Recent advances in our understanding of the organization of dorsal horn neuron populations and their contribution to cutaneous mechanical allodynia

The dorsal horns of the spinal cord and the trigeminal nuclei in the brainstem contain neuron populations that are critical to process sensory information. Neurons in these areas are highly heterogeneous in their morphology, molecular phenotype and intrinsic properties, making it difficult to identify functionally distinct cell populations, and to determine how these are engaged in pathophysiological conditions. There is a growing consensus concerning the classification of neuron populations, based on transcriptomic and transductomic analyses of the dorsal horn. These approaches have led to the discovery of several molecularly defined cell types that have been implicated in cutaneous mechanical allodynia, a highly prevalent and difficult-to-treat symptom of chronic pain, in which touch becomes painful. The main objective of this review is to provide a contemporary view of dorsal horn neuronal populations, and describe recent advances in our understanding of on how they participate in cutaneous mechanical allodynia

Etiology, distribution, treatment modalities and complications of maxillofacial fractures

Purpose: This study evaluated the trends and factors associated with maxillofacial fractures treated from 1997 to 2007 in the Oral and Maxillofacial Surgery Department of the Clermont-Ferrand University Hospital. Material and Methods: This study included 364 patients of which 82% were men and 45%, 20-29-years old. The etio- logy, anatomical distribution, treatment modality and complications of maxillofacial fractures were examined. Results: Overall, interpersonal violence, traffic accidents and falls were the most common mechanisms of injury. There was a decreasing trend in traffic accidents and increasing one in falls as a cause of fracture over the 11-years period of this study. Young male patients were preferentially victim of interpersonal violence and traffic accidents, while middle-aged ones were of falls and work-related accidents. Middle-aged female patients were preferentially victim of traffic accidents and interpersonal violence, while older ones were of falls. And the number of fractures per patient varied according to the mechanism of injury: low after work-related accidents and high after traffic accidents. About two-third of fractures involved the mandible. Most of these mandibular fractures were treated by osteosynthesis with or without intermaxillary fixation, with the proportion of the latter increasing over time. There were very few postoperative infections and only in mandible. Conclusions: Maxillofacial fractures predominantly occur in young men, due to interpersonal violence. There is nevertheless an increasing trend in falls as a cause of fracture, especially in female patients, consistent with the increasing trend in presentation of older people. Most maxillofacial fractures involve the mandible and there is an increasing trend in treating these fractures by osteosynthesis without intermaxillary fixation. Antibiotic prophy - laxis associated with dental hygiene care can be indicated to prevent postoperative infections

Glycine Inhibitory Dysfunction Turns Touch into Pain through PKCgamma Interneurons

Dynamic mechanical allodynia is a widespread and intractable symptom of neuropathic pain for which there is a lack of effective therapy. During tactile allodynia, activation of the sensory fibers which normally detect touch elicits pain. Here we provide a new behavioral investigation into the dynamic component of tactile allodynia that developed in rats after segmental removal of glycine inhibition. Using in vivo electrophysiological recordings, we show that in this condition innocuous mechanical stimuli could activate superficial dorsal horn nociceptive specific neurons. These neurons do not normally respond to touch. We anatomically show that the activation was mediated through a local circuit involving neurons expressing the gamma isoform of protein kinase C (PKCγ). Selective inhibition of PKCγ as well as selective blockade of glutamate NMDA receptors in the superficial dorsal horn prevented both activation of the circuit and allodynia. Thus, our data demonstrates that a normally inactive circuit in the dorsal horn can be recruited to convert touch into pain. It also provides evidence that glycine inhibitory dysfunction gates tactile input to nociceptive specific neurons through PKCγ-dependent activation of a local, excitatory, NMDA receptor-dependent, circuit. As a consequence of these findings, we suggest that pharmacological inhibition of PKCγ might provide a new tool for alleviating allodynia in the clinical setting

Chronic pain associated with the Chikungunya Fever: long lasting burden of an acute illness

<p>Abstract</p> <p>Background</p> <p>Chikungunya virus (CHIKV) is responsible for major epidemics worldwide. Autochthonous cases were recently reported in several European countries. Acute infection is thought to be monophasic. However reports on chronic pain related to CHIKV infection have been made. In particular, the fact that many of these patients do not respond well to usual analgesics suggests that the nature of chronic pain may be not only nociceptive but also neuropathic. Neuropathic pain syndromes require specific treatment and the identification of neuropathic characteristics (NC) in a pain syndrome is a major step towards pain control.</p> <p>Methods</p> <p>We carried out a cross-sectional study at the end of the major two-wave outbreak lasting 17 months in Réunion Island. We assessed pain in 106 patients seeking general practitioners with confirmed infection with the CHIK virus, and evaluated its impact on quality of life (QoL).</p> <p>Results</p> <p>The mean intensity of pain on the visual-analogical scale (VAS) was 5.8 ± 2.1, and its mean duration was 89 ± 2 days. Fifty-six patients fulfilled the definition of chronic pain. Pain had NC in 18.9% according to the DN4 questionnaire. Conversely, about two thirds (65%) of patients with NC had chronic pain. The average pain intensity was similar between patients with or without NC (6.0 ± 1.7 vs 6.1 ± 2.0). However, the total score of the Short Form-McGill Pain Questionnaire (SF-MPQ)(15.5 ± 5.2 vs 11.6 ± 5.2; p < 0.01) and both the affective (18.8 ± 6.2 vs 13.4 ± 6.7; p < 0.01) and sensory subscores (34.3 ± 10.7 vs 25.0 ± 9.9; p < 0.01) were significantly higher in patients with NC. The mean pain interference in life activities calculated from the Brief Pain Inventory (BPI) was significantly higher in patients with chronic pain than in patients without it (6.8 ± 1.9 vs 5.9 ± 1.9, p < 0.05). This score was also significantly higher in patients with NC than in those without such a feature (7.2 ± 1.5 vs 6.1 ± 1.9, p < 0.05).</p> <p>Conclusions</p> <p>There exists a specific chronic pain condition associated to CHIKV. Pain with NC seems to be associated with more aggressive clinical picture, more intense impact in QoL and more challenging pharmacological treatment.</p

Advances in the understanding and treatment of pain and headache

International audienc

Enseignement de la douleur dans les unités de formation et de recherche d'odontologie en France (état actuel et propositions pour un enseignement intégré)

La prévalence et les conséquences des douleurs oro-faciales sont importantes, leur prise en charge est une obligation éthique, réglementaire et légale. L'objectif de ce travail est de faire un état des lieux de la formation de la douleur dans les UFR d'odontologie française. Pour cela une enquête a été réalisée par l'intermédiaire de trois questionnaires destinés aux doyens, aux responsables de sous section et aux étudiants. On constate que les différentes disciplines nécessaires à la compréhension de la douleur sont enseignées de manière fragmentée dans le cursus, et qu'il n'existe en général pas d'enseignement clinique. Les connaissances et compétences des étudiants concernant notamment la douleur chronique sont faibles et les étudiants se sentent insuffisamment formés. Ces résultats différent pour un groupe d'étudiants ayant bénéficié d'un enseignement intégré et multidisciplinaire. Ceci semble montrer que ce type d'enseignement pourrait être efficace.CLERMONT FD-BCIU Odontol. (631132226) / SudocPARIS-BIUM (751062103) / SudocCLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

Etude immunocytochimique de l'expression des récepteurs GABA B par les interneurones de projection du sous-noyau caudal du complexe du sensitive du trijumeau chez le rat

CLERMONT FD-BCIU Odontol. (631132226) / SudocPARIS-BIUM (751062103) / SudocCLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

INTERET DE LA KETAMINE DANS LE CONTROLE DES DOULEURS OROFACIALES INFLAMMATOIRES

CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

L'anxiété face aux soins dentaires chez l'enfant (éviter la genèse d'une phobie)

CLERMONT FD-BCIU Odontol. (631132226) / SudocPARIS-BIUM (751062103) / SudocCLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

Evaluation d'un dossier clinique standardisé pour les consultations spécialisées de douleur orofaciale et rééducation de l'appareil manducateur

CLERMONT FD-BCIU Odontol. (631132226) / SudocPARIS-BIUM (751062103) / SudocCLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF