Functional MRI of neuronal activation in epilepsy patients with malformations of cortical development

Nikolova, Simona; Bartha, Robert; Parrent, Andrew G.; Steven, David; Diosy, David; Burneo, Jorge G.

doi:10.1016/j.eplepsyres.2015.06.012

Cited by 10 publications

(10 citation statements)

References 29 publications

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“…In accordance with this heterogeneous epileptogenicity, several fMRI studies have demonstrated that PMG may still harbour function, including primary somatosensory and motor functions as well as language in cases of perisylvian PMG extending to frontal and rolandic cortex (Araujo et al ., 2006; Vitali et al ., 2008). A functional reorganization extending beyond the limit of the PMG may be encountered (Vitali et al ., 2008), although it has not been systematically observed (Nikolova et al ., 2015). Combined fMRI and transcranial magnetic stimulation studies in patients with PMG and hemiparesis have demonstrated that PMG cortex can show various degrees of participation in motor functions; ipsilateral corticospinal projections from the contralesional hemisphere to the paretic hand, corticospinal projections to the paretic hand originating in the PMG cortex, and bilateral motor representation were all recorded (Staudt et al ., 2004).…”

Section: Presurgical Evaluation For Polymicrogyriamentioning

confidence: 99%

Epilepsy surgery for polymicrogyria: a challenge to be undertaken

Maillard¹,

Ramantani²

2018

Epileptic Disorders

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Polymicrogyria (PMG) is one of the most common malformations of cortical development (MCDs), with epilepsy affecting most patients. PMG-related drug-resistant epilepsy patients can be considered for epilepsy surgery in well-selected cases. In this context, a comprehensive presurgical evaluation, often including stereo-electroencephalography (SEEG), is warranted to accurately delineate the epileptogenic zone. The heterogeneity of intrinsic epileptogenicity in PMG, together with the additional or predominant involvement of remote cortical areas, calls for a different strategy in PMG compared to other MCDs, namely one that is not predominantly MRI-but rather SEEG-oriented. Favourable results in terms of seizure freedom and antiepileptic drug cessation are feasible in a large proportion of patients with unilateral PMG. PMG extent should not deter from exploring the possibility of epilepsy surgery. On the other hand, patients with hemispheric PMG can be excellent hemispherotomy candidates, particularly when presenting with contralateral hemiparesis. Recent findings support the early consideration of surgery in PMG-related drug-resistant epilepsy.

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Section: Presurgical Evaluation For Polymicrogyriamentioning

confidence: 99%

Epilepsy surgery for polymicrogyria: a challenge to be undertaken

Maillard¹,

Ramantani²

2018

Epileptic Disorders

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“…Based on the morphological and functional features of the brain, machine learning techniques such as the support vector machine (SVM), artificial neural network, clustering, and Bayesian networks, have been widely used in distinguishing patients with brain disorders from healthy controls ( 20 – 24 ). Existing studies have demonstrated that neuroimaging data were considered potential biomarkers for LTLE and RTLE diagnosis ( 25 – 30 ). For example, anatomical connectivity was reported for the separation of patients with LTLE from normal individuals with accuracy up to 93 and 90.0% for the RTLE ( 27 ), voxel-based MRI classification using diffusion tensor imaging (DTI), and T1-weighted MRI of the LTLE or RTLE patients could reach 90–100% ( 28 , 29 ), the large-scale functional brain network measures as informative biomarkers for epilepsy pattern classification achieved a cross-validated classification accuracy of 83.9% ( 31 ).…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Feature Selection Methods for the Discriminative Analysis of Temporal Lobe Epilepsy

et al. 2017

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It is crucial to differentiate patients with temporal lobe epilepsy (TLE) from the healthy population and determine abnormal brain regions in TLE. The cortical features and changes can reveal the unique anatomical patterns of brain regions from structural magnetic resonance (MR) images. In this study, structural MR images from 41 patients with left TLE, 34 patients with right TLE, and 58 normal controls (NC) were acquired, and four kinds of cortical measures, namely cortical thickness, cortical surface area, gray matter volume (GMV), and mean curvature, were explored for discriminative analysis. Three feature selection methods including the independent sample t-test filtering, the sparse-constrained dimensionality reduction model (SCDRM), and the support vector machine-recursive feature elimination (SVM-RFE) were investigated to extract dominant features among the compared groups for classification using the support vector machine (SVM) classifier. The results showed that the SVM-RFE achieved the highest performance (most classifications with more than 84% accuracy), followed by the SCDRM, and the t-test. Especially, the surface area and GMV exhibited prominent discriminative ability, and the performance of the SVM was improved significantly when the four cortical measures were combined. Additionally, the dominant regions with higher classification weights were mainly located in the temporal and the frontal lobe, including the entorhinal cortex, rostral middle frontal, parahippocampal cortex, superior frontal, insula, and cuneus. This study concluded that the cortical features provided effective information for the recognition of abnormal anatomical patterns and the proposed methods had the potential to improve the clinical diagnosis of TLE.

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“…Despite the associated substantial derangement of the affected cortical anatomy and the severely disrupted neuronal layering, PMG is known to have functionally relevant sensorimotor and visual representations. 16 This observation is welldocumented in smaller series 4,5,17,18 by fMRI, transcranial magnetic stimulation, 5 and magnetoencephalography. 19 PMG can potentially affect any supratentorial brain region except for the striatum, hippocampus, and gyrus rectus.…”

Section: Discussionmentioning

confidence: 88%

“…Complete resection of the epileptogenic zone is a strong prognostic factor for surgical success 2 and supports extensive surgery. However, there is often preserved function in the polymicrogyric cortex, [3][4][5] with the risk of postoperative de novo deficits.…”

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confidence: 99%