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Simon S Keller - One of the best experts on this subject based on the ideXlab platform.

  • hippocampal Internal Architecture and postoperative seizure outcome in temporal lobe epilepsy due to hippocampal sclerosis
    Seizure-european Journal of Epilepsy, 2016
    Co-Authors: Samia Elkommos, Bernd Weber, Pitt Niehusmann, Elisa Volmering, Mark P Richardson, Anthony G Marson, Christian E Elger, Simon S Keller
    Abstract:

    Purpose Semi-quantitative analysis of hippocampal Internal Architecture (HIA) on MRI has been shown to be a reliable predictor of the side of seizure onset in patients with temporal lobe epilepsy (TLE). In the present study, we investigated the relationship between postoperative seizure outcome and preoperative semi-quantitative measures of HIA.

  • hippocampal Internal Architecture and postoperative outcome in temporal lobe epilepsy
    Journal of Neurology Neurosurgery and Psychiatry, 2015
    Co-Authors: Samia Elkommos, Bernd Weber, Pitt Niehusmann, Elisa Volmering, Mark P Richardson, Anthony G Marson, Christian E Elger, Simon S Keller
    Abstract:

    Introduction It is unknown why over one-third of patients with mesial temporal lobe epilepsy (mTLE) and hippocampal sclerosis (HS) continue to experience seizures despite temporal lobe surgery. We investigated the relationship between hippocampal Internal Architecture (HIA) on preoperative MRI, and postoperative seizure outcome in patients with refractory mTLE and HS. Methods HIA was assessed on preoperative T2-STIR MR images using a published scoring system1 for 79 patients undergoing evaluation at University Hospital Bonn, Germany. Patients underwent amygdalohippocampectomy and received postoperative outcome assessment using the International League Against Epilepsy (ILAE) classification. Hippocampal volumes were obtained using 3D T1-weighted images. Quantitative histopathological assessment was performed on resected hippocampal specimens. Results No significant differences in ipsilateral or contralateral HIA ratings, or HIA score asymmetry, were found between patients rendered seizure free (ILAE I) compared to those continuing to experience postoperative seizures (ILAE II-VI). HIA significantly correlated with neuronal density in CA3 and CA4 in the pathologic hippocampus, and hippocampal volumes bilaterally. There was no significant correlation between HIA and clinical variables. Conclusion Although valuable in determining seizure laterality, HIA does not predict postoperative outcome. Acknowledgements This work was supported by a UK MRC grant awarded to SSK (Grant Number: MR/K023152/1). References:1Ver Hoef 2013

Robert C Knowlton - One of the best experts on this subject based on the ideXlab platform.

  • predictive value of hippocampal Internal Architecture asymmetry in temporal lobe epilepsy
    Epilepsy Research, 2013
    Co-Authors: Lawrence Ver W Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Robert C Knowlton
    Abstract:

    Summary Background Asymmetry of hippocampal Internal Architecture (HIA) clarity has been suggested to be a sign of hippocampal sclerosis (HS) and is frequently associated with other MRI findings of HS. The goal of this work is to use a previously developed HIA visual scoring system ( Ver Hoef et al., 2013 ) to quantify HIA asymmetry in a retrospective series of consecutive temporal lobe epilepsy (TLE) patients and evaluate its value in predicting laterality of seizure onset both in patients with other signs of HS (HS+) and those without (HS−). Methods The HIA scoring system was used to rate hippocampal asymmetry and to assess the agreement between HIA and seizure lateralization. The median values of the average HIA scores for each hippocampus were compared for HS+ epileptogenic hippocampi, HS− epileptogenic hippocampi, and non-epileptogenic hippocampi with a Kruskal–Wallis one-way analysis of variance by ranks. Pair-wise differences between groups were evaluated with the two-tailed Mann–Whitney U test. A logistic regression model examined the utility of average HIA asymmetry score in predicting the true laterality of seizure onset as determined by video-EEG. Sensitivity and specificity are calculated using various asymmetry thresholds in each patient group. Results Fifty-five patients were identified who met inclusion criteria. Thirteen patients (24%) were found to have hippocampal atrophy and/or signal abnormality indicative of HS (HS+) and 42 did not (HS−). Significant differences were observed in the distribution of individual and average HIA scores between each of the groups of hippocampi, with HS+ hippocampi having the lowest HIA scores and non-epileptogenic hippocampi having the highest. Logistic regression analysis showed that the average HIA asymmetry score was a strong predictor of the laterality of seizure onset (β = 3.93508, p  Conclusions In this report we show for the first time that HIA asymmetry is a significant predictor of the laterality of seizure onset in TLE patients with otherwise normal MRI findings, and that the proposed HIA scoring system has high specificity and moderate sensitivity for lateralizing seizure onset in patients with TLE.

  • evaluating hippocampal Internal Architecture on mri inter rater reliability of a proposed scoring system
    Epilepsy Research, 2013
    Co-Authors: Lawrence Ver W Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Lebron A Paige, Kristen O Riley, Joel K Cure, Mehdi Soltani, Robert C Knowlton
    Abstract:

    Summary Background Asymmetry of hippocampal Internal Architecture (HIA) has been reported to be a frequent imaging finding in epilepsy patients with temporal lobe epilepsy (TLE) who exhibit other signs of hippocampal sclerosis. HIA asymmetry may also be an independent predictor of the side of seizure onset in patients with otherwise normal MRI scans. The study of HIA asymmetry and its relationship to the laterality of TLE would benefit from a reliable method of assessing the clarity of HIA in MRI scans. We propose a visual scoring system that rates HIA clarity from 1 (imperceptible) to 4 (excellent) and report the inter-rater reliability (IRR) of this system. Methods In the initial preliminary phase of this study we examined IRR using a kappa statistic ( κ ) among a mixed group of expert and non-expert reviewers using only a brief description of the scoring system to score single images from a series of patients. In the second phase we explored the effect of training on the use of our HIA scoring system by assessing IRR among neuroimaging experts before and after a brief interactive training session. In this phase, multiple slices from each patient were scored. Separate κ values and intraclass correlation coefficients (ICC) were calculated from the scores given to each hippocampal image and from the asymmetry of scores between left and right for each slice. In the third phase the effect of training on non-expert reviewers was explored using a similar approach as with the expert reviewers. Results In the preliminary phase of the study, HIA scoring of single images showed substantial agreement among expert reviewers ( κ HIA =0.65), fair agreement among non-expert reviewers ( κ HIA =0.27), and a fair to moderate degree of agreement among all the reviewers as a whole ( κ HIA =0.40). In the second phase, prior to training there was substantial agreement among expert reviewers in regard to the individual HIA scores ( κ HIA =0.62; ICC HIA =0.81) but only moderate agreement on the degree of asymmetry ( κ Asym =0.47; ICC Asym =0.71). Training improved agreement on the individual HIA scores ( κ HIA =0.58–0.72; ICC HIA =0.76–0.84) and on the degree of asymmetry ( κ Asym =0.61–0.67; ICC Asym =0.81–0.85). Among non-expert reviewers, scores improved from only a fair degree of agreement pre-training ( κ HIA =0.25, κ Asym =0.25; ICC HIA =0.68, ICC Asym =0.66) to a moderate level of agreement after training ( κ HIA =0.54, κ Asym =0.52; ICC HIA =0.78, ICC Asym =0.81). Conclusions The proposed HIA scoring system has a substantial degree of inter-rater reliability among experienced neuroimaging reviewers. Training improves the detection of asymmetries in HIA score in particular. Non-expert reviewers can employ the system with a moderate degree of reliability, and training has an even greater impact on the improvement of scoring reliability.

  • Evaluating hippocampal Internal Architecture on MRI: inter-rater reliability of a proposed scoring system.
    Epilepsy research, 2013
    Co-Authors: Lawrence W Ver Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Kristen O Riley, Joel K Cure, Mehdi Soltani, A Lebron Paige, Robert C Knowlton
    Abstract:

    Asymmetry of hippocampal Internal Architecture (HIA) has been reported to be a frequent imaging finding in epilepsy patients with temporal lobe epilepsy (TLE) who exhibit other signs of hippocampal sclerosis. HIA asymmetry may also be an independent predictor of the side of seizure onset in patients with otherwise normal MRI scans. The study of HIA asymmetry and its relationship to the laterality of TLE would benefit from a reliable method of assessing the clarity of HIA in MRI scans. We propose a visual scoring system that rates HIA clarity from 1 (imperceptible) to 4 (excellent) and report the inter-rater reliability (IRR) of this system. In the initial preliminary phase of this study we examined IRR using a kappa statistic (κ) among a mixed group of expert and non-expert reviewers using only a brief description of the scoring system to score single images from a series of patients. In the second phase we explored the effect of training on the use of our HIA scoring system by assessing IRR among neuroimaging experts before and after a brief interactive training session. In this phase, multiple slices from each patient were scored. Separate κ values and intraclass correlation coefficients (ICC) were calculated from the scores given to each hippocampal image and from the asymmetry of scores between left and right for each slice. In the third phase the effect of training on non-expert reviewers was explored using a similar approach as with the expert reviewers. In the preliminary phase of the study, HIA scoring of single images showed substantial agreement among expert reviewers (κHIA=0.65), fair agreement among non-expert reviewers (κHIA=0.27), and a fair to moderate degree of agreement among all the reviewers as a whole (κHIA=0.40). In the second phase, prior to training there was substantial agreement among expert reviewers in regard to the individual HIA scores (κHIA=0.62; ICCHIA=0.81) but only moderate agreement on the degree of asymmetry (κAsym=0.47; ICCAsym=0.71). Training improved agreement on the individual HIA scores (κHIA=0.58-0.72; ICCHIA=0.76-0.84) and on the degree of asymmetry (κAsym=0.61-0.67; ICCAsym=0.81-0.85). Among non-expert reviewers, scores improved from only a fair degree of agreement pre-training (κHIA=0.25, κAsym=0.25; ICCHIA=0.68, ICCAsym=0.66) to a moderate level of agreement after training (κHIA=0.54, κAsym=0.52; ICCHIA=0.78, ICCAsym=0.81). The proposed HIA scoring system has a substantial degree of inter-rater reliability among experienced neuroimaging reviewers. Training improves the detection of asymmetries in HIA score in particular. Non-expert reviewers can employ the system with a moderate degree of reliability, and training has an even greater impact on the improvement of scoring reliability. Copyright © 2013 Elsevier B.V. All rights reserved.

  • Predictive value of hippocampal Internal Architecture asymmetry in temporal lobe epilepsy.
    Epilepsy research, 2013
    Co-Authors: Lawrence Ver W Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Robert C Knowlton
    Abstract:

    Asymmetry of hippocampal Internal Architecture (HIA) clarity has been suggested to be a sign of hippocampal sclerosis (HS) and is frequently associated with other MRI findings of HS. The goal of this work is to use a previously developed HIA visual scoring system (Ver Hoef et al., 2013) to quantify HIA asymmetry in a retrospective series of consecutive temporal lobe epilepsy (TLE) patients and evaluate its value in predicting laterality of seizure onset both in patients with other signs of HS (HS+) and those without (HS-). The HIA scoring system was used to rate hippocampal asymmetry and to assess the agreement between HIA and seizure lateralization. The median values of the average HIA scores for each hippocampus were compared for HS+ epileptogenic hippocampi, HS- epileptogenic hippocampi, and non-epileptogenic hippocampi with a Kruskal-Wallis one-way analysis of variance by ranks. Pair-wise differences between groups were evaluated with the two-tailed Mann-Whitney U test. A logistic regression model examined the utility of average HIA asymmetry score in predicting the true laterality of seizure onset as determined by video-EEG. Sensitivity and specificity are calculated using various asymmetry thresholds in each patient group. Fifty-five patients were identified who met inclusion criteria. Thirteen patients (24%) were found to have hippocampal atrophy and/or signal abnormality indicative of HS (HS+) and 42 did not (HS-). Significant differences were observed in the distribution of individual and average HIA scores between each of the groups of hippocampi, with HS+ hippocampi having the lowest HIA scores and non-epileptogenic hippocampi having the highest. Logistic regression analysis showed that the average HIA asymmetry score was a strong predictor of the laterality of seizure onset (β=3.93508, p<0.001). HIA asymmetry remained significant even after adjustment for HS+/HS- status (β=3.8854, p<0.001). Among HS- patients, when the average HIA asymmetry score was equal to or exceeded a threshold value of 0.5, the specificity for correctly predicting the side of seizure onset was between 95% and 100% with a sensitivity of 40-45%. Among HS+ patients, a threshold of 0.3 yielded a sensitivity of 85% and specificity of 100%. In this report we show for the first time that HIA asymmetry is a significant predictor of the laterality of seizure onset in TLE patients with otherwise normal MRI findings, and that the proposed HIA scoring system has high specificity and moderate sensitivity for lateralizing seizure onset in patients with TLE. Copyright © 2013 Elsevier B.V. All rights reserved.

Bernadette Tessier - One of the best experts on this subject based on the ideXlab platform.

  • Internal Architecture and evolution of bioclastic beach ridges in a megatidal chenier plain field data and wave flume experiment
    Sedimentology, 2013
    Co-Authors: Pierre Weill, Dominique Mouaze, Bernadette Tessier
    Abstract:

    Beach ridges in macrotidal environments experience strong multi-annual to multi-decennial fluctuations of tidal inundation. The duration of tide flooding directly controls the duration of sediment reworking by waves, and thus the ridge dynamics. Flume modelling was used to investigate the impact of low-frequency tidal cycles on beach ridge evolution and Internal Architecture. The experiment was performed using natural bioclastic sediment, constant wave parameters and low-frequency variations of the mean water level. The morphological response of the beach ridge to water level fluctuations and the preservation of sedimentary structures were monitored by using side-view and plan-view photographs. Results were compared with the Internal Architecture of modern bioclastic beach ridges in a macrotidal chenier plain (Mont St. Michel Bay, France) surveyed with ground-penetrating radar. The experimentally obtained morphologies and Internal structures matched those observed in the field, and the three ridge development stages identified in ground-penetrating radar profiles (early transgressive, late transgressive and progradational) were modelled successfully. Flume experiments indicate that flat bioclastic shapes play a key role in sediment sorting in the breaker zone, and in sediment layering in the beach and washover fans. Water level controls washover geometry, beach ridge evolution and Internal structure. Low water levels allow beach ridge stabilization and sediment accumulation lower on tidal flats. During subsequent water level rise, accumulated sediment becomes available for deposition of new washover units and for bayward extension of the beach ridges. In the field, low-frequency water level fluctuations are related to the 4·4 year and 18·6 year tidal cycles. Experimental results suggest that these cycles may represent the underlying factor in the evolution of the macrotidal chenier coast at the multi-decadal to centennial time scale.

  • Internal Architecture and evolution of bioclastic beach ridges in a megatidal chenier plain: wave flume experiments and field data
    2012
    Co-Authors: Pierre Weill, Dominique Mouaze, Bernadette Tessier
    Abstract:

    Forcing parameters of chenier ridges formation and Internal structure are investigated using field data and wave flume experiments. This work focuses on modern, coarse bioclastic beach ridges such as those located on the uppermost part of the tidal flat in Mt. St. Michel Bay (NW France), in the context of a prograding megatidal chenier plain. These ridges migrate landward over the upper tidal flat and salt marshes by washover processes during coincidence of high spring tide and enhanced wave activity, until they are stabilized and integrated in the chenier plain. The Internal Architecture of these ridges has been investigated on the field using high-frequency ground-penetrating radar (GPR). Three types of ridges were identified, that represent a continuum of evolution between active transgressive, mature transgressive (Fig. 1), and mature progradational ridges (Fig. 2). Each type reflects major differences in external morphology and Internal structure. The altitude of the banks regarding to the level of tidal flooding, as well as local sediment supply, are assumed to be important forcing parameters in chenier development and evolution.

  • migration and Internal Architecture of marine dunes in the eastern english channel over 14 and 56 year intervals the influence of tides and decennial storms
    Earth Surface Processes and Landforms, 2010
    Co-Authors: Y Ferret, Bernadette Tessier, Thierry Garlan, Robert Lafite
    Abstract:

    Submarine dune dynamics are controlled by tidal currents and wind forces. According to the relative influence of these forces and the nature of dune sediment, different bedform behaviors can be observed. The footprint of the different hydrodynamic agents is recorded into the Internal Architecture of dunes. This paper is concerned with bedforms that compose the thick sediment wedge located in the eastern English Channel, off the Bay of Somme. This sedimentary archive constitutes an interesting feature to achieve a better understanding of seabed sediment dynamics and its timeline building stages. The dynamics of large submarine dunes, which are organized in fields, are studied thanks to bathymetric and seismic data over the periods 1937-1993 and 1993-2007. Dune morphology presents low lee and stoss side slopes (on average 8° and 3°, respectively) and dune migration rate is not very high. Dune movements are in the direction of residual tidal currents, i.e. toward the east, with mean migration rates around 0*8 to 5 0*25 m yr-1 and up to 6*6 0*7 m yr-1, respectively, at multi-decennial and decennial time scales. The dune Internal archi-tecture is complex with superimposed eastward prograding units, displaying locally opposite progradation. Second-order discon- tinuities (dip of 0*5°-4° perpendicular to dune crests) constitute dune master bedding. By counting the number of second-order reflectors between 1937-1993 and 1993-2007, the formation periodicity of these bounding surfaces is estimated to range from 4 to 18 years. These time intervals coincide with the long-term tidal cyclicities and also with the inter-annual to decennial variability of storm activity in northern Europe. Two theories were made to interpret the dune Internal structures: the second-order surfaces are interpreted either as the depositional surfaces corresponding to the marks of weak energy periods (weak tidal and storm action), or as erosive surfaces due to an opposite direction of dune migration provoked temporarily by exceptional storms from the northeast.

Lawrence Ver W Hoef - One of the best experts on this subject based on the ideXlab platform.

  • predictive value of hippocampal Internal Architecture asymmetry in temporal lobe epilepsy
    Epilepsy Research, 2013
    Co-Authors: Lawrence Ver W Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Robert C Knowlton
    Abstract:

    Summary Background Asymmetry of hippocampal Internal Architecture (HIA) clarity has been suggested to be a sign of hippocampal sclerosis (HS) and is frequently associated with other MRI findings of HS. The goal of this work is to use a previously developed HIA visual scoring system ( Ver Hoef et al., 2013 ) to quantify HIA asymmetry in a retrospective series of consecutive temporal lobe epilepsy (TLE) patients and evaluate its value in predicting laterality of seizure onset both in patients with other signs of HS (HS+) and those without (HS−). Methods The HIA scoring system was used to rate hippocampal asymmetry and to assess the agreement between HIA and seizure lateralization. The median values of the average HIA scores for each hippocampus were compared for HS+ epileptogenic hippocampi, HS− epileptogenic hippocampi, and non-epileptogenic hippocampi with a Kruskal–Wallis one-way analysis of variance by ranks. Pair-wise differences between groups were evaluated with the two-tailed Mann–Whitney U test. A logistic regression model examined the utility of average HIA asymmetry score in predicting the true laterality of seizure onset as determined by video-EEG. Sensitivity and specificity are calculated using various asymmetry thresholds in each patient group. Results Fifty-five patients were identified who met inclusion criteria. Thirteen patients (24%) were found to have hippocampal atrophy and/or signal abnormality indicative of HS (HS+) and 42 did not (HS−). Significant differences were observed in the distribution of individual and average HIA scores between each of the groups of hippocampi, with HS+ hippocampi having the lowest HIA scores and non-epileptogenic hippocampi having the highest. Logistic regression analysis showed that the average HIA asymmetry score was a strong predictor of the laterality of seizure onset (β = 3.93508, p  Conclusions In this report we show for the first time that HIA asymmetry is a significant predictor of the laterality of seizure onset in TLE patients with otherwise normal MRI findings, and that the proposed HIA scoring system has high specificity and moderate sensitivity for lateralizing seizure onset in patients with TLE.

  • evaluating hippocampal Internal Architecture on mri inter rater reliability of a proposed scoring system
    Epilepsy Research, 2013
    Co-Authors: Lawrence Ver W Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Lebron A Paige, Kristen O Riley, Joel K Cure, Mehdi Soltani, Robert C Knowlton
    Abstract:

    Summary Background Asymmetry of hippocampal Internal Architecture (HIA) has been reported to be a frequent imaging finding in epilepsy patients with temporal lobe epilepsy (TLE) who exhibit other signs of hippocampal sclerosis. HIA asymmetry may also be an independent predictor of the side of seizure onset in patients with otherwise normal MRI scans. The study of HIA asymmetry and its relationship to the laterality of TLE would benefit from a reliable method of assessing the clarity of HIA in MRI scans. We propose a visual scoring system that rates HIA clarity from 1 (imperceptible) to 4 (excellent) and report the inter-rater reliability (IRR) of this system. Methods In the initial preliminary phase of this study we examined IRR using a kappa statistic ( κ ) among a mixed group of expert and non-expert reviewers using only a brief description of the scoring system to score single images from a series of patients. In the second phase we explored the effect of training on the use of our HIA scoring system by assessing IRR among neuroimaging experts before and after a brief interactive training session. In this phase, multiple slices from each patient were scored. Separate κ values and intraclass correlation coefficients (ICC) were calculated from the scores given to each hippocampal image and from the asymmetry of scores between left and right for each slice. In the third phase the effect of training on non-expert reviewers was explored using a similar approach as with the expert reviewers. Results In the preliminary phase of the study, HIA scoring of single images showed substantial agreement among expert reviewers ( κ HIA =0.65), fair agreement among non-expert reviewers ( κ HIA =0.27), and a fair to moderate degree of agreement among all the reviewers as a whole ( κ HIA =0.40). In the second phase, prior to training there was substantial agreement among expert reviewers in regard to the individual HIA scores ( κ HIA =0.62; ICC HIA =0.81) but only moderate agreement on the degree of asymmetry ( κ Asym =0.47; ICC Asym =0.71). Training improved agreement on the individual HIA scores ( κ HIA =0.58–0.72; ICC HIA =0.76–0.84) and on the degree of asymmetry ( κ Asym =0.61–0.67; ICC Asym =0.81–0.85). Among non-expert reviewers, scores improved from only a fair degree of agreement pre-training ( κ HIA =0.25, κ Asym =0.25; ICC HIA =0.68, ICC Asym =0.66) to a moderate level of agreement after training ( κ HIA =0.54, κ Asym =0.52; ICC HIA =0.78, ICC Asym =0.81). Conclusions The proposed HIA scoring system has a substantial degree of inter-rater reliability among experienced neuroimaging reviewers. Training improves the detection of asymmetries in HIA score in particular. Non-expert reviewers can employ the system with a moderate degree of reliability, and training has an even greater impact on the improvement of scoring reliability.

  • Predictive value of hippocampal Internal Architecture asymmetry in temporal lobe epilepsy.
    Epilepsy research, 2013
    Co-Authors: Lawrence Ver W Hoef, Frank B Williams, Richard E Kennedy, Jerzy P Szaflarski, Robert C Knowlton
    Abstract:

    Asymmetry of hippocampal Internal Architecture (HIA) clarity has been suggested to be a sign of hippocampal sclerosis (HS) and is frequently associated with other MRI findings of HS. The goal of this work is to use a previously developed HIA visual scoring system (Ver Hoef et al., 2013) to quantify HIA asymmetry in a retrospective series of consecutive temporal lobe epilepsy (TLE) patients and evaluate its value in predicting laterality of seizure onset both in patients with other signs of HS (HS+) and those without (HS-). The HIA scoring system was used to rate hippocampal asymmetry and to assess the agreement between HIA and seizure lateralization. The median values of the average HIA scores for each hippocampus were compared for HS+ epileptogenic hippocampi, HS- epileptogenic hippocampi, and non-epileptogenic hippocampi with a Kruskal-Wallis one-way analysis of variance by ranks. Pair-wise differences between groups were evaluated with the two-tailed Mann-Whitney U test. A logistic regression model examined the utility of average HIA asymmetry score in predicting the true laterality of seizure onset as determined by video-EEG. Sensitivity and specificity are calculated using various asymmetry thresholds in each patient group. Fifty-five patients were identified who met inclusion criteria. Thirteen patients (24%) were found to have hippocampal atrophy and/or signal abnormality indicative of HS (HS+) and 42 did not (HS-). Significant differences were observed in the distribution of individual and average HIA scores between each of the groups of hippocampi, with HS+ hippocampi having the lowest HIA scores and non-epileptogenic hippocampi having the highest. Logistic regression analysis showed that the average HIA asymmetry score was a strong predictor of the laterality of seizure onset (β=3.93508, p<0.001). HIA asymmetry remained significant even after adjustment for HS+/HS- status (β=3.8854, p<0.001). Among HS- patients, when the average HIA asymmetry score was equal to or exceeded a threshold value of 0.5, the specificity for correctly predicting the side of seizure onset was between 95% and 100% with a sensitivity of 40-45%. Among HS+ patients, a threshold of 0.3 yielded a sensitivity of 85% and specificity of 100%. In this report we show for the first time that HIA asymmetry is a significant predictor of the laterality of seizure onset in TLE patients with otherwise normal MRI findings, and that the proposed HIA scoring system has high specificity and moderate sensitivity for lateralizing seizure onset in patients with TLE. Copyright © 2013 Elsevier B.V. All rights reserved.

James Rose - One of the best experts on this subject based on the ideXlab platform.

  • till as a glacial tectomict its Internal Architecture and the development of a typing method for till differentiation
    Geomorphology, 2006
    Co-Authors: John Menzies, Jaap J M Van Der Meer, James Rose
    Abstract:

    Abstract Till has been studied for over a century, yet still a clear understanding of the mechanics of deposition and/or emplacement of till eludes us. Tills, in the past, have been generally subdivided into sediments formed in various sub-environments of the glacial system. As such it has been generally agreed that tills can be separated in terms of these types based on various attributes, such as clast fabric. Increasingly, such separation into various sub-types of till has become, however, highly debatable and tenuous. Based upon the use of micromorphology and a greater in-depth appreciation of the Internal Architecture of till, it has become apparent that previously established classifications of till are erroneous. Micromorphology reveals that deposition and/or emplacement of tills is a complex ‘tectonic’ process such that lodgement, melt-out and flow tills, as previously defined, do not appear to exist. Rather a new term better describes tills as glacial ‘tectomicts’. By using micromorphology in establishing the presence of sets of microstructures a statistical method is introduced that permits differentiation of tills from other diamictons. The implications for this new understanding of tills, allied to statistical ‘typing’, is considerable in terms of till formation, glacial stratigraphy and understanding glacial environments in terms of stress histories, porewater transmission, subglacial deformation mechanics, till rheological phase changes, and the timeline of till formation.

  • Till—as a glacial “tectomict”, its Internal Architecture, and the development of a “typing” method for till differentiation
    Geomorphology, 2006
    Co-Authors: John Menzies, Jaap J M Van Der Meer, James Rose
    Abstract:

    Abstract Till has been studied for over a century, yet still a clear understanding of the mechanics of deposition and/or emplacement of till eludes us. Tills, in the past, have been generally subdivided into sediments formed in various sub-environments of the glacial system. As such it has been generally agreed that tills can be separated in terms of these types based on various attributes, such as clast fabric. Increasingly, such separation into various sub-types of till has become, however, highly debatable and tenuous. Based upon the use of micromorphology and a greater in-depth appreciation of the Internal Architecture of till, it has become apparent that previously established classifications of till are erroneous. Micromorphology reveals that deposition and/or emplacement of tills is a complex ‘tectonic’ process such that lodgement, melt-out and flow tills, as previously defined, do not appear to exist. Rather a new term better describes tills as glacial ‘tectomicts’. By using micromorphology in establishing the presence of sets of microstructures a statistical method is introduced that permits differentiation of tills from other diamictons. The implications for this new understanding of tills, allied to statistical ‘typing’, is considerable in terms of till formation, glacial stratigraphy and understanding glacial environments in terms of stress histories, porewater transmission, subglacial deformation mechanics, till rheological phase changes, and the timeline of till formation.