Now showing 1 - 5 of 5
  • 2009Journal Article
    [["dc.bibliographiccitation.firstpage","1484"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Epilepsia"],["dc.bibliographiccitation.lastpage","1490"],["dc.bibliographiccitation.volume","50"],["dc.contributor.author","Focke, Niels K."],["dc.contributor.author","Bonelli, Silvia B."],["dc.contributor.author","Yogarajah, Mahinda"],["dc.contributor.author","Scott, Catherine"],["dc.contributor.author","Symms, Mark R."],["dc.contributor.author","Duncan, John S."],["dc.date.accessioned","2018-11-07T08:29:07Z"],["dc.date.available","2018-11-07T08:29:07Z"],["dc.date.issued","2009"],["dc.description.abstract","Background: Patients with focal epilepsy that is refractory to medical treatment are often considered candidates for resective surgery. Magnetic resonance imaging (MRI) has a very important role in the presurgical work-up of these patients, but is unremarkable in about one-third of cases. These patients are often deferred from surgery or have a less positive outcome if surgery is eventually undertaken. The aim of this study was to evaluate our recently described voxel-based technique using routine T2-FLAIR (fluid-attenuated inversion-recovery) scans in MRI-negative patients and to compare the results with video-EEG (electroencephalography) telemetry (VT) findings. Methods: We identified 70 epilepsy patients with refractory focal seizures who underwent VT and had a normal routine MRI. T2-FLAIR scans were bias-corrected, and intensity and spatially normalized (nFSI) using Statistical Parametric Mapping 5 (SPM5) as previously described. Individual scans were then compared against a set of 25 normal controls using a voxel-based method. Results: SPM5 identified 10 patients with suprathreshold clusters (14.3%). In 50% of these there was concordance between the lobe of the most significant cluster and the presumed lobe of seizure onset, as defined by VT. All cases were concordant with respect to lateralization of the putative focus. Conclusion: Using nFSI we identified focal structural cerebral abnormalities in 11.4% of patients with refractory focal seizures, and normal conventional MRI, that were fully or partially concordant with scalp VT. This voxel-based analysis of FLAIR scans, which are widely available, could provide a useful tool in the presurgical evaluation of epilepsy patients. Ongoing work is to compare these imaging findings with the results of intracranial EEG and histology of surgical resections."],["dc.identifier.doi","10.1111/j.1528-1167.2009.02022.x"],["dc.identifier.isi","000266838100019"],["dc.identifier.pmid","19292759"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16571"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell Publishing, Inc"],["dc.relation.issn","0013-9580"],["dc.title","Automated normalized FLAIR imaging in MRI-negative patients with refractory focal epilepsy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2009Conference Abstract
    [["dc.bibliographiccitation.journal","Epilepsia"],["dc.bibliographiccitation.volume","50"],["dc.contributor.author","Yogarajah, Mahinda"],["dc.contributor.author","Focke, Niels K."],["dc.contributor.author","Bonelli, Silvia B."],["dc.contributor.author","Parker, G."],["dc.contributor.author","Alexander, Daniel C."],["dc.contributor.author","Thompson, P."],["dc.contributor.author","Symms, M."],["dc.contributor.author","Koepp, M."],["dc.contributor.author","Duncan, John S."],["dc.date.accessioned","2018-11-07T11:23:29Z"],["dc.date.available","2018-11-07T11:23:29Z"],["dc.date.issued","2009"],["dc.format.extent","131"],["dc.identifier.isi","000270433800474"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/56210"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell Publishing, Inc"],["dc.publisher.place","Malden"],["dc.relation.conference","28th International Epilespy Congress"],["dc.relation.eventlocation","Budapest, HUNGARY"],["dc.relation.issn","0013-9580"],["dc.title","TRACTOGRAPHY AND THE DISTRIBUTED NETWORK DAMAGE UNDERLYING MEMORY IMPAIRMENT IN TEMPORAL LOBE EPILEPSY"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2008Journal Article
    [["dc.bibliographiccitation.firstpage","728"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","NeuroImage"],["dc.bibliographiccitation.lastpage","737"],["dc.bibliographiccitation.volume","40"],["dc.contributor.author","Focke, Niels K."],["dc.contributor.author","Yogarajah, Mahinda"],["dc.contributor.author","Bonelli, Silvia B."],["dc.contributor.author","Bartlett, Philippa A."],["dc.contributor.author","Symms, Mark R."],["dc.contributor.author","Duncan, John S."],["dc.date.accessioned","2018-11-07T11:16:47Z"],["dc.date.available","2018-11-07T11:16:47Z"],["dc.date.issued","2008"],["dc.description.abstract","Background: Mesial temporal lobe epilepsy (mTLE) with hippocampus sclerosis (HS) is an important cause for focal epilepsy. In this study, we explored the integrity of connecting networks using diffusion tensor imaging (DTI) and two whole-brain voxel-based methods: statistical parametric mapping (SPM) and tract-based spatial statistics (TBSS). Methods: Thirty-three consecutive patients with mTLE and HS undergoing presurgical evaluation were scanned at 3 T, a DTI data set was acquired and parametric maps of fractional anisotropy (FA) and mean diffusivity (MD) were calculated. Twenty-one patients had left hippocampal sclerosis (LHS) and 12 patients had right HS (RHS). These groups were compared to 37 normal control subjects using both SPM5 and TBSS. Results: The ipsilateral temporal lobe showed widespread FA reduction in both groups. The limbic system was clearly abnormal in the LHS group, also involving the arcuate fasciculus. In RHS, changes were more restricted but also showed involvement of the contralateral temporal and inferior frontal lobe. Increased MD was found in the ipsilateral hippocampus by SPM that was only marginally detected by TBSS. In white matter regions, however, TBSS was more sensitive to changes than SPM. Conclusion: DT1 detects extensive changes in mTLE with HS. The affected networks were principally in the ipsilateral temporal lobe and the limbic system but also the arcuate fasciculus. SPM and TBSS gave complementary information with higher sensitivity to FA changes using TBSS. (c) 2008 Elsevier Inc. All rights reserved."],["dc.description.sponsorship","Medical Research Council [G9805989]; Wellcome Trust [, 067176]"],["dc.identifier.doi","10.1016/j.neuroimage.2007.12.031"],["dc.identifier.isi","000254627700033"],["dc.identifier.pmid","18261930"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54673"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","Najko"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1053-8119"],["dc.title","Voxel-based diffusion tensor imaging in patients with mesial temporal lobe epilepsy and hippocampal sclerosis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2010Conference Abstract
    [["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Journal of Neurology Neurosurgery & Psychiatry"],["dc.bibliographiccitation.volume","81"],["dc.contributor.author","Yogarajah, Mahinda"],["dc.contributor.author","McEvoy, Andrew W."],["dc.contributor.author","Focke, Niels K."],["dc.contributor.author","Duncan, John S."],["dc.contributor.author","Koepp, M."],["dc.contributor.author","Symms, M."],["dc.contributor.author","Bonelli, Silvia B."],["dc.contributor.author","Thompson, P."],["dc.contributor.author","Vollmar, Christian"],["dc.date.accessioned","2018-11-07T08:37:38Z"],["dc.date.available","2018-11-07T08:37:38Z"],["dc.date.issued","2010"],["dc.format.extent","E24"],["dc.identifier.doi","10.1136/jnnp.2010.226340.29"],["dc.identifier.isi","000283354800030"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18583"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","Najko"],["dc.publisher","B M J Publishing Group"],["dc.publisher.place","London"],["dc.relation.conference","Annual Meeting of the Association-of-British-Neurologists"],["dc.relation.eventlocation","Bournemouth, ENGLAND"],["dc.relation.issn","0022-3050"],["dc.title","STRUCTURAL PLASTICITY OF WHITE MATTER NETWORKS FOLLOWING ANTERIOR TEMPORAL LOBE RESECTION"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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  • 2012Journal Article
    [["dc.bibliographiccitation.firstpage","356"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","NeuroImage"],["dc.bibliographiccitation.lastpage","362"],["dc.bibliographiccitation.volume","59"],["dc.contributor.author","Focke, Niels K."],["dc.contributor.author","Yogarajah, Mahinda"],["dc.contributor.author","Symms, Mark R."],["dc.contributor.author","Gruber, Oliver"],["dc.contributor.author","Paulus, Walter J."],["dc.contributor.author","Duncan, John S."],["dc.date.accessioned","2018-11-07T09:14:28Z"],["dc.date.available","2018-11-07T09:14:28Z"],["dc.date.issued","2012"],["dc.description.abstract","In those with drug refractory focal epilepsy, MR imaging is important for identifying structural causes of seizures that may be amenable to surgical treatment. In up to 25% of potential surgical candidates, however, MRI is reported as unremarkable even when employing epilepsy specific sequences. Automated MRI classification is a desirable tool to augment the interpretation of images, especially when changes are subtle or distributed and may be missed on visual inspection. Support vector machines (SVM) have recently been described to be useful for voxel-based MR image classification. In the present study we sought to evaluate whether this method is feasible in temporal lobe epilepsy, with adequate accuracy. We studied 38 patients with hippocampal sclerosis and unilateral (mesial) temporal lobe epilepsy (mTLE) (20 left) undergoing presurgical evaluation and 22 neurologically normal control subjects. 3D T1-weighted images were acquired at 3T (GE Excite), segmented into tissue classes, normalized and smoothed with SPM8. Diffusion tensor imaging (DTI) and double echo images for T2 relaxometry were also acquired and processed. The SVM analysis was done with the libsvm software package in a leave-one-out cross-validation design and predictive accuracy was measured. Local weighting was applied by SPM F-contrast maps. Best accuracies were achieved using the gray matter based segmentation (90-100%) and mean diffusivity (95-97%). For the three-way classification, accuracies were 88 and 93% respectively. Local weighting generally improved the accuracies except in the FA-based processing for which no effect was noted. Removing the hippocampus from the analysis, on the other hand, reduced the obtainable diagnostic indices but these were still > 90% for DTI-based methods and lateralization based on gray matter maps. These findings show that automated SVM image classification can achieve high diagnostic accuracy in mTLE and that voxel-based MRI can be used at the individual subject level. This could be helpful for screening assessments of MRI scans in patients with epilepsy and when no lesion is detected on visual evaluation. (C) 2011 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.neuroimage.2011.07.068"],["dc.identifier.isi","000296265500036"],["dc.identifier.pmid","21835245"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/27417"],["dc.notes.status","zu prĂĽfen"],["dc.notes.submitter","Najko"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1053-8119"],["dc.title","Automated MR image classification in temporal lobe epilepsy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]
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