Different features of histopathological subtypes of pediatric focal cortical dysplasia

Kršek, Pavel; Maton, Bruno; Korman, Brandon; Pacheco-Jácome, Esperanza; Jayakar, Prasanna; Dunoyer, Catalina; Rey, Gustavo; Morrison, Glenn; Ragheb, John; Vinters, Harry V.; Resnick, Trevor; Duchowny, Michael

doi:10.1002/ana.21398

Cited by 259 publications

(299 citation statements)

References 52 publications

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“…Focal cortical dysplasia type I lesions have highly idiosyncratic presentations and are usually more diffuse than type II lesions, making them the most challenging ones to be detected by structural imaging methodology. [28][29][30] In addition to the accurate definition, delineation of the boundaries of type I focal cortical dysplasia is also difficult, as the microscopically dysplastic lesion may extend well beyond the margins defined by the MRI-visible abnormality (in MRIpositive cases), [30][31][32] even with the use of highresolution dedicated epilepsy MRI protocols and review of the images by expert neuroradiologists. 26,32 Our finding of MRI-negative patients with hippocampal sclerosis is also consistent with previous literature that up to 30% of patients with hippocampal sclerosis may have normal findings on conventional MRI.…”

Section: Discussionmentioning

confidence: 99%

The pathology of magnetic-resonance-imaging-negative epilepsy

et al. 2013

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Patients with magnetic-resonance-imaging (MRI)-negative (or 'nonlesional') pharmacoresistant focal epilepsy are the most challenging group undergoing presurgical evaluation. Few large-scale studies have systematically reviewed the pathological substrates underlying MRI-negative epilepsies. In the current study, histopathological specimens were retrospectively reviewed from MRI-negative epilepsy patients (n ¼ 95, mean age ¼ 30 years, 50% female subjects). Focal cortical dysplasia cases were classified according to the International League Against Epilepsy (ILAE) and Palmini et al classifications. The most common pathologies found in this MRI-negative cohort included: focal cortical dysplasia (n ¼ 43, 45%), gliosis (n ¼ 21, 22%), hamartia þ gliosis (n ¼ 12, 13%), and hippocampal sclerosis (n ¼ 9, 9%). The majority of focal cortical dysplasia were ILAE type I (n ¼ 37) or Palmini type I (n ¼ 39). Seven patients had no identifiable pathological abnormalities. The existence of positive pathology was not significantly associated with age or temporal/extratemporal resection. Follow-up data post surgery was available in 90 patients; 63 (70%) and 57 (63%) attained seizure freedom at 6 and 12 months, respectively. The finding of positive pathology was significantly associated with seizure-free outcome at 6 months (P ¼ 0.035), but not at 12 months. In subgroup analysis, the focal cortical dysplasia group was not significantly correlated with seizure-free outcome, as compared with the negative-pathology groups at either 6 or 12 months. Of note, the finding of hippocampal sclerosis had a significant positive correlation with seizurefree outcome when compared with the negative-pathology group (P ¼ 0.009 and 0.004 for 6-and 12-month outcome, respectively). Absence of a significant histopathology in the resected surgical specimen did not preclude seizure freedom. In conclusion, our study highlights the heterogeneity of epileptic pathologies in MRInegative epilepsies, with focal cortical dysplasia being the most common finding. The existence of positive pathology in surgical specimen may be a good indication for short-term good seizure outcome. There is a small subset of cases in which no pathological abnormalities are identified.

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Section: Discussionmentioning

confidence: 99%

The pathology of magnetic-resonance-imaging-negative epilepsy

et al. 2013

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“…There have been a few studies specifically assessing MRI features of CD correlated with pathology and outcome in pediatric (or mostly pediatric) patients, with the investigators using more modern pathological classification systems. 14,16,17,19,33 Most of these studies also included CD in the temporal lobe associated with hippocampal sclerosis (ILAE Type IIIa), 3 which complicates evaluation of the imaging, pathology, and outcome correlations in this population. For our study, to provide the most homogeneous cohort for evaluation, we excluded these patients, as well as patients with other brain abnormalities and CD (Types IIIb, IIIc, and dual pathology).…”

Section: Discussionmentioning

confidence: 99%

“…Although MRI findings and outcome assessments have been described in some children with CD, 15,16,19,20 the underlying pathological basis for imaging findings in a consistent cohort of children has been incompletely assessed. We could find no prior study in which a resection region-specific evaluation was used to directly relate histopathological and imaging findings in pediatric subjects.…”

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confidence: 99%

Magnetic resonance imaging abnormalities in the resection region correlate with histopathological type, gliosis extent, and postoperative outcome in pediatric cortical dysplasia

Leach¹,

Miles²,

Henkel³

et al. 2014

PED

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Object The authors conducted a study to correlate histopathological features, MRI findings, and postsurgical outcomes in children with cortical dysplasia (CD) by performing a novel resection site–specific evaluation. Methods The study cohort comprised 43 children with intractable epilepsy and CD. The MR image review was blinded to pathology but with knowledge of the resection location. An MRI score (range 0–7) was calculated for each resection region based on the number of imaging features of CD and was classified as “lesional” or “nonlesional” according to all imaging features. Outcome was determined using the International League Against Epilepsy (ILAE) scale. The determination of pathological CD type was based on the ILAE 2011 consensus classification system, and the cortical gliosis pattern was assessed on GFAP staining. Results There were 89 resection regions (50 ILAE Type I, 29 Type IIa, and 10 Type IIb). Eleven (25.6%) of 43 children had more than one type of CD. The authors observed MRI abnormalities in 63% of patients, characteristic enough to direct resection (lesional) in 42%. Most MRI features, MRI score ≥ 3, and lesional abnormalities were more common in patients with Type II CD. Increased cortical signal was more common in those with Type IIb (70%) rather than Type IIa (17.2%) CD (p = 0.004). A good outcome was demonstrated in 39% of children with Type I CD and 72% of those with Type II CD (61% in Type IIa and 100% in Type IIb) (p = 0.03). A lesional MRI abnormality and an MRI score greater than 3 correlated with good outcome in 78% and 90% of patients, respectively (p < 0.03). Diffuse cortical gliosis was more prevalent in Type II CD and in resection regions exhibiting MRI abnormalities. Complete surgical exclusion of the MRI abnormality was associated with a better postoperative outcome. Conclusions This study provides a detailed correlation of MRI findings, neuropathological features, and outcomes in children with intractable epilepsy by using a novel resection site–specific evaluation. Because 25% of the patients had multiple CD subtypes, a regional analysis approach was mandated. Those children with lesional MRI abnormalities, Type II CD, and surgical exclusion of the MRI abnormality had better outcomes. Type II CD is more detectable by MRI than other types, partly because of the greater extent of associated gliosis in Type II. Although MRI findings were correlated with the pathological CD type and outcome in this study, the majority of patients (58%) did not have MRI findings that could direct surgical therapy, underscoring the need for improved MRI techniques for detection and for the continued use of multimodal evaluation methods in patient selection.

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“…A recent study 13 showed that children with FCD Type IIB had more localized ictal electroencephalographic patterns and MRI changes, while hippocampal sclerosis and hypoplasia/atrophy were common in FCD Type I. The same authors 14 found that incomplete resection of the FCD is the main predictor of poor postsurgical outcome, because the only significant predictor of surgical success was completeness of surgical resection.…”

Section: Malformations Due To Abnormal Neuronal and Glial Proliferatimentioning

confidence: 98%

“…Most patients have medically intractable partial epilepsy, frequently with disabling motor and secondary generalized seizures, including status epilepticus. These patients often are correctly diagnosed before surgery, but surgical results still are not fully satisfactory in many of them.A recent study 13 showed that children with FCD Type IIB had more localized ictal electroencephalographic patterns and MRI changes, while hippocampal sclerosis and hypoplasia/atrophy were common in FCD Type I. The same authors 14 found that incomplete resection of the FCD is the main predictor of poor postsurgical outcome, because the only significant predictor of surgical success was completeness of surgical resection.…”

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confidence: 96%

Malformations of cortical development

Guerreiro

2009

Arq. Neuro-Psiquiatr.

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-Malformations of cortical development (MCD) have been increasingly identified. The purpose of this presentation is to review the current knowledge of the MCD. Before we address this issue, we will briefly present a review of cortical development. The second part of this presentation will address the most important MCD. Finally, the last part of this presentation will address the correlation between MCD and epilepsy.KEY WORDS: malformations of cortical development, focal cortical dysplasias, neuronal migration disorders, cortical organization disorders. Malformações do desenvolvimento corticalResumo -As malformações do desenvolvimento cortical (MDC) são cada vez mais identificadas e diagnosticadas. O propósito desta apresentação é rever o conhecimento recente sobre as MDC. Antes de abordarmos o assunto em questão, apresentaremos brevemente uma revisão sobre a formação cortical. A seguir, abordaremos as principais entidades compreendidas dentro da classificação das MDC e, finalmente, resumiremos a correlação entre MDC e epilepsia.PALAVRAS-CHAVE: malformações do desenvolvimento cortical, displasias corticais focais, distúrbios da migração neuronal, distúrbios da organização cortical. Malformations of cortical development (MCD) have been increasingly identified as a major cause of several disorders, particularly in childhood. Patients with MCD present with a wide spectrum of clinical manifestations ranging from asymptomatic cases to those with epilepsy and neurodevelopmental problems. The advent of the magnetic resonance imaging (MRI) has been the most important factor in the improvement of the diagnosis, which has allowed a better clinical management. Structural imaging has become more sensitive with developments of MRI hardware, acquisition and postprocessing methods.The purpose of this presentation is to review the current knowledge of MCD. Before we address this issue, we will briefly present a review of cortical development. The second part of this presentation will address the most important MCD. Finally, the last part of this presentation will address the correlation between MCD and epilepsy. Barkovich et al. 1 proposed a classification of the malformations of cortical development, taking into account pathological, genetic and neuroimaging features of the different stages of development. They state that there are three main consecutive stages of cortical development, each of them partially overlapping with the previous stage. They are: cellular proliferation and differentiation, neuronal migration, and cortical organization. CORTICAL DEVELOPMENTThe first step of cortical development is cellular proliferation and differentiation, which takes place between the 5 th week and 20 th week of gestation. The germinal or primordial cell multiplies and differentiates becoming either a neuron or glial cell. A general rule of the developing nervous system is that a cell is generated in a different location from its final position in the central nervous system (CNS). The process of changing position from birth ...

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Different features of histopathological subtypes of pediatric focal cortical dysplasia

Cited by 259 publications

References 52 publications

The pathology of magnetic-resonance-imaging-negative epilepsy

The pathology of magnetic-resonance-imaging-negative epilepsy

Magnetic resonance imaging abnormalities in the resection region correlate with histopathological type, gliosis extent, and postoperative outcome in pediatric cortical dysplasia

Malformations of cortical development

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