Articles: neuropathic-pain.
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Conflicting data regarding the efficacy of high-frequency spinal cord stimulation (HF SCS) has prompted the issue of the possible importance of the shape of the stimulating pulses. The aim of this pilot study was to compare HF SCS applied with monophasic and biphasic pulses of two different durations with conventional SCS in a rat model of neuropathic pain. ⋯ There is no significant difference in efficacy between HF SCS applied with low amplitude ("subparesthetic") monophasic and biphasic pulses. However, short PWs providing only 12 μsec of cathodal stimulation was ineffective, presumably because of insufficient electric charge transfer from the lead contacts to the nervous tissue.
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Trigeminal neuralgia is accompanied by severe mechanical, thermal and chemical hypersensitivity of the orofacial area innervated by neurons of trigeminal ganglion (TG). We examined the role of the voltage-gated sodium channel subtype Nav1.9 in the development of trigeminal neuralgia. ⋯ These results demonstrate that Nav1.9 channels play a critical role in the development of orofacial neuropathic pain. New routes for the treatment of orofacial neuropathic pain focussing on regulation of the voltage-gated Nav1.9 sodium channel activity should be investigated.
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Sanguis draxonis (SD) is a kind of red resin obtained from the wood of Dracaena cochinchinensis (Lour.) S. C. Chen (D. cochinchinensis). The active components of total flavonoids from SD (SDF) have analgesic effect. ⋯ SDF has potentially reduced mechanical hypersensitivity induced by SNI model of neuropathic pain which may be attributed to inhibition of astrocytic function (like release pro-inflammatory cytokines) and NO release as well as p-CREB activation in the spinal dorsal horn.
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The pharmacological management of chronic pain is a major therapeutic problem. The need of repeated treatments reduces the usefulness of classical analgesic drugs, like μ opioid receptor (MOP) agonists, characterized by tolerance development, side effects and abuse. Moreover, the pathological persistence of pain modifies nociceptive signals and pain-devoted structure activity weakening MOP agonists and making difficult the research of new active molecules. ⋯ The pain reliever efficacy of NOP agonists against persistent pain, mainly neuropathic pain, has been highlighted after intrathecal infusions in rats and non human primates (NHPs). The differences emerged between the effects of NOP stimulation in rodents and NHPs allow to hypothesize the relevance of NOP modulators in higher organisms strongly encouraging the development of compounds active by a systemic route. Possible applicative perspectives are (i) selective NOP agonists as such, (ii) NOP modulation as adjuvant of MOP-based treatments, or (iii) mixed non-selective agonists vs NOP and classical opioid receptors.