Millions of people are affected by pain-related conditions worldwide. Literature has consistently shown that each individual experiences and perceives pain in a unique manner due to biological, environmental, and cultural factors in which they have been raised. It has been established that biological males and females perceive pain differently and that it may be partially explained by their distinct hormonal profiles since birth, which are only further magnified during puberty. For biological males, high levels of testosterone have shown to increase their pain threshold; and for biological females, estrogen fluctuations have shown to increase pain intensity and perception. However, sex hormones have not been studied in the context of pain treatment or their impact on biochemical pathways involved in pain perception. For this purpose, the transgender community serves as a unique population to investigate the impact of hormone replacement therapy on molecular pathways involved in the perception of pain. The purpose of this review is to explore the biochemistry of hormone replacement in transgender patients who also have other pain-related conditions such as headaches, fibromyalgia, temporomandibular myalgia, and visceral pain.

Ovarian hormones play an important role in pain perception, and are responsible, at least in part, for the pain threshold differences between the sexes. Modulation of pain and its perception are mediated by neurochemical changes in several pathways, affecting both the central and peripheral nervous systems. One of the most studied neurotransmitters related to pain disorders is serotonin. Estrogen can modify serotonin synthesis and metabolism, promoting a general increase in its tonic effects. Studies evaluating the relationship between serotonin and disorders such as irritable bowel syndrome, fibromyalgia, migraine, and other types of headache suggest a clear impact of this neurotransmitter, thereby increasing the interest in serotonin as a possible future therapeutic target. This literature review describes the importance of substances such as serotonin and ovarian hormones in pain perception and illustrates the relationship between those two, and their direct influence on the presentation of the aforementioned pain-related conditions. Additionally, we review the pathways and receptors implicated in each disorder. Finally, the objective was to stimulate future pharmacological research to experimentally evaluate the potential of serotonin modulators and ovarian hormones as therapeutic agents to regulate pain in specific subpopulations.

Background: Multimodal analgesia is a fundamental part of modern surgery and enhanced recovery pathways. Duloxetine, a serotonin and norepinephrine reuptake inhibitor, has been validated for the treatment of chronic neuropathic pain. The evidence for duloxetine as an adjunct for the treatment of acute postoperative pain remains controversial. We conducted a meta-analysis to determine the efficacy of duloxetine in the acute perioperative setting.Methods: A literature search was conducted in the major databases (PubMed, EMBASE and Google Scholar) for randomized controlled trials (RCTs) evaluating duloxetine compared with placebo control for acute postoperative pain. The primary outcome was postoperative pain assessed at 2, 4, 6, 24 and 48 hours time frames. Secondary outcomes included postoperative opioid administration, as well as side effects, such as postoperative nausea/vomiting (PONV), pruritus, dizziness and headache.Results: 574 patients (n=9 RCTs) were included in the analysis, divided between duloxetine (n=285 patients) and placebo (n=289 patients). Duloxetine use was associated with a significant reduction in pain scores as early as 4 (mean difference (MD) −0.9, 95% CI −1.33 to −0.47) and as late as 48 (MD −0.94, 95% CI −1.56 to −0.33) hours postoperatively compared with placebo. In addition, duloxetine was associated with a significant reduction in opioid administration at 24 (standardized MD (SMD) −2.24, 95% CI −4.28 to −0.19) and 48 (SMD −2.21, 95% CI −4.13 to −0.28) hours as well as a significant reduction in PONV (risk ratio 0.69, 95% CI 0.49 to 0.95, p=0.03) compared with placebo. There was no difference between groups in other side effects.Conclusion: Duloxetine, a non-opioid neuromodulator, may provide efficacy for the treatment of acute perioperative pain. Additional prospective studies are required to establish optimal perioperative dosing regimens, role in the setting of a comprehensive multimodal analgesic plan and impact on chronic postsurgical pain.PROSPERO registration number: CRD42019121416

The purpose of this paper is to report a rare case of a pediatric pineal gliosarcoma. Gliomas on the pineal region are uncommon, representing 0.4%-1% of all brain tumors. Furthermore, pediatric gliosarcomas are a very rare entity. We present a case of a 5-year-old girl, with a history of headache, vomiting, diplopia, and gait disturbances. A pineal tumor was found with pathology results consistent with a gliosarcoma. A total of 25 cases of pediatric gliosarcomas have been reported, none of them in pineal topography. Only 3 gliosarcomas were found in the pineal region, but these were found in adults. To our knowledge, this is the first pediatric pineal gliosarcoma reported in the literature.

Introduction: Heart transplant recipients present unique perioperative challenges for surgery. Specifically, autonomic system denervation has significant implications for commonly used perioperative drugs. This study investigates neuromuscular blocking antagonists in this population when undergoing subsequent non-cardiac surgery.Material and methods: A retrospective review was performed for the period 2015–2019 across our health care enterprise. Patients with previous orthotopic heart transplant and subsequent non-cardiac surgery were identified. A total of 185 patients were found, 67 receiving neostigmine (NEO) and 118 receiving sugammadex (SGX). Information of patient characteristics, prior heart transplant, and subsequent non-cardiac surgery was collected. Our primary outcome was the incidence of bradycardia (heart rate < 60 bpm) and/or hypotension (mean blood pressure (MAP) < 65 mmHg) following neuromuscular blockade reversal. Secondary outcomes included need of intra-operative inotropic agents, arrhythmia, cardiac arrest, hospital length of stay (hLOS), ICU admission, and death within 30 postoperative days.Results: In unadjusted analysis, no significant differences were found between the two groups in change in heart rate [0 (–26, 14) vs. 1 (–19, 10), P = 0.59], change in MAP [0 (–22, 28) vs. 0 (–40, 47), P = 0.96], hLOS [2 days (1, 72) vs. 2 (0, 161), P = 0.92], or intraoperative hypotension [4 (6.0%) vs. 5 (4.2%), OR = 0.70, P = 0.60] for NEO and SGX respectively. After multivariable analysis, the results were similar for change in heart rate (P = 0.59) and MAP (P = 0.90).Conclusions: No significant differences in the incidence of bradycardia and hypotension were found in the NEO versus SGX groups. NEO and SGX may have similar safety profiles in patients with prior heart transplant undergoing non-cardiac surgery.