The journal of pain : official journal of the American Pain Society
-
Existing data suggest placebo responses to treatments are small, but some people may be more likely to respond. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) on interindividual variability in response to placebo interventions MEDLINE, EMBASE, CINAHL, Web of Science Core Collection, CENTRAL, and SPORTDiscus were searched from inception to September 2023. Trial registry searches, citation tracking, and searches for prior systematic reviews were completed. ⋯ PERSPECTIVE: This study systematically reviewed and analyzed RCTs to assess interindividual variability in placebo responses for musculoskeletal pain. Findings suggest minimal variability in placebo response, with no distinct subgroups more likely to respond. Wide prediction intervals indicate uncertainty, highlighting the need for future individual participant data meta-analyses to better elucidate potential responder subgroups.
-
Fibromyalgia (FM) impacts patients' health status, functioning and quality of life. Accurate diagnosis and effective treatment planning require reliable, valid and responsive measures of these domains. This study aimed to assess the psychometric properties of performance based tests (PBTs) in FM and to quantify the availability of reliable, valid and responsive PBTs linked to key International Classification of Functioning, Disability and Health (ICF) categories related to functional impact. ⋯ PERSPECTIVE: This review confirms that the current understanding of the psychometric properties of PBTs for FM patients is limited, hindered by heterogeneous tests and insufficient evidence, complicating outcome comparisons across studies. This gap underscores the need for future research to enhance methodological quality and address missing ICF categories related to FM. REGISTERED PROTOCOL AT PROSPERO: Registration number: CRD42022380709.
-
Sickle cell disease (SCD) is an inherited hemolytic disorder accompanied by chronic pain and recurrent acute painful episodes known as vaso-occlusive crises (VOCs). Increased Glx (glutamate+glutamine) and lowered GABA concentration have been reported in the insula of patients with fibromyalgia, a nociplastic chronic pain condition, and may affect the pathophysiology of pain-related syndromes. Therefore, proton magnetic resonance spectroscopy (1H-MRS) was conducted to measure levels of Glx and other brain metabolites using a single voxel (size: 2×3×3 cm3) in the right posterior insula cortex (PIC) in 17 individuals with SCD and 17 ethnicity-, age- and sex-matched healthy controls (HCs). ⋯ These results suggest that elevated excitatory neurotransmission in the insula might contribute to nociplastic pain in SCD. PERSPECTIVE: Our work highlighted the innovative finding of elevated levels of the excitatory neurotransmitter glutamate with glutamine in patients with SCD compared to healthy controls. The positive relationship between Glx/tCr and the frequency of VOCs suggests that an excitatory brain neurotransmitter imbalance may be involved in VOCs.
-
The risk of developing chronic pain is twice as high among people with a history of childhood maltreatment compared to those without these experiences. It is unclear, however, whether childhood maltreatment might lead to lower or higher perception of pain. In this paper, we investigate the association between childhood maltreatment and pain sensitivity. ⋯ Individuals reporting childhood sexual abuse, emotional abuse or neglect and physical neglect could on average withstand hot and cold pain of 1.03 °C [0.13, 1.84] to 3.20 °C [0.62, 5.97] more across different types of abuse compared to those with no emotional abuse or (physical) neglect history. Physical abuse was not associated with pain sensitivity. The current findings suggest that childhood maltreatment might lead to habituation to painful stimuli as opposed to increased pain sensitivity.