Current pain and headache reports
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Occipital neuralgia is a painful condition that affects the posterior aspect of the head and can be difficult to distinguish from other common forms of headaches. This article reviews the anatomy, pathophysiology, clinical presentation, differential diagnosis, diagnostic testing, and management approaches for occipital neuralgia. ⋯ Non-pharmacological treatments aim to alleviate muscle tension and improve posture. Acupuncture shows some promise. The occipital nerve block is considered the first line in a minimally invasive intervention, but the duration of relief may be short term. An onabotulinum toxin A injection may improve the sharp but not the dull component of the pain of occipital neuralgia. Radiofrequency ablation and occipital nerve stimulation may provide effective long-term relief in refractory patients. Surgical decompression, neurotomies, and neurolysis are last-resort treatment options. Occipital neuralgia is a debilitating condition that can be difficult to treat. Studies with larger sample sizes and randomized control trials are needed to further determine the effectiveness and safety of different therapies.
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Curr Pain Headache Rep · Jul 2021
ReviewKetamine in the Past, Present, and Future: Mechanisms, Metabolites, and Toxicity.
While ketamine's analgesia has mostly been attributed to antagonism of N-methyl-D-aspartate receptors, evidence suggests multiple other pathways are involved in its antidepressant and possibly analgesic activity. These mechanisms and ketamine's role in the nociplastic pain paradigm are discussed. Animal studies demonstrating ketamine's neurotoxicity have unclear human translatability and findings from key rodent and human studies are presented. ⋯ Ketamine's metabolites, and (2R,6R)-hydroxynorketamine in particular, may play a greater role in its clinical activity than previously believed. The activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and the mammalian target of rapamycin by ketamine are mechanisms that are still being elucidated. Ketamine might work best in nociplastic pain, which involves altered pain processing. While much is known about ketamine, new studies will continue to define its role in clinical medicine. Evidence supporting ketamine's neurotoxicity in humans is lacking and should not impede future ketamine clinical trials.
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It was reported that migraine was associated with increased vascular risks, and the association between high blood pressure (BP) and migraine was believed by some to be the missing link. The current review focused on the associations between migraine and hypertension and BP per se, and evidence on the directionality of the associations was also reviewed. ⋯ In cross-sectional studies, the findings regarding whether migraine was associated with hypertension were inconsistent, and positive, neutral, or even inverse associations were reported. When individual BP parameters were examined separately, migraine was associated with higher diastolic BPs, and perhaps lower pulse pressures, although the associations with systolic BPs were incongruent. When studies mainly recruiting elderly patients are excluded, it appeared that studies reporting a positive association between migraine and high BPs, particularly high diastolic BPs, outnumbered those with an inverse or neutral association. In longitudinal studies, there was evidence that migraine patients were at increased risks of developing hypertension at follow-up. However, studies examining whether high BP could predict new-onset migraine yielded conflicting results. The association between migraine and hypertension is still a controversial issue, and a firm conclusion is precluded by the heterogeneities in methodologies and study populations. Migraine patients are at increased risk of developing hypertension. However, whether hypertension predicts migraine remains inconclusive. Further studies are needed to clarify the complicated association between BP and migraine.
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Curr Pain Headache Rep · Jul 2021
ReviewTemperature-Mediated Nerve Blocks in the Treatment of Pain.
Analgesic hot and cold temperatures have been used for both conservative and ablative therapies for millennia. There are well-known locoregional neurovascular changes associated with the application of heat or ice in the literature and in practice. The oscillation between heat and cold has recently been identified as a synergistic mechanism of action with early translational results in humans. ⋯ Recent mechanistic work in the feline model has demonstrated that a reliable, reversible nerve block can be achieved within a temperature range that is non-destructive (15-45°C). The underlying mechanism is a newly described hysteresis in the responsiveness of peripheral nerves to alternating thermal stimuli resulting in nerve blockade. Recently presented feasibility data reports positive results in subjects with occipital pain and peripheral scar pain in terms of pain and associated symptom improvement. Temperature-mediated changes in pain and sensation have been observed for hot and cold applications at a variety of temperatures. Recent insights into the synergy between preheating followed by cooling resulting in peripheral nerve fiber block has potential in a variety of conditions in which peripheral nerve etiology is noted. Recent findings in chronic headache patients report decreased pain and symptom improvement. Further studies are ongoing to understand the indications for this novel therapy.
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Chronic pain is highly prevalent in patients with rheumatoid arthritis (RA) and can cause various physical and psychological impairments. Unfortunately, the appropriate diagnosis of chronic pain syndromes in this population can be challenging because pain may be primary to RA-specific inflammation and/or secondary to other conditions, typically osteoarthritis (OA) and fibromyalgia (FM). This disparity further poses a clinical challenge, given that chronic pain can often be discordant or undetected with standard RA-specific surveillance strategies, including serological markers and imaging studies. In this review, we provide a robust exploration of chronic pain in the RA population with emphasis on epidemiology, mechanisms, and management strategies. ⋯ Chronic pain associated with RA typically occurs in patients with anxiety, female sex, and elevated inflammatory status. Up to 50% of these patients are thought to have chronic pain despite appropriate inflammatory suppression, typically due to peripheral and central sensitization as well as secondary OA and FM. In addition to the standard-of-care management for OA and FM, patients with RA and chronic pain benefit from behavioral and psychological treatment options. Moreover, early and multimodal therapies, including non-pharmacological, pharmacological, interventional, and surgical strategies, exist, albeit with varying efficacy, to help suppress inflammation, provide necessary analgesia, and optimize functional outcomes. Overall, chronic pain in RA is a difficult entity for both patients and providers. Early diagnosis, improved understanding of its mechanisms, and initiation of early, targeted approaches to pain control may help to improve outcomes in this population.