scholarly journals Following Neuropathic Pain Route: Glial Alteration in the Thalamus

2019 ◽  
Vol 32 (4) ◽  
pp. 221-223
Author(s):  
S. Abou Rachid ◽  
E. Nigi ◽  
A. Shiba ◽  
V. Zhukova

Les cellules gliales jouent un rôle important dans l’initiation et la maintenance de la sensation de la douleur. La plupart des études portant sur ce sujet ont été réalisées au niveau de la moelle épinière et relativement peu au niveau supraspinal et notamment thalamique. Les noyaux thalamiques traitent les messages nociceptifs avant d’être adressés au cortex ; en particulier, le noyau thalamique ventropostérolatéral (VPL) est impliqué dans les aspects sensoriels et discriminatifs du traitement de la douleur. L’article présenté par L. Blaszczyk et al. révèle les nouveaux rôles de la microglie et des astrocytes situés dans le VPL et impliqués dans la douleur neuropathique. Dans cette étude, Blasczyk et al. ont utilisé une ligation du nerf spinal L5/L6 chez le rat comme modèle du douleur neuropathique. Des allodynies statiques mécaniques et une hyperalgésie ont été observées chez les animaux après la chirurgie. Plusieurs analyses ont ensuite été effectuées sur les cellules du VPL. Une analyse morphométrique fondée sur les marqueurs gliaux, combinée à un comptage conventionnel et stéréologique de cellules, a indiqué une diminution transitoire de la population de microglies après 14 jours et suggère également une hypertrophie des astrocytes au 28e jour. La réactivité des microglies a été évaluée en utilisant leurs marqueurs spécifiques au 14e jour. Ces résultats révèlent un modèle d’activation séquentiel, sans précédent, des microglies et des astrocytes, pouvant aider à découvrir leur rôle dans l’apparition mais également le maintien de ce dysfonctionnement somatosensoriel.

Author(s):  
Gabriel Taricani Kubota ◽  
Daniel Ciampi Araújo de Andrade

A dor neuropática é uma condição clinicamente definida e provocada por uma lesão ou doença de vias neurológicas somatossensitivas. Ela ocorre em aproximadamente 7% a 10% da população mundial, e resulta em grande impacto econômico e sobre a qualidade de vida dos doentes. Os seus critérios diagnósticos levam em consideração: a história compatível com dor neuropática por uma lesão e/ou doença relevante; distribuição neuroanatomicamente plausível da dor, e testes diagnósticos que confirmem a presença da lesão e/ou doença em questão. Instrumentos de rastreio, como o Douleur Neuropathique en 4 Questions (DN-4) podem auxiliar em sua identificação, especialmente por não especialistas. Cuidados multidisciplinares são parte importante do tratamento destes doentes, porém a farmacoterapia é ainda hoje o seu elemento fundamental. As diretrizes da NeuPSIG (Neuropathic Pain – Special Interest Group) recomendam ligantes da subunidade α2δ de canais de cálcio sensíveis a voltagem (gabapentina e pregabalina), inibidores de recaptação de serotonina e noradrenalina (duloxetina e venlataxina) e antidepressivos tricíclicos como primeira linha terapêutica; emplastros de lidocaína 5% e de capsaicina 8%, e tramadol como segunda linha; e onabotulinumtoxina A e opioides fortes (morfina e oxicodona) como terceira linha. A escolha da melhor estratégia terapêutica, no entanto, deve ser individualizada e levar em consideração o tipo de dor neuropática (periférica vs. central), extensão da área acometida, comorbidades e preferências do paciente, riscos de interações farmacológicas e de efeitos colaterais. Casos refratários devem ser conduzidos preferencialmente por médico especialista em dor, e para eles modalidades terapêuticas invasivas e neuromodulação podem ser considerados. Unitermos: Dor crônica. Dor neuropática. Analgesia, diagnóstico, tratamento.


2019 ◽  
Vol 32 (4) ◽  
pp. 224-226
Author(s):  
M. Armbruster ◽  
O. Bouadi O ◽  
V.C. Morais-Brazil ◽  
G. Morciano

Les patients souffrant de douleurs neuropathiques (DN) ont des sensations anormales de douleurs dues à un mauvais contrôle de la transmission des signaux de la douleur. Les neurones GABA, glycine et parvalbumine des cornes dorsales médullaires et épinières communiquent par des synapses électriques formées de jonctions communicantes constituées de connexine 36 (Cx36). Ces neurones auraient une fonction de portail, bloquant ou autorisant la transmission de la douleur au cerveau. Un dysfonctionnement dans ce mécanisme entraînerait des DN. Par conséquent, les auteurs de cet article ont voulu étudier le rôle de la méfloquine, un bloqueur de Cx36, et l’expression de Cx36 dans un modèle de DN obtenu par constriction chronique du nerf infraorbitaire (CCI-IoN) chez le rat. Cx36 est surexprimé spécifiquement dans les neurones GABA de la corne dorsale de la moelle épinière médullaire en conditions neuropathiques. La méfloquine a permis de diminuer l’allodynie mécanique chez les rats CCI-IoN. Ces résultats suggèrent que les jonctions communicantes qui contiennent la Cx36 sont impliquées dans l’allodynie mécanique des douleurs orofaciales en conditions neuropathiques. Cela suggère que les neurones GABA jouent un rôle important dans la perception de douleur et que de futures études sont nécessaires.


2016 ◽  
Vol 95 (4) ◽  
pp. 756-759 ◽  
Author(s):  
Jamilly C. V. Santana ◽  
Francisco P. Reis ◽  
Vera L. C. Feitosa ◽  
Julianne C. V. Santana ◽  
Luis E. Cuevas ◽  
...  

2021 ◽  
Vol 27 ◽  
pp. 257-263
Author(s):  
Ashok K Saxena ◽  
Dipanshu Khrolia ◽  
Geetanjali T Chilkoti ◽  
R Kumar Malhotra

Objectives: The Douleur Neuropathique 4 (DN4) questionnaire is a widely used tool for the diagnosis of neuropathic pain (NP). The aim was to validate the Complete Hindi version of DN4 (CH-DN4) questionnaire. Materials and Methods: A systematic translation process was used to translate the original English DN4 into Hindi. The Hindi version was validated among patients appearing in the pain clinic of a tertiary hospital in the capital of Delhi by two different raters. We assessed the internal consistency, test–retest reliability, and inter-rater agreement, validity, sensitivity, specificity, positive and negative predictive values, and area under the curve (AUC). Results: A total of 285 participants, out of which 153 had NP and 132 had non NP (NNP) were included in the study. The results showed our CH-DN4 to have good diagnostic accuracy, a score of ≥ 3.5 was found to be the best cut–off for the diagnosis of NP, with a sensitivity of 0.78, specificity of 0.76, a positive predictive value of 78.5%, and a negative predictive value of 74.5%. Cronbach’s α was 0.82 (95% confidence interval: 0.80–0.84), and interclass correlation coefficients was 0.95. The AUC was >0.8 indicating excellent discrimination between NP and NNP. Conclusion: The CH-DN4 questionnaire has been found to be a reliable and valid screening tool with an excellent power to discriminate between NP and NNP.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4056-4056
Author(s):  
Vincenzo Federico ◽  
Russo Eleonora ◽  
Andrea Truini ◽  
Anna Levi ◽  
Fabiana Gentilini ◽  
...  

Abstract Abstract 4056 Background: Peripheral neuropathy (PN) and neuropathic pain are common and severe dose-limiting side effects of Bortezomib and/or IMIDs used in the management of multiple myeloma patients, which often requires dose reduction or interruption of treatment. Aims: We performed a monocentric prospective study to investigate the incidence, clinical characteristics and predictive factors of peripheral neuropathy and neuropathic pain in multiple myeloma patients treated with Bortezomib and/or IMIDs. Methods: All patients underwent clinical examination and were studied for the standard nerve conduction using the sural nerve action potential (SAP) trend. Neurological evaluation was performed monthly before, during and after Bortezomib and/or IMIDs treatment. Neuropathic pain was evaluated using the Douleur Neuropathique 4 (DN4) questionnaire and the Total Neuropathy Score reduced version. Results: Between January 2007 and June 2011, 145 consecutive patients, treated with Bortezomib and/or IMIDs, were prospectively studied. The clinical characteristics were: median age 60 years (range 32–78); 68 men and 77 women; 80 and 65 patients were, respectively, in Durie and Salmon stages I-II and III. Fifty-eight patients (40%) were treated with Bortezomib, 20 (14%) with Thalidomide, 37 (26%) with Lenalidomide and 30 (20%) with the Bortezomib-Thalidomide combination. After a median time of 3 months (range 1–22) from the start of our study, 100 patients (69%) developed a peripheral neuropathy during treatment; 78 (54%) patients had pain according to the DN4 questionnaire and 45 (31%) experienced neuropathic pain according to the Total Neuropathy Score. A significant difference (p<0.01) in terms of age and median time from diagnosis to the neurological examination was observed between patients with and without peripheral neuropathy. Patients with peripheral neuropathy were older and had a longer median time from diagnosis to the neurological examination: median age 59 vs 43 years (range 45–78 vs 32–62) and 45 vs 22 months (range 1–160 vs 1–36) from diagnosis. In addition, the different treatments were significantly associated with the development of peripheral neuropathy: the Bortezomib-Thalidomide combination and Bortezomib or Thalidomide alone were more frequently associated with peripheral neuropathy than Lenalidomide (p<0.05). No correlation between PN occurrence and cumulative dose of Bortezomib and IMIDs was observed. Among 30 patients (20%) treated with the Bortezomib-Thalidomide combination as first line of therapy, 22 (72%) experienced a peripheral neuropathy. In this group of patients, according to the SAP study, the neuropathy appeared after a median of 1.6 months of treatment and worsened after 3 months (Fig. 1). Sixteen patients continued Bortezomib-Thalidomide at the same dosage and 6 patients required a Bortezomib-Thalidomide dose reduction. An improvement of the neuropathy was observed after 4 months from the stop of treatment. Conclusions: Our data underline the clinical importance of peripheral neuropathy and pain in patients with multiple myeloma. Age, duration of disease and treatment are predictive factors of peripheral neuropathy development. The Douleur Neuropathique 4 (DN4) and Total Neuropathy Score questionnaires are useful tools to evaluate neuropathic pain. We also observed that a reduction of SAP occurs early in patients who developed a neuropathy that improves after the end of treatment. This finding could suggest the presence of biological factors predisposing to the development of neuropathy. Disclosures: Petrucci: Janssen, Celgene: Honoraria.


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