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Increased pain and sensory hyperinnervation of the ligamentum flavum in patients with lumbar spinal stenosis.

Nociceptive sensory nerve fibers have never been investigated in the ligamentum flavum (LF) of patients with LSS. The aim was to analyze nociceptive sensory nerve fibers in the ligamentum flavum (LF) of patients with LSS. A prospective study in patients with lumbar spinal stenosis (LSS) undergoing invasive surgical treatment for lumbar spinal stenosis (LSS) with flavectomy was performed. Patients with LSS were subjected to flavectomy and density of sensory and sympathetic nerve fibers, macrophages, vessels, activated fibroblasts, and cells were investigated by immunostaining techniques. A group of patients with acute disc herniation served as control group. We found a higher density of sensory nerve fibers in LSS patients versus controls. These findings support the role of LF in associated low back pain. Density of sensory nerve fibers in LSS, was positively correlated with typical markers of clinical pain and functional disability, but not with LF density of activated fibroblasts. Inflammation as estimated by macrophage infiltration and higher vascularity does not play a marked role in LF in our LSS patients. In the present study, compared to men with LSS, women with LSS demonstrate more pain and depression, and show a higher density of sensory nerve fibers in LF. This study shed new light on nociceptive nerve fibers, which are increased in LSS compared to controls. The findings speak against a strong inflammatory component in LSS. A higher pain levels in women compared to men can be explained by a higher density of nociceptive nerve fibers. This article is protected by copyright. All rights reserved.

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Premedication With Gabapentin Significantly Reduces the Risk of Postherpetic Neuralgia in Patients With Neuropathy.

Postherpetic neuralgia (PHN) is the most common complication of varicella zoster virus (VZV) reactivation and a cause of considerable physical and psychosocial morbidity. No known treatment effectively prevents the development of PHN in patients with VZV reactivation. In this study, our objective was to evaluate the efficacy of premedication with gabapentin for reducing the risk of PHN in patients with diabetic and nondiabetic neuropathy. We retrospectively searched the electronic health records of patients with diabetic and nondiabetic neuropathy treated with gabapentin at Mayo Clinic before diagnosis of VZV reactivation. In total, PHN developed in 7 patients with diabetic neuropathy receiving gabapentin (n=62 [11.3%]) compared with 26 not receiving premedication with gabapentin (n=50 [52.0%]) (odds ratio, 0.12; 95% CI, 0.05-0.31; P<.001); PHN developed in 11 patients with nondiabetic neuropathy receiving gabapentin (n=109 [10.1%]) compared with 108 not receiving premedication with gabapentin (n=217 [49.8%]) (odds ratio, 0.11; 95% CI, 0.06-0.22; P<.001). In this cohort of patients with neuropathy, gabapentin administration before the onset of VZV reactivation significantly reduced the risk of PHN.

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Abnormal visuo-vestibular interactions in vestibular migraine: a cross sectional study.

Vestibular migraine is among the commonest causes of episodic vertigo. Chronically, patients with vestibular migraine develop abnormal responsiveness to both vestibular and visual stimuli characterized by heightened self-motion sensitivity and visually-induced dizziness. Yet, the neural mechanisms mediating such symptoms remain unknown. We postulate that such symptoms are attributable to impaired visuo-vestibular cortical interactions, which in turn disrupts normal vestibular function. To assess this, we investigated whether prolonged, full-field visual motion exposure, which has been previously shown to modulate visual cortical excitability in both healthy individuals and avestibular patients, could disrupt vestibular ocular reflex and vestibular-perceptual thresholds of self-motion during rotations. Our findings reveal that vestibular migraine patients exhibited abnormally elevated reflexive and perceptual vestibular thresholds at baseline. Following visual motion exposure, both reflex and perceptual thresholds were significantly further increased in vestibular migraine patients relative to healthy controls, migraineurs without vestibular symptoms and patients with episodic vertigo due to a peripheral inner-ear disorder. Our results provide support for the notion of altered visuo-vestibular cortical interactions in vestibular migraine, as evidenced by vestibular threshold elevation following visual motion exposure.

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Analysis of HCRTR2 Gene Variants and Cluster Headache in Sweden.

The purpose of this study was to investigate the HCRTR2 gene variants rs3122156, rs2653342, and rs2653349 in a large homogenous Swedish case-control cohort in order to further evaluate the possible contribution of HCRTR2 to cluster headache.

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Care Coordination for Patients on Chronic Opioid Therapy Following Surgery: A Cohort Study.

MINI: This study sought to examine if early care-coordination between a patient's surgeon and usual prescriber of long-term opioid therapy could mitigate high-risk opioid prescribing following surgery. In this national cohort, 74.3% of chronic opioid users were exposed to episodes of high risk prescribing following surgery. Having a usual preoperative opioid prescriber and visiting this prescriber within 30 days after surgery was associated with decreased odds of having multiple prescribers in the postoperative period.

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Prognostic ability of the German version of the STarT Back tool: analysis of 12-month follow-up data from a randomized controlled trial.

Stratified care is an up-to-date treatment approach suggested for patients with back pain in several guidelines. A comprehensively studied stratification instrument is the STarT Back Tool (SBT). It was developed to stratify patients with back pain into three subgroups, according to their risk of persistent disabling symptoms. The primary aim was to analyse the disability differences in patients with back pain 12 months after inclusion according to the subgroups determined at baseline using the German version of the SBT (STarT-G). Moreover, the potential to improve prognosis for disability by adding further predictor variables, an analysis for differences in pain intensity according to the STarT-Classification, and discriminative ability were investigated.

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Efficacy and safety of a monthly buprenorphine depot injection for opioid use disorder: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

RBP-6000, referred to as BUP-XR (extended-release buprenorphine), is a subcutaneously injected, monthly buprenorphine treatment for opioid use disorder. BUP-XR provides sustained buprenorphine plasma concentrations to block drug-liking of abused opioids over the entire monthly dosing period, while controlling withdrawal and craving symptoms. Administration of BUP-XR in a health-care setting also mitigates abuse, misuse, diversion, and unintentional exposure. We aimed to investigate the efficacy of different BUP-XR dosing regimens in participants with opioid use disorder.

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Geographical Differences in Trigger Factors of Tension-Type Headaches and Migraines.

In this review, we discussed the types and frequencies of trigger factors of primary headache [migraine and tension-type headache (TTH)] among adult patients. We assessed the influence of geographical location, ethnicity and gender on the various trigger factors of a migraine and a TTH. We also evaluated the trigger factors among the multi-ethnic Southeast Asian adult patients. In a recent study, odor triggered more migrainous headaches compared to the other primary headaches. Odor was observed to be specific of migraines. Moreover, stress is one of the most common trigger factors for patients with migraines and TTHs worldwide. Migrainous patients have an increased sensitivity in comparison to non-migrainous patients. Furthermore, these patients have much difficulty in adapting to the high level of sensitivity, and the sensitized brain is therefore more vulnerable to trigger factors. In addition, the presence of one trigger factor may increase the exposure of other trigger factors. This phenomenon is more marked in the patients with migraines who have stress and menstruation as triggers, predisposing them to be more sensitive to other triggers. In conclusion, the geographical location factor has an influence on the trigger factors of headaches. Ethnicity may have an effect due to the cultural differences. Change in weather and sunlight are important commonly identified trigger factors for headaches. Moreover, gender differences in some trigger factors are present among the patients with headaches, especially sunlight and sleep deprivation. More research studies can be conducted to have a better understanding on trigger factors in the future. This will enable proper identification of trigger factors, leading to a decrease in the number of headache episodes and an improvement in quality of life for patients.

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Assessment of the FDA Risk Evaluation and Mitigation Strategy for Transmucosal Immediate-Release Fentanyl Products.

Transmucosal immediate-release fentanyls (TIRFs), indicated solely for breakthrough cancer pain in opioid-tolerant patients, are subject to a US Food and Drug Administration (FDA) Risk Evaluation and Mitigation Strategy (REMS) to prevent them from being prescribed inappropriately.

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Persistent autonomic dysfunction and bladder sensitivity in primary dysmenorrhea.

Menstrual pain, also known as dysmenorrhea, is a leading risk factor for bladder pain syndrome (BPS). A better understanding of the mechanisms that predispose dysmenorrheic women to BPS is needed to develop prophylactic strategies. Abnormal autonomic regulation, a key factor implicated in BPS and chronic pain, has not been adequately characterized in women with dysmenorrhea. Thus, we examined heart rate variability (HRV) in healthy (n = 34), dysmenorrheic (n = 103), and BPS participants (n = 23) in their luteal phase across a bladder-filling task. Both dysmenorrheic and BPS participants reported increased bladder pain sensitivity when compared to controls (p's < 0.001). Similarly, dysmenorrheic and BPS participants had increased heart rate (p's < 0.01), increased diastolic blood pressure (p's < 0.01), and reduced HRV (p's < 0.05) when compared to controls. Dysmenorrheic participants also exhibited little change in heart rate between maximum bladder capacity and after micturition when compared to controls (p = 0.013). Our findings demonstrate menstrual pain's association with abnormal autonomic activity and bladder sensitivity, even two weeks after menses. Our findings of autonomic dysfunction in both early episodic and chronic visceral pain states points to an urgent need to elucidate the development of such imbalance, perhaps beginning in adolescence.

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