Articles: hyperalgesia.
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Review Meta Analysis
Systematic review and co-ordinate based meta-analysis to summarize the utilization of functional brain imaging in conjunction with human models of peripheral and central sensitization.
Functional magnetic resonance imaging, in conjunction with models of peripheral and/or central sensitization, has been used to assess analgesic efficacy in healthy humans. This review aims to summarize the use of these techniques to characterize brain mechanisms of hyperalgesia/allodynia and to evaluate the efficacy of analgesics. ⋯ Experimental pain models that provide a surrogate for features of pathological pain conditions in healthy humans and functional imaging techniques are both highly valuable research tools. This review shows that when used together, they provide a wealth of information about brain activity during pain states and analgesia. These tools are promising candidates to help bridge the gap between animal and human studies, to improve translatability and provide opportunities for identification of new targets for back-translation to animal studies.
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Curr Opin Anaesthesiol · Aug 2024
ReviewRemifentanil-induced hyperalgesia: the current state of affairs.
Remifentanil-induced hyperalgesia (RIH) is a part of a general opioid-induced hyperalgesia (OIH) syndrome, seemingly resulting from abrupt cessation of continuous remifentanil infusion at rates equal or exceeding 0.3 mcg/kg/min. The intricate mechanisms of its development are still not completely understood. ⋯ Several ways of prevention and management have been suggested, such as slow withdrawal of remifentanil infusion, the addition of propofol, pretreatment with or concomitant administration of ketamine, buprenorphine, cyclooxygenase-2 inhibitors (NSAIDs), methadone, dexmedetomidine. In clinical and animal studies, these strategies exhibited varying success, and many are still being investigated.
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Secreted microRNAs (miRNAs) have been detected in various body fluids including the cerebrospinal fluid, yet their direct role in regulating synaptic transmission remains uncertain. We found that intrathecal injection of low dose of let-7b (1 μg) induced short-term (<24 hours) mechanical allodynia and heat hyperalgesia, a response that is compromised in Tlr7-/- or Trpa1-/- mice. Ex vivo and in vivo calcium imaging in GCaMP6-report mice revealed increased calcium signal in spinal cord afferent terminals and doral root ganglion/dorsal root ganglia neurons following spinal perfusion and intraplantar injection of let-7b. ⋯ The high dose of let-7b also induced microgliosis in the spinal cord. Of interest, intrathecal minocycline only inhibited let-7b-induced mechanical allodynia in male but not female mice. Our findings indicate that the secreted microRNA let-7b has the capacity to provoke pain through both neuronal and glial signaling, thereby establishing miRNA as an emerging neuromodulator.
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Peripheral neuropathic pain is a result of damage/illness of the peripheral nerves. The mechanisms caused by its pathophysiology are not completely understood. ⋯ Therefore, it can be concluded that citicoline (as an adjuvant substance) enhanced the efficacy of imipramine for the modulation of pain behavior in nerve-ligated mice.
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Review Meta Analysis
SOMATOSENSORY PROFILING OF PATIENTS WITH CLUSTER HEADACHE: A SYSTEMATIC REVIEW AND META-ANALYSIS.
The objectives were 1) to synthesize quantitative sensory testing results in cluster headache (CH) patients and to identify somatosensory differences from healthy subjects (HS), and 2) between symptomatic and asymptomatic sides in CH patients. Two independent reviewers conducted a literature search in MEDLINE, EMBASE, Web of Science, and CINAHL databases. Studies with observational designs were included. ⋯ These results are of clinical relevance because their presence could be associated with a poorer prognosis, chronification, and treatment response. PERSPECTIVE: This study provides consistent findings on the somatosensory profile characterizing patients with CH. Clinicians should assess PPTs and other quantitative sensory testing variables in the trigeminal and extratrigeminal (cervical) regions.