Accepted

Post-mastectomy pain syndrome (PMPS) is a surgical complication of breast surgery characterized by chronic neuropathic pain. The development of PMPS is multifactorial and research on its prevention is limited. The objective of this systematic review is to synthesize the existing evidence on interventions for lowering the incidence of persistent neuropathic pain after breast surgery.

Intervertebral disc (IVD) herniation and degeneration contributes significantly to low back pain (LBP), of which the molecular pathogenesis is not fully understood. Disc herniation may cause LBP and radicular pain, but not all LBP patients have disc herniation. Degenerated discs could be the source of pain, but not all degenerated discs are symptomatic. We previously found that disc degeneration and herniation accompanied by inflammation. We further found that anti-inflammatory molecules blocked immune responses, alleviated IVD degeneration and pain. Based on our recent findings and the work of others, we hypothesize that immune system may play a prominent role in the production of disc herniation or disc degeneration associated pain. While the nucleus pulposus (NP) is an immune-privileged organ, the damage of the physical barrier between NP and systemic circulation, or the innervation and vascularization of the degenerated NP, on one hand exposes NP as a foreign antigen to immune system, and on the other hand presents compression on the nerve root or dorsal root ganglion (DRG), which both elicit immune responses induced by immune cells and their mediators. The inflammation can remain for a long time at remote distance, with various types of cytokines and immune cells involved in this pain-inducing process. In this review, we aim to revisit the autoimmunity of the NP, immune cell infiltration after break of physical barrier, the inflammatory activities in the DRG and the generation of pain. We also summarize the involvement of immune system, including immune cells and cytokines, in degenerated or herniated IVDs and affected DRG.

In the midst of the COVID-19 pandemic, data has shown that age-adjusted overdose death rates involving synthetic opioids, psychostimulants, cocaine, and heroin have been increasing, including prescription opioid deaths, which were declining, but, recently, reversing the trends. Contrary to widely held perceptions, the problem of misuse, abuse, and diversion of prescription opioids has been the least of all the factors in recent years. Consequently, it is important to properly distinguish between the role of illicit and prescription opioids in the current opioid crisis. Multiple efforts have been based on consensus on administrative policies for certain harm reduction strategies for individuals actively using illicit drugs and reducing opioid prescriptions leading to curbing of medically needed opioids, which have been ineffective. While there is no denial that prescription opioids can be misused, abused, and diverted, the policies have oversimplified the issue by curbing prescription opioids and the pendulum has swung too far in the direction of severely limiting prescription opioids, without acknowledgement that opioids have legitimate uses for persons suffering from chronic pain. Similar to the opioid crisis, interventional pain management procedures have been affected by various policies being applied to reduce overuse, abuse, and finally utilization. Medical policies have been becoming more restrictive with reduction of access to certain procedures, with the pendulum swinging too far in the direction of limiting interventional techniques. Recent utilization assessments have shown a consistent decline for most interventional techniques, with a 18.7% decrease from 2019 to 2020. The causes for these dynamic changes are multifactorial likely including the misapplication of the 2016 Centers for Disease Control and Prevention (CDC) guidelines for prescribing opioids for chronic pain, the relative ease of access to illicit synthetic opioids and more recently issues related to the COVID-19 pandemic. In addition, recent publications have shown association of dose tapering with overdose or mental health crisis among patients prescribed long-term opioids. These findings are leading to the hypothesis that federal guidelines may inadvertently be contributing to an increase in overall opioid deaths and diminished access to interventional techniques. Together, these have resulted in a fourth wave of the opioid epidemic.

Chronic back pain (CBP) is a common symptom throughout the world, and those undergoing it often experience a profound degradation of life. Despite extensive research, it remains an elusive symptom. In most cases, CBP is "non-specific," since bio-mechanisms examined in the clinic do not account for it; another way of saying this is that it is "of obscure origins." This paper re-directs attention towards origins that are distal and usually out of sight from the vantage point of the clinic. CBP as considered here is non-specific, persists ≥ 3 months, and, additionally, interferes with activities of daily life, such as family interaction or work. A theory proposed in the paper draws upon Durkheim's to explain exposures in the distal social contexts of family and workplace are fundamentally implicated in CBP. The theory is formed out of previously published studies on family and workplace social contexts of CBP and, in effect, provides a theoretical framework with which to review them. After treatment of CBP in the clinic, patients return to family and workplace contexts. Unless exposures in these contexts are addressed, they serve as continually renewing sources of CBP that remain unabated regardless of mechanism-based treatment in the clinic.

Cluster headache is the most common primary headache disorder of the trigeminal autonomic cephalalgias, and it is highly disabling.