Transcultural adaptation and French validation of the Pain Sensitivity Questionnaire.

PURPOSE: To validate a French translation of the Pain Sensitivity Questionnaire (PSQ), which is a valuable tool to predict an individual's natural disposition to feel pain that could be used after surgery. METHODS: We studied content validity, internal consistency, convergent validity (anxiety, depression and catastrophism) and test-retest reliability of the French version of the PSQ (PSQ-F) in 146 patients either before scheduled surgery or during pregnancy; then, convergent and concurrent validity in 85 healthy volunteers submitted to nociceptive tests. RESULTS: Internal consistency of the PSQ-F was found to be excellent, with Cronbach's α at 0.866, 0.886, and 0.927, respectively for its "minor", "moderate" and "total" scores. Test-retest reliability was significant, with intraclass correlation coefficients at 0.629, 0.629, and 0.635, respectively for the above- mentioned scores. These three scores correlated with anxiety, depression and catastrophizing scores in patients, but not in healthy volunteers, possibly because of low and few variant psychometric scores in this group. They were inversely correlated to the temperature needed to evoke heat pain rated 6 out of 10, but not to the mechanical pain threshold (electronic von Frey), nor to the heat pain threshold. Finally, they directly correlated to the pain induced by the cold pressor test (minor and total scores only). DISCUSSION: This validated version can now be used by French-speaking researchers and physicians. TRIAL REGISTRATION: www.ClinicalTrials.gov (NCT03113903); 14 April, 2017.

RéSUMé: OBJECTIF: Valider une version en langue française du Pain Sensitivity Questionnaire (PSQ), qui permet d'identifier la sensibilité naturelle d'un individu à la douleur, ce qui pourrait être applicable après une chirurgie. MéTHODE: Nous avons étudié la validité de structure interne, la validité convergente (anxiété, dépression et catastrophisme) et la reproductibilité par test-retest de la version française du PSQ (PSQ-F) chez 146 patients en situation préopératoire ou en cours de grossesse, puis la validité convergente et de structure contre critère externe chez 85 sujets volontaires sains soumis à des tests nociceptifs. RéSULTATS: La consistance interne du PSQ-F était excellente avec des α de Cronbach égaux à 0,866, 0,886 et 0,927, respectivement pour ses scores « mineur ¼, « modéré ¼ et « total ¼. La reproductibilité était satisfaisante, avec des coefficients de corrélation intra-classe, respectivement à 0,629, 0,629 et 0,635. Ces trois scores étaient corrélés à l'anxiété, la dépression et le catastrophisme, mais pas chez les volontaires sains qui avaient des scores psychométriques bas et peu variables. Ils étaient anti-corrélés au seuil de nociception thermique chaud en épreuve supra-liminale, mais pas au seuil de nociception mécanique ponctuelle, ni au seuil de nociception thermique chaud en épreuve liminale. Enfin, les scores « mineur ¼ et « total ¼ étaient corrélés à la douleur moyenne ressentie à l'immersion du pied en eau froide. CONCLUSION: Cette version validée peut être utilisée par les chercheurs et cliniciens francophones. ENREGISTREMENT DE L'éTUDE: www.ClinicalTrials.gov (NCT03113903); le 14 avril 2017.

Oral magnesium treatment in patients with neuropathic pain: a randomized clinical trial.

Studies in animals and in patients have suggested that magnesium (Mg), a physiological blocker of N-methyl-D-aspartate receptor, could have an antinociceptive effect in painful situations. This randomised, double-blind, controlled trial in two parallel groups aims at studying oral Mg effects in patients with neuropathic pain. It explores the impact of Mg (6x419 mg Mg chloride/capsule per day for a month), versus placebo (lactose) on pain [Neuropathic Pain Symptom Inventory (NPSI) and numerical scale (NS)], and on quality of life indicators after 4 weeks treatment, in 45 patients suffering from neuropathic pain. After 4 weeks, NPSI, NS and quality of life are not different in the Mg and placebo groups, while the frequency of pain paroxysms diminishes and the emotional component improves in the Mg group compared to baseline. This clinical trial displays a large placebo response and could not demonstrate any significant difference in pain alleviation after a month of oral treatment between Mg and placebo in patients suffering from neuropathic pain. Frequency of pain paroxysms and emotional impact will be explored in future studies as they constitute major aspects of pain alleviation in chronic pain conditions.