Long-term outcome after cognitive and behavioral regression in nonlesional epilepsy with continuous spike-waves during slow-wave sleep.

PURPOSE: To present the long-term follow-up of 10 adolescents and young adults with documented cognitive and behavioral regression as children due to nonlesional focal, mainly frontal, epilepsy with continuous spike-waves during slow wave sleep (CSWS). METHODS: Past medical and electroencephalography (EEG) data were reviewed and neuropsychological tests exploring main cognitive functions were administered. KEY FINDINGS: After a mean duration of follow-up of 15.6 years (range, 8-23 years), none of the 10 patients had recovered fully, but four regained borderline to normal intelligence and were almost independent. Patients with prolonged global intellectual regression had the worst outcome, whereas those with more specific and short-lived deficits recovered best. The marked behavioral disorders resolved in all but one patient. Executive functions were neither severely nor homogenously affected. Three patients with a frontal syndrome during the active phase (AP) disclosed only mild residual executive and social cognition deficits. The main cognitive gains occurred shortly after the AP, but qualitative improvements continued to occur. Long-term outcome correlated best with duration of CSWS. SIGNIFICANCE: Our findings emphasize that cognitive recovery after cessation of CSWS depends on the severity and duration of the initial regression. None of our patients had major executive and social cognition deficits with preserved intelligence, as reported in adults with early destructive lesions of the frontal lobes. Early recognition of epilepsy with CSWS and rapid introduction of effective therapy are crucial for a best possible outcome.

Bilateral symmetry of radial pulse in high-level tennis players: implications for the validity of central aortic pulse wave analysis.

BACKGROUND: Reconstruction of the central aortic pressure wave from the noninvasive recording of the radial pulse with applanation tonometry has become a standard tool in the field of hypertension. It is not presently known whether recording the radial pulse on the dominant or the nondominant side has any effect on such reconstruction. METHOD: We carried out radial applanation tonometry on both forearms in young, healthy, male volunteers, who were either sedentary (n = 11) or high-level tennis players (n = 10). The purpose of including tennis players was to investigate individuals with extreme asymmetry between the dominant and nondominant upper limb. RESULTS: In the sedentary individuals, forearm circumference and handgrip strength were slightly larger on the dominant (mean +/- SD respectively 27.9 +/- 1.5 cm and 53.8 +/- 10 kg) than on nondominant side (27.3 +/- 1.6 cm, P < 0.001 vs. dominant, and 52.1 +/- 11 kg, P = NS). In the tennis players, differences between sides were more conspicuous (forearm circumference: dominant 28.0 +/- 1.7 cm nondominant 26.4 +/- 1.5 cm, P < 0.001; handgrip strength 61.4 +/- 10.8 vs. 53.4 +/- 9.7 kg, P < 0.001). We found that in both sedentary individuals and tennis players, the radial pulse had identical shape on both sides and, consequently, the reconstructed central aortic pressure waveforms, as well as derived indices of central pulsatility, were not dependent on the side where applanation tonometry was carried out. CONCLUSION: Evidence from individuals with maximal asymmetry of dominant vs. nondominant upper limb indicates that laterality of measurement is not a methodological issue for central pulse wave analysis carried out with radial applanation tonometry.

Laser scanning-based recognition of rotational movements on a deep seated gravitational instability: The Cinque Torri case (North-Eastern Italian Alps)

The Cinque Torri group (Cortina d'Ampezzo, Italy) is an articulated system of unstable carbonatic rock monoliths located in a very important tourism area and therefore characterized by a significant risk. The instability phenomena involved represent an example of lateral spreading developed over a larger deep seated gravitational slope deformation (DSGSD) area. After the recent fall of a monolith of more than 10 000 m3, a scientific study was initiated to monitor the more unstable sectors and to characterize the past movements as a fundamental tool for predicting future movements and hazard assessment. To achieve greater insight on the ongoing lateral spreading process, a method for a quantitative analysis of rotational movements associated with the lateral spreading has been developed, applied and validated. The method is based on: i) detailed geometrical characterization of the area by means of laser scanner techniques; ii) recognition of the discontinuity sets and definition of a reference frame for each set, iii) correlation between the obtained reference frames related to a specific sector and a stable external reference frame, and iv) determination of the 3D rotations in terms of Euler angles to describe the present settlement of the Cinque Torri system with respect to the surrounding stable areas. In this way, significant information on the processes involved in the fragmentation and spreading of a former dolomitic plateau into different rock cliffs has been gained. The method is suitable to be applied to similar case studies.

Confounding effects of heart rate on pulse wave velocity in paced patients with a low degree of atherosclerosis.

BACKGROUND: Pulse wave velocity (PWV), an index of arterial wall stiffness, is modulated by blood pressure (BP). Whether heart rate (HR) is also a modulator of PWV is controversial. Recent research involving mainly patients with high aortic PWV have found either no change or a positive correlation between the two. Given that PWV is increasingly being measured in cardiovascular studies, the relationship between HR and PWV should be known in patients with preserved arterial wall elasticity. OBJECTIVE: The aim of this study was to evaluate the importance of HR as a determinant of the variability in PWV in patients with a low degree of atherosclerosis. DESIGN AND METHODS: Fourteen patients (five female, nine male; aged 68 +/- 8 years) were evaluated post pacemaker implantation due to sick sinus or carotid hypersensitivity syndromes. Carotid-femoral PWV was measured at rest and during atrial pacing at 80, 90 and 100 bpm (paced HR). Arterial femoral blood flow (AFBF) was measured by echodoppler. RESULTS: PWV increased from 6.2 +/- 1.5 m/s (mean +/- SD) during resting sinus rhythm (HR 62 +/- 8 bpm; mean +/- SD) to 6.8 +/- 1.0, 7.0 +/- 0.9, and 7.6 +/- 1.1 m/s at pacing rates of 80, 90 and 100 bpm, respectively (P < 0.0001). Systolic (SBP) and mean blood pressure (MBP) remained constant at all HR levels, whereas AFBF increased in a linear fashion. CONCLUSIONS: These results demonstrate that even in patients with a low degree of atherosclerosis, HR is a potential modulator of carotid-femoral PWV.

Criteria for establishing shielding of multi-detector computed tomography (MDCT) rooms.

The aim of this work is to compare two methods used for determining the proper shielding of computed tomography (CT) rooms while considering recent technological advances in CT scanners. The approaches of the German Institute for Standardisation and the US National Council on Radiation Protection and Measurements were compared and a series of radiation measurements were performed in several CT rooms at the Lausanne University Hospital. The following three-step procedure is proposed for assuring sufficient shielding of rooms hosting new CT units with spiral mode acquisition and various X-ray beam collimation widths: (1) calculate the ambient equivalent dose for a representative average weekly dose length product at the position where shielding is required; (2) from the maximum permissible weekly dose at the location of interest, calculate the transmission factor F that must be taken to ensure proper shielding and (3) convert the transmission factor into a thickness of lead shielding. A similar approach could be adopted to use when designing shielding for fluoroscopy rooms, where the basic quantity would be the dose area product instead of the load of current (milliampere-minute).

An introductory review on gravitational-deformation induced structures, fabrics and modeling

Recent studies have pointed out a similarity between tectonics and slope tectonic-induced structures. Numerous studies have demonstrated that structures and fabrics previously interpreted as of purely geodynamical origin are instead the result of large slope deformation, and this led in the past to erroneous interpretations. Nevertheless, their limit seems not clearly defined, but it is somehow transitional. Some studies point out continuity between failures developing at surface with upper crust movements. In this contribution, the main studies which examine the link between rock structures and slope movements are reviewed. The aspects regarding model and scale of observation are discussed together with the role of pre-existing weaknesses in the rock mass. As slope failures can develop through progressive failure, structures and their changes in time and space can be recognized. Furthermore, recognition of the origin of these structures can help in avoiding misinterpretations of regional geology. This also suggests the importance of integrating different slope movement classifications based on distribution and pattern of deformation and the application of structural geology techniques. A structural geology approach in the landslide community is a tool that can greatly support the hazard quantification and related risks, because most of the physical parameters, which are used for landslide modeling, are derived from geotechnical tests or the emerging geophysical approaches.

Detailed assessment of the deep-seated gravitational deformation at Stampa above Flåm, Norway

The unstable rock slope above the village of Flåm shows signs of active and postglacial gravitational deformation over an area of 11 km2. We performed detailed structural field mapping, annual differential Global Navigation Satellite System (GNSS) surveys, and generated a detailed topographic model based on airborne and terrestrial laser scanning. Kinematic analyses of the structural data indicates that deformation is complex and varies over the slope. Both sliding and toppling are locally feasible. Using differential GNSS, 18 points were measured annually over a period of up to 6 years. Two of these points show an average yearly movement of around 10 mm/year. They are located at the frontal cliff on almost completely detached blocks. Large fractures indicate deep-seated gravitational deformation of volumes up to 80 million m3, but the movement rates in these areas are below 2 mm/year. Based upon these combined observations, we interpret that small collapses of blocks along the frontal cliff will be more frequent. Larger collapses of free-standing blocks along the cliff with volumes >100,000 m3, thus large enough to reach the fjord, cannot be ruled out. A large collapse involving more than 10 million m3, however, is of very low likelihood at present.

Flow-R, a model for susceptibility mapping of debris flows and other gravitational hazards at a regional scale: some case studies

Every year, debris flows cause huge damage in mountainous areas. Due to population pressure in hazardous zones, the socio-economic impact is much higher than in the past. Therefore, the development of indicative susceptibility hazard maps is of primary importance, particularly in developing countries. However, the complexity of the phenomenon and the variability of local controlling factors limit the use of processbased models for a first assessment. A debris flow model has been developed for regional susceptibility assessments using digital elevation model (DEM) with a GIS-based approach.. The automatic identification of source areas and the estimation of debris flow spreading, based on GIS tools, provide a substantial basis for a preliminary susceptibility assessment at a regional scale. One of the main advantages of this model is its workability. In fact, everything is open to the user, from the data choice to the selection of the algorithms and their parameters. The Flow-R model was tested in three different contexts: two in Switzerland and one in Pakistan, for indicative susceptibility hazard mapping. It was shown that the quality of the DEM is the most important parameter to obtain reliable results for propagation, but also to identify the potential debris flows sources.

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography : a pilot study to etablish normative values for transcatheters therapies

Rapport de synthèse : Mesures de l'aorte ascendante par scanner synchronisé au rythme cardiaque: une étude pilote pour établir des valeurs normatives dans le cadre des futures thérapies par transcathéter. Objectif : L'objectif de cette étude est d'établir les valeurs morphométriques normatives de l'aorte ascendante à l'aide de l'angiographie par scanner synchronisé au rythme cardiaque, afin d'aider au développement des futurs traitements par transcathéter. Matériels et méthodes : Chez soixante-dix-sept patients (âgé de 22 à 83 ans, âge moyen: 54,7 ans), une angiographie par scanner synchronisé au rythme cardiaque a été réalisée pour évaluation des vaisseaux coronaires. Les examens ont été revus afin d'étudier l'anatomie de la chambre de chasse du ventricule gauche jusqu'au tronc brachio-céphalique droit. A l'aide de programmes de reconstructions multiplanaires et de segmentation automatique, différents diamètres et longueurs considérés comme importants pour les futurs traitements par transcathéter ont été mesurés. Les valeurs sont exprimées en moyennes, médianes, maximums, minimums, écart-types et en coefficients de variation. Les variations de diamètre de l'aorte ascendante durant le cycle cardiaque ont été aussi considérées. Résultats : Le diamètre moyen de la chambre de chasse du ventricule gauche était de 20.3+/-3.4 mm. Au niveau du sinus coronaire de l'aorte, il était de 34.2+/-4.1 mm et au niveau de la jonction sinotubulaire il était de 29.7+/-3.4 mm. Le diamètre moyen de l'aorte ascendante était de 32.7+/-3.8 mm. Le coefficient de variation de ces mesures variait de 12 à 17%. La distance moyenne entre l'insertion proximale des valvules aortiques et le départ du tronc brachio-céphalique droit était de 92.6+/-11.8 mm. La distance moyenne entre l'insertion proximale des valvules aortiques et l'origine de l'artère coronaire proximale était de 12.1+/-3.7 mm avec un coefficient de variation de 31%. La distance moyenne entre les deux ostia coronaires était de 7.2+/-3.1 mm avec un coefficient de variation de 43%. La longueur moyenne du petit arc de l'aorte ascendante entre l'artère coronaire gauche et le tronc brachio-céphalique droit était de 52.9+/-9.5 mm. La longueur moyenne de la continuité fibreuse entre la valve aortique et la valvule mitrale antérieure était de 14.6+/-3.3 mm avec un coefficient de variation de 23%. L'aire moyenne de la valve aortique était de 582.0+/-131.9 mm2. La variation du diamètre antéro-postérieur et transverse de l'aorte ascendante était respectivement de 8.4% et de 7.3%. Conclusion Il existe d'importantes variations inter-individuelles dans les mesures de l'aorte ascendante avec cependant des variations intra-individuelles faibles durant le cycle cardiaque. De ce fait, une approche personnalisée pour chaque patient est recommandée dans la confection des futures endoprothèses de l'aorte ascendante. Le scanner synchronisé au rythme cardiaque jouera un rôle prépondérant dans le bilan préthérapeutique. Abstract : The aim of this study was to provide an insight into normative values of the ascending aorta in regards to novel endovascular procedures using ECG-gated multi-detector CT angiography. Seventy-seven adult patients without ascending aortic abnormalities were evaluated. Measurements at relevant levels of the aortic root and ascending aorta were obtained. Diameter variations of the ascending aorta during cardiac cycle were also considered. Mean diameters (mm) were as follows: LV outflow tract 20.3+/-3.4, coronary sinus 34.2+/-4.1, sinotubular junction 29.7+-3.4 and mid ascending aorta 32.7+/-3.8 with coefficients of variation (CV) ranging from 12 to 17%. Mean distances (mm) were: from the plane passing through the proximal insertions of the aortic valve cusps to the right brachio-cephalic artery (BCA) 92.6111.8, from the plane passing through the proximal insertions of the aortic valve cusps to the proximal coronary ostium 12.1+/-3.7, and between both coronary ostia 7.2+/-3.1, minimal arc of the ascending aorta from left coronary ostium to right BCA 52.9 X9.5, and the fibrous continuity between the aortic valve and the anterior leaflet of the mitral valve 14.óf3.3, CV 13-43%. Mean aortic valve area was 582+-131.9 mm2. The variations of the antero-posterior and transverse diameters of the ascending aorta during the cardiac cycle were 8.4% and 7.3%, respectively. Results showed large inter-individual variations in diameters and distances but with limited intra-individual variations during the cardiac cycle. A personalized approach for planning endovascular devices must be considered.

Parametric estimation of pulse arrival time: a robust approach to pulse wave velocity.

Pulse wave velocity (PWV) is a surrogate of arterial stiffness and represents a non-invasive marker of cardiovascular risk. The non-invasive measurement of PWV requires tracking the arrival time of pressure pulses recorded in vivo, commonly referred to as pulse arrival time (PAT). In the state of the art, PAT is estimated by identifying a characteristic point of the pressure pulse waveform. This paper demonstrates that for ambulatory scenarios, where signal-to-noise ratios are below 10 dB, the performance in terms of repeatability of PAT measurements through characteristic points identification degrades drastically. Hence, we introduce a novel family of PAT estimators based on the parametric modeling of the anacrotic phase of a pressure pulse. In particular, we propose a parametric PAT estimator (TANH) that depicts high correlation with the Complior(R) characteristic point D1 (CC = 0.99), increases noise robustness and reduces by a five-fold factor the number of heartbeats required to obtain reliable PAT measurements.

Latest Miocene - Pliocene Larger Foraminifera and depositional environments of the carbonate bank of La Désirade Island, Guadeloupe (French Antilles)

In this paper we present first results of the study of planktonic Foraminifera, large benthic Foraminifera and carbonate facies of La Désirade, aiming at a definition of the age and depositional environments of the Neogene carbonates of this island. The study of planktonic Foraminifera from the Detrital Offshore Limestones (DOL) of the Anciènne Carrière allows to constrain the biochronology of this formation to the lower Zone N19 and indicates a latest Miocene to early Pliocene (5.48 - 4.52 Ma) age. Large benthic Foraminifera were studied both as isolated and often naturally split specimens from the DOL, and in thin sections of limestones from the DOL and the Limestone Table (LT). The assemblages of Foraminifera include Nummulitidae, Amphisteginidae, Asterigerinidae, Peneroplidae, Soritidae, Rotalidae (Globigerinidae: Globigerinoides, Sphaeroidenellopsis, Orbulina) and incrusting Foraminifera (Homotrema and Sporadotrema). The genera Amphistegina, Archaias and Operculina are discussed. Concerning the Nummulitidae we include both "Paraspiroclypeus" chawneri and "Nummulites" cojimarensis, as well as a newly described species, Operculina desiradensis new species, in the genus Operculina, because the differences between these 3 species are rather on the specific than the generic level, while their morphology, studied by SEM, is compatible with the definition of the genus Operculina (D'Orbigny1826, emend. Hottinger 1977). The three species can be easily distinguished on the basis of their differences in spiral growth: while O. desiradensis has an overall logarithmic spiral growth, O. cojimarensis and especially O. chawneri show a tighter and more geometric spiral growth. O. cojimarensis and O. chawneri were originally described from Cuba in outcrops originally dated as Oligocene and later redated as early Pliocene. Therefore, O. chawneri was considered until now as restricted to the early Pliocene. However, in the absence of a detailed morphometric and biostratigraphic study of the Caribbean Neogene nummulitids, it is difficult to evaluate the biochronologic range of these species.The history of the carbonates begins with the initial tectonic uplift and erosion of the Jurassic igneous basement of La Désirade, that must have occurred at latest in late Miocene times, when sea-level oscillated around a long term stable mean. The rhythmic deposition of the Désirade Limestone Table (LT) can be explained by synsedimentary subsidence in a context of rapidly oscillating sea-level due to precession-driven (19-21 kyr) glacio-eustatic sea-level changes during the latest Miocene- Pliocene. Except for a thin reef cap present at the eastern edge of the LT, no other in-place reefal constructions have been observed in the LT. The DOL of western Désirade are interpreted as below wave base gravity deposits that accumulated beneath a steep fore-reef slope. They document the mobilisation of carbonate material (including Larger Foraminifera) from an adjacent carbonate platform by storms and their gravitational emplacement as debris and grain flows. The provenance of both the reefal carbonate debris and the tuffaceous components redeposited in the carbonates of La Désirade must be to the west, i. e. the carbonate platforms of Marie Galante and Grande Terre.

Influence of structural heterogeneities and of large scale topography on imbricate gravitational rock slope failures: New insights from 3-D physical modeling and geomorphological analysis

Initial topography and inherited structural discontinuities are known to play a dominant role in rock slope stability. Previous 2-D physical modeling results demonstrated that even if few preexisting fractures are activated/propagated during gravitational failure all of those heterogeneities had a great influence on mobilized volume and its kinematics. The question we address in the present study is to determine if such a result is also observed in 3-D. As in 2-D previous models we examine geologically stable model configuration, based upon the well documented landslide at Randa, Switzerland. The 3-D models consisted of a homogeneous material in which several fracture zones were introduced in order to study simplified but realistic configurations of discontinuities (e.g. based on natural example rather than a parametric study). Results showed that the type of gravitational failure (deep-seated landslide or sequential failure) and resulting slope morphology evolution are the result of the interplay of initial topography and inherited preexisting fractures (orientation and density). The three main results are i) the initial topography exerts a strong control on gravitational slope failure. Indeed in each tested configuration (even in the isotropic one without fractures) the model is affected by a rock slide, ii) the number of simulated fracture sets greatly influences the volume mobilized and its kinematics, and iii) the failure zone involved in the 1991 event is smaller than the results produced by the analog modeling. This failure may indicate that the zone mobilized in 1991 is potentially only a part of a larger deep-seated landslide and/or wider deep seated gravitational slope deformation.

Constraints on the permeability structure of alluvial aquifers from P-wave sonic logs

Modern sonic logging tools designed for shallow environmental and engineering applications allow for P-wave phase velocity measurements over a wide frequency band. Methodological considerations indicate that, for saturated unconsolidated sediments in the silt to sand range and source frequencies ranging from approximately 1 to 30 kHz, the observable poro-elastic P-wave velocity dispersion is sufficiently pronounced to allow for reliable first-order estimations of the underlying permeability structure. These predictions have been tested on and verified for a surficial alluvial aquifer. Our results indicate that, even without any further calibration, the thus obtained permeability estimates as well as their variabilities within the pertinent lithological units are remarkably close to those expected based on the corresponding granulometric characteristics.

Flow-R, a model for susceptibility mapping of debris flows and other gravitational hazards at a regional scale

The development of susceptibility maps for debris flows is of primary importance due to population pressure in hazardous zones. However, hazard assessment by processbased modelling at a regional scale is difficult due to the complex nature of the phenomenon, the variability of local controlling factors, and the uncertainty in modelling parameters. A regional assessment must consider a simplified approach that is not highly parameter dependant and that can provide zonation with minimum data requirements. A distributed empirical model has thus been developed for regional susceptibility assessments using essentially a digital elevation model (DEM). The model is called Flow-R for Flow path assessment of gravitational hazards at a Regional scale (available free of charge under www.flow-r.org) and has been successfully applied to different case studies in various countries with variable data quality. It provides a substantial basis for a preliminary susceptibility assessment at a regional scale. The model was also found relevant to assess other natural hazards such as rockfall, snow avalanches and floods. The model allows for automatic source area delineation, given user criteria, and for the assessment of the propagation extent based on various spreading algorithms and simple frictional laws.We developed a new spreading algorithm, an improved version of Holmgren's direction algorithm, that is less sensitive to small variations of the DEM and that is avoiding over-channelization, and so produces more realistic extents. The choices of the datasets and the algorithms are open to the user, which makes it compliant for various applications and dataset availability. Amongst the possible datasets, the DEM is the only one that is really needed for both the source area delineation and the propagation assessment; its quality is of major importance for the results accuracy. We consider a 10m DEM resolution as a good compromise between processing time and quality of results. However, valuable results have still been obtained on the basis of lower quality DEMs with 25m resolution.

Stoneley wave modeling in heterogeneous porous media with viscous pore fluids

We implemented Biot-type porous wave equations in a pseudo-spectral numerical modeling algorithm for the simulation of Stoneley waves in porous media. Fourier and Chebyshev methods are used to compute the spatial derivatives along the horizontal and vertical directions, respectively. To prevent from overly short time steps due to the small grid spacing at the top and bottom of the model as a consequence of the Chebyshev operator, the mesh is stretched in the vertical direction. As a large benefit, the Chebyshev operator allows for an explicit treatment of interfaces. Boundary conditions can be implemented with a characteristics approach. The characteristic variables are evaluated at zero viscosity. We use this approach to model seismic wave propagation at the interface between a fluid and a porous medium. Each medium is represented by a different mesh and the two meshes are connected through the above described characteristics domain-decomposition method. We show an experiment for sealed pore boundary conditions, where we first compare the numerical solution to an analytical solution. We then show the influence of heterogeneity and viscosity of the pore fluid on the propagation of the Stoneley wave and surface waves in general.