Surgical treatment of intractable epilepsy associated with focal cortical dysplasia

Abstract

<jats:p>Focal cortical dysplasias (FCDs) are congenital malformations of cortical development that are a frequent cause of refractory epilepsy in both children and adults. With advances in structural and functional neuroimaging, these lesions are increasingly being identified as a cause of intractable epilepsy in patients undergoing surgical management for intractable epilepsy. Comprehensive histological classification of FCDs with the establishment of uniform terminology and reproducible pathological features has aided in our understanding of FCDs as an epilepsy substrate. Complete resection of FCDs and the associated epileptogenic zone can result in a good surgical outcome in the majority of patients.</jats:p>

Epilepsy Surgery in Children

“…The best option to treat refractory cases is the complete resection of the lesion and the associated epileptogenic zone (Diaz et al, 2008).…”

Surgical Treatment of Intractable Epilepsy Associated with Focal Cortical Dysplasia

“…Concordance amongst the different modalities used to identify the lesion producing seizures is critical for surgical planning. Preoperative understanding of the epileptogenic zone, surrounding, or encompassing functional cortex, and the characteristic vascularization of the area in individual patients provides a map for planning the surgical approach, the limits of excision, and determining the potential risk to function (Diaz, et al,2008). The purpose of surgical intervention in the management intractable epilepsy with underlying histological evidence of cortical dysplasia is to improve seizure control and maximize the potential for normal neuropsychological development.…”

“…Seizure onset commonly occurs within or near cortical areas for language, motor function, or vision. Structural and functional overlap is frequent in FCD (Goldring,1987;Diaz, et al,2008;Crino,2009;Duchowny,2009;Roper,2009;Kim, et al,2010). Invasive video-EEG monitoring with subdural grids or depth electrodes may be indicated to aid in localization of the epileptogenic zone particularly in patients with cryptogenic lesions on MR imaging, lesions located in or near eloquent cortex, or evidence of bilateral or multifocal seizure onset as determined by scalp video-EEG.…”

“…Intra-operative challenges to complete resection include poorly defined epileptogenic zone margins on neuroimaging or EEG, the presence of important vascular structures in the epileptogenic zone, proximity of the epileptogenic zone to eloquent cortex, or an epileptogenic zone that has important cortical function. It is important to understand that epileptic foci and underlying cortical dysplasia may occur outside of the clearly delineated areas of abnormality demonstrated on MR imaging (Diaz, et al,2008). Morbidity (<3%) and mortality (0.2%) are low for patients with CD undergoing epilepsy neurosurgery.…”

“…Using the UCLA cohort as an example, cortical dysplasia was the histopathologic substrate identified in 75% of infants and children operated in the first 2 years of life. By comparison, cortical dysplasia was found in less than 10% in those having surgery who were older than age 21 years (Diaz, et al, 2008). Surgical evaluation and treatment of FCDs requires an understanding of pathological, presurgical imaging, EEG findings and intraoperative mapping of epileptogenic zone and functional areas (Sisodiya,2011).…”