The glossopharyngeal nerve (IX cranial nerve pair): anatomical considerations and neuralgia: literature review / O nervo glossofaringeo (IX par de nervo craniano): considerações anatômicas e neuralgia: revisão da literatura

The glossopharyngeal nerve (IX cranial nerve) is a mixed nerve, with both motor and sensory function. This relates to the tongue and pharynx. Glossopharyngeal neuralgia is a rare nervous neuropathy, with poristic, lancinating and paritary crises, usually unilateral. The aim of the study was to review the literature on glossopharyngeal neuralgia of the nerve (IX cranial nerve), highlighting the anatomical aspects of this nerve and the possible causes and complications of neuralgia as well as forms of treatment. A literature review was carried out in the international Pubmed database. The literature review included 72 articles from 2015 to 2021. The keywords used were: "anatomy of glossopharyngeal neuralgia". Of the 72 articles, 7 were used for this literature review. Uncommon as nervous/glossophingeal etiologies and pathologies are neurological abnormalities/neurovarises and pathologies are neurovascular/neurovariseal lesions. Pharmacological treatment approaches mentioned in the literature were therapy with antiepileptics and antidepressants such as carbamazepine and gabapentin; a microvascular decompression; and gamma knife radiosurgery(AU)

O nervo glossofaríngeo (IX par de nervo craniano) é um nervo misto, contendo função tanto motora como sensitiva. Este nervo relaciona-se com a língua e com a faringe. A neuralgia do nervo glossofaríngeo é uma neurapatia rara, sendo caracterizada por crises dolorosas, lancinantes e paroxísticas, geralmente unilaterais. O objetivo do estudo foi realizar uma revisão de literatura sobre a neuralgia do nervo glossofaríngeo (IX par de nervo craniano), destacando os aspectos anatômicos deste nervo e as possíveis causas e complicações da neuralgia bem como formas de tratamento. Foi realizada uma revisão da literatura na base de dados internacional Pubmed. A revisão da literatura incluiu 72 artigos no período de 2015 a 2021. As palavras-chave utilizadas foram: "anatomia da neuralgia do glossofaríngeo". Dos 72 artigos, 7 foram utilizados para esta revisão de literatura. Verificouse que a neuralgia do nervo glossofaríngeo é incomum e as etiologias mais encontradas foram compressão neurovascular/variações vasculares, patologias e traumas. As abordagens dos tratamentos mencionadas na literatura foram a terapia farmacológica da área com antiepilépticos e antidepressivos, como carbamazepina e gabapentina; a descompressão microvascular; e radiocirurgia com faca gama(AU)

Prevalence of Neuropathic Pain in Patients with Osteoarthritis / Prevalência de dor neuropática em pacientes com osteoartrite

Abstract Objective The aim of this study was to determine the prevalence of neuropathic pain and characterize the quality of life of patients with osteoarthritis who consulted a pain clinic in Southwestern Colombia. Methods A cross-sectional study was conducted via telephone survey. Participants ≥18 years of age with a diagnosis of osteoarthritis were included. The LANSS questionnaire was used to evaluate symptoms and signs of neuropathic pain, and the Short Form-8 was used to evaluate quality of life. Results Response rate was 54.1% (46/85). The male-to-female ratio was 5:1, with an average age of 72 ±10 years. Most participants (91.3%) had severe pain. The prevalence of neuropathic pain was 28.3% (95%CI = 15.99-43.46), and the prevalence of neuropathic pain amongst women was 84.6% (95%CI = 54.55-98.01 ). Dysesthesias and paroxysmal pain were present in 92.3% of individuals with neuropathic pain. Regarding quality of life, limitations in physical activity were the most significant, as 63% of individuals reported such limitations. Conclusion Neuropathic pain was found to be prevalent and had a negative impact on physical function, highlighting the need for therapeutic strategies targeted to specific neuropathic pain pathways in patients with osteoarthritis.

Resumo Objetivo O objetivo deste estudo foi determinar a prevalência de dor neuropática e caracterizar a qualidade de vida de pacientes com osteoartrite que consultaram um ambulatório de dor no sudoeste da Colômbia. Métodos Este foi um estudo transversal realizado por meio de entrevista telefônica. Foram incluídos participantes ≥18 anos de idade com diagnóstico de osteoartrite. O questionário Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) foi utilizado para avaliação dos sintomas e sinais de dor neuropática e o Short Form-8 analisou a qualidade de vida. Resultados A taxa de resposta foi de 54,1% (46/85). A razão homem:mulher foi de 5:1, com média de idade de 72 ±10 anos. A maioria dos participantes (91,3%) apresentava dor intensa. A prevalência de dor neuropática foi de 28,3% (intervalo de confiança [IC] de 95% = 15,99-43,46) e a prevalência de dor neuropática entre mulheres foi de 84,6% (IC 95% = 54,55-98,01). Disestesias e dor paroxística foram relatadas por 92,3% dos indivíduos com dor neuropática. Em relação à qualidade de vida, as limitações na prática de atividade física foram as mais significativas e relatadas por 63% dos indivíduos. Conclusão A dor neuropática foi prevalente e tinha impacto negativo na função física. Isso destaca a necessidade de estratégias terapêuticas direcionadas a vias específicas da dor neuropática em pacientes com osteoartrite.

Treadmill exercise alleviates neuropathic pain by regulating mitophagy of the anterior cingulate cortex in rats / 生理学报

This study aimed to investigate the effect of treadmill exercise on neuropathic pain and to determine whether mitophagy of the anterior cingulate cortex (ACC) contributes to exercise-mediated amelioration of neuropathic pain. Chronic constriction injury of the sciatic nerve (CCI) was used to establish a neuropathic pain model in Sprague-Dawley (SD) rats. Von-Frey filaments were used to assess the mechanical paw withdrawal threshold (PWT), and a thermal radiation meter was used to assess the thermal paw withdrawal latency (PWL) in rats. qPCR was used to evaluate the mRNA levels of Pink1, Parkin, Fundc1, and Bnip3. Western blot was used to evaluate the protein levels of PINK1 and PARKIN. To determine the impact of the mitophagy inducer carbonyl cyanide m-chlorophenylhydrazone (CCCP) on pain behaviors in CCI rats, 24 SD rats were randomly divided into CCI drug control group (CCI+Veh group), CCI+CCCP low-dose group (CCI+CCCP0.25), CCI+CCCP medium-dose group (CCI+CCCP2.5), and CCI+CCCP high-dose group (CCI+CCCP5). Pain behaviors were assessed on 0, 1, 3, 5, and 7 days after modeling. To explore whether exercise regulates pain through mitophagy, 24 SD rats were divided into sham, CCI, and CCI+Exercise (CCI+Exe) groups. The rats in the CCI+Exe group underwent 4-week low-moderate treadmill training one week after modeling. The mechanical pain and thermal pain behaviors of the rats in each group were assessed on 0, 7, 14, 21, and 35 days after modeling. Western blot was used to detect the levels of the mitophagy-related proteins PINK1, PARKIN, LC3 II/LC3 I, and P62 in ACC tissues. Transmission electron microscopy was used to observe the ultrastructure of mitochondrial morphology in the ACC. The results showed that: (1) Compared with the sham group, the pain thresholds of the ipsilateral side of the CCI group decreased significantly (P < 0.001). Meanwhile, the mRNA and protein levels of Pink1 were significantly higher, and those of Parkin were lower in the CCI group (P < 0.05). (2) Compared with the CCI+Veh group, each CCCP-dose group showed higher mechanical and thermal pain thresholds, and the levels of PINK1 and LC3 II/LC3 I were elevated significantly (P < 0.05, P < 0.01). (3) The pain thresholds of the CCI+Exe group increased significantly compared with those of the CCI group after treadmill intervention (P < 0.001, P < 0.01). Compared with the CCI group, the protein levels of PINK1 and P62 were decreased (P < 0.001, P < 0.01), and the protein levels of PARKIN and LC3 II/LC3 I were increased in the CCI+Exe group (P < 0.01, P < 0.05). Rod-shaped mitochondria were observed in the ACC of CCI+Exe group, and there were little mitochondrial fragmentation, swelling, or vacuoles. The results suggest that the mitochondrial PINK1/PARKIN autophagy pathway is blocked in the ACC of neuropathic pain model rats. Treadmill exercise could restore mitochondrial homeostasis and relieve neuropathic pain via the PINK1/PARKIN pathway.

CircFhit Modulates GABAergic Synaptic Transmission via Regulating the Parental Gene Fhit Expression in the Spinal Dorsal Horn in a Rat Model of Neuropathic Pain / 神经科学通报·英文版

Effective treatments for neuropathic pain are lacking due to our limited understanding of the mechanisms. The circRNAs are mainly enriched in the central nervous system. However, their function in various physiological and pathological conditions have yet to be determined. Here, we identified circFhit, an exon-intron circRNA expressed in GABAergic neurons, which reduced the inhibitory synaptic transmission in the spinal dorsal horn to mediate spared nerve injury-induced neuropathic pain. Moreover, we found that circFhit decreased the expression of GAD65 and induced hyperexcitation in NK1R+ neurons by promoting the expression of its parental gene Fhit in cis. Mechanistically, circFhit was directly bound to the intronic region of Fhit, and formed a circFhit/HNRNPK complex to promote Pol II phosphorylation and H2B monoubiquitination by recruiting CDK9 and RNF40 to the Fhit intron. In summary, we revealed that the exon-intron circFhit contributes to GABAergic neuron-mediated NK1R+ neuronal hyperexcitation and neuropathic pain via regulating Fhit in cis.

Netrin-3 Suppresses Diabetic Neuropathic Pain by Gating the Intra-epidermal Sprouting of Sensory Axons / 神经科学通报·英文版

Diabetic neuropathic pain (DNP) is the most common disabling complication of diabetes. Emerging evidence has linked the pathogenesis of DNP to the aberrant sprouting of sensory axons into the epidermal area; however, the underlying molecular events remain poorly understood. Here we found that an axon guidance molecule, Netrin-3 (Ntn-3), was expressed in the sensory neurons of mouse dorsal root ganglia (DRGs), and downregulation of Ntn-3 expression was highly correlated with the severity of DNP in a diabetic mouse model. Genetic ablation of Ntn-3 increased the intra-epidermal sprouting of sensory axons and worsened the DNP in diabetic mice. In contrast, the elevation of Ntn-3 levels in DRGs significantly inhibited the intra-epidermal axon sprouting and alleviated DNP in diabetic mice. In conclusion, our studies identified Ntn-3 as an important regulator of DNP pathogenesis by gating the aberrant sprouting of sensory axons, indicating that Ntn-3 is a potential druggable target for DNP treatment.

Thalamocortical Circuit Controls Neuropathic Pain via Up-regulation of HCN2 in the Ventral Posterolateral Thalamus / 神经科学通报·英文版

The thalamocortical (TC) circuit is closely associated with pain processing. The hyperpolarization-activated cyclic nucleotide-gated (HCN) 2 channel is predominantly expressed in the ventral posterolateral thalamus (VPL) that has been shown to mediate neuropathic pain. However, the role of VPL HCN2 in modulating TC circuit activity is largely unknown. Here, by using optogenetics, neuronal tracing, electrophysiological recordings, and virus knockdown strategies, we showed that the activation of VPL TC neurons potentiates excitatory synaptic transmission to the hindlimb region of the primary somatosensory cortex (S1HL) as well as mechanical hypersensitivity following spared nerve injury (SNI)-induced neuropathic pain in mice. Either pharmacological blockade or virus knockdown of HCN2 (shRNA-Hcn2) in the VPL was sufficient to alleviate SNI-induced hyperalgesia. Moreover, shRNA-Hcn2 decreased the excitability of TC neurons and synaptic transmission of the VPL-S1HL circuit. Together, our studies provide a novel mechanism by which HCN2 enhances the excitability of the TC circuit to facilitate neuropathic pain.

Neuralgia del nervio glosofaríngeo posamigdalectomía: reporte de dos casos / Post-tonsillectomy glossopharyngeal nerve neuralgia: report of two cases

Resumen La amigdalectomía es uno de los procedimientos quirúrgicos más frecuentes que realiza el otorrinolaringólogo. Dentro de las complicaciones posoperatorias, la neuralgia del nervio glosofaríngeo es extremadamente poco frecuente. En este artículo se presentan dos casos clínicos pediátricos con neuralgia del glosofaríngeo posamigdalectomía que fueron resueltos con tratamiento médico.

Abstract Tonsillectomy is one of the most common procedures done by the otolaryngologist. Among post-operative complications, the glossopharyngeal neuralgia is extremely uncommon. This article presents two pediatric clinical cases with post-tonsillectomy glossopharyngeal neuralgia that were resolved with medical treatment.

A3 receptor agonist modulates IL-1ß hippocampus levels in a rat model of neuropathic pain

Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed to evaluate the effect of a single dose of adenosine A3 receptor IB-MECA on inflammatory and neurotrophic parameters in rats subjected to a neuropathic pain model. Methods: 64 adult male Wistar rats were used. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve and the treatment consisted of a 0.5 µmol/kg dose of IB-MECA, a selective A3 adenosine receptor agonist, dissolved in 3% DMSO; vehicle groups received DMSO 3% in saline solution, and morphine groups received 5 mg/kg. Cerebral cortex and hippocampus IL-1ß, BDNF, and NGF levels were determined by Enzyme-Linked Immunosorbent assay. Results: The main outcome was that a single dose of IB-MECA was able to modulate the IL-1ß hippocampal levels in neuropathic pain induced by CCI and the DMSO increased IL-1ß and NGF hippocampal levels in sham-operated rats. However, we did not observe this effect when the DMSO was used as vehicle for IB-MECA, indicating that IB-MECA was able to prevent the effect of DMSO. Conclusions: Considering that the IL-1ß role in neuropathic pain and the contributions of the hippocampus are well explored, our result corroborates the relationship between the A3 receptor and the process of chronic pain maintenance.

Involvement of Opioid Peptides in the Analgesic Effect of Spinal Cord Stimulation in a Rat Model of Neuropathic Pain / 神经科学通报·英文版

Spinal cord stimulation (SCS)-induced analgesia was characterized, and its underlying mechanisms were examined in a spared nerve injury model of neuropathic pain in rats. The analgesic effect of SCS with moderate mechanical hypersensitivity was increased with increasing stimulation intensity between the 20% and 80% motor thresholds. Various frequencies (2, 15, 50, 100, 10000 Hz, and 2/100 Hz dense-dispersed) of SCS were similarly effective. SCS-induced analgesia was maintained without tolerance within 24 h of continuous stimulation. SCS at 2 Hz significantly increased methionine enkephalin content in the cerebrospinal fluid. The analgesic effect of 2 Hz was abolished by μ or κ opioid receptor antagonist. The effect of 100 Hz was prevented by a κ antagonist, and that of 10 kHz was blocked by any of the μ, δ, or κ receptor antagonists, suggesting that the analgesic effect of SCS at different frequencies is mediated by different endorphins and opioid receptors.

Mechanism of emodin in relieving neuropathic pain by regulating serum metabolism / 中国中药杂志

The present study investigated the effect of emodin on the serum metabolite profiles in the chronic constriction injury(CCI) model by non-target metabolomics and explored its analgesic mechanism. Twenty-four Sprague Dawley(SD) rats were randomly divided into a sham group(S), a CCI group(C), and an emodin group(E). The rats in the emodin group were taken emodin via gavage once a day for fifteen days(50 mg·kg~(-1)) on the first day after the CCI surgery. Mechanical withdrawal threshold(MWT) and thermal withdrawal threshold(TWL) in each group were performed before the CCI surgery and 3,7, 11, and 15 days after surgery. After 15 days, blood samples were collected from the abdominal aorta. The differential metabolites were screened out by non-target metabolomics and analyzed with Kyoto Encyclopedia of Genes and Genomes(KEGG) and ingenuity pathway analysis(IPA). From the third day after CCI surgery, the MWT and TWL values were reduced significantly in both CCI group and emodin group, compared with the sham group(P<0.01). At 15 days post-surgery, the MWT and TWL values in emodin group increased significantly compared with the CCI group(P<0.05). As revealed by non-target metabolomics, 72 differential serum metabolites were screened out from the C-S comparison, including 41 up-regulated and 31 down-regulated ones, while 26 differential serum metabolites from E-C comparison, including 10 up-regulated and 16 down-regulated ones. KEGG analysis showed that the differential metabolites in E-C comparison were enriched in the signaling pathways, such as sphingolipid metabolism, arginine biosynthesis, glycerophospholipid metabolism, and tryptophan metabolism. IPA showed that the differential metabolites were mainly involved in the lipid metabolism-molecular transport-small molecule biochemistry network. In conclusion, emodin can exert an analgesic role via regulating sphingolipid metabolism and arginine biosynthesis.

Tetrahydropalmatine alleviated diabetic neuropathic pain by inhibiting activation of microglia via p38 MAPK signaling pathway / 中国中药杂志

Neuropathic pain is one of the common complications of diabetes. Tetrahydropalmatine(THP) is a main active component of Corydalis Rhizoma with excellent anti-inflammatory and pain-alleviating properties. This study aims to investigate the therapeutic effect of THP on diabetic neuropathic pain(DNP) and the underlying mechanism. High-fat and high-sugar diet(4 weeks) and streptozotocin(STZ, 35 mg·kg~(-1), single intraperitoneal injection) were employed to induce type-2 DNP in rats. Moreover, lipopolysaccharide(LPS) was used to induce the activation of BV2 microglia in vitro to establish an inflammatory cellular model. Fasting blood glucose(FBG) was measured by a blood glucose meter. Mechanical withdrawal threshold(MWT) was assessed with von Frey filaments, and thermal withdrawal latency(TWL) with hot plate apparatus. The protein expression levels of OX42, inducible nitric oxide synthase(iNOS), CD206, p38, and p-p38 were determined by Western blot, the fluorescence expression levels of OX42 and p-p38 in the dorsal horn of the rat spinal cord by immunofluorescence, the mRNA content of p38 and OX42 in rat spinal cord tissue by qRT-PCR, and levels of nitric oxide(NO), interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), interleukin-10(IL-10), and serum fasting insulin(FINS) by enzyme-linked immunosorbent assay(ELISA). RESULTS:: showed that the mo-del group demonstrated significant decrease in MWT and TWL, with pain symptoms. THP significantly improved the MWT and TWL of DNP rats, inhibited the activation of microglia and p38 MAPK signaling pathway in rat spinal cord, and ameliorated its inflammatory response. Meanwhile, THP promoted the change of LPS-induced BV2 microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, suppressed the activation of the p38 MAPK signaling pathway, decreased the expression levels of inflammatory factors NO, IL-1β, IL-6, and TNF-α, and increased the expression level of anti-inflammatory factor IL-10. The findings suggested that THP can significantly ameliorate the pain symptoms of DNP rats possibly by inhibiting the inflammatory response caused by M1 polarization of microglia via the p38 MAPK pathway.

A novel cell tool for α2δ-1-NMDAR target-based analgesic drug discovery / 生物工程学报

The α2δ-1 protein coded by Cacna2d1 is dramatically up-regulated in dorsal root ganglion (DRG) neurons and spinal dorsal horn following sensory nerve injury in various animal models of neuropathic pain. Cacna2d1 overexpression potentiates presynaptic and postsynaptic NMDAR activity of spinal dorsal horn neurons to cause pain hypersensitivity. The α2δ-1-NMDAR interaction promotes surface trafficking and synaptic targeting of NMDARs in neuropathic pain caused by chemotherapeutic agents and peripheral nerve injury, as well as in other pathological conditions such as in the paraventricular nucleus (PVN) with neurogenic hypertension and in the brain with ischemic stroke. The lentiviral transfection method was used to construct a human embryonic kidney HEK293T cell line that could stably express α2δ-1-NMDAR complex. A stably transfected cell line was observed by florescence microscope, and identified by RT-qPCR and Western blotting. The results showed that the HEK293T cell line was successfully transfected and the genes could be stably expressed. Subsequently, the transfected cell line was successfully developed into a target drug screening system using patch clamp techniques. It provides a promising cell model for further research on the interaction mechanism of α2δ-1-NMDAR complex and drug screening for chronic pain and related diseases with low side effects.

Effect of electroacupuncture and pretreatment of electroacupuncture on pain sensitization and expression of P2X7R in spinal dorsal horn in rats with diabetic neuropathic pain / 中国针灸

OBJECTIVE@#To observe the occurrence time of neuralgia and the expression of purinergic ligand-gated ion channel 7 receptor (P2X7R) in the dorsal horn of the spinal cord after intraperitoneal injection of streptozotocin (STZ) in diabetic rats, and to explore the effect of electroacupuncture (EA) and pretreatment of EA on the heat pain threshold and expression of P2X7R in the spinal dorsal horn in rats with diabetic neuropathic pain (DNP), and to explore the possible mechanism of EA for DNP.@*METHODS@#PartⅠ: Thirty male SD rats were randomly selected from 64 male SD rats as the control group; the remaining rats were given intraperitoneal injection of STZ (10 mg/mL) at a dose of 65 mg/kg to establish the diabetes model, and 30 rats were successfully modeled as the model group. The control group and the model group were divided into three subgroups respectively at 7, 14 and 21 days, with 10 rats in each subgroup. Body mass, fasting blood glucose (FBG) and thermal pain threshold were recorded at 7, 14 and 21 days after injection; the expression of P2X7R in spinal dorsal horn was detected by Western blot. PartⅡ: Eight SD rats were randomly selected from 35 male SD rats as the blank group, and the remaining 27 rats were given intraperitoneal injection of STZ (10 mg/mL) at a dose of 65 mg/kg to establish the diabetes model. The 24 rats with successful diabetes model were randomly divided into a DNP group, an EA group and a pre-EA group, 8 rats in each group. Fifteen to 21 days after STZ injection, the EA group received EA at "Zusanli" (ST 36) and "Kunlun" (BL 60), continuous wave, frequency of 2 Hz, 30 min each time, once a day; the intervention method in the pre-EA group was the same as that in the EA group. The intervention time was 8 to 14 days after STZ injection. The body mass, FBG and thermal pain threshold were recorded before STZ injection and 7, 14 and 21 days after STZ injection; the expression of P2X7R in spinal dorsal horn was detected by Western blot 21 days after injection.@*RESULTS@#PartⅠ: Compared with the control group, in the model group, the body mass was decreased and FBG was increased 7, 14 and 21 days after STZ injection (P<0.01), and the thermal pain threshold was decreased 14 and 21 days after STZ injection (P<0.05), and the expression of P2X7R in spinal dorsal horn was increased 7, 14 and 21 days after STZ injection (P<0.05, P<0.01). PartⅡ: Compared with the blank group, in the DNP group, the body mass was decreased and fasting blood glucose were increased 7, 14 and 21 days after STZ injection (P<0.01). Compared with the DNP group, in the pre-EA group, the heat pain threshold was increased 14 and 21 days after STZ injection (P<0.05), while in the EA group, the heat pain threshold was increased 21 days after STZ injection (P<0.01), and the expression of P2X7R in the dorsal horn in the EA group and the pre-EA group was decreased (P<0.01).@*CONCLUSION@#The diabetic neuropathic pain is observed 14 days after STZ injection. EA could not only treat but also prevent the occurrence of DNP, and its mechanism may be related to down-regulation of P2X7R expression in the dorsal horn of the spinal cord.

The distribution of Mas-related G protein-coupled receptor A in cerebrospinal fluid-contacting nucleus of normal rats and its up-regulation in neuropathic pain / 生理学报

This study was aimed to observe the distribution of Mas-related G protein-coupled receptor A (MrgA) in cerebrospinal fluid (CSF)-contacting nucleus of normal rats and its expression in neuropathic pain, and to provide morphological evidence for CSF-contacting nucleus to participate in neuropathic pain. The model of neuropathic pain with chronic constriction injury (CCI) of the sciatic nerve was made in Sprague-Dawley rats. The thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) were measured. The expressions of MrgA in the CSF-contacting nucleus were examined by double labeling with immunofluorescent staining. The results showed that on the 5th, 7th, 10th and 14th days, the values of MWT and TWL in CCI group were all lower than those in sham group (P < 0.05). MrgA was found to be distributed in CSF-contacting nucleus of normal rats; and the expression was markedly up-regulated in rats at the peak of neuropathic pain. Our data suggest that CSF-contacting nucleus may participate in neuropathic pain through the MrgA-mediated signaling pathway.

Treatment of patients with neuropathic pain and provision of drug information by clinical pharmacists

Abstract Patient's satisfaction with healthcare services has an influence on pain management, which can be improved by patient education. Therefore, this study was aimed at identifying primary care health service opportunities in the treatment of neuropathic pain and assessing patients' satisfaction with the provision of drug information by clinical pharmacists. This was a cross- sectional, prospective study conducted at a pain unit during March-May 2017. Patients aged >18 years; diagnosed with neuropathic pain; and who used amitriptyline, gabapentin, pregabalin, or duloxetine were included. They were verbally informed about drug treatment by a clinical pharmacist, and their satisfaction was evaluated after 1 month. In all, 90 patients were included. The median duration for which the patients experienced pain until hospital admission was 3.6 years; furthermore, this duration was longer among women (p < 0.05). However, the median time to seeking advice from doctors was 3 months. The patients (15.6%) were less likely to admit pain unit initially and 46.7% had visited different units before being admitted to a pain unit. More than 95% of the patients indicated that they had received information from a pharmacist at a clinic and were satisfied with the provision of information (median duration, 8.5 min). Thus, the involvement of pharmacists in multidisciplinary pain management may help improve health- related outcomes at hospitals and/or in community care settings

Impact of neuropathic pain on quality of life in adults with sickle cell disease: observational study

Abstract Introduction: Knowledge on the characteristics of neuropathic pain in people with sickle cell disease (SCD) may help to provide more effective treatment procedures. Objective: To describe the characteristics of neuropathic pain in patients with sickle cell disease and identify the impact on their quality of life. Method: A cross-sectional study (CAAE 57274516.8.0000.5544) was conducted at a reference center in Salvador, Bahia, Brazil. The instruments used were the Brief Pain Inventory (BPI), the Douleur Neuropatique Questionnaire (DN-4), the Anxiety and Depression Hospital scale (ADH) and the abbreviated version of the World Health Organization of Quality of Life questionnaire (WHOQOL-brief). The Mann-Whitney test was used to evaluate the association between the scores (5% alpha). Results: A total of 100 adults with SCD participated in the study, 69.7% of whom had neuropathic pain. Anxiety was present in 99% of the sample and depression, in 100%. Patients with neuropathic pain had worse scores in all domains of quality of life (p < 0.05), but no association was found with pain intensity. Conclusion: Neuropathic pain was more frequent than nociceptive pain in adults with SCD and generated worse scores in all domains of quality of life. Anxiety and depression were present in patients with both types of pain.

Caracterización neurofisiológica de la función de fibra pequeña en mujeres heterocigotas con enfermedad de Fabry / Neurophysiologic characterization of small fiber function in heterozigous women with Fabry disease

RESUMEN INTRODUCCIÓN: La enfermedad de Fabry (EF) es una enfermedad genética, causada por el déficit de la enzima alfa galactosidasa A (α-Gal A), lo que provoca la acumulación de glicoesfingolípidos en los tejidos. Sus manifestaciones clínicas son variables. Estudios en mujeres heterocigotas reportan la existencia de dolor neuropático como manifestación de neuropatía de fibra pequeña. OBJETIVO: Determinar la presencia de neuropatía de fibra pequeña en mujeres heterocigotas para la EF, mediante la prueba cuantitativa sensorial. MATERIALES Y MÉTODOS: Se evaluaron 33 mujeres heterocigotas para EF y 33 mujeres sanas, con características demográficas similares. A todas se les aplicó la prueba cuantitativa sensorial (Quantitative Sensory Testing por medio de la detección de umbrales de frío (Colà Detection Threshold), calor (Warm Detection Threshold), dolor inducido por calor (Heat-pain Detection Thresholds) y vibración (Vibratory Detection Threshold) en los miembros superior e inferior, utilizando un sistema asistido por computador versión IV (CASE IV, WR Medical Electronics Co., Stillwater, MN). Adicionalmente, al grupo de mujeres heterocigotas para EF, se le evaluó la percepción subjetiva de dolor neuropàtico mediante el cuestionario de síntomas sensitivos neuropáticos positivos (Positive Neuropathic Sensory Symptom). Los resultados de la prueba cuantitativa sensorial se compararon entre los grupos. También se estableció la correlación entre la prueba cuantitativa sensorial y los resultados del cuestionario de síntomas sensitivos neuropáticos positivos. RESULTADOS: Se encontró una diferencia estadísticamente significativa en las pruebas de vibración (p = 0,008), calor (p = 0,017) y dolor inducido por calor (p = 0,04) en el miembro inferior en las mujeres heterocigotas para EF, comparado con el grupo control. Se encontró una correlación inversa estadísticamente significativa entre la intensidad del dolor quemante y el dolor inducido por calor en el miembro inferior (p = 0,018, r = -0,48) y entre la intensidad del dolor al ser rozado o tocado y el dolor inducido por calor en el miembro inferior (p = 0,006, r = -0,49). CONCLUSIÓN: En las mujeres heterocigotas para EF, las pruebas objetivas para establecer la presencia de neuropatía de fibra pequeña son anormales en miembros inferiores y se correlacionan con los síntomas sensitivos.

SUMMARY INTRODUCTION: Fabry disease is a genetic condition caused by alpha-galactosidase A deficiency triggering glycosphingolipid accumulation in tissues. Clinical manifestations are variable. Studies in heterozigous females report the existence of neuropathic pain as manifestation of small fiber neuropathy. OBJECTIVE: To determine presence of small fiber neuropathy in heterozigous females with Fabry disease through Quantitative Sensory Testing (QST). MATERIALS AND METHODS: 33 heterozigous females with fabry disease and 33 healthy females with similar demographic characteristics were evaluated. QST was performed to every female evaluating Cold detection Threshold (CDT), Warm Detection Threshold (WDT), Heat-pain Detection Threshold (HPDT) and Vibratory Detection Threshold (VDT) in upper and lower limbs through Computer Assisted Sensory Examination software (CASE IV, WR Medical Electronics Co., Stillwater, MN). Subjective perception of neuropathic pain was measured through Positive Neuropathic Sensory Symptom questionnaire (P-NSS) in heterozigous females with Fabry disease. QST results were compared between groups. Correlations between QST and P-NSS were established. RESULTS: Statistically significant differences were observed in VDT (p= 0,008), WDT (p= 0,017) and HPDT (p= 0,04) in lower limbs of heterozigous females with Fabry disease compared with control group. Negative correlation was found among burning pain intensity and HPDT at lower limbs (p= 0,018, r= -0,48) and among pain intensity to light touch and HPDT in lower limbs (p= 0,006, r=-0,49). CONCLUSIONS: Objective tests to establish presence of small fiber neuropathy in heterozigous females with Fabry disease are abnormal at lower limbs and correlate with sensory symptoms.

Spinal cord stimulation in the management of neuropathic pain in cancer patients: case report / Neuroestimulación medular en el manejo del dolor neuropàtico en pacientes con cáncer: reporte de caso

Abstract Introduction Neuropathic pain is present in up to 40 % of all cancer patients. A considerable number of patients fail to achieve enough pain relief with conventional treatment, which is why therapeutic alternatives such as spinal cord stimulation should be considered. Case description and results This is the case of a female patient with chronic neuropathic pain secondary to a partial femoral nerve injury sustained during resection and lymph node dissection surgery with curative intent for a large stage II cell squamous cell carcinoma T2N0M0, localized in the right popliteal fossa. The patient presented with difficult to manage chronic neuropathic pain, despite receiving multiple oral analgesics and nerve blocks. A medullary neurostimulator was implanted that relieved the patient's pain intensity in up to 80%, in addition to improved function and quality of life. Conclusions Spinal cord stimulation is considered an effective neuromodulatory intervention which has shown satisfactory results in the treatment of various types of refractory chronic pain in cancer patients, including neuropathic pain.

Resumen Introducción El dolor neuropático está presente hasta en el 40 % de los pacientes con cáncer. Un número considerable de pacientes no logran un alivio suficiente del dolor con el tratamiento convencional, por lo cual deben considerarse alternativas terapéuticas como la estimulación de la médula espinal. Descripción del caso y resultados Caso de una paciente con dolor neuropático crónico secundario a lesión parcial de nervio femoral durante cirugía de resección y vaciamiento ganglionar con objetivos curativos de carcinoma escamocelular de célula grande T2N0M0 estadio II, localizado en la fosa poplítea derecha, quien cursó con dolor neuropático crónico de difícil manejo a pesar de recibir múltiples analgésicos orales y bloqueos nerviosos. Se implantó un neuroestimulador medular con lo cual se logró un alivio hasta del 80 % en intensidad de dolor de la paciente, además de una mejoría de su funcionalidad y calidad de vida. Conclusiones La estimulación de la médula espinal se considera una intervención neuromoduladora eficaz, que ha demostrado resultados satisfactorios para tratar diversas formas de dolor crónico refractario en los pacientes con cáncer, incluido el dolor neuropático.

Dolor neuropático localizado / Localized neuropathic pain

Resumen El dolor neuropático localizado (DNL) es de origen periférico y se caracteriza por áreas circunscritas de dolor con sensibilidad anormal de la piel o síntomas espontáneos característicos de dolor neuropático, por ejemplo, dolor urente. Se debe resaltar que el DNL está confinado a un área específica no mayor a una hoja de papel tamaño carta. El DNL representa 60 % de las condiciones de dolor neuropático. No existe una única etiología. El abordaje diagnóstico es similar al de otros síndromes dolorosos neuropáticos. Se utilizan herramientas diagnósticas generales para evaluar las características clínicas. En la actualidad no existen guías específicas de manejo del DNL, por lo que se utilizan las guías para dolor neuropático en general. En las guías de la Sociedad Canadiense de Dolor se incluyen los tratamientos tópicos como parte de las estrategias de segunda línea. Pese a la falta de guías, los parches de lidocaína a 5 % y los parches de capsaicina a 8 % han demostrado ser efectivos en modelos de DNL.

Abstract Localized neuropathic pain (LNP) is of peripheral origin and is characterized by circumscribed areas of pain with abnormal skin sensitivity or spontaneous symptoms that are characteristic of neuropathic pain, e.g. burning pain. It should be noted that LNP is confined to a specific area no larger than a letter size sheet of paper. LNP accounts for 60 % of neuropathic pain conditions. There is no single etiology of LNP. The diagnostic approach is similar to that for other neuropathic pain syndromes. General diagnostic tools are used to assess clinical features. So far, there are no specific guidelines for the management of LNP; for this reason, guidelines for general neuropathic pain are used. Topical treatments are included as part of second-line strategies in the Canadian Pain Society guidelines. Despite the lack of guidelines, 5 % lidocaine patches and 8 % capsaicin patches have been proven effective in LNP models.