Canal lombaire étroit. Corrélation entre imagerie et mobilité chez des sujets présentant une sténose canalaire lombaire

La sténose du canal médullaire lombaire peut aujourd'hui se traiter de deux façons différentes à savoir le traitement non- chirurgical (physiothérapie, AINS, infiltrations de corticostéroïdes) pour les patients souffrant de symptômes modérés et le traitement chirurgical (décompression canalaire) pour les patients avec des symptômes graves et des déficits fonctionnels. Plusieurs études ont tenté de comparer ces deux approches thérapeutiques. Pour ce faire, on se servit de questionnaires d'évaluation subjective des capacités fonctionnelles (Oswestry Disability Index) souvent associés à des mesures des capacités de marche en laboratoire.¦Notre étude utilise des capteurs gyroscopiques placés sur le corps des sujets afin de mesurer des paramètres de positions, de transferts de position et de la marche pendant 5 jours consécutifs. Cette méthode nous permet d'effectuer ces mesures objectives dans le cadre de vie des patients, dans leurs activités quotidiennes. Nous espérons ainsi obtenir des résultats qui soient plus représentatifs de leur mobilité.¦Dans le cadre de mon travail de master, je me suis concentré sur la phase pilote d'une étude du Dr Schizas. Cette phase ne regroupe qu'un nombre limité de sujets (14) répartis en deux groupes de 7 suivant le traitement reçu (chir. contre non-chir). Nous avons alors émis trois hypothèses. La première dit que, avant traitement, les patients non-opérés marchent mieux que les patients destinés à la chirurgie (symptômes moins intenses). La deuxième postule que le traitement chirurgical permet d'atténuer suffisamment les symptômes pour que les capacités de marche se rapprochent de celles des patients non opérés avant traitement (efficacité de la chirurgie). Pour finir, notre dernière hypothèse prétend que, après la chirurgie, les patients opérés voient une amélioration de leur capacité de marche par rapport à celles qu'ils avaient avant l'intervention. 4 paramètres ont été retenus afin de caractériser la marche: la longueur des pas, la vitesse, la cadence des pas et la distance parcourue. C'est à partir des moyennes et des coefficients de variabilité de ces paramètres que nous avons effectué nos comparaisons.¦Après l'analyse de nos résultats, il s'avère que nos valeurs tendent à valider nos trois hypothèses à quelques exceptions près. Hypothèse n°1: avant traitement, les patients non destinés à la chirurgie marchent plus vite (2.96 contre 2.87 P 0.84) et avec une cadence des pas plus importante (101.78 contre 94.59 P 0.047). Seule la longueur des pas est plus importante chez les futurs opérés (1.01 contre 0.96 P 0.72). Les coefficients de variabilité (CV) sont tous plus faibles chez les non-opérés (marche plus homogène). Concernant notre 2ème hypothèse, nous sommes plutôt satisfaits des résultats. A 3 mois après la chirurgie, les patients opérés, comparés aux non-opérés avant traitement ont une longueur de pas similaire (1.02 contre 0.96 P 0.70) et une vitesse plus importante (3.08 contre 2.96 P 0.83). Seule la cadence des pas est plus élevée chez les non-opérés (101.78 contre 100.23 P 0.72). Les CV confirment également un rapprochement des capacités de marche de nos patients opérés de celles des non-opérés. Pour la troisième hypothèse, nous sommes heureux de constater que les moyennes et les CV sont tous en accord avec l'idée de base. A trois mois post-traitement les patients opérés font des pas de longueur similaire (1.02 contre 1.01 P 0.93), marchent plus vite (3.08 contre 2.89 P 0.52) et à une cadence plus importante (100.23 contre 94.59 P 0.19).¦Avec seulement 14 patients, il est bien clair que ces résultats n'ont que peu de valeur statistique. Cependant, ces résultats nous encouragent à poursuivre cette étude sur un collectif de patients plus important dans le but de mieux comprendre les troubles de la mobilité des personnes atteintes de canal lombaire étroit.

Erosion and channel change as factors of landslides and valley formation in Champlain sea clays: The Chacoura river, Quebec, Canada

The Champlain Sea clays of Eastern Canada are incised by numerous rivers. Their slopes have been modified by landslides: on the Chacoura River near Trois-Rivières (Quebec), several large landslide scars, more or less recent, are visible. The role of erosion (channel incision, lateral channel migration and erosion of slopes due to agricultural drainage) as a trigger of these landslides is important. The aim of this study is to understand how erosion and landslides are related to valley development. From a detailed analysis of aerial photographs and DEMs, a map of the phenomena has been drawn by identifying various elements such as landslides, limits of the slope, position of the channel, and the area covered by forest. It is shown that channel change and erosion are strongly linked to landslides by the fact that they change the bank morphology in an unstable way. A slide in itself is a natural way for the slope to achieve stability. But when it occurs in a stream, it creates a disturbance to the stream flow enhancing local erosion which may change the river path and generate more erosion downstream or upstream resulting in more slides. Cross-valley sections and a longitudinal profile show that landslides are a major factor of valley formation. It appears that the upper part of the Chacoura River valley is still unaffected by landslides and has V-shaped sections. The lower part has been subject to intense erosion and many landslide scars can be seen. This shows that the valley morphology is transient, and that future activity is more likely to occur in the upper part of the river. Therefore the identification of areas prone to erosion will help determine the possible location of future large landslides just like the ones that occurred in the lower part.

Horizontal vestibulo-ocular reflex dynamics in acute vestibular neuritis and viral labyrinthitis: evidence of otolith-canal interaction.

OBJECTIVE: To evaluate the dynamic properties of the horizontal vestibulo-ocular reflex (h-VOR) in the acute stage of two common labyrinthine diseases that provoke severe attacks of vertigo with spontaneous nystagmus: vestibular neuritis (vestibular loss alone) and viral labyrinthitis (cochleovestibular loss). MATERIAL AND METHODS: Sixty-three patients were investigated: 42 were diagnosed with vestibular neuritis and 21 with viral labyrinthitis. The h-VOR function was evaluated by conventional caloric and impulsive testing. A simplified model of vestibular function was used to analyze the vestibulo-ocular response to rotational stimulation. RESULTS: The results showed a significant difference in h-VOR characteristics between the two pathologies. Patients with vestibular neuritis exhibited a strong horizontal semicircular canal deficit, but no h-VOR asymmetry between the two rotational directions. In contrast, patients with viral labyrinthitis demonstrated moderate canal paresis and a marked h-VOR deficit in rotation toward the affected ear. CONCLUSION: These findings support the hypothesis that the h-VOR dynamic asymmetry that occurs after an acute unilateral inner ear lesion is not due to canal dysfunction alone, but involves complex adaptive changes in the central VOR that may implicate the otolith system. Based on histopathologic and clinical differences in the two pathologies reported in the literature, we postulate that this otolith-canal interaction is mainly linked to the loss of saccular function.

Hémorragie par le canal de Wirsung: forme rare d'hémorragie digestive haute. A propos d'une observation [Hemorrhage through Wirsung's duct: rare form of upper gastrointestinal hemorrhage. A case report].

The case of a 41-year-old alcoholic patient who presented with massive upper gastrointestinal bleeding is reported. The diagnosis was established rapidly by endoscopy which revealed bleeding through the papilla of Vater. Selective angiography of the superior mesenteric artery opacified the pancreatic duct as well as the duodenum. CT scan showed signs of chronic pancreatitis. Because of the recurrence of bleeding and shock, an urgent operation was necessary and a Whipple procedure was performed. Recovery was complete. The clinical presentation, the etiology, the diagnostic modalities and the treatment of this particular condition are discussed. Usually, hemorrhage through the pancreatic duct presents as repeated episodes of upper gastrointestinal bleeding with no source found at endoscopy. The presence of chronic pancreatitis or of epigastric pain during bleeding should suggest the diagnosis. Upper gastrointestinal endoscopy and angiography are the principal diagnostic tools. Definitive treatment requires surgery, and resection in most of the cases.

Could concomitant radio-chemotherapy improve the outcomes of early-stage node negative anal canal cancer patients? A retrospective analysis of 122 patients.

One hundred twenty-two early-stage anal canal cancer patients (median age: 69 years) were treated with curative radiotherapy with (70 patients) or without (52 patients) concomitant chemotherapy. Median follow-up was 65 months (range: 4-238). At multivariate analysis, concomitant chemotherapy significantly improved local control (p = .007). Local control significantly influenced all considered endpoints, except the metastases free survival. The global rates of G3-G4 acute and late toxicity were 13.1% and 8.2%, respectively, and they were not increased by concomitant chemotherapy. Finally, concomitant chemotherapy is efficacious and safe in the treatment of T1-2N0 anal canal cancer patients and should be prospectively studied.

Helical tomotherapy for the treatment of anal canal cancer: a dosimetric comparison with 3D conformal radiotherapy.

AIMS AND BACKGROUND: The standard treatment of anal canal cancer (ACC) is combined chemotherapy and radiation therapy (RT), which is complex because of the shape of the target volumes and the need to minimize the irradiation of normal pelvic structures. In this study we compared the dosimetric results of helical tomotherapy (HT) plans with traditional 3D conformal RT (3DRT) plans for the treatment of ACC. METHODS AND STUDY DESIGN: Twelve patients (median age 57 years, range 38-83; F/M 8/4) treated with HT and concurrent chemotherapy for locally advanced ACC were selected. All had histologically confirmed squamous-cell carcinoma. A clinical target volume including the tumor and pelvic and inguinal lymph nodes was treated with HT to a total dose of 36 Gy in 1.8-Gy daily fractions. Then a sequential boost of 23.4 Gy in 1.8-Gy daily fractions (total dose 59.4 Gy) was delivered to the tumor and involved nodes. For all 12 patients, 3DRT plans were generated for comparison. Treatment plans were evaluated by means of standard dose-volume histograms. Dose coverage of the planning target volumes (PTVs), homogeneity index (HI), and mean doses to organs at risk (OARs) were compared. RESULTS: The coverage of PTV was comparable between the two treatment plans. HI was better in the HT vs. 3DRT plans (1.25 and 3.57, respectively; p<0.0001). HT plans resulted in better sparing of OARs (p<0.0001). CONCLUSIONS: HT showed superior target dose conformality and significant sparing of pelvic structures compared with 3DRT. Further investigation should determine if these dosimetric improvements will improve clinical outcomes regarding locoregional control, survival, and treatment-related acute and late morbidity.

Role of brachytherapy in the treatment of cancers of the anal canal. Long-term follow-up and multivariate analysis of a large monocentric retrospective series.

BACKGROUND AND PURPOSE: There are few data on long-term clinical results and tolerance of brachytherapy in anal canal cancer. We present one of the largest retrospective analyses of anal canal cancers treated with external beam radiotherapy with/without (±) chemotherapy followed by a brachytherapy boost. MATERIALS AND METHODS: We performed a retrospective analysis of clinical results in terms of efficacy and toxicity. The impact of different clinical and therapeutic variables on these outcomes was studied. RESULTS: From May 1992 to December 2009, 209 patients received brachytherapy after external beam radiotherapy ± chemotherapy. Of these patients, 163 were stage II or stage IIIA (UICC 2002) and 58 were N1-3. According to age, ECOG performance status (PS), and comorbidities, patients received either radiotherapy alone (58/209) or radiochemotherapy (151/209). The median follow-up was 72.8 months. The 5- and 10-year local control rates were 78.6 and 73.9 %, respectively. Globally, severe acute and late G3-4 reactions (NCI-CTC scale v. 4.0) occurred in 11.2 and 6.3 % of patients, respectively. Univariate analysis showed the statistical impact of the pelvic treatment volume (p = 0.046) and of the total dose (p = 0.02) on the risk of severe acute and late toxicities, respectively. Only six patients required permanent colostomy because of severe late anorectal toxicities. CONCLUSION: After a long follow-up time, brachytherapy showed an acceptable toxicity profile and high local control rates in patients with anal canal cancer.

Resultate und ausser- gewöhnliche Komplikationen der Chirurgie der Gehörgangexostosen [Results and extraordinary complications of surgery for exostoses of the external auditory canal].

We present a retrospective study on 22 operations of exostosis of the external auditory canal in 20 patients. 8 patients were passionated by water sports. The most frequent indication for surgery (13 operations) was recurrent external otitis or ceruminal obstruction. In 7 cases the need for a wider access to the middle ear indicated surgery. Surgery was usually performed as an outpatient procedure, maximum hospitalization was 3 days. The mean healing period was 6 (3-10) weeks. Mean follow up was 43 (3-110) months. There were no severe intraoperative complications such as facial paresis, lesions of the ossicles or of the inner ear. As intraoperative complications we found 2 perforations of the tympanic membrane, 2 expositions of the capsule of the mandibular joint, one of which was followed by chronic pain. As postoperative complications we found an early soft tissue stenosis of the external auditory canal and one late soft tissue stenosis which recurred after revision surgery. No recurrence of exostosis was seen. We describe an up to now unknown complication: the appearance of bilateral petrositis caused by staphylococcus epidermidis after bilateral surgery in an otherwise healthy patient. This study confirms that severe complications are rare, minor ones however relatively common. And that also minor complications may have a troublesome follow. Therefore and because of the potential of severe complications indication for surgery must be made cautiously and risks of the operation must not be underestimated.

Les WNK kinases et les effets de WNK3 sur l'activité du canal ENaC

Les WNK kinases sont une famille de sérine/thréonine protéines kinases, des enzymes capables de phosphoryler le résidu OH de sérine ou thréonine. Quatre membres (WNK 1-4) ont été identifiés, largement distribués dans les cellules et tissus des mammifères et dont les fonctions sont de réguler des canaux ioniques et cotransporteurs. Leur particularité se situe au niveau de leur structure puisque une lysine a été substituée par une cystéine dans le domaine catalytique, d'où leur nom « with-no-lysine kinase » (McCormick and Ellison, 2011). Leur rôle dans le bon fonctionnement du rein et plus particulièrement dans le contrôle et maintien du bilan hydro-sodé n'est plus à vérifier puisque des mutations dans WNK 1 et WNK 4 sont connues pour causer la maladie de l'hypertension familiale ou syndrome de pseudohypoaldostéronisme de type 2, aussi appelé syndrome de Gordon (ou Fhht = Familial hyperkalaemic hypertension) (Furgeson and Linas, 2010). Le syndrome de Gordon est une maladie génétique autosomale dominante caractérisée par une hypertension, une hyperkaliémie et une acidose métabolique. Les WNKs contrôlent de nombreux canaux et transporteurs dans le rein, devenant des acteurs importants dans la régulation du bilan sodique et potassique. Leurs effets sont nombreux et variables et les canaux jouant un rôle clé dans cette régulation sont ENaC, NCC et ROMK (Kahle et al., 2008). Dans ce travail, nous commencerons par une partie théorique faisant le point sur l'organisation des néphrons et la régulation du bilan sodique et les différents mécanismes entrant en jeu. Nous intégrerons des informations générales concernant les WNKs ainsi qu'une revue plus détaillée de leurs effets respectifs dans le néphron. Pour terminer, nous aborderons les résultats d'une expérience qui a été réalisée en laboratoire sur des oocytes de Xenopus laevis. L'implication de WNK1 et WNK4 dans le contrôle du sodium ayant déjà été prouvée à de nombreuses reprises, nous nous sommes intéressés ici aux effets de WNK3 sur le canal ENaC ainsi que l'implication de Nedd4-2 dans ce procédé.