ISMRM 24th Annual Meeting & Exhibition • 07-13 May 2016 • Singapore

Scientific Session: Epilepsy

Wednesday, May 11, 2016
Hall 606
16:00 - 18:00
Moderators: Konstantinos Arfanakis, David Abbott, Fernando Boada

Perivascular Space Analysis in Non-lesional Epilepsy: Exploring a Biomarker for Epilepsy
Rebecca Emily Feldman1, Jack Rutland2, Bradley Neil Delman3, Jiyeoun Yoo4, Madeline Cara Fields4, Lara Vanessa Marcuse4, and Priti Balchandani1
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Wake Forest University, Winston-Salem, NC, United States, 3Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Neurology, Mount Sinai Hospital, New York, NY, United States
Epilepsy is a chronic condition, affecting approximately 150,000 people in the United States. 7T MRI facilitates the visualization of the brain with unprecedented resolution and contrast. Perivascular spaces (PVS) have been reported in previous work but with uncertain significance. However, due to the increased resolution enabled at 7T, PVSs are detected with increasing frequency, both in healthy volunteers and in epilepsy patients. We investigated the symmetry in the distribution of PVSs in the brains of non-lesional epilepsy patients. 

Structural Connectivity Changes in Refractory Childhood Absence Epilepsy
Graeme Jackson1,2,3,4, Farnoosh Sadeghian1, Patrick Carney1, David Raffelt1, Fernando Calamante1,2, and Alan Connelly1,2
1The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2The Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Australia, 3Department of Medicine, The University of Melbourne, Melbourne, Australia, 4Department of Neurology, Austin Health, Melbourne, Australia
Childhood absence epilepsy (CAE) is a common neurological condition. Here we assessed white matter connectivity using fixel-based analysis (FBA) and grey matter structure using voxel-based morphometry in adult patients with refractory CAE. We identified increased grey matter volume in frontal lobe as well as decreased fibre connectivity in superior longitudinal fasciculi, right cingulum, motor area of corpus callosum and cerebellar peduncles. Our results reinforce the concept that the midline frontal areas are critically involved in the phenotype of generalised spike and wave discharges. These structural connectivity changes in CAE could be either developmental or as a consequence of seizures.

7 tesla MRI in the pre-surgical evaluation of 26 patients with focal epilepsy
Tim J Veersema1, Cyrille H Ferrier1, Pieter van Eijsden1, Peter H Gosselaar1, Fredy Visser2,3, Jaco JM Zwanenburg2,4, Hans Hoogduin2, Gerárd AP de Kort2, Jeroen Hendrike2, and Kees PJ Braun1
1Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 3Philips Healthcare, Best, Netherlands, 4Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands
For this series we assessed all 26 epilepsy patients who underwent 7T MRI for pre-surgical evaluation in our center, and whose scans (both 7T and lower field) were discussed during epilepsy surgery meetings (ESM). We compared the conclusions of the visual assessments of 1.5T or 3T, and 7T MRI as agreed upon by the ESM team. 7T MRI holds a promise to improve identification of epileptogenic structural abnormalities in patients with intractable epilepsy. In our series of 26 patients with refractory focal epilepsy, multidisciplinary evaluation of 7T MRI identified additional lesions not seen on lower-field MRI in five patients (19.2%).  

In Vivo Whole-Brain T1-rho Mapping in evaluation of Mesial Temporal Lobe epilepsy
Xixi Zhao1, Junling Wang1, Xiangliang Tan1, Xiang Xiao1, Jiajun Zhang1, Yingjie Mei2, Queenie Chan3, and Yikai Xu1
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 2Philips Healthcare, Guangzhou, China, People's Republic of, 3Philips Healthcare, HongKong, China, People's Republic of
In human brain, T1ρ has been proven to be relevant with the macromolecular composition of tissues, and supposed to be sensitive to neuronal degeneration. We used T1rho MR imaging to investigate the variations in T1rho values of subcortical gray matter structures automatic-drawn using FIRST segmentation among temporal lobe epilepsy patients and the underlying relation between the significantly altered T1rho values or volumes of subcortical structures and duration of epilepsy or age at epilepsy onset. Our results demonstrate the feasibility of ROI-wise analysis by atlas-based segmentation of T1rho imaging among mTLE patients

Sodium MRI for Evaluation of Sodium Ion Homeostasis in Epilepsy: Clinical Implementation and Initial Impressions
Timothy Michael Shepherd1, Yongxian Qian1, Karthik Lakshmanan1, Ruben Kuzniecky2, Graham Wiggins1, and Fernando Boada1
1Radiology, New York University, New York, NY, United States, 2Neurology, New York University, New York, NY, United States
The detection and localization of sodium tissue abnormalities in patients with epilepsy may have potential to improve seizure localization, identify effective pharmacotherapy and/or provide prognostic information for individual patients. Here, we report initial results evaluating a newly developed coil for performing 23Na MRI at 3-T in three patients with epilepsy. 

7T MRI detection of epileptogenic foci in previously non-lesional patients with focal epilepsy - Permission Withheld
Rebecca Emily Feldman1, Bradley Neil Delman2, Hadrien A Dyvorne1, Jiyeoun Yoo3, Madeline Cara Fields3, Lara Vanessa Marcuse3, and Priti Balchandani1
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States,3Neurology, Mount Sinai Hospital, New York, NY, United States
Epilepsy affects over 150,000 people in the United States. Thirty percent of epilepsy is refractory to pharmacotherapy, and in these cases surgery may be curative. There are focal epileptogenic lesions, amenable to surgery, which are not visualized by current imaging protocols. 7T MRI scanners may increase the conspicuity of epileptogenic lesions and provide more accurate delineation of lesion boundaries. Reported are the results for a patient study, with comparison to healthy controls, to assess the value of 7T imaging to reveal subtle abnormalities acting as epileptogenic foci in patients with focal epilepsy who have non-lesional diagnostic MRI scans. 

MRI monitoring of epileptogenesis with direct histological validation
Niels Leonard Schwaderlapp1, Philipp Janz2, Ute Häussler2, Jan Korvink3, Dominik Elverfeldt1, Jürgen Hennig1, Carola Haas2, and Pierre LeVan1
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Experimental Epilepsy Research, University Medical Center Freiburg, Freiburg, Germany, 3Institut für Mikrostrukturtechnik, Karlsruher Institut für Technologie, Karlsruhe, Germany
Cellular-level pathological changes in the kainate mouse model of temporal lobe epilepsy (TLE) have been well-characterized immunohistochemically (IHC) and include neuronal injury followed by granule cell dispersion. In this work, we demonstrate the possibility to non-invasively track granule cell dispersion and neuronal injury using diffusion imaging and 1H-spectroscopy. The volume of the dispersed granule cell layer quantified by DTI and the initial injury reflected by a reduction of NAA and glutamate are quantitatively validated with IHC and can be used as early markers of epileptogenicity in this mouse model of TLE.

Decreased Fibre Density in Frontal Lobe Epilepsies related to DEPDC5 mutations
David Raffelt1, Farnoosh Sadeghian1, Brigid Regan2, Sarah Garry2, Samuel Berkovic2, Ingrid Scheffer2, and Alan Connelly1,2
1Florey Institute of Neuroscience, Melbourne, Australia, 2Department of Medicine, University of Melbourne, Melbourne, Australia
Mutations in the gene DEPDC5 cause up to 12% of Familial Focal Epilepsy with Variable Foci. In this work we performed a fixel-based analysis of diffusion MRI data to understand how white matter might be altered in patients with DEPDC5 mediated frontal lobe epilepsy (FLE). We identified significant reductions in fibre density in several pathways, including the superior longitudinal fasciculi, corpus callosum, inferior longitudinal fasciculus and cingulum. We also investigated FLE mediated by KCNT1 mutation, and found similar pathways affected. In KCNT1+ve subjects, pathways had reduced cross-section, suggesting the observed effects may be related to development and not seizure effects. 

Automated fibre quantification of the fornix predicts outcome after surgery for intractable temporal lobe epilepsy - Permission Withheld
Russell Glenn1, Leonardo Bonilha1, Barbara Kreilkamp2, Mark P Richardson3, Bernd Weber4, and Simon S Keller2
1Medical University of South Carolina, Charleston, SC, United States, 2University of Liverpool, Liverpool, United Kingdom, 3King's College London, London, United Kingdom, 4University Hospital Bonn, Bonn, Germany
Imaging markers of postoperative seizure control in refractory temporal lobe epilepsy (TLE) would provide a useful clinical tool for surgical decision making. In the present diffusion tensor imaging study, we report that regional tissue characteristics of the fornix ipsilateral to the side of intended resection are related to postoperative seizure control in patients with TLE. Interestingly, areas found to be abnormal only in patients with a suboptimal outcome were located outside the margins of resection. The identification of fornical abnormalities outside the area of intended resection may be an important prognostic marker of suboptimal seizure control after temporal lobe surgery. 

Individual measures of network efficiency in patients with epilepsy based on cortical thickness
Gerhard Drenthen1,2, Marielle Vlooswijk2,3, Marian Majoie2, Paul Hofman1,2, Albert Aldenkamp2,3, Walter Backes1,2, and Jacobus Jansen1,2
1Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands, 2School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands,3Department of Neurology, Maastricht University Medical Center, Maastricht, Netherlands
Brain network analysis that infers on interregional correlations of anatomical features usually makes use of intersubject correlation matrices that characterize variations over subjects. Here, a novel method is introduced that provides measures of network efficiency on an individual basis in patients with epilepsy. To this end, for each participant a measure of deviation from a group of healthy controls is calculated, and compared to the small-world parameters (clustering coefficient and minimum path length) of a reference graph obtained for the native control group. Results show that patients with epilepsy exhibit a less efficient network compared to controls.

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