Prevalence of Burning Mouth Syndrome in Parkinson's Disease: A Prospective Case-Control Study.

Objective: To determine the prevalence of Burning mouth syndrome (BMS) in patients with Parkinson's disease (PD) and compare it with an age- and sex-matched control group.

Methods: The study included 150 PD patients and 150 age- and sex-matched control subjects. Participants were asked about any possible burning or tingling sensation in the oral mucosa.

Sex influences the progression of cephalic mechanical and light hypersensitivities in a mouse model of chronic migraine.

Objectives/background: Our aim was to compare the temporal dynamics of light and cephalic mechanical sensitivities in male and female mice as they relate to migraine chronicization. Cutaneous and light hypersensitivities are among the most common features of migraine, with greater severity observed in females. In 3% of patients, episodic migraine progresses to a chronic form, and sensory hypersensitivity becomes persistent.

Intraoral Factors Modulating Pain in Burning Mouth Syndrome.

Background: Understanding intraoral factors that modulate pain in patients with burning mouth syndrome (BMS) could provide insight into its pathophysiological mechanisms, facilitating improved management strategies.

Methods: This retrospective study included 120 BMS patients who were asked, without predefined options, about factors that alleviated or exacerbated their pain. Data collected included pain characteristics (intensity, localisation, duration) and associated conditions such as salivary abnormalities and taste disturbances.

Contribution of peripheral and central delta opioid receptors in the relief of migraine-like headache in female and male rats.

Background And Purpose: Preclinical studies in mice highlight delta opioid receptors (DOPs) as a potential migraine treatment. Here, we examined their role in a rat model of migraine in both sexes.

Experimental Approach: We assessed DOP distribution in the trigeminal ganglion (TG) using RNAscope, the action of the DOP agonist SNC80 on facial mechanical sensitivity using von Frey hairs and responses of trigeminal nucleus caudalis wide dynamic range (WDR) neurons using in vivo electrophysiology, in physiological conditions and a migraine model induced by isosorbide dinitrate (ISDN) injections.

Validation of an 8-item self-administered questionnaire for assessing migraine-related sensory hypersensitivities (MHQ-8).

Background: In addition to headache, migraine patients often experience sensory hypersensitivity to external stimuli. While photophobia and phonophobia are part of the diagnostic criteria of migraine, many patients also exhibit cutaneous allodynia and osmophobia. However, the presence and intensity of these four hypersensitivities are rarely assessed systematically and simultaneously due to the lack of a simple and rapid self-report questionnaire.

Astrocytic Kir4.1 ion channel deficit drives persistent inflammatory facial pain in males.

Chronic facial pain, a frequent and disabling condition, is maintained by central sensitization, which results in pain hypersensitivity. Although it is well established that reactive astrocytes play a key role in persistent pain mechanisms, the role of disruption of the normal capacity of astrocytes to maintain neuronal homeostasis is much less known. Here we show that persistent facial inflammation disturbs potassium homeostasis in the medullary dorsal horn of male rats, due to a sex-specific, drastic downregulation of astroglial inward rectifier potassium Kir4.

The role of the sympathetic component of the autonomic nervous system on pain before and after third molar extraction- an observational cohort study.

Background: Assessing heart rate variability (HRV) before a standardized surgery would help to explore further the relationship between the autonomic nervous system and pain.

Methods: A single-center prospective cohort of 117 patients (55% female) scheduled for third molar extraction underwent a preoperative resting measurement of arterial pressure followed by an HRV recording, then potentiated by a Valsalva maneuver and a deep breathing challenge. Finally, pain sensitivity was assessed by hand immersion in hot water.

FLT3 signaling inhibition abrogates opioid tolerance and hyperalgesia while preserving analgesia.

Navigating the duality of opioids' potent analgesia and side effects, including tolerance and hyperalgesia, is a significant challenge in chronic pain management, often prompting hazardous dose escalation to maintain analgesic effects. The peripheral mu-opioid receptor (MOR) is known to mediate these contradictory effects. Here, we show that the fms-like tyrosine kinase receptor 3 (FLT3) in peripheral somatosensory neurons drives morphine tolerance and hyperalgesia in a male rodent model.

Estrous cycle regulates cephalic mechanical sensitivity and sensitization of the trigemino-cervical complex in a female rat model of chronic migraine.

The higher incidence of migraines in women compared with men has led to the inclusion of female animals in pain research models. However, the critical role of the hormonal cycle is frequently overlooked, despite its clear correlation with migraine occurrences. In this study, we show in a rat model of migraine induced by repeated dural infusions of an inflammatory soup (IS) that a second IS (IS2) injection performed in proestrus/estrus (PE, high estrogen) female rats evokes higher cephalic mechanical hypersensitivities than when performed in metestrus/diestrus (MD, low estrogen) or ovariectomized (OV) rats.

Synthesis of diversely substituted pyridin-2(1)-ones and evaluation of their anti-allodynic effect on cutaneous inflammatory mechanical allodynia.

A series of 3,5-disubtituted pyridin-2(1)-ones was synthesized. As part of a structure-activity relationship study performed in this series, structural modifications were based on 3-(indol-4-yl)-5-(pyridin-4-ylamino)pyridin-2(1)-one B, which exhibited a potent anti-allodynic effect in a rat model of inflammatory pain. In this study, new compounds were assessed for their ability to inhibit cutaneous mechanical allodynia in rats by using the capsaicin pain model.

Synergistic effect of combining dual enkephalinase inhibitor PL37 and sumatriptan in a preclinical model of migraine.

Objective: The aim of this study was to test whether a combination of sumatriptan with dual enkephalinase inhibitor PL37 would result in an additive or a synergistic effect.

Background: Combination treatment is frequently used to improve the therapeutic efficacy of drugs. The co-administration of two drugs may result in efficacy at lower doses than those needed for either drug alone, thus minimizing side effects.

[Specificities of orofacial neuropathic pain].

Head pain and notably orofacial pain differs from spinal pain on pathophysiological, clinical, therapeutic and prognostic levels. Its high prevalence, important impact on quality of life and significant socio-economical burden justify specific study of such type of pain. Among them, neuropathic orofacial pain resulting from disease or trauma of the trigeminal nervous system is among the most difficult types of pain to diagnose and to treat.

Enhanced pain facilitation rather than impaired pain inhibition in burning mouth syndrome female patients.

Background: Deficient endogenous pain modulation has been implicated in the development and exacerbation of chronic orofacial pain. To date, relatively little is known regarding the function of the endogenous pain modulation in patients with burning mouth syndrome (BMS). This case-control study investigated endogenous pain modulation in women with BMS.

GABA and Glycine Receptor-Mediated Inhibitory Synaptic Transmission onto Adult Rat Lamina II PKCγ-Interneurons: Pharmacological but Not Anatomical Specialization.

Mechanical allodynia (pain to normally innocuous tactile stimuli) is a widespread symptom of inflammatory and neuropathic pain. Spinal or medullary dorsal horn (SDH or MDH) circuits mediating tactile sensation and pain need to interact in order to evoke mechanical allodynia. PKCγ-expressing (PKCγ) interneurons and inhibitory controls within SDH/MDH inner lamina II (II) are pivotal in connecting touch and pain circuits.

Dual enkephalinase inhibitor PL37 as a potential novel treatment of migraine: evidence from a rat model.

The dual enkephalinase inhibitor PL37, a small molecule that protects enkephalins from rapid degradation, has demonstrated analgesic properties in animal pain models and in early human clinical trials. This study tested the antimigraine potential of PL37 on cutaneous mechanical hypersensitivity affecting cephalic regions in migraineurs. Using behavioural testing and c-Fos immunoreactivity in male rats, we investigated the effects of single (oral or intravenous) and repeated oral administration of PL37 on changes in cutaneous mechanical sensitivity and sensitization of the trigeminocervical complex induced by repeated administration of the nitric oxide donor, isosorbide dinitrate.

Chronic facial inflammatory pain-induced anxiety is associated with bilateral deactivation of the rostral anterior cingulate cortex.

Patients with chronic pain, especially orofacial pain, often suffer from affective disorders, including anxiety. Previous studies largely focused on the role of the caudal anterior cingulate cortex (cACC) in affective responses to pain, long-term potentiation (LTP) in cACC being thought to mediate the interaction between anxiety and chronic pain. But recent evidence indicates that the rostral ACC (rACC), too, is implicated in processing affective pain.

Postnatal development of inner lamina II interneurons of the rat medullary dorsal horn.

Pain processing in young mammals is immature. Despite the central role of the medullary dorsal horn (MDH) in processing orofacial sensory information, the maturation of the neurons within the MDH has been largely overlooked. Combining in vitro electrophysiological recordings and 3D morphological analysis over the first postnatal month in rats, we investigated the age-dependent development of the neurons within the inner lamina II (IIi) of the MDH.

Improved potency of pyridin-2(1H)one derivatives for the treatment of mechanical allodynia.

Mechanical allodynia, a painful sensation caused by innocuous touch, is a major chronic pain symptom, which often remains without an effective treatment. There is thus a need for new anti-allodynic treatments based on new drug classes. We recently synthetized new 3,5-disubstituted pyridin-2(1H)-one derivatives.

Characteristics of pain in patients with pituitary adenomas: A cross-sectional study.

Background: This study determines the prevalence and particularities of headache and pain with neuropathic characteristics (NC) in a large French group of patients with pituitary adenoma (PA).

Methods: Analysis of validated self-administered questionnaires, radiological characteristics and treatment strategies of PA was performed.

Results: Of the 221 sent questionnaires, 146 could be used for statistical analysis, 50% of which were completed by women.

Five Predictors Affecting the Prognosis of Patients with Severe Odontogenic Infections.

: Dental cellulitis management is no longer a simple procedure, as more and more patients are needing long-time hospitalization, several surgeries and intensive care follow-up. This prospective study seeks to highlight criteria that can split patients with severe odontogenic infection into two groups: those with simple evolution and those for whom complex management is necessary. : In this observational study, all patients considered with a severe odontogenic infection (which necessitated hospital admission, intravenous antibiotics and general anaesthesia) were enrolled between January 2004 and December 2014 from Clermont-Ferrand University Hospital (France).

Ketamine-Magnesium for Refractory Chronic Cluster Headache: A Case Series.

Objectives: To evaluate the safety and efficacy of ketamine-magnesium combination to reduce attacks in a series of patients with refractory chronic cluster headache (rCCH).

Background: Refractory chronic cluster headache (CCH) is a rare but highly debilitating condition that needs new treatment options. A previous publication reported that a single infusion of ketamine-magnesium combination was effective in 2 patients with rCCH.

High Prevalence of Headaches During Covid-19 Infection: A Retrospective Cohort Study.

Objectives: To document the prevalence of new headaches in patients with Covid-19 infection and the potential association with other neuro-sensorial symptoms (anosmia and ageusia). The persistence of these symptoms 1 month after recovery was also documented.

Background: Headaches are a very common symptom of viral infections.

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.