13 research outputs found

    Improvement of Pyramidal Tract Side Effect Prediction Using a Data-Driven Method in Subthalamic Stimulation

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    International audienceOBJECTIVE: Subthalamic nucleus deep brain stimulation (STN DBS) is limited by the occurrence of pyramidal tract side effect (PTSE) induced by electrical activation of the pyramidal tract. Predictive models are needed to assist the surgeon during the electrode trajectory pre-planning. The objective of the study was to compare two methods of PTSE prediction based on clinical assessment of PTSE induced by STN DBS in patients with Parkinson's disease. METHODS: Two clinicians assessed PTSE postoperatively in 20 patients implanted for at least 3 months in the STN. The resulting dataset of electro-clinical tests was used to evaluate two methods of PTSE prediction. The first method was based on the volume of tissue activated (VTA) modeling and the second one was a data-driven based method named PyMAN (Pyramidal tract side effect Model based on Artificial Neural network) developed in our laboratory. This method was based on the nonlinear correlation between the PTSE current threshold and the 3D electrode coordinates. PTSE prediction from both methods was compared using Mann-Whitney U test. RESULTS: 1696 electro-clinical tests were used to design and compare the two methods. Sensitivity, specificity, positive and negative predictive values were significantly higher with the PyMAN method than with the VTA-based method (P \textless0.05). CONCLUSION: The PyMAN method was more effective than the VTA-based method to predict PTSE. SIGNIFICANCE: This data-driven tool could help the neurosurgeon in predicting adverse side-effects induced by DBS during the electrode trajectory pre-planning

    Image-guided preoperative prediction of pyramidal tract side effect in deep brain stimulation: proof of concept and application to the pyramidal tract side effect induced by pallidal stimulation

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    International audienceDeep brain stimulation of the medial globus pallidus (GPm) is a surgical procedure for treating patients suffering from Parkinson's disease. Its therapeutic effect may be limited by the presence of pyramidal tract side effect (PTSE). PTSE is a contraction time-locked to the stimulation when the current spreading reaches the motor fibers of the pyramidal tract within the internal capsule. The objective of the study was to propose a preoperative predictive model of PTSE. A machine learning-based method called PyMAN (PTSE model based on artificial neural network) accounting for the current used in stimulation, the three-dimensional electrode coordinates and the angle of the trajectory, was designed to predict the occurrence of PTSE. Ten patients implanted in the GPm have been tested by a clinician to create a labeled dataset of the stimulation parameters that trigger PTSE. The kappa index value between the data predicted by PyMAN and the labeled data was 0.78. Further evaluation studies are desirable to confirm whether PyMAN could be a reliable tool for assisting the surgeon to prevent PTSE during the preoperative planning

    L'habitat rural du second ùge du Fer: Rythmes de création et d'abandon au nord de la Loire

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    National audienceThis book, resulting from a national investigation conducted by Inrap, is an analytical presentation of the rhythms of the emergence and abandonment of rural settlements during the Second Iron Age in the northern half of France. Depending on the region studied, between the 5th century BC and the 1st century AD, rural settlements were established, and have now been studied through preventative archaeological operations covering large surfaces. These studied updated our knowledge of the Gallic countryside, integrating paleobotanical, zooarchaeological and climatic data. Through systematic studies and presentations, this book offers a useful glimpse into this period, linking archaeology and historic information, such as the Celtic migration, the arrival of the Belgians and the Gallic Wars.Cet ouvrage, issu d’une enquĂȘte nationale menĂ©e par l’Inrap, livre une prĂ©sentation analytique, Ă  l’échelle d’une grande moitiĂ© nord de la France, des rythmes de crĂ©ation et d’abandon des Ă©tablissements ruraux au second Ăąge du Fer. Selon les rĂ©gions Ă©tudiĂ©es, entre le Ve siĂšcle avant notre Ăšre et le Ier siĂšcle de notre Ăšre, furent crĂ©Ă©s des Ă©tablissements ruraux qui ont pu ĂȘtre Ă©tudiĂ©s grĂące aux opĂ©rations d’archĂ©ologie prĂ©ventive sur de larges superficies. Ces Ă©tudes ont renouvelĂ© nos connaissances sur les campagnes gauloises, intĂ©grant des donnĂ©es palĂ©obotaniques, archĂ©ozoologiques et climatiques. GrĂące Ă  l’aspect systĂ©matique des Ă©tudes et de la prĂ©sentation des recherches, cet ouvrage offre un bon aperçu de cette pĂ©riode, alliant l’archĂ©ologie et les faits historiques telles les migrations celtiques, l’arrivĂ©e des Belges et la guerre des Gaules

    L'habitat rural du second ùge du Fer: Rythmes de création et d'abandon au nord de la Loire

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    National audienceThis book, resulting from a national investigation conducted by Inrap, is an analytical presentation of the rhythms of the emergence and abandonment of rural settlements during the Second Iron Age in the northern half of France. Depending on the region studied, between the 5th century BC and the 1st century AD, rural settlements were established, and have now been studied through preventative archaeological operations covering large surfaces. These studied updated our knowledge of the Gallic countryside, integrating paleobotanical, zooarchaeological and climatic data. Through systematic studies and presentations, this book offers a useful glimpse into this period, linking archaeology and historic information, such as the Celtic migration, the arrival of the Belgians and the Gallic Wars.Cet ouvrage, issu d’une enquĂȘte nationale menĂ©e par l’Inrap, livre une prĂ©sentation analytique, Ă  l’échelle d’une grande moitiĂ© nord de la France, des rythmes de crĂ©ation et d’abandon des Ă©tablissements ruraux au second Ăąge du Fer. Selon les rĂ©gions Ă©tudiĂ©es, entre le Ve siĂšcle avant notre Ăšre et le Ier siĂšcle de notre Ăšre, furent crĂ©Ă©s des Ă©tablissements ruraux qui ont pu ĂȘtre Ă©tudiĂ©s grĂące aux opĂ©rations d’archĂ©ologie prĂ©ventive sur de larges superficies. Ces Ă©tudes ont renouvelĂ© nos connaissances sur les campagnes gauloises, intĂ©grant des donnĂ©es palĂ©obotaniques, archĂ©ozoologiques et climatiques. GrĂące Ă  l’aspect systĂ©matique des Ă©tudes et de la prĂ©sentation des recherches, cet ouvrage offre un bon aperçu de cette pĂ©riode, alliant l’archĂ©ologie et les faits historiques telles les migrations celtiques, l’arrivĂ©e des Belges et la guerre des Gaules

    Phenotype and imaging features associated with APP duplications

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    Abstract Background APP duplication is a rare genetic cause of Alzheimer disease and cerebral amyloid angiopathy (CAA). We aimed to evaluate the phenotypes of APP duplications carriers. Methods Clinical, radiological, and neuropathological features of 43 APP duplication carriers from 24 French families were retrospectively analyzed, and MRI features and cerebrospinal fluid (CSF) biomarkers were compared to 40 APP-negative CAA controls. Results Major neurocognitive disorders were found in 90.2% symptomatic APP duplication carriers, with prominent behavioral impairment in 9.7%. Symptomatic intracerebral hemorrhages were reported in 29.2% and seizures in 51.2%. CSF AÎČ42 levels were abnormal in 18/19 patients and 14/19 patients fulfilled MRI radiological criteria for CAA, while only 5 displayed no hemorrhagic features. We found no correlation between CAA radiological signs and duplication size. Compared to CAA controls, APP duplication carriers showed less disseminated cortical superficial siderosis (0% vs 37.5%, p = 0.004 adjusted for the delay between symptoms onset and MRI). Deep microbleeds were found in two APP duplication carriers. In addition to neurofibrillary tangles and senile plaques, CAA was diffuse and severe with thickening of leptomeningeal vessels in all 9 autopsies. Lewy bodies were found in substantia nigra, locus coeruleus, and cortical structures of 2/9 patients, and one presented vascular amyloid deposits in basal ganglia. Discussion Phenotypes associated with APP duplications were heterogeneous with different clinical presentations including dementia, hemorrhage, and seizure and different radiological presentations, even within families. No apparent correlation with duplication size was found. Amyloid burden was severe and widely extended to cerebral vessels as suggested by hemorrhagic features on MRI and neuropathological data, making APP duplication an interesting model of CAA
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