Research directions
Evaluation of the satisfaction of the patient care offered at the Pain Center of the CHUV on chronic pain patients.
Chronic pain is defined as pain that persists beyond 3 months. The burden on the healthcare system is consequential: chronic pain is a significant cause of disability, not only physically but also psychologically and socially. Nineteen percent of the European population suffers from chronic pain and 40% of them are dissatisfied with their treatment. In the Pain Center of the CHUV, we propose several interventional pain management therapies depending on the indication such as epidural injections, peripheral nerve block or intravenous lidocaine or ketamine infusion. Pain is a difficult outcome to measure due to its multifaceted (sensory /emotional /cognitive /social) and subjective nature.
Patient satisfaction is an important and commonly used indicator for measuring the quality of health care. The need to explore patient satisfaction is high because of the increasing demand for scientifically valid demonstrations of treatment efficacy and patient satisfaction in chronic pain care. This will allow us to improve the patient care.
The aims of the project are to:
1. Evaluate the satisfaction of care offered at the Pain Center of the CHUV from chronic pain patients.
2. Characterize the type of patients attending the ambulatory consultation of the Pain Centre.
3. Evaluate the effects of the different interventional pain management therapies on pain and other factors affecting the quality of life of the patients of the Pain Center.
Evaluation of the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the symptoms of long COVID patients
Long COVID involves a complex heterologous range of symptoms and leads to disability. It has been suggested that long COVID symptoms may be due to sustained inflammatory responses and prolonged immune response after infection. Transcutaneous auricular vagus nerve stimulation (taVNS) has anti-inflammatory effects and can be self-administered. It is an at-home and noninvasively method. A recent study showed a trend suggesting that taVNS may have a mild to moderate effect in reducing mental fatigue symptoms. Patients suffering from long COVID symptoms are offered to test taVNS therapy at the Pain Center of the CHUV.
This project will evaluate the taVNS therapy as a tool to alleviate different symptoms of the long COVID patients.
This project is a unique opportunity to work on clinical (reporting to patients) and research aspects (evaluation of the taVNS therapy) of pain management of long COVID patient.
The aims of the project are:
1. Evaluate the efficacy of the taVNS on the symptoms of long COVID patients.
2. Validate the questionnaires chosen for the different symptoms of long COVID in the population followed at the Pain Center of the CHUV.
Evaluation des paramètres de la marche à l'aide d'accéléromètres : une mesure objective de l'efficacité des blocs des nerfs géniculés en cas de gonalgies chroniques ?
Les gonalgies sont fréquentes au sein de la population, et causées le plus souvent par l'arthrose, généralement de manière chronique. Cette pathologie touche 25% de la population suisse et 19% des moins de 66 ans. Au vu du vieillissement de la population et de l'épidémie d'obésité, principaux facteurs de risque de l'arthrose primaire, on peut s'attendre à ce que cette augmentation continue. Il y donc un réel besoin d'identifier les stratégies ayant le meilleur rapport coût-efficacité pour la prévention et la prise en charge de cette pathologie.
L'ablation des nerfs géniculés par radiofréquence/cryothérapie en antalgie interventionnelle est une procédure efficace pour le traitement de la douleur chronique du genou. Cependant, les critères de sélection des patients, les indications précises, les protocoles cliniques et leur efficacité sont encore peu définis et peu étudiés.
Avant de procéder à une ablation thérapeutique, le clinicien effectue des blocs diagnostiques, càd une infiltration test d'anesthésique local autour des nerfs. Ce bloc diagnostic permet d'une part de confirmer que l'origine des douleurs est transmise par ces nerfs et d'autre part d'estimer si le patient pourrait bénéficier de cette intervention (valeur pronostique).
Une mesure objective et fonctionnelle permettrait éventuellement une meilleure analyse de l'efficacité d'un bloc diagnostique et ainsi une meilleure sélection des candidats
Cette étude vise à tester les bases méthodologiques permettant de collecter une mesure objective fonctionnelle de la marche à l'aide d'accéléromètres Physilog®5 développés par Gait Up. Ce pilote permettra de sélectionner les mesures de l'accéléromètre les plus utiles ainsi que leur variabilité en vue du développement d'une étude clinique évaluant l'utilité de ces mesures pour prédire l'effet de l'ablation par radiofréquence.
L'étudiant sera impliqué dans le recrutement des patients, collecte et analyse des données de l'étude.
Exploring the pathophysiology of neuroinflammation in chronic pain condition
Pain research points to an important role of microglia (macrophage-like cells that regulate homeostasis in the central nervous system) in the spinal cord and macrophage in the dorsal root ganglion in the development of chronic pain. Both react strongly after surgical incision and nerve injury, in parallel to the development of chronic pain. This is characterized by increased proliferation, morphological changes, and release of proinflammatory and algesic cytokines.
Our past work has shown that blocking this reactivity, by targeting specific peripheral nerves significantly prevents the development of injury-induced chronic pain. We discovered that microglia/macrophages modify their membrane potential in early timepoints after nerve injury, mainly related to modulation of Kir potassium channels.
We now thrive to unravel the links between membrane potential of microglia/macrophages and their phenotype / pain hypersensitivity and how to target membrane potential therapeutically. The central hypothesis is that membrane potential is an early and key determinant of their reactivity.
Aims of the project:
1) The first aim is to describe the role of microglia/macrophages membrane potential modification in a neuropathic pain model, to explore the causing determinants and inversely to determine the consequences of modifying the membrane potential on their phenotype.
2) The second aim is to discover the contributing part of early abnormal peripheral activity to their reactivity. Mainly we will investigate which primary afferent activity, type of fiber (C-, Adelta- or Abeta-fibers), duration, or intensity is necessary to induce their reactivity.
The following techniques will be used:
- Isolation and culture of DRG neurons, macrophages and microglia
- FACS sorting
- In vitro optogenetic stimulations
- In vitro mobility/phagocytic assays
- Tissue collection (perfusion, dissection) and preparation
- Immunohistochemistry
