Etude des mécanismes et des circuits neuronaux impliqués dans la douleur neuropathique trigéminale post-traumatique

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

PKCγ-positive neurons gate light tactile inputs to pain pathway through pERK1/2 neuronal network in trigeminal neuropathic pain model

© 2015 by Quintessence Publishing Co Inc. Aims: To explore the possible relationship between protein kinase C gamma (PKCγ) and phosphorylated forms of extracellular signal-regulated kinases 1/2 (pERK1/2) in the rat medullary dorsal horn and the facial hypersensitivity indicative of dynamic mechanical allodynia (DMA) following chronic constriction of the infraorbital nerve (CCI-IoN). Methods: A well-established rat model of trigeminal neuropathic pain involving CCI-IoN was used. Facial mechanical hypersensitivity was tested with non-noxious dynamic mechanical stimulation (air-puff), and the medullary dorsal horn was examined immunohistochemically using PKCγ and pERK1/2 as pain markers. Statistical analysis was performed using Student t test or one-way analysis of variance (ANOVA). Results: Increased PKCγ and pERK1/2 expressions within the medullary dorsal horn were associated with DMA following CCI-IoN. A segmental network composed of PKCγ-positive cells located in medullary dorsal hor

Role of vitamin B6 in idiopathic burning mouth syndrome: some clinical observations

Introduction: Idiopathic burning mouth syndrome (iBMS) is a chronic oral pain syndrome mainly characterized by a burning sensation in the oral mucosa and an etiopathogenesis that remains unclear, with therapeutic options that are disappointing. Any clinical observation providing insight into the disorder can therefore be of interest. Among metabolic factors, deficiencies of vitamins have been pointed out, but only a few studies have focused on the role of vitamin B6 (vitB6) in this syndrome. In this report, we aimed to highlight the involvement of increased but not decreased vitB6 serum levels in a subgroup of BMS Patients. Patients and Methods: Medical files of patients who attended the chronic orofacial pain consultation, in the dental departement of the Groupe Hospitalier Pitié-Salpêtrière (GHPS) in Paris (France) between 09/03/2008 and 12/19/2015 were retrieved from the hospital database and analyzed. This retrospective study was approved by the board of the dental department and authorization for use of patient data was obtained from the National Personal Data Protection Committee (Commission Nationale de l’Informatique et des Libertés (CNIL)) (#1913570). Results: Seven per- or postmenopausal female patients out of 42 diagnosed with iBMS (17%) displayed an increase in their serum levels of vitB6, one to six times the upper normal limits. There was a statistically significant correlation between pain and vitB6 levels. Moreover, in two patients, the reversal of vitB6 levels to normal values resulted in significant decreases in pain severity. Conclusion: These clinical observations report for the first time a potential implication of elevated vitB6 serum levels in the burning sensation which might be specific to a subgroup of iBMS patients

Electrical Synapses are Involved in Orofacial Neuropathic Pain

International audienc

Nigrostriatal dopaminergic depletion increases static orofacial allodynia

International audienc

Exploring the time course of painful post-traumatic trigeminal neuropathy: a pilot study

Patients suffering from painful post-traumatic trigeminal neuropathy (PTTN) often report circadian variations in pain. This pilot study aimed to assess the daily evolution of pain in patients fulfilling the following criteria: PTTN diagnosed based on ICHD-3 criteria; >18 years of age; no impairment in communication and signed informed consent. Primary study outcome was a self-declared quantitative assessment of pain intensity using an 11-point numerical scale (0–10) for 8 consecutive days. Impact on oral function and quality of life was also assessed, using psychometric questionnaires GOHAI and HADS. Eleven patients with PTTN were recruited (mean age: 66.1 ± 6.8 years old). Mean pain intensity was 3.6 ± 0.99. Mean pain intensity increased progressively and significantly during the day, from 1.8 ± 1.3 to 4.6 ± 2.3 (p < 0.0001). Mean HADS score was 7.8 ± 2.7. Mean GOHAI score was weak (35/60). In conclusion, PTTN seems to follow a circadian rhythm

Could methylene blue be used to manage burning mouth syndrome? A pilot case series

Objective: Burning mouth syndrome is a disabling condition of complex pathophysiology characterized by spontaneous pain felt in the oral mucosa in the absence of evident mucosal lesions which lacks efficient treatments to this day. The purpose of this study was to demonstrate the efficacy of methylene blue in the management of burning mouth syndrome. Methods: The study was conducted at the dental clinic of the Anta Diop University and Newtown dental clinic of Dakar, Senegal. A solution of methylene blue as a mouth-rinse (0.5%) was applied for 5 minutes in five patients satisfying the ICHD-3 diagnostic criteria for burning mouth syndrome. This procedure was repeated every 6 hours 3 times per 24h, during 7 days. Using numeric rating scale, pain severity was assessed as the mean pain felt during the last day of application. Results: After 7 days, the pain was significantly reduced by two-thirds and almost absent at 3 and 6 months follow-up. No secondary effects of the use of methylene blue were observed. Putative mechanisms of action and potential implications for treatment are discussed. Conclusion: Methylene blue is an old compound but a novel topical therapy that could prove beneficial in the management of burning mouth syndrome