Articles: neuralgia.
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Nerve injury can lead to ectopic activation of injured nociceptorsand central sensitization characterized by allodynia and hyperalgesia. Reduction in the activity of primary afferent neurons has been shown to be sufficient in alleviating peripherally generated pain. The cell bodies of such trigeminal nociceptors are located in the trigeminal ganglia (TG) with central processes that terminate in the brainstem trigeminal nucleus caudalis (TNC). The TG is therefore a strategic locus where afferent input can be manipulated. We hypothesized that chemogenetic inhibition of TG would suppress TNC neuronal activity and attenuate pain behaviour in a rat model of painful traumatic trigeminal neuropathy (PTTN). ⋯ Trigeminal neuropathic pain is highly resistant to therapy and we are in dire need of novel approaches. This study provides further evidence for the successful application of DREADDs as an effective tool for modulating central nervous system function. CNO mediated activation of hM4Di-DREADDs in the trigeminal ganglion (TG) attenuates nerve injury induced neuropathic pain by acting on hyperactive TG cells. It also establishes the TG as an effective target to manage pain in the face and head. Accessing the TG in clinical populations is a relatively simple and safe procedure, making this approach highly significant. Moreover, the methodology described here has applications in trigeminal neuropathic pain from traumatic other etiologies and in spinal neuropathic pain. Chronic pain syndromes are characterized by a progressive failure of brain centers to adequately inhibit pain and as these are identified, we may be able to target them for therapy. Therefore, our findings might have wide application in chronic pain syndromes.
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Neuropathic pain research and clinical care is limited in low- and middle-income countries with high prevalence of chronic pain such as Nepal. We translated and cross-culturally adapted the Self-report version of the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS)-a commonly used, reliable and valid instrument to screen for pain of predominantly neuropathic origin (POPNO)-into Nepali (S-LANSS-NP) and validated it using recommended guidelines. We recruited 30 patients with chronic pain in an outpatient setting for cognitive debriefing and recruited 287 individuals with chronic pain via door-to-door interviews for validation. ⋯ The S-LANSS-NP is a comprehensible, unidimensional, internally consistent, and valid instrument to screen POPNO in individuals with chronic pain with predominantly low-levels of literacy for clinical and research use. PERSPECTIVE: This paper shows that the Nepali version of the S-LANSS is comprehensible, reliable and valid in adults with chronic pain and predominantly low-levels of literacy in rural Nepal. The study could potentially develop research and clinical care of neuropathic pain in this resource-limited setting where chronic pain is a significant problem.