Browse by Audience
Vestibular migraine (VM) is a multidisciplinary disease under exploration. Multiple temporal patterns of vertigo and migraine make it difficult to diagnose VM, and their effect on the clinical features of VM is still unclear. Here we investigated the clinical features of VM under three temporal patterns. 172 VM patients were enrolled in this study and divided into three groups: 86 patients in group A had an earlier onset of migraine than vertigo, 35 patients in group B had an earlier onset of vertigo than migraine, and 51 patients in group C had concurrent vertigo and migraine. No significant difference was found among three groups regarding types, intensity and accompanying symptoms of the vestibular attack. Patients in group C presented higher frequency and longer duration of vertigo than group A and B, while patients in group A presented lower frequency and shorter duration of headaches than group B and C. Additionally, the frequency, duration, intensity and accompanying symptoms of headache in group A decreased significantly after the onset of vertigo, especially in women around menopause. We hypothesized that vestibular stimulation could inhibit the trigeminal pain pathway, while painful trigeminal stimulation could excite the vestibular system. Our findings may contribute to the clinical identification of VM and further clarification of its pathogenesis.
Learn More >Although the broad role of fear and hypervigilance in conditions of the gut-brain axis like irritable bowel syndrome is supported by converging evidence, the underlying mechanisms remain incompletely understood. Even in healthy individuals, it remains unclear how pain-related fear may contribute to pain-related attentional biases for acute visceral pain. Building on our classical fear conditioning work in a clinically relevant model of visceral pain, we herein elucidated pain-related attentional biases shaped by associative learning in healthy women and men, aiming to elucidate possible sex differences and the role of psychological traits. To this end, we compared the impact of differentially conditioned pain-predictive cues on attentional biases in healthy women and men. Sixty-four volunteers accomplished a visual dot-probe task and subsequently underwent pain-related fear conditioning where one visual cue (CS) was contingently paired with a painful rectal distention (US) while another cue remained unpaired (CS). During the following test phase, the dot-probe task was repeated to investigate changes in attentional biases in response to differentially valenced cues. While pain-related learning was comparable between groups, men revealed more pronounced attentional engagement with the CS and CS whereas women demonstrated stronger difficulties to disengage from the CS when presented with a neutral cue. However, when both CS and CS were presented together, women revealed stronger difficulties to disengage from the CS. Regression analyses revealed an interaction of sex, with negative affect predicting stronger avoidance of the CS and stronger difficulties to disengage attention from the CS in men. These results provide first evidence that pain-related fear conditioning may induce attentional biases differentially in healthy women and men. Hence, sex differences may play a role in attentional mechanisms underlying hypervigilance, and may be modulated by psychological vulnerability factors relevant to chronic visceral pain.
Learn More >Cannabis related online searches are associated with positive attitudes toward medical cannabis, particularly when information is obtained from dispensaries. Since pain is the main reason for medicinal cannabis use, information from dispensary websites has the potential to shape the attitude of pain patients towards cannabis. This is relevant because cannabis has demonstrated efficacy in neuropathic pain with low tetrahydrocannabinol (THC) concentrations (< 5-10%), in contrast to potent cannabis (>15% THC), which is highly rewarded in the recreational realm. The role of CBD in pain is not clear, however it has gained popularity. Thus, we hypothesize that the potency of medical cannabis that is advertised online is similar to the cannabis advertised for recreational purposes, which would potentially create a misconception towards medical cannabis. The current lack of knowledge surrounding advertised potencies in the legal cannabis market limits the ability to generate clear policies regarding online advertising to protect patients that are willing to use cannabis for their condition. Thus, we evaluated the advertised THC and CBD content of cannabis products offered online in dispensaries in the United States to determine products' suitability to medicinal use and compare the strength of products offered in legal medical and recreational programs. We recorded THC and CBD concentrations for all herb cannabis products provided by dispensary websites and compared them between or within states. Four Western states (CA, CO, NM, WA) and five Northeastern states (ME, MA, NH, RI, VT) were included. A total of 8,505 cannabis products across 653 dispensaries were sampled. Despite the clear differences between medicinal and recreational uses of cannabis, the average THC concentration advertised online in medicinal programs was similar (19.2% ±6.2) to recreational programs (21.5% ±6.0) when compared between states with different programs, or between medicinal and recreational programs within the same states (CO or WA). Lower CBD concentrations accompanied higher THC products. The majority of products, regardless of medicinal or recreational programs, were advertised to have >15% THC (70.3% – 91.4% of products). These stated concentrations seem unsuitable for medicinal purposes, particularly for patients with chronic neuropathic pain. Therefore, this information could induce the misconception that high potency cannabis is safe to treat pain. This data is consistent with reports in which THC and CBD in products from legal dispensaries or in nationwide products from the illegal market were actually measured, which indicates that patients consuming these products may be at risk of acute intoxication or long-term side effects. Our study offers grounds to develop policies that help prevent misconceptions toward cannabis and reduce risks in pain patients.
Learn More >This study investigated psychological characteristics of patients with chronic complex regional pain syndrome (CRPS) and examined relationships between psychosocial factors and pain severity.
Learn More >Tumor-related cancer pain often comprises mixed pain with both nociceptive and neuropathic components. Whether tumor-related cancer pain includes a neuropathic component impacts the therapeutic strategy. The aim of this cross-sectional study was to investigate the usefulness of two screening tools for neuropathic pain, painDETECT and Self-Report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS), in identifying the neuropathic component of mixed pain among patients with tumor-related cancer pain.
Learn More >Relief of cancer-related pain remains challenging despite the availability of a range of opioid and non-opioid medications. Animal models demonstrate that T lymphocytes may mediate analgesia by producing endogenous opioids, but definitive clinical data are limited. Adoptive transfer of ex vivo activated T cell products (ACT) is being tested as an anti-cancer therapy. We retrospectively reviewed the medical charts of 357 patients with various malignancies who received three intravenous infusions of autologous cytokine-activated T cell-enriched products. Among these were fifty-five (55) patients who required opioids for moderate or severe cancer-related pain. Opioid dosage and cancer pain score were recorded daily for 2 consecutive weeks prior to and 2 weeks after the ACT infusions. The average oral morphine equivalent doses (OMED) and cancer pain scores were significantly decreased following the ACT infusions. The proportion of patients with breakthrough pain also declined. Moreover, higher frequencies of expanded CD3+, CD3+/CD4+, and CD3+/CD8+ T cells within the ACT product were associated with favorable analgesic effects. Transient elevations in CD3+ and CD3+/CD8+ T cell subpopulations and decreases in CD4CD25 Treg were observed in patients' blood after the ACT. In conclusion, ACT was capable of reducing cancer pain severity and opioid consumption and favorably modulating peripheral blood T cell populations.
Learn More >Brain derived neurotrophic factor (BDNF) and the high affinity receptor tropomyosin receptor kinase B (TrkB) have important roles in neuronal survival and in spinal sensitization mechanisms associated with chronic pain. Recent clinical evidence also supports a peripheral role of BDNF in osteoarthritis (OA), with synovial expression of TrkB associated with higher OA pain. The aim of this study was to use clinical samples and animal models to explore the potential contribution of knee joint BDNF / TrkB signalling to chronic OA pain.BDNF and TrkB mRNA and protein were present in knee synovia from OA patients (16 women, 14 men, median age 67 [IQR: 61 – 73]). There was a significant positive correlation between mRNA expression of NTRK2 (TrkB) and the pro-inflammatory chemokine fractalkine in the OA synovia.Using the surgical medial meniscal transection (MNX) model and the chemical monosodium iodoacetate (MIA) model of OA pain in male rats, the effects of peripheral BDNF injection, versus sequestering endogenous BDNF with TrkB-Fc chimera, on established pain behaviour were determined. Intra-articular injection of BDNF augmented established OA pain behaviour in MIA rats, but had no effect in controls. Intra-articular injection of the TrkB-Fc chimera acutely reversed pain behaviour to a similar extent in both models of OA pain (weight-bearing asymmetry MIA: -11±4%, MNX: -12±4%), compared to vehicle treatment. Our data suggesting a contribution of peripheral knee joint BDNF / TrkB signalling in the maintenance of chronic OA joint pain support further investigation of the therapeutic potential of this target.
Learn More >Opioids and non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed for chronic musculoskeletal pain, despite limited evidence of effectiveness and well-documented adverse effects. We assessed the effects of participating in a structured, personalized self-experiment ("N-of-1 trial") on analgesic prescribing in patients with chronic musculoskeletal pain.
Learn More >Nemolizumab targets the interleukin 31 receptor alpha subunit (IL-31RA) involved in atopic dermatitis (AD) pathogenesis.
Learn More >Cohort/psychometric study OBJECTIVES: The primary objective was to determine the psychometric properties and the utility of the Neuropathic Pain Symptom Inventory (NPSI) in subgrouping people with moderate to severe neuropathic pain after spinal cord injury (SCI).
Learn More >