Integrating Magnetic Resonance Imaging Postprocessing Results into Neuronavigation for Electrode Implantation and Resection of Subtle Focal Cortical Dysplasia in Previously Cryptogenic Epilepsy

Wellmer, Jörg; Parpaley, Yaroslav; Lehe, Marec von; Huppertz, Hans‐Jürgen

doi:10.1227/01.neu.0000359329.92781.b7

Cited by 42 publications

(41 citation statements)

References 12 publications

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“…When combined with conventional visual analysis, MAP identified 98% of all pathologically-confirmed FCD type II lesions. 32 Our choice of z-score threshold is also consistent with the literature, 50 although optimization of z-score for lesion detection and delineation should be provided by further studies.…”

Section: Discussionsupporting

confidence: 72%

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Linking MRI postprocessing with magnetic source imaging in MRI‐negative epilepsy

Wang

Alexopoulos

Jones

et al. 2014

Annals of Neurology

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Objective MRI-negative (MRI–) pharmacoresistant focal epilepsy (PFE) patients are most challenging for epilepsy surgical management. This study utilizes a voxel-based MRI postprocessing technique, implemented using a morphometric analysis program (MAP), aiming to facilitate detection of subtle focal cortical dysplasia (FCD) in MRI– patients. Furthermore, the study examines the concordance between MAP-identified regions and localization from magnetic source imaging (MSI). Methods Included in this retrospective study were 25 MRI– surgical patients. MAP was performed on T1-weighted MRI, with comparison to a normal database. The pertinence of MAP+ areas was confirmed by MSI, surgical outcome and pathology. Analyses of MAP and MSI were performed blindly from patients' clinical information and independently from each other. Results The detection rate of subtle changes by MAP was 48% (12/25). Once MAP+ areas were resected, patients were more likely to be seizure-free (p = 0.02). There were no false positives in the 25 age-matched normal controls. Seven patients had a concordant MSI correlate. Patients in whom a concordant area was identified by both MAP and MSI had a significantly higher chance of achieving a seizure-free outcome following complete resection of this area (p = 0.008). In the 9 resected MAP+ areas, pathology revealed FCD type IA in 7 and type IIB in 2. Interpretation MAP shows promise in identifying subtle FCD abnormalities and increasing the diagnostic yield of conventional MRI visual analysis in presurgical evaluation of PFE. Concordant MRI postprocessing and MSI analyses may lead to the noninvasive identification of a structurally and electrically abnormal subtle lesion that can be surgically targeted.

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Section: Discussionsupporting

confidence: 72%

“…10 For these reasons the finding of a concordant MSI/MAP+ area can become an important determinant of accurate ICEEG/epilepsy localization and seizure-free outcome in the challenging cohort of MRI– PFE. 50 …”

Section: Discussionmentioning

confidence: 99%

Linking MRI postprocessing with magnetic source imaging in MRI‐negative epilepsy

Wang

Alexopoulos

Jones

et al. 2014

Annals of Neurology

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“…The choice of z-score threshold was consistent with those reported in the literature. 11, 12, 35 Candidate MAP+ regions were searched for in the entire brain. High-z-score areas caused by signal inhomogeneities due to technical reasons and nonspecific white matter lesions were not included.…”

Section: Methodsmentioning

confidence: 99%

Voxel‐based morphometric magnetic resonance imaging (MRI) postprocessing in MRI‐negative epilepsies

Wang

Jones

Jaisani

et al. 2015

Annals of Neurology

136

150

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Objective In the presurgical workup of MRI-negative (MRI−, or “nonlesional”) pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel-based MRI post-processing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI− surgical candidates. Methods Included in this retrospective study was a consecutive cohort of 150 MRI-surgical patients. MAP was performed on T1-weighted MRI, with comparison to a scanner-specific normal database. Review and analysis of MAP were performed blinded to patients’ clinical information. The pertinence of MAP+ areas was confirmed by surgical outcome and pathology. Results MAP showed a 43% positive rate, sensitivity of 0.9 and specificity of 0.67. Overall, patients with MAP+ region completely resected had the best seizure outcomes, followed by the MAP− patients, and patients who had no/partial resection of the MAP+ region had the worst outcome (p<0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP+. False-positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP+ areas contained mainly non-balloon-cell FCD. Multiple MAP+ regions were present in 7% of patients. Conclusions MAP can be a practical and valuable tool to: (1) guide the search for subtle MRI abnormalities, and (2) confirm visually identified questionable abnormalities in patients with PFE due to suspected FCD. A MAP+ region, when concordant with the patient’s electro-clinical presentation, should provide a legitimate target for surgical exploration.

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“…Because of non temporo-mesial seizure semiology this was regarded as unspecific. For intracranial EEG recordings each one depth electrode (AD-tech, Racine, WI U.S.A) was stereotactically inserted into the regions-of-interest derived from morphometric MRI-analysis (MRIcro (Chris Rorden, Version 1.37) imported into Iplan software, Brainlab, Feldkirchen, Germany; Wellmer et al 2010) (Fig. 1c, d).…”

Section: Patient and Methodsmentioning

confidence: 99%

Zoomed MRI Guided by Combined EEG/MEG Source Analysis: A Multimodal Approach for Optimizing Presurgical Epilepsy Work-up and its Application in a Multi-focal Epilepsy Patient Case Study

et al. 2017

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In recent years, the use of source analysis based on electroencephalography (EEG) and magnetoencephalography (MEG) has gained considerable attention in presurgical epilepsy diagnosis. However, in many cases the source analysis alone is not used to tailor surgery unless the findings are confirmed by lesions, such as, e.g., cortical malformations in MRI. For many patients, the histology of tissue resected from MRI negative epilepsy shows small lesions, which indicates the need for more sensitive MR sequences. In this paper, we describe a technique to maximize the synergy between combined EEG/MEG (EMEG) source analysis and high resolution MRI. The procedure has three main steps: (1) construction of a detailed and calibrated finite element head model that considers the variation of individual skull conductivities and white matter anisotropy, (2) EMEG source analysis performed on averaged interictal epileptic discharges (IED), (3) high resolution (0.5 mm) zoomed MR imaging, limited to small areas centered at the EMEG source locations. The proposed new diagnosis procedure was then applied in a particularly challenging case of an epilepsy patient: EMEG analysis at the peak of the IED coincided with a right frontal focal cortical dysplasia (FCD), which had been detected at standard 1 mm resolution MRI. Of higher interest, zoomed MR imaging (applying parallel transmission, ‘ZOOMit’) guided by EMEG at the spike onset revealed a second, fairly subtle, FCD in the left fronto-central region. The evaluation revealed that this second FCD, which had not been detectable with standard 1 mm resolution, was the trigger of the seizures.

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Integrating Magnetic Resonance Imaging Postprocessing Results into Neuronavigation for Electrode Implantation and Resection of Subtle Focal Cortical Dysplasia in Previously Cryptogenic Epilepsy

Cited by 42 publications

References 12 publications

Linking MRI postprocessing with magnetic source imaging in MRI‐negative epilepsy

Linking MRI postprocessing with magnetic source imaging in MRI‐negative epilepsy

Voxel‐based morphometric magnetic resonance imaging (MRI) postprocessing in MRI‐negative epilepsies

Zoomed MRI Guided by Combined EEG/MEG Source Analysis: A Multimodal Approach for Optimizing Presurgical Epilepsy Work-up and its Application in a Multi-focal Epilepsy Patient Case Study

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