Assessment of U-Net in the segmentation of short tracts: Transferring to clinical MRI routine.

Accurately studying structural connectivity requires precise tract segmentation strategies. The U-Net network has been widely recognized for its exceptional capacity in image segmentation tasks and provides remarkable results in large tract segmentation when high-quality diffusion-weighted imaging (DWI) data are used. However, short tracts, which are associated with various neurological diseases, pose specific challenges, particularly when high-quality DWI data acquisition within clinical settings is concerned. Here, we aimed to evaluate the U-Net network ability to segment short tracts by using DWI data acquired in different experimental conditions. To this end, we conducted three types of training experiments involving 350 healthy subjects and 11 white matter tracts, including the anterior, posterior, and hippocampal commissure, fornix, and uncinated fasciculus. In the first experiment, the model was exclusively trained with high-quality data of the Human Connectome Project (HCP) dataset. The second experiment focused on images of healthy subjects acquired from a local hospital dataset, representing a typical clinical routine acquisition. In the third experiment, a hybrid training approach was employed, combining data of the HCP and local hospital datasets. Then, the best model was also tested in unseen DWIs of 10 epilepsy patients of the local hospital and 10 healthy subjects acquired on a scanner from another company. The outcomes of the third experiment demonstrated a notable enhancement in performance when contrasted with the preceding trials. Specifically, the short tracts within the local hospital dataset achieved Dice scores ranging between 0.60 and 0.65. Similar intervals were obtained with HCP data in the first experiment, and a substantial improvement compared to the scores between 0.37 and 0.50 obtained with the local hospital dataset at the same experiment. This improvement persisted when the method was applied to diverse scenarios, including different scanner acquisitions and epilepsy patients. These results indicate that combining datasets from different sources, coupled with resolution standardization strengthens the neural network ability to generalize predictions across a spectrum of datasets. Nevertheless, short tract segmentation performance is intricately linked to the training composition, to validation, and to testing data. Moreover, curved tracts have intricate structural nature, which adds complexities to their segmenting. Although the network training approach tested herein has provided promising results, caution must be taken when extrapolating its application to datasets acquired under distinct experimental conditions, even in the case of higher-quality data or analysis of long or short tracts.

Brain MRI Abnormalities, Epilepsy and Intellectual Disability in LAMA2 Related Dystrophy - a Genotype/Phenotype Correlation.

BACKGROUND: LAMA2-related muscular dystrophy is a disorder that causes muscle weakness and varies in severity, from a severe, congenital type to a milder, late-onset form. However, the disease does not only affect the muscles, but has systemic involvement and can lead to alterations such as brain malformation, epilepsy and intellectual disability. OBJECTIVE: Describe the frequency of cortical malformations, epilepsy and intellectual disability in LAMA2-RD in a Brazilian cohort and correlate the neurological findings to genetic and motor function. METHODS: This is an observational study of 52 LAMA2-RD patients, who were divided into motor function subgroups and compared based on brain MRI findings, epilepsy, intellectual disability, and type of variants and variant domains. RESULTS: 44 patients (84.6%) were only able to sit, and 8 patients (15.4%) were able to walk. 10 patients (19.2%) presented with cortical malformations (polymicrogyria, lissencephaly-pachygyria, and cobblestone),10 patients (19.2%) presented with epilepsy, and 8 (15.4%) had intellectual disability. CNS manifestations correlated with a more severe motor phenotype and none of the patients able to walk presented with cortical malformation or epilepsy. There was a relation between gene variants affecting the laminin-α2 LG-domain and the presence of brain malformation (P = 0.016). There was also a relation between the presence of null variants and central nervous system involvement. A new brazilian possible founder variant was found in 11 patients (21,15%) (c.1255del; p. Ile419Leufs*4). CONCLUSION: Cortical malformations, epilepsy and intellectual disability are more frequent among LAMA2-RD patients than previously reported and correlate with motor function severity and the presence of variants affecting the laminin-α2 LG domain. This brings more insight fore phenotype-genotype correlations, shows the importance of reviewing the brain MRI of patients with LAMA2-RD and allows greater attention to the risk of brain malformation, epilepsy, and intellectual disability in those patients with variants that affect the LG domain.

Neurocysticercosis and epilepsy: Imaging and clinical characteristics.

The ILAE Neuroimaging Task Force aimed to publish educational case reports highlighting basic aspects related to neuroimaging in epilepsy consistent with the educational mission of the ILAE. Neurocysticercosis (NCC) is highly endemic in resource-limited countries and increasingly more often seen in non-endemic regions due to migration. Cysts with larva of the tapeworm Taenia solium lodge in the brain and cause several neurological conditions, of which seizures are the most common. There is great heterogeneity in the clinical presentation of neurocysticercosis because cysts vary in number, larval stage, and location among patients. We here present two illustrative cases with different clinical features to highlight the varying severity of symptoms secondary to this parasitic infestation. We also present several examples of imaging characteristics of the disease at various stages, which emphasize the central role of neuroimaging in the diagnosis of neurocysticercosis.

[Correlation between clinical and tomographic variables in patients with neurocysticercosis. A study in a cohort of patients in Sierra Norte, Ecuador, between 2019 and 2020]. / Correlación entre variables clínicas y tomográficas en pacientes con neurocisticercosis. Estudio en una cohorte de pacientes de la Sierra Norte ecuatoriana entre 2019 y 2020.

INTRODUCTION: Neurocysticercosis (NCC) is the most frequent parasitic disease in the central nervous system of humans. OBJECTIVE: to establish the correlation between clinical and tomographic variables in patients with neurocysticercosis in the neurology consultation of Hospital San Vicente de Paul and Hospital IESS Ibarra, during the year 2020. PATIENTS AND METHODS: descriptive, correlational and cross-sectional research. POPULATION AND SAMPLE: 93 patients. The information was collected in the neurology consultation. Clinical and imaging criteria were used for diagnosis. Odds Ratio (OR; 95% CI) was calculated. For multivariate analysis, binary logistic regression models were used. Statistical significance was considered when the value of p <0.05. SYMPTOMS: headache (77.4%), epilepsy (41.9%). Tomographic findings: size < 1 cm (67.7%), single lesion (54.8%), supratentorial (93.5%). There were several clinical / tomographic correlations in the bivariate analysis, the presence of epilepsy was associated with lesions of size >1 cm (OR: 9.65; 95% CI: 3.48-26.7), the vesicular + ventricular colloidal stage + nodular (OR: 3.90; 95% CI: 1.64-9.28) and parenchymal topography (OR: 5.03; 95% CI: 2.03-12.4) (p < 0.05). In the multivariate analysis, epilepsy was not associated with tomographic aspects such as the size, stage and topography of the cysticerci (p < 0.05). Headache and reduced muscle strength were associated with parenchymal topography and stage of lesions respectively (p < 0.05). CONCLUSIONS: Despite having a wide clinical spectrum, the presence of epilepsy, headache, and reduced muscle strength seem to be the most representative manifestations, so their inclusion in the development of prognostic scores should be evaluated, which allow evaluating the approach diagnostic and evolutionary in subsequent research.

TITLE: Correlación entre variables clínicas y tomográficas en pacientes con neurocisticercosis. Estudio en una cohorte de pacientes de la Sierra Norte ecuatoriana entre 2019 y 2020.Introducción. La neurocisticercosis es la enfermedad parasitaria más frecuente en el sistema nervioso central de los humanos. Objetivo. Establecer la correlación entre variables clínicas y tomográficas en pacientes con neurocisticercosis en la consulta de neurología del Hospital San Vicente de Paúl y el Hospital Instituto Ecuatoriano de Seguridad Social de Ibarra durante 2020. Pacientes y métodos. Investigación descriptiva, correlacional y transversal. Población y muestra: 93 pacientes. La información se recolectó en la consulta de neurología. Para el diagnóstico se utilizaron criterios clínicos e imagenológicos. Se calculó la odds ratio (OR) ­intervalo de confianza al 95% (IC 95%)­. Para el análisis multivariado, se utilizaron modelos de regresión logística binaria. Se consideró significación estadística cuando p menor de 0,05. Resultados. Síntomas: cefalea (77,4%) y crisis epilépticas (41,9%). Hallazgos tomográficos: tamaño menor de 1 cm (67,7%), lesión única (54,8%) y lesión supratentorial (93,5%). Hubo varias correlaciones clinicotomográficas en el análisis bivariado: la presencia de crisis epilépticas se asoció con lesiones de tamaño > 1 cm (OR: 9,65; IC 95%: 3,48-26,7), el estadio vesicular + ventricular coloidal + nodular (OR: 3,9; IC 95%: 1,64-9,28) y la topografía parenquimatosa (OR: 5,03; IC 95%: 2,03-12,4) (p menor de 0,05). La cefalea y la reducción de la fuerza muscular se asociaron con topografía parenquimatosa y estadio de las lesiones, respectivamente (p menor de 0,05). Conclusiones. A pesar de cursar con un amplio espectro clínico, la presencia de crisis epilépticas, cefalea y reducción de la fuerza muscular parece ser la manifestación más representativa, por lo que debería evaluarse su inclusión en el desarrollo de puntuaciones pronósticas que permitan evaluar el enfoque diagnóstico y evolutivo por estudio de imagen en investigaciones posteriores.

Estimating the Parameters of the Epileptor Model for Epileptic Seizure Suppression.

Epilepsy is one of the most common brain disorders worldwide, affecting millions of people every year. Given the partially successful existing treatments for epileptiform activity suppression, dynamic mathematical models have been proposed with the purpose of better understanding the factors that might trigger an epileptic seizure and how to mitigate it, among which Epileptor stands out, due to its relative simplicity and consistency with experimental observations. Recent studies using this model have provided evidence that establishing a feedback-based control approach is possible. However, for this strategy to work properly, Epileptor's parameters, which describe the dynamic characteristics of a seizure, must be known beforehand. Therefore, this work proposes a methodology for estimating such parameters based on a successive optimization technique. The results show that it is feasible to approximate their values as they converge to reference values based on different initial conditions, which are modeled by an uncertainty factor or noise addition. Also, interictal (healthy) and ictal (ongoing seizure) conditions, as well as time resolution, must be taken into account for an appropriate estimation. At last, integrating such a parameter estimation approach with observers and controllers for purposes of seizure suppression is carried out, which might provide an interesting alternative for seizure suppression in practice in the future.

Relationship of white matter hyperintensities with clinical features of seizures in patients with epilepsy / A relação das hiperintensidades da substância branca com as características clínicas das crises em pacientes com epilepsia

ABSTRACT Background: Although epilepsy is primarily known as a cortical disorder, there is growing body of research demonstrating white matter alterations in patients with epilepsy. Objective: To investigate the prevalence of white matter hyperintensities (WMH) and its association with seizure characteristics in patients with epilepsy. Methods: The prevalence of WMH in 94 patients with epilepsy and 41 healthy controls were compared. Within the patient sample, the relationship between the presence of WMH and type of epilepsy, frequency of seizures, duration of disease and the number of antiepileptic medications were investigated. Results: The mean age and sex were not different between patients and healthy controls (p>0.2). WMH was present in 27.7% of patients and in 14.6% of healthy controls. Diagnosis of epilepsy was independently associated with the presence of WMH (ß=3.09, 95%CI 1.06-9.0, p=0.039). Patients with focal epilepsy had higher prevalence of WMH (35.5%) than patients with generalized epilepsy (14.7%). The presence of WMH was associated with older age but not with seizure characteristics. Conclusions: WMH is more common in patients with focal epilepsy than healthy controls. The presence of WMH is associated with older age, but not with seizure characteristics.

RESUMO Antecedentes: Embora a epilepsia seja principalmente conhecida como um distúrbio cortical, há um crescente corpo de pesquisas que demonstra alterações na substância branca em pacientes com epilepsia. Objetivo: Investigar a prevalência de hiperintensidades da substância branca (WMH) e sua associação com características das crises em pacientes com epilepsia. Métodos: A prevalência de WMH em 94 pacientes com epilepsia e 41 controles saudáveis ​​foi comparada. Na amostra de pacientes, foi investigada a relação entre a presença de WMH e o tipo de epilepsia, a frequência das crises, a duração da doença e o número de medicamentos antiepilépticos. Resultados: A média de idade e o sexo não diferiram entre pacientes e controles saudáveis ​​(p>0,2). WMH estava presente em 27,7% dos pacientes, enquanto em 14,6% dos controles saudáveis. O diagnóstico de epilepsia foi independentemente associado à presença de WMH (ß=3,09, IC95% 1,06-9,0, p=0,039). Pacientes com epilepsia focal apresentaram maior prevalência de WMH (35,5%) do que pacientes com epilepsia generalizada (14,7%). A presença de WMH foi associada à idade avançada, mas não a características das crises. Conclusões: Pacientes com epilepsia focal têm WMH mais comum do que controles saudáveis. A presença de WMH está associada à idade avançada, mas não a características das crises epilépticas.

Relationship of white matter hyperintensities with clinical features of seizures in patients with epilepsy.

BACKGROUND: Although epilepsy is primarily known as a cortical disorder, there is growing body of research demonstrating white matter alterations in patients with epilepsy. OBJECTIVE: To investigate the prevalence of white matter hyperintensities (WMH) and its association with seizure characteristics in patients with epilepsy. METHODS: The prevalence of WMH in 94 patients with epilepsy and 41 healthy controls were compared. Within the patient sample, the relationship between the presence of WMH and type of epilepsy, frequency of seizures, duration of disease and the number of antiepileptic medications were investigated. RESULTS: The mean age and sex were not different between patients and healthy controls (p>0.2). WMH was present in 27.7% of patients and in 14.6% of healthy controls. Diagnosis of epilepsy was independently associated with the presence of WMH (ß=3.09, 95%CI 1.06-9.0, p=0.039). Patients with focal epilepsy had higher prevalence of WMH (35.5%) than patients with generalized epilepsy (14.7%). The presence of WMH was associated with older age but not with seizure characteristics. CONCLUSIONS: WMH is more common in patients with focal epilepsy than healthy controls. The presence of WMH is associated with older age, but not with seizure characteristics.

Anatomical Variations, Mimics, and Pitfalls in Imaging of Patients with Epilepsy.

Epilepsy is among one of the most common neurologic disorders. The role of magnetic resonance imaging (MRI) in the diagnosis and management of patients with epilepsy is well established, and most patients with epilepsy are likely to undergo at least one or more MRI examinations in the course of their disease. Recent advances in high-field MRI have enabled high resolution in vivo visualization of small and intricate anatomic structures that are of great importance in the assessment of seizure disorders. Familiarity with normal anatomic variations is essential in the accurate diagnosis and image interpretation, as these variations may be mistaken for epileptogenic foci, leading to unnecessary follow-up imaging, or worse, unnecessary treatment. After a brief overview of normal imaging anatomy of the mesial temporal lobe, this article will review a few important common and uncommon anatomic variations, mimics, and pitfalls that may be encountered in the imaging evaluation of patients with epilepsy.

Continuous epileptiform discharges during sleep as an evolutionary pattern in patients with congenital Zika virus syndrome.

Congenital Zika virus syndrome (CZVS) is associated with severe neurological deficits. Clinical characteristics of epilepsy and the electroencephalographic (EEG) pattern in CZVS were documented in infancy. In this study, we aimed to describe the EEG findings observed during the follow-up of children with CZVS. Seventy-six EEGs of 55 children (60% female; mean age = 50 months) with confirmed CZVS were analyzed, considering the background, interictal, and ictal epileptiform discharges. Continuous (or almost continuous) epileptiform discharges during non-rapid eye movement sleep were identified in 22 (40%) patients. In 20 (90.1%) patients, the pattern was symmetrical, with an anterior predominance of the epileptiform activity. All patients with this pattern had epilepsy, which was severe in 15 (68.2%) and demanded polytherapy in 19 (86.4%). Subcortical calcifications (77.3%) and multifocal EEGs (72.8%) in earlier ages occurred more often in patients with this pattern. Other unspecific interictal EEG patterns were focal epileptiform discharges in 23 (41.8%) and multifocal activity in six (10.9%). In CZVS, continuous (or almost continuous) epileptiform discharges during sleep emerge as a pattern after the second year of life. This was associated with severe and drug-resistant epilepsy, but not necessarily with an apparent regression. Subcortical calcifications and multifocal epileptiform discharges in infancy are associated with this pattern.

Epilepsy Lesion Localization is not Predicted by Developmental Venous Anomaly Location or its FDG-PET Metabolic Activity.

BACKGROUND AND PURPOSE: This study's purpose is to correlate location and metabolic activity of developmental venous anomalies (DVAs) in epilepsy patients to the seizure focus as determined by ictal/interictal encephaloelectrogram (EEG). METHODS: A retrospective search was performed for epilepsy patients with DVAs who underwent brain 18 F-fluorodeoxyglucose positron emission tomography (18 F-FDG-PET) and magnetic resonance imaging (MRI). MRI exams were analyzed to characterize DVA location and associated structural findings. MRI and PET images were co-registered and assessment of 18 F-FDG uptake in the DVA territory was performed. The electronic medical record was reviewed for each subject to determine seizure semiology and site of seizure focus by ictal/interictal EEG. RESULTS: Twenty-eight DVAs in 25 patients were included. Twelve DVAs demonstrated regional metabolic abnormality on 18 F-FDG-PET. There was no significant correlation between DVA site and seizure focus on EEG. DVA location was concordant with EEG seizure focus in three subjects, and all three demonstrated hypometabolism on 18 F-FDG-PET. This significance remains indeterminate, as one of these DVAs was associated with cavernoma, which could serve as the true seizure focus, and one of the patients underwent resection of the DVA without decrease in seizure frequency. Furthermore, there was no statistically significant relationship between DVA metabolic activity and DVA-EEG lobar or laterality concordance. CONCLUSIONS: In this sample, there is no significant correlation between location of DVA and seizure focus, and hypometabolism within the DVA territory is not predictive of EEG/DVA co-localization. As use of 18 F-FDG-PET for evaluation of epilepsy increases, knowledge of this poor correlation is important to avoid diagnostic confusion and potentially unnecessary surgery in epilepsy patients.

A novel approach for pre-surgical evaluation of facial morphometry in children using magnetic resonance imaging scans of the brain: a feasibility analysis / Un enfoque novedoso para la evaluación prequirúrgica de la morfometría facial en niños mediante imágenes por resonancia magnética de cerebro: un análisis de viabilidad

Pre-surgical evaluation of facial morphometry is frequently warranted for children with facial dysmorphism. Though many methods utilized previously for such purposes, data is scarce on using magnetic resonance (MRI) brain images for such purposes. The purpose of this study was to appraise the feasibility of utilizing MRI brain scans done in epilepsy imaging protocol to assess facial morphometry. Measurements of the face; orbit, mouth, and nose of children aged 1 to 7 years were obtained using T1 sagittal, T2 axial and three dimensional (3D) MRI images of the brain (n=20). Ability to obtain facial measurements, inter and intra-observer variability calculated. The mean age of the studied children was 4±2 years, of which 40% (n=8) were boys, and 60% (n=12) were girls. Obtaining facial measurements were reliable with high intra-observer (α=0.757 to 0.999) and inter-observer agreements (α=0.823 to 0.997). The landmarks of the cranium, upper face, and upper nose could be identified (100%) in both two dimensional (2D) and 3D images when such landmarks were contained in the imaging field of view (FOV). Landmarks of lower nose, (subalar width = 0%) or mouth (0%) were not contained in the FOV of 2D images, but contained in 3D images (100%). Both 2D and 3D images did not allow assessment of lower face or the mandible as such landmarks were not contained in the FOV.We conclude thatBrain MRIs performed to evaluate cerebral pathology can be executed to assess facial measurements, provided the FOV of the scan is adjusted to include all significant landmarks.

La evaluación prequirúrgica de la morfometría facial con frecuencia se justifica para niños con dismorfismo facial. Aunque muchos métodos se utilizaron anteriormente para tales fines, los datos son escasos sobre el uso de imágenes cerebrales por resonancia magnética (MRI) para tales fines. El propósito de este estudio fue evaluar la viabilidad de utilizar resonancias magnéticas cerebrales realizadas en el protocolo de imágenes de epilepsia para evaluar la morfometría facial.Medidas de la cara, la órbita, la boca y la nariz de niños de 1 a 7 años se obtuvieron mediante imágenes de resonancia magnética cerebral T1 sagital, axial T2 y tridimensional (3D) del cerebro (n = 20). Se obtuvieron las medidas faciales, y fue calculada la variabilidad inter e intraobservador.La edad de los niños estudiados fue de 4 ± 2 años, de los cuales el 40% (n = 8) hombre y el 60% (n = 12) mujer. La obtención de medidas faciales fue confiable con altos acuerdos intraobservador (α = 0,757 a 0,999) e interobservador (α = 0,823 a 0,997). Los puntos de referencia del cráneo, la cara superior y la nariz superior se pudieron identificar (100%) tanto en imágenes bidimensionales (2D) como en 3D cuando dichos puntos de referencia estaban contenidos en el campo de visión de la imagen (FOV). Los puntos de referencia de la parte inferior de la nariz (ancho subalar = 0%) o la boca (0%) no estaban contenidos en el campo de visión de las imágenes 2D, sino que estaban contenidos en las imágenes 3D (100%). Tanto las imágenes 2D como las 3D no permitieron la evaluación de la parte inferior de la cara o la mandíbula, ya que tales puntos de referencia no estaban contenidos en el campo de visión.Concluimos que las resonancias magnéticas cerebrales realizadas para evaluar la patología cerebral se pueden usar para evaluar las medidas faciales, siempre que el campo de visión de la exploración se ajuste para incluir todos los puntos de referencia importantes.

Visual analysis of automated segmentation in the diagnosis of focal cortical dysplasias with magnetic resonance imaging.

Focal cortical dysplasias (FCDs) are a frequent cause of epilepsy. It has been reported that up to 40% of them cannot be visualized with conventional magnetic resonance imaging (MRI). The main objective of this work was to evaluate by means of a retrospective descriptive observational study whether the automated brain segmentation is useful for detecting FCD. One hundred and fifty-five patients, who underwent surgery between the years 2009 and 2016, were reviewed. Twenty patients with FCD confirmed by histology and a preoperative segmentation study, with ages ranging from 3 to 43 years (14 men), were analyzed. Three expert neuroradiologists visually analyzed conventional and advanced MRI with automated segmentation. They were classified into positive and negative concerning visualization of FCD by consensus. Of the 20 patients evaluated with conventional MRI, 12 were positive for FCD. Of the negative studies for FCD with conventional MRI, 2 (25%) were positive when they were analyzed with automated segmentation. In 13 of the 20 patients (with positive segmentation for FCD), cortical thickening was observed in 5 (38.5%), while pseudothickening was observed in the rest of patients (8, 61.5%) in the anatomical region of the brain corresponding to the dysplasia. This work demonstrated that automated brain segmentation helps to increase detection of FCDs that are unable to be visualized in conventional MRI images.

An adaptive probabilistic atlas for anomalous brain segmentation in MR images.

PURPOSE: Automated segmentation of brain structures (objects) in MR three-dimensional (3D) images for quantitative analysis has been a challenge and probabilistic atlases (PAs) are among the most well-succeeded approaches. However, the existing models do not adapt to possible object anomalies due to the presence of a disease or a surgical procedure. Post-processing operation does not solve the problem, for example, tissue classification to detect and remove such anomalies inside the resulting segmentation mask, because segmentation errors on healthy tissues cannot be fixed. Such anomalies very often alter the shape and texture of the brain structures, making them different from the appearance of the model. In this paper, we present an effective and efficient adaptive probabilistic atlas, named AdaPro, to circumvent the problem and evaluate it on a challenging task - the segmentation of the left hemisphere, right hemisphere, and cerebellum, without pons and medulla, in 3D MR-T1 brain images of Epilepsy patients. This task is challenging due to temporal lobe resections, artifacts, and the absence of contrast in some parts between the structures of interest. METHODS: In AdaPro, we first build one probabilistic atlas per object of interest from a training set with normal 3D images and the corresponding 3D object masks. Second, we incorporate a texture classifier based on convex optimization which dynamically indicates the regions of the target 3D image where the PAs (shape constraints) should be further adapted. This strategy is mathematically more elegant and avoids problems with post-processing. Third, we add a new object-based delineation algorithm based on combinatorial optimization and diffusion filtering. AdaPro can then be used to locate and delineate the objects in the coordinate space of the atlas or of the test image. We also compare AdaPro with three other state-of-the-art methods: an statistical shape model based on synergistic object search and delineation, and two methods based on multi-atlas label fusion (MALF). RESULTS: We evaluate the methods quantitatively on 3D MR-T1 brain images of 2T and 3T from epilepsy patients, before and after temporal lobe resections, and on the template and native coordinate spaces. The results show that AdaPro is considerably faster and consistently more accurate than the baselines with statistical significance in both coordinate spaces. CONCLUSION: AdaPro can be used as a fast and effective step for brain tissue segmentation and it can also be easily extended to segment subcortical brain structures. By choice of its components, probabilistic atlas, texture classifier, and delineation algorithm, it can also be extended to other organs and imaging modalities.

Frecuencia y determinantes de epilepsia luego de un primer ictus isquémico arterial en una cohorte de niños / Frequency and risk factors for the development of epilepsy after an arterial ischemic stroke in a children's cohort

Existen pocos estudios evaluando los factores de riesgo para el desarrollo de epilepsia posterior a un ictus isquémico arterial (IIA) en la infancia. Objetivo: Evaluar los predictores clínicos y radiológicos para epilepsia post-ictus (EPI) en una cohorte de niños chilenos con un primer IIA. Metodología: Estudio analítico longitudinal observacional prospectivo de una cohorte de niños con diagnóstico de IIA entre 1 mes y 18 años, enrolados de forma consecutiva en la base de datos de Patología Cerebrovascular del Hospital Clínico de la Pontificia Universidad Católica de Chile entre los años 2003 y 2013. Todos los participantes con imágenes por resonancia magnética encefálica al momento del diagnóstico. Las variables estudiadas incluyeron características clínicas y radiológicas del evento agudo asociadas a EPI según estudios previos. Creamos un modelo multivariado por regresión logística para estimar los Odds Ratios (ORs) y sus respectivos intervalos de confianza al 95% (ICs) de cada variable estudiada para EPI (significancia <0,05). Resultados: De 81 niños reclutados, 41 (50,6%) con EPI. El análisis multivariado determinó que los predictores independientes de EPI incluyen edad menor al momento del IIA (OR=0,81; IC=0,69-0,95), ocurrencia de crisis sintomáticas agudas (OR=8,63; IC=2,03-36,7), infarto cortical (OR=17,2; IC=3,12-95,3) y arteriopatías del sistema nervioso central (OR=12; IC=1,47-97,8). Conclusiones: las crisis agudas, menor edad, infarto cortical y arteriopatías son factores de riesgo independientes para EPI en niños con un primer IIA.

Abstract. There are few studies evaluating the risk factors for the development of epilepsy after an arterial ischemic stroke (IIA) in childhood. Objective: To assess the clinical and radiological predictors for epilepsy post-stroke (EPI) in a cohort of Chilean children with a first IIA. Methodology: prospective observational longitudinal analytical study of a cohort of children with a IIA diagnosis, from 1 month to 18 years old, consecutively enrolled in the brain stroke database of the Hospital of the Pontificia Universidad Católica de Chile between 2003 and 2013. All participants had a brain magnetic resonance performed at the time of the diagnosis. The variables studied included clinical and radiological features of the acute event associated to EPI according to previous studies. We created a multivariate logistic regression model to estimate the Odds Ratios (ORs) and their respective intervals of confidence 95% (ICs) of each variable studied for EPI (significance < 0,05). Results: of 81 children recruited, 41 (50.6%) had EPI. The multivariate analysis determined that the independent predictors of PPE include: younger age at the time of the IIA (OR = 0. 81; IC = 0, 69-0, 95), occurrence of acute symptomatic crisis (OR = 8, 63; IC = 2, 03-36, 7), cortical infarction (OR = 17, 2; IC = 3, 12-95, 3) and arteriopathies of the central nervous system (OR = 12; IC = 1, 47-97, 8). Conclusions: acute crises, younger age, cortical infarction and arterial disease are independent risk factors for EPI in children with a first IIA.

Motor Abnormalities and Epilepsy in Infants and Children With Evidence of Congenital Zika Virus Infection.

Initial reports of congenital Zika virus (ZIKV) infection focused on microcephaly at birth with severe brain anomalies; the phenotype has broadened to include microcephaly that develops after birth and neurodevelopmental sequelae. In this narrative review, we summarize medical literature describing motor abnormalities and epilepsy in infants with evidence of congenital ZIKV infection and provide information on the impact of these conditions. Specific scenarios are used to illustrate the complex clinical course in infants with abnormalities that are consistent with congenital Zika syndrome. A search of the English-language medical literature was done to identify motor abnormalities and epilepsy in infants with evidence of congenital ZIKV infection by using Medline and PubMed, Embase, Scientific Electronic Library Online, Scopus, the OpenGrey Repository, and the Grey Literature Report in Public Health. Search terms included "Zika" only and "Zika" in combination with any of the following terms: "epilepsy," "seizure," "motor," and "cerebral palsy." Clinical features of motor abnormalities and epilepsy in these children were reviewed. Thirty-six publications were identified; 8 were selected for further review. Among infants with clinical findings that are consistent with congenital Zika syndrome, 54% had epilepsy and 100% had motor abnormalities. In these infants, impairments that are consistent with diagnoses of cerebral palsy and epilepsy occur frequently. Pyramidal and extrapyramidal motor abnormalities were notable for their early development and co-occurrence. Prompt identification of potential disabilities enables early intervention to improve the quality of life for affected children. Long-term studies of developmental outcomes and interventions in children with congenital ZIKV infection are needed.

On the relationship between calcified neurocysticercosis and epilepsy in an endemic village: A large-scale, computed tomography-based population study in rural Ecuador.

OBJECTIVE: Using a large-scale population-based study, we aimed to assess prevalence and patterns of presentation of neurocysticercosis (NCC) and its relationship with epilepsy in community-dwellers aged ≥20 years living in Atahualpa (rural Ecuador). METHODS: In a three-phase epidemiological study, individuals with suspected seizures were identified during a door-to-door survey and an interview (phase I). Then, neurologists evaluated suspected cases and randomly selected negative persons to estimate epilepsy prevalence (phase II). In phase III, all participants were offered noncontrast computed tomography (CT) for identifying NCC cases. The independent association between NCC (exposure) and epilepsy (outcome) was assessed by the use of multivariate logistic regression models adjusted for age, sex, level of education, and alcohol intake. CT findings were subsequently compared to archived brain magnetic resonance imaging in a sizable subgroup of participants. RESULTS: Of 1,604 villagers aged ≥20 years, 1,462 (91%) were enrolled. Forty-one persons with epilepsy (PWE) were identified, for a crude prevalence of epilepsy of 28 per 1,000 population (95% confidence interval [CI] = 20.7-38.2). A head CT was performed in 1,228 (84%) of 1,462 participants, including 39 of 41 PWE. CT showed lesions consistent with calcified parenchymal brain cysticerci in 118 (9.6%) cases (95% CI = 8.1-11.4%). No patient had other forms of NCC. Nine of 39 PWE, as opposed to 109 of 1,189 participants without epilepsy, had NCC (23.1% vs. 9.2%, p = 0.004). This difference persisted in the adjusted logistic regression model (odds ratio = 3.04, 95% CI = 1.35-6.81, p = 0.007). SIGNIFICANCE: This large CT-based study demonstrates that PWE had three times the odds of having NCC than those without epilepsy, providing robust epidemiological evidence favoring the relationship between NCC and epilepsy.

Imaging of Laser Therapy in Epilepsy.

BACKGROUND AND PURPOSE: MR-guided laser interstitial thermal therapy (MRgLITT) is an increasingly popular neuroablative method for the surgical treatment of epilepsy patients. This article intends to demonstrate the utility and pitfalls of imaging in the context of patient care with MRgLITT. MATERIAL AND METHODS: A retrospective review of the medical records and imaging database with six illustrative cases selected to demonstrate the use of imaging throughout patient management with MRgLITT in diverse clinical situations and pathologies. A review of the knowledge in the literature was applied to the relevant points discussed. RESULTS: Imaging findings were described in the setting of laser therapy in nonlesional epilepsy, mesial temporal sclerosis, dual pathology, periventricular nodular heterotopia, and schizencephaly. Discussion of imaging principles, potential pitfalls, as well as its use in the patient work-up and follow-up, is shown. CONCLUSIONS: MRgLITT is an alternative minimally invasive therapy for refractory epilepsy, which is becoming widely sought for. Imaging plays a crucial role prior to, during, and after the procedure.

Usefulness of Ilae 2010 classification in Mexican epilepsy patients.

OBJECTIVE: Advances in neuroimaging, genomics, and molecular biology have improved the understanding of the pathogenesis of epilepsy. That is why the International League Against Epilepsy (ILAE) has created a new classification system. The present study aims to evaluate the association between epilepsy cases classified by the ILAE 2010 classification proposal, electroencephalography (EEG), and magnetic resonance imaging brain findings (MRI). METHODS: Prospective cross-sectional design of 277 cases of epilepsy seen at the Epilepsy Clinic, Hospital Central "Dr. Ignacio Morones Prieto", were compared with the ILAE classification based on the etiology and clinical manifestations and their MRI and EEG findings. STATISTICAL ANALYSIS: Cochran, Mantell, Haenzel test with significance p<0.05. RESULTS: MRI findings were associated with the etiology of the ILAE classification. According to EEG findings, the structural-metabolic etiology patients had more dysfunctional reports than genetic or unknown etiology patients (p<0.05). SIGNIFICANCE: The adoption of the ILAE classification is recommended, as it can provide useful guidance towards the etiology of cases of epilepsy even when brain MRIs and EEGs are not available.