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Abstract: Objectives: Neurologic TOS with amyotrophy is exceptional and the diagnosis is usually delayed compromising the outcome after treatment. The aims of this study were to define clinical features, anatomical causes, surgical results and prognostic factors of this disease. Methods: All of the TOS with objective neurologic deficit treated in our unit between 1989 and 2011 were assessed retrospectively. Thirty cases were identified in 28 patients (two bilateral cases). The mean-age was 44years (16 to 70). Results: Muscular atrophy always predominated in the lateral thenar muscles. Seventeen also had sensory symptoms. Twenty-two patients (24 cases) were surgically treated. Twenty-three cases could be assessed with a mean follow-up of 39months. Recovery was complete in four cases (17%), marked in nine cases (39%) and minimal in ten cases (44%). Conclusions: Neurological TOS with objective manifestations have to be distinguished from other types of neurological TOS. Muscular atrophy in the hand appears insidiously and the pain, which is inconstant, stays always in the background. Duration of symptoms before surgical treatment is the main prognostic factor. [Copyright &y& Elsevier]

Résumé: Les compressions du nerf médian au coude et à l’avant-bras représentent 7 à 10 % des mononeuropathies du nerf médian. La littérature distingue de façon discutable deux syndromes distincts : le syndrome du rond pronateur et celui du nerf interosseux antérieur. Nous rapportons une série rétrospective de 35 cas de compression proximale du nerf médian, incluant 13 cas déjà évalués en 2001, chez 34 patients pris en charge entre 1994 et 2011. La série était composée de 15 hommes et 19 femmes ayant un âge moyen de 57ans. Les symptômes subjectifs, associés ou non à un déficit, étaient le principal motif de consultation. La neurographie montrait des anomalies dans 18 cas et la myographie des anomalies dans 30 cas. Au moins un site de compression a été retrouvé à l’intervention. Parmi les 31 cas revus avec un recul moyen de 69 mois, dont neuf des 13 cas déjà évalués en 2001, 28 se considéraient améliorés, et tous sauf un avaient été objectivement améliorés par la chirurgie. Les neuf cas déjà évalués en 2001 avaient de meilleurs résultats en 2011. Il n’y avait pas de critère clinique ou électroneuromyographique préopératoire permettant d’individualiser deux entités et la compression siégeait toujours sur le tronc du nerf médian. Sans amélioration après un traitement médical, le traitement chirurgical doit être proposé, tous les sites potentiels de compression doivent être explorés. Les patients doivent être informés que l’amélioration peut prendre plusieurs années. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Posterior interosseous nerve palsy is a rare syndrome frequently unrecognized, while the clinical presentation is characteristic: finger extension paresis associated with wrist extension in radially deviated position. Here, we assessed our results of surgical treatment. Methods: A 20-year retrospective study was carried out in our unit. Analysis of causes and an assessment of postoperative functional outcome were performed. Our study was compared with literature data. Results: Eighteen cases were treated with a predominance in men manual workers. The etiology of the posterior interosseous nerve palsy was tumor in four cases, traumatic in two cases, iatrogenic in two cases and idiopathic in ten cases. In seven of these ten cases, compression under the arch of the extensor carpi radialis brevis was found. The postoperative results were satisfactory with full recovery in nine out of fifteen cases treated by neurolysis, depending on the duration of the paralysis. In the literature, we found 264 cases over 50 years through a variety of clinical cases and five case series. A predominance of tumor etiology was found. Conclusion: Ignorance of the clinical presentation of a posterior interosseous nerve palsy frequently leads to misdiagnosis. Early complete neurolysis enables a satisfactory functional recovery. [Copyright &y& Elsevier]

GENETICS OF AMYOTROPHIC LATERAL SCLEROSIS. Approximately 10 to 15% of people with amyotrophic lateral sclerosis (ALS) have a family history of the disease. In 2/3 of them, but also in 10% of subjects without any family history of ALS, a pathogenic genetic variant can be identified. Many genes are involved, the four main ones being C9orf72 (which can also be responsible for dementia), SOD1, TARDBP and FUS. ALS of genetic origin is almost always inherited in an autosomal dominant pattern. The progress made in recent years in the knowledge of the genetic forms of ALS has led to a better understanding of the pathophysiology of the disease and has opened up new therapeutic avenues, some of which are already being explored. For all these reasons, it is now recommended that all patients with ALS, whether familial or not, undergo a genetic investigation, with analyses appropriate to their age and family history. When a pathogenic variant is found, it can then be sought in at-risk relatives who so desire. These tests must follow legally mandated procedures and can only be conducted in a specialized ALS center under the supervision of a geneticist after a thorough discussion of the personal and family implications of the result and written consent from the patient., Competing Interests: S. Weber déclare des interventions ponctuelles et avoir été pris en charge, à l’occasion de déplacement pour congrès, par Pfizer. P. Corcia déclare avoir participé à des activités de conseil pour Biogen, Amylyx, Cytokinetics et des essais cliniques pour Amylyx, Cytokinetics, Mitsubishi, AB Science, Sanofi, Alexion, Apellis, Orion Pharma. F. Viader déclare n’avoir aucun lien d’intérêts.

Diagnosis of amyotrophic lateral. SCLEROSIS Amyotrophic lateral sclerosis (ALS) is the most frequent motor neuron disorder in adult. In France, every day, 4 new cases are diagnosed. Although, ALS is currently considered easy to identify, in the presence of the combination of diffuse upper and lower motor neuron signs, the delay remains over 12 months for a disease with a median survival of 36 months. This finding strongly explains why clinicians feel uncomfortable for ascertaining the diagnosis especially during the early stages of the disease. Other explanations for such a delay might rely on the phenotypic heterogeneity of ALS and at least the absence of diagnostic marker that hampers the role of clinicians in their clinical practice., Competing Interests: P. Corcia déclare avoir été pris en charge, à l’occasion de déplacement pour congrès, par CSL Behrig, Teva et Biogenidec. S. Beltran déclare n'avoir aucun lien d'intérêts. P. Couratier déclare participer à des essais cliniques (Nogo A, Parexel) pour l’entreprise GSK et Cytokinetics, et avoir été pris en charge lors de congrès par Pfizer.

Epidemiology of amyotrophic lateral sclerosis. Amyotrophic lateral sclerosis (ALS) is the most common motorneuron disease. The incidence of ALS in France is 2.5/100 000 persons-years of follow-up, or 1,500 cases per year. The peak incidence is between 65 and 75 years. The prevalence of ALS is 8/100 000, or 6 000 cases in France with a sex ratio close to 1. The average survival time is close to 36 months after the onset of symptoms, with a large variation between patients. The main prognostic factors are the age of onset, initial site of involvement, the time to diagnosis, respiratory status and nutritional status. 5 to 10% of cases are family related to a mutation of the four major genes SOD1, FUS, TARDP and C9ORF72. In sporadic forms an interaction between a genetic susceptibility factor and an environmental factor is suspected. There is to date no association between exogenous risk factor for sporadic ALS occurrence of which could be demonstrated reproducibly with the notable exception of smoking., Competing Interests: P. Couratier déclare participer à des essais cliniques (Nogo A, Parexel) pour l’entreprise GSK et Cytokinetics, et avoir été pris en charge lors de congrès par Pfizer. P. Corcia déclare avoir été pris en charge, à l’occasion de déplacement pour congrès, par CSL Behrig, Teva et Biogenidec. G.Lautrette, M. Nicol, P.-M. Preux et B. Marin déclarent n'avoir aucun lien d'intérêts.

Although the pathophysiology of amyotrophic lateral sclerosis remains currently unknown, involvement of genetic factors is worldwide accepted as a key clue in the motor neuron death. Since 1993 and the discovery of mutation in the SOD1 gene, number of genes linked to or promoting ALS had always growing. Among them, only four (SOD1, TARDBP, FUS and C9ORF72 genes) are unanimously recognized as convincing causative genetic factors for more than 60% of familial and probably 10% of sporadic ALS cases. Geographic origin of the studied populations tends to become one of the major items in the gene-ALS relationship: this was extremely stressed for C9ORF72. Concerning susceptibility genes factors, an increase of the risk of ALS is clearly shown for SMN1 and ATXN2 genes and accepted for some VEGF haplotypes. Finally, some modulating effects might also exist as underline for the relationships between ApoE and ALS that differ between European and North American studies. In inherited ALS, The European Federation of Neurological Societies (EFNS) edited rules that gave a legal frame to situations for which research of mutations were justified. Progress in the field of genetic raises major questions concerning the relevance of genetic studies from asymptomatic relatives. This first implies that the mutation identified in the proband case is perfectly characterized as a pathogenic mutation., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Numerous biomarkers studies in ALS used targeted and non-targeted approaches, to help for the diagnosis, the prognosis or to identify new pathophysiological ways. The emerging approaches such as "omics" studies are very promising, but the practical and technical limits do not enable their optimization. Even if some biomarkers such as cystatin C or glutamate are highlighted in ALS, to date, no biomarker is currently used in routine practice. Diffusion-based neuroimaging has emerged as a tool to identify the involvement of the central neuron, but a recent meta-analysis shows a poor sensitivity and specificity. Spinal cord imaging has the advantage of simultaneoulsy investigating both the corticospinal tract and the peripheral motor neurons in the anterior horns of the spinal cord. Its interest to provide biomarkers in ALS is illustrated by recent studies that used a multiparametric approach. The limits of biomarkers studies are principally based on small cohorts, involving a control population who does not allow to assess specificity. The discrepancies between the biomarkers identified in the different studies are based on a strong heterogeneity of the disease and a lack of standardization of the research methodology, including the step of the validation of these molecules in independent cohorts. The perspectives in biomarker research in ALS imply the combination of analytical methods, human abilities and harmonization of the strategies., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Median nerve entrapment at the elbow and the proximal forearm represents 7 to 10 % of median nerve mononeuropathies. Literature distinguishes two distinct syndromes: the pronator syndrome and the anterior interosseous nerve syndrome. We report a retrospective series of 35 cases of proximal compression of the median nerve, including a previous study of 13 cases assessed in 2001. Thirty-four patients were operated on between 1994 and 2011. The series included 15 men and 19 women with a mean age of 57 years. Subjective complaints were the main reason of consulting with or without a deficit. All but one benefited from a preoperative electrical study. Neurography showed abnormalities in 18 cases and myography in 30 cases. At least one site of compression was found at surgery. Thirty-one cases, including nine of the 13 cases previously evaluated in 2001, were assessed with a mean follow-up of 69 months. Twenty-height considered them improved and all but one were objectively improved by surgery. The nine cases evaluated in 2001 had better results in 2011. Through this series and an exhaustive literature review, we concluded that there are no preoperative criteria that can differentiate a pronator teres syndrome from an anterior interosseous nerve syndrome. If no improvement occurs, surgical treatment should be proposed, one must then assess all potential sites of nerve entrapment. Patients must be informed that improvement can take several years., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)