The journal of pain : official journal of the American Pain Society
-
Native Americans (NAs) have a higher prevalence of chronic pain than any other U. S. racial/ethnic group; however, little is known about the mechanisms for this pain disparity. This study used quantitative sensory testing to assess pain experience in healthy, pain-free adults (n = 137 NAs (87 female), n = 145 non-Hispanic whites (NHW; 68 female)) after painful electric, heat, cold, ischemic, and pressure stimuli. ⋯ This could place NAs at risk for future chronic pain and could ultimately lead to a vicious cycle that maintains pain (eg, pain → anxiety/catastrophizing → pain). PERSPECTIVE: NAs experienced heightened sensory, anxiety, and catastrophizing reactions in response to multiple pain stimuli. Given the potential for anxiety and catastrophic thoughts to amplify pain, this characteristic may place them at risk for pain disorders and could lead to a vicious cycle that maintains pain.
-
Central sensitization is considered to have a pathophysiological role in chronic low back pain (LBP). Whether individuals with increased central sensitization early in their condition are more likely to develop persistent pain or whether it increases over time is unclear. This study aimed to determine whether sensory profiles during acute LBP differ between individuals who did and did not recover by 6 months and to identify subgroups associated with outcomes. ⋯ Two subgroups were identified that associated with more ("high sensitivity") or less ("high sensitivity and negative psychological state") recovery. These data seem to suggest that central sensitization during the acute phase resolves for many patients, but is a precursor to the transition to chronicity when combined with other psychological features. PERSPECTIVE: Central sensitization signs during early acute LBP does not necessarily precede poor outcome, but may be sustained in conjunction with other psychological factors and facilitate pain persistence.
-
There is substantial evidence supporting the notion that the primary somatosensory (S1) cortex is an important structure involved in the perceptional component of pain. However, investigations have mainly focused on other pain-related formations, and few reports have been provided to investigate the synaptic plasticity in the S1 cortex in response to persistent pain. In the present study, we report that bee venom (BV) injection triggered an imbalance between excitatory and inhibitory synaptic transmission in the S1 cortex in rats. ⋯ Perspective: Increased synaptic plasticity was detected in S1 after peripheral nociception, with enhanced excitatory and decreased inhibitory synaptic transmissions. Increased GluR1, and decreased GABAAα1 and GluR2 membrane trafficking were detected. Therefore, the disrupted excitatory/inhibitory balance in transmissions is involved in nociception processing, and S1 can be a potential antinociceptive site.
-
Randomized Controlled Trial Multicenter Study
Perioperative Pregabalin and Intraoperative Lidocaine Infusion to Reduce Persistent Neuropathic Pain After Breast Cancer Surgery: A Multicenter, Factorial, Randomized, Controlled Pilot Trial.
Persistent postsurgical pain is defined as pain localized to the area of surgery of a duration of ≥2 months and is, unfortunately, a common complication after breast cancer surgery. Although there is insufficient evidence to support any preventative strategy, prior literature suggests the possible efficacy of intravenous lidocaine and perioperative pregabalin in preventing persistent pain after surgery. To determine feasibility of conducting a larger definitive trial, we conducted a multicenter 2 × 2 factorial, randomized, placebo-controlled pilot trial of 100 female patients undergoing breast cancer surgery. ⋯ Our pilot trial successfully demonstrated feasibility and provided promising data for conducting further trials of intraoperative lidocaine infusions during breast cancer surgeries. Clinical trial number: NCT02240199 PERSPECTIVE: This article reports the findings of a pilot randomized, controlled trial evaluating the effects of perioperative pregabalin and intraoperative lidocaine infusions in patients undergoing breast cancer surgery. This trial demonstrated the feasibility of conducting a larger trial and provided promising data that these interventions may decrease the development of persistent pain.