Vincent Tiffreau

Low back pain is a common, expensive, and disabling condition in industrialized countries. There is still no consensus for its ideal management. Believing in the beneficial effect of traction, we developed a novel external dynamic distraction device. The purpose of this work was to demonstrate that external distraction allows limiting the pressure exerted in standing-up position on the lower intervertebral discs. Numerical and cadaveric studies were used as complementary approaches. Firstly, we implemented the device into a numerical model of a validated musculoskeletal software (Anybody Modeling System) and we calculated the lower disc pressure while traction forces were applied. Secondly, we performed an anatomical study using a non-formalin preserved cadaver placed in a sitting position. A pressure sensor was placed in the lower discs under fluoroscopic control through a Jamshidi needle. The intradiscal pressure was then measured continuously at rest while applying a traction force of 200 N. Both numerical and cadaveric studies demonstrated a decrease in intradiscal pressures after applying a traction force with the external device. Using the numerical model, we showed that tensile forces below 500 N in total were sufficient. The application of higher forces seems useless and potentially deleterious. External dynamic distraction device is able to significantly decrease the intradiscal pressure in a sitting or standing position. However, the therapeutic effects need to be proven using clinical studies.

The subsequent full-text publication of abstracts presented at a scientific congress reflects the latter's scientific quality. The aim of this paper was to evaluate the publication rate for abstracts presented at the 2008 European Congress of Physical and Rehabilitation Medicine (ECPRM), characterize the publications and identify factors that were predictive of publication. It is a bibliography search. We used the PubMed database to search for subsequent publication of abstracts. We screened the abstracts' characteristics for features that were predictive of publication among abstracts features, such the status of the authors, the topic and the type of work. We performed univariate analyses and a logistic regression analysis. Of 779 abstracts presented at ECPRM 2008, 169 (21.2%) were subsequently published. The mean time to publication was 12±15.7 months and the mean impact factor of the publishing journals was 2.05±2.1. In a univariate analysis, university status (P<10-6), geographic origin (P=10-3), oral presentation (P<10-6), and original research (P<10-6) (and particularly multicentre trials [P<0.01] and randomized controlled trials [P=10-3]) were predictive of publication. In a logistic regression analysis, oral presentation (odds ratio [OR]=0.37) and university status (OR=0.36) were significant, independent predictors of publication. ECPRM 2008 publication rate and impact factor were relatively low, when compared with most other national and international conferences in this field. University status, the type of abstract and oral presentation were predictive of subsequent publication.

Charcot-Marie-Tooth type 1A disease (CMT1A) is a rare orphan inherited neuropathy caused by an autosomal dominant duplication of a gene encoding for the structural myelin protein PMP22, which induces abnormal Schwann cell differentiation and dysmyelination, eventually leading to axonal suffering then loss and muscle wasting. We favour the idea that diseases can be more efficiently treated when targeting multiple disease-relevant pathways. In CMT1A patients, we therefore tested the potential of PXT3003, a low-dose combination of three already approved compounds (baclofen, naltrexone and sorbitol). Our study conceptually builds on preclinical experiments highlighting a pleiotropic mechanism of action that includes downregulation of PMP22. The primary objective was to assess safety and tolerability of PXT3003. The secondary objective aimed at an exploratory analysis of efficacy of PXT3003 in CMT1A, to be used for designing next clinical development stages (Phase 2b/3). 80 adult patients with mild-to-moderate CMT1A received in double-blind for 1 year Placebo or one of the three increasing doses of PXT3003 tested, in four equal groups. Safety and tolerability were assessed with the incidence of related adverse events. Efficacy was assessed using the Charcot-Marie-Tooth Neuropathy Score (CMTNS) and the Overall Neuropathy Limitations Scale (ONLS) as main endpoints, as well as various clinical and electrophysiological outcomes. This trial confirmed the safety and tolerability of PXT3003. The highest dose (HD) showed consistent evidence of improvement beyond stabilization. CMTNS and ONLS, with a significant improvement of respectively of 8% (0.4% - 16.2%) and 12.1% (2% - 23.2%) in the HD group versus the pool of all other groups, appear to be the most sensitive clinical endpoints to treatment despite their quasi-stability over one year under Placebo. Patients who did not deteriorate over one year were significantly more frequent in the HD group. These results confirm that PXT3003 deserves further investigation in adults and could greatly benefit CMT1A-diagnosed children, usually less affected than adults. EudraCT Number: 2010-023097-40. ClinicalTrials.gov Identifier: NCT01401257 . The Committee for Orphan Medicinal Products issued in February 2014 a positive opinion on the application for orphan designation for PXT3003 (EMA/OD/193/13).

In a 12-year old girl suffering from autosomal recessive axonal Charcot-Marie-Tooth (CMT) neuropathy, pes cavovarus was treated with botulinum toxin injection in the tibialis posterior. The patient underwent a clinical evaluation, video analysis of spatiotemporal gait parameters and dynamic foot plantar pressure assessment before treatment and then two weeks, three months and six months thereafter. The video gait analysis revealed a decrease in varus during the swing phase of gait. The dynamic foot plantar pressure decreased by 50% in the excessive pressure at the side of the foot six months after the injection (maximal pressure=42.6N/cm2 before treatment and 18.9 N/cm2 after 6 month). Botulinum toxin injection appears to be an efficacious means of correcting pes cavovarus in CMT disease. A larger-scale clinical trial is now required to evaluate the putative longer-term preventive effect of this treatment on the pes cavus deformity.