The journal of pain : official journal of the American Pain Society
-
In United States military veterans, chronic pain represents a risk factor for opioid and alcohol misuse, yet few studies have examined interactions among chronic pain, opioid prescription, and opioid and alcohol misuse. Previous work found substantial risk of co-morbid alcohol and opioid misuse in a community sample of opioid-prescribed individuals with chronic pain, a finding expanded upon here. Specifically, 211 veterans assessed within a chronic pain treatment service for opioid-prescribed individuals completed self-report measures of opioid misuse, alcohol misuse, pain intensity, depression, pain catastrophizing, and post-traumatic stress symptoms (PTS). ⋯ PERSPECTIVE: Opioid and alcohol misuse was examined in 211 Veterans prescribed opioids for chronic pain. In total, 32% were not misusing either, 23% were misusing both, 40% were misusing opioids, and 5% were misusing alcohol. Veterans not misusing either were generally less disabled and distressed compared to those misusing opioids or both.
-
Preclinical studies demonstrate opposing effects of long-chain polyunsaturated fatty acid (PUFA) metabolites on inflammation and nociception. Omega-6 (n-6) PUFAs amplify both processes while omega-3 (n-3) PUFAs inhibit them. This cross-sectional study examined relationships between PUFAs in circulating erythrocytes and 2 chronic idiopathic pain conditions: temporomandibular disorder (TMD) and low back pain in a community-based sample of 503 U. ⋯ As systemic inflammation is not a hallmark of these conditions, PUFAs may influence idiopathic pain through other mechanisms. PERSPECTIVE: This cross-sectional clinical study found that a higher ratio of circulating n-6/n-3 long-chain PUFAs was associated with greater odds of 2 common chronic overlapping pain conditions. This suggests that the pro and antinociceptive properties of n-6 and n-3 PUFAs, respectively, influence pain independently of their well-established inflammatory pathways.
-
The strong need for a new foundational molecular framework for human nervous system research at the nociceptive level is now matched by comprehensive and quantitative capabilities for analyzing nociceptive tissues such as pathologic peripheral tissue, damaged peripheral nerve, dorsal root ganglia, spinal cord, and brain, where possible. However, this idea must be matched by equally strong organization and infrastructures for multisite tissue recovery, molecular analyses, data sharing, and long-term archiving. Experience from other human tissue analysis projects shows that a decades-long activity may be expected, hence "Be in it for the long haul." While certain milestones can be met fairly quickly, others aimed at molecular and neuroanatomical characterization of chronic pain disorders will require the sustained attention of the groups involved. ⋯ PERSPECTIVE: A concerted effort is needed to build human nociceptive tissue banks for multi-omic research. In addition to collecting tissue, a careful characterization of pain problems from donors is essential, as is a parallel effort to assess their concurrent medical problems, medications, and the many variables of general human activity and lifestyle that can impact the results. Given the projected long time frame, in addition to maintaining funding, sustaining motivation and momentum are critical factors for success.
-
Psychedelic substances have played important roles in diverse cultures, and ingesting various plant preparations to evoke altered states of consciousness has been described throughout recorded history. Accounts of the subjective effects of psychedelics typically focus on spiritual and mystical-type experiences, including feelings of unity, sacredness, and transcendence. Over the past 2 decades, there has been increasing interest in psychedelics as treatments for various medical disorders, including chronic pain. ⋯ Challenges in evaluating psychedelics as treatments for chronic pain include identifying neurobiologic and psychosocial mechanisms of action and determining which pain conditions to investigate. Truly informative proof-of-concept and confirmatory randomized clinical trials will require careful selection of control groups, efforts to minimize bias from unblinding, and attention to the roles of patient mental set and treatment setting. PERSPECTIVE: There is considerable promise for the use of psychedelic therapy for pain, but evidence-based recommendations for the design of future studies are needed to ensure that the results of this research are truly informative.
-
Observational Study
Preoperative Predictors of Complex Regional Pain Syndrome Outcomes in the 6 Months Following Total Knee Arthroplasty.
This prospective observational study evaluated preoperative predictors of complex regional pain syndrome (CRPS) outcomes in the 6 months following total knee arthroplasty (TKA). Participants were n = 110 osteoarthritis patients (64.5% female) undergoing unilateral TKA with no prior CRPS history. Domains of negative affect (depression, anxiety, catastrophizing), pain (intensity, widespread pain, temporal summation of pain [TSP]), pain interference, sleep disturbance, and pro-inflammatory status (tumor necrosis factor-alpha [TNF-a]) were assessed preoperatively. ⋯ Preoperative negative affect is unlikely to directly influence long-term CRPS risk. PERSPECTIVE: This article identifies preoperative predictors of CRPS features at 6 months following total knee arthroplasty, including more widespread pain and higher pain intensity, temporal summation of pain, pain interference, and tumor necrosis factor-alpha levels. Findings suggest the importance of central sensitization and inflammatory mechanisms in CRPS risk following tissue trauma.