary care consultation prevalence of CWP and investigate risk factors associated with onset. A validated algorithm for identifying CWP status from primary care electronic healthcare records was applied to a child or adolescent population (aged 8-18 years). ⋯ Findings show a significant proportion of the child or adolescent primary care population has CWP. Most risk factors involved pain-related conditions, suggesting potential pathways of pain development. Further work is now needed to better understand the development of CWP in children and adolescents.
-
Different pathophysiological mechanisms contribute to the pain development in osteoarthritis (OA). Sensitization mechanisms play an important role in the amplification and chronification of pain and may predict the therapeutic outcome. Stratification of patients according to their pain mechanisms could help to target pain therapy. ⋯ The most adequate bedside tools to detect sensitization were pressure pain sensitivity (pain intensity at 4 mL pressure using a 10-mL blunted syringe), mechanical pinprick pain sensitivity (pain intensity of a 0.7 mm nylon filament) over the most affected knee, and extrasegmental pressure pain sensitivity (pain threshold). This pilot study presents a first attempt to develop an easy-to-use bedside test to probe sensitization in patients with chronic OA knee pain or chronic pain after TKR. This tool may be used to optimize individualized, mechanism-based pain therapy.